unsloth/studio/backend/core/inference/llama_cpp.py
Daniel Han 8848a310df
Studio: clean-room compact RAG (knowledge bases, hybrid search, fast indexing) (#5910)
Adds a self-contained RAG stack to Studio: knowledge bases with chunked indexing, hybrid (dense + lexical) retrieval, and an automatic first-pass context inject into chat. Embeddings run through a local llama-server GGUF backend (default unsloth/bge-small-en-v1.5-GGUF) with a sentence-transformers fallback. The chat tool loop gains a search_knowledge_base tool, a per-turn re-search cap, and source citation, layered on top of the shared ToolLoopController.
2026-06-09 21:17:04 -07:00

5516 lines
244 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
"""llama-server inference backend for GGUF models.
Manages a llama-server subprocess and proxies chat completions through its
OpenAI-compatible /v1/chat/completions endpoint.
"""
import atexit
import contextlib
import json
import os
import re
import struct
import structlog
from loggers import get_logger
import shutil
import signal
import socket
import subprocess
import sys
import threading
import time
from pathlib import Path
from typing import Generator, Iterable, List, Optional
import httpx
from core.inference.llama_server_args import (
parse_cache_override,
parse_ctx_override,
resolve_cache_type_kv,
resolve_requested_ctx,
)
from core.tool_healing import (
_TC_END_TAG_RE,
_TC_FUNC_CLOSE_RE,
_TC_FUNC_START_RE,
_TC_JSON_START_RE,
_TC_PARAM_CLOSE_RE,
_TC_PARAM_START_RE,
_TOOL_ALL_PATS,
_TOOL_CLOSED_PATS,
parse_tool_calls_from_text,
strip_tool_call_markup,
)
from utils.native_path_leases import child_env_without_native_path_secret
from utils.subprocess_compat import (
windows_hidden_subprocess_kwargs as _windows_hidden_subprocess_kwargs,
)
from core.inference.tool_call_parser import (
RAG_MAX_SEARCHES_PER_TURN,
RAG_SEARCH_CAP_NUDGE,
TOOL_XML_SIGNALS,
parse_tool_calls_from_text as _shared_parse_tool_calls_from_text,
)
from core.inference.tool_loop_controller import (
ToolLoopController,
tool_event_provenance,
)
logger = get_logger(__name__)
# ── Pre-compiled patterns for plan-without-action re-prompt ──
# Forward-looking intent signals: the model is describing what it *will*
# do rather than giving a final answer.
_INTENT_SIGNAL = re.compile(
r"(?i)("
# Direct intent ("I'll ...", "Let me ...", straight + curly apostrophes).
# Excludes "I can"/"I should"/"I want to"/"let's" (common in answers).
# Negative lookahead drops negated forms ("I will not") so a refusal
# doesn't trigger a re-prompt.
r"\b(i['\u2019](ll|m going to|m gonna)|i am (going to|gonna)|i will|i shall|let me|allow me)\b(?!\s+(?:not|never)\b)"
r"|"
# Step/plan framing: "First ...", "Step 1:", "Here's my plan"
r"\b(?:first\b|step \d+:?|here['\u2019]?s (?:my |the |a )?(?:plan|approach))"
r"|"
# "Now I" / "Next I" patterns
r"\b(?:now i|next i)\b"
r")"
)
_MAX_REPROMPTS = 1
# Without max_tokens, llama-server defaults n_predict = n_ctx (up to 262144 for
# Qwen3.5), causing many-minute zombie decodes when cancel fails.
# t_max_predict_ms is a wall-clock backstop but per the llama.cpp README only
# fires after a newline, so we keep a token cap as the front-line limiter.
# The cap is the effective context length when known, else this floor. 4096 was
# too low: Qwen3 / gpt-oss reasoning traces and max_tokens-omitting OpenAI-API
# callers (langchain, llama-index, curl) got truncated mid-sentence.
_DEFAULT_MAX_TOKENS_FLOOR = 32768
_DEFAULT_T_MAX_PREDICT_MS = 600_000 # 10 min
_REPROMPT_MAX_CHARS = 2000
_FORCED_REPEAT_PLAN_SIGNAL = re.compile(
r"\b(?:i\s+will|i'll|let\s+me|going\s+to|need\s+to|call|use|run|search|fetch|render)\b",
re.I,
)
_FINAL_ANSWER_SIGNAL = re.compile(
r"\b(?:final\s+answer|answer\s*:|here\s+is|here's|in\s+summary|result\s*:)\b",
re.I,
)
def _is_short_intent_without_action(text: str) -> bool:
stripped = text.strip()
return 0 < len(stripped) < _REPROMPT_MAX_CHARS and _INTENT_SIGNAL.search(stripped) is not None
def _should_suppress_forced_no_tool_output(text: str) -> bool:
"""Suppress only repeated forced-turn planning text, not final answers."""
stripped = text.strip()
if not stripped or len(stripped) >= _REPROMPT_MAX_CHARS:
return False
if _FINAL_ANSWER_SIGNAL.search(stripped):
return False
return _FORCED_REPEAT_PLAN_SIGNAL.search(stripped) is not None
# ── Pre-compiled patterns for GGUF shard detection ───────────
_SHARD_FULL_RE = re.compile(r"^(.*)-(\d{5})-of-(\d{5})\.gguf$")
_SHARD_RE = re.compile(r"^(.*)-\d{5}-of-\d{5}\.gguf$")
# ── Sliding-window-pattern resolver ───────────────────────────
# Resolves the per-layer SWA mask when a GGUF reports a sliding window but
# no `sliding_window_pattern` field. Tier order in `_resolve_swa_pattern`:
# GGUF metadata, on-disk cache, bootstrap dict below, transformers
# introspection, HF Hub config.json, legacy 1/4 fallback. Period N means
# layer i is SWA iff `(i + 1) % N != 0`, matching transformers. Skipped on
# purpose: phi3 (no key/val length in GGUF, window >= ctx anyway), qwen2
# family (converter strips sliding_window when use_sliding_window=False),
# mistral v0.1/v0.2 (all-SWA can't be a period).
_BOOTSTRAP_SWA_DEFAULTS: dict[str, int] = {
"gemma2": 2, # Gemma2Config.sliding_window_pattern
"gemma3": 6, # Gemma3TextConfig.sliding_window_pattern
"gemma3n": 5, # text_config.layer_types: SWA*4 + FULL
"gpt_oss": 2, # text_config.layer_types: alternating
"cohere2": 4, # Cohere2Config.sliding_window_pattern
}
# Process-wide cache backed by JSON on disk. Values are int period or
# list[bool] mask. Lazy-loaded.
_SWA_CACHE: Optional[dict] = None
_SWA_CACHE_LOCK = threading.Lock()
def _probe_dns_dead(host: str = "huggingface.co", timeout: float = 2.0) -> bool:
"""Quick DNS check on a daemon thread, so concurrent sockets aren't
affected by socket.setdefaulttimeout."""
result: list[Optional[bool]] = [None]
def _probe() -> None:
try:
socket.gethostbyname(host)
result[0] = False
except Exception:
result[0] = True
t = threading.Thread(target = _probe, daemon = True)
t.start()
t.join(timeout)
# Thread still running -> resolver wedged -> dead.
return True if result[0] is None else result[0]
@contextlib.contextmanager
def _hf_offline_if_dns_dead():
"""Set HF_HUB_OFFLINE for this block only when DNS to huggingface.co fails;
restores env on exit so a transient hiccup can't quarantine the process.
No-op if the user already set it."""
if "HF_HUB_OFFLINE" in os.environ:
yield False
return
if not _probe_dns_dead():
yield False
return
transformers_was_set = "TRANSFORMERS_OFFLINE" in os.environ
os.environ["HF_HUB_OFFLINE"] = "1"
if not transformers_was_set:
os.environ["TRANSFORMERS_OFFLINE"] = "1"
logger.warning("huggingface.co unreachable; using local HF cache for this load.")
try:
yield True
finally:
os.environ.pop("HF_HUB_OFFLINE", None)
if not transformers_was_set:
os.environ.pop("TRANSFORMERS_OFFLINE", None)
def _swa_cache_path() -> Path:
home = os.environ.get("UNSLOTH_STUDIO_HOME") or os.environ.get("STUDIO_HOME")
base = Path(home) if home else Path.home() / ".unsloth" / "studio"
return base / "swa_cache.json"
def _load_swa_cache() -> dict:
global _SWA_CACHE
with _SWA_CACHE_LOCK:
if _SWA_CACHE is not None:
return _SWA_CACHE
try:
with open(_swa_cache_path()) as f:
_SWA_CACHE = json.load(f)
if not isinstance(_SWA_CACHE, dict):
_SWA_CACHE = {}
except (FileNotFoundError, json.JSONDecodeError, OSError):
_SWA_CACHE = {}
return _SWA_CACHE
def _save_swa_cache(cache: dict) -> None:
try:
path = _swa_cache_path()
path.parent.mkdir(parents = True, exist_ok = True)
tmp = path.with_suffix(".json.tmp")
with open(tmp, "w") as f:
json.dump(cache, f, indent = 2, sort_keys = True)
tmp.replace(path)
except OSError:
pass
def _period_from_layer_types(layer_types: list) -> Optional[int]:
"""Smallest period N where `(i+1) % N != 0` matches the SWA mask, else None."""
if not layer_types:
return None
is_swa = ["full" not in str(t).lower() for t in layer_types]
n = len(is_swa)
for N in range(1, n + 1):
if all(((i + 1) % N != 0) == is_swa[i] for i in range(n)):
return N
return None
def _fetch_swa_entry_from_hf(repo_id: str) -> Optional[object]:
try:
from huggingface_hub import hf_hub_download
cfg_path = hf_hub_download(repo_id, "config.json", repo_type = "model")
with open(cfg_path) as f:
cfg = json.load(f)
except Exception:
return None
src = cfg.get("text_config") if isinstance(cfg.get("text_config"), dict) else cfg
period = src.get("sliding_window_pattern")
if isinstance(period, int) and period > 0:
return period
lt = src.get("layer_types")
if isinstance(lt, list) and lt:
return _period_from_layer_types(lt) or ["full" not in str(t).lower() for t in lt]
return None
def _arch_aliases(arch: str) -> tuple:
# GGUF emits `falcon-h1`; HF model_type is `falcon_h1`. Normalise both ways.
seen = []
for a in (arch, arch.replace("-", "_"), arch.replace("_", "-")):
if a and a not in seen:
seen.append(a)
return tuple(seen)
def _swa_entry_from_config_obj(cfg) -> Optional[object]:
src = getattr(cfg, "text_config", None) or cfg
period = getattr(src, "sliding_window_pattern", None)
if isinstance(period, int) and period > 0:
return period
lt = getattr(src, "layer_types", None)
if isinstance(lt, list) and lt:
return _period_from_layer_types(lt) or ["full" not in str(t).lower() for t in lt]
return None
_SWA_PATTERN_SOURCE_RE = re.compile(r"sliding_window_pattern\s*(?::\s*[\w\[\], ]*)?\s*=\s*(\d+)")
def _resolve_swa_entry_from_transformers(arch: str) -> Optional[object]:
"""Default-instantiate the matching Config; on failure, regex-parse its
source for `sliding_window_pattern = N`."""
try:
from transformers.models.auto.configuration_auto import (
CONFIG_MAPPING,
CONFIG_MAPPING_NAMES,
)
except Exception:
return None
cfg_class = None
for alias in _arch_aliases(arch):
if alias in CONFIG_MAPPING_NAMES:
try:
cfg_class = CONFIG_MAPPING[alias]
break
except Exception:
cfg_class = None
if cfg_class is None:
return None
try:
if (entry := _swa_entry_from_config_obj(cfg_class())) is not None:
return entry
except Exception:
pass
import inspect
candidates = [cfg_class]
text_cfg_class = getattr(cfg_class, "sub_configs", {}).get("text_config")
if text_cfg_class is not None:
candidates.append(text_cfg_class)
for cls in candidates:
try:
src = inspect.getsource(cls)
except (OSError, TypeError):
continue
if m := _SWA_PATTERN_SOURCE_RE.search(src):
period = int(m.group(1))
if period > 0:
return period
return None
def _resolve_swa_pattern(
arch: Optional[str],
n_layers: Optional[int],
source_repo_candidates: tuple = (),
*,
allow_network: Optional[bool] = None,
) -> Optional[list]:
if not arch or not n_layers:
return None
if allow_network is None:
allow_network = os.environ.get("UNSLOTH_STUDIO_OFFLINE", "0") not in (
"1",
"true",
"True",
"yes",
)
cache = _load_swa_cache()
def _entry_to_mask(entry):
if isinstance(entry, int) and entry > 0:
return [(i + 1) % entry != 0 for i in range(n_layers)]
if isinstance(entry, list) and entry:
return [bool(entry[i % len(entry)]) for i in range(n_layers)]
return None
def _persist(entry):
with _SWA_CACHE_LOCK:
cache[arch] = entry
_save_swa_cache(cache)
if (entry := cache.get(arch)) is not None:
if (mask := _entry_to_mask(entry)) is not None:
return mask
if (entry := _BOOTSTRAP_SWA_DEFAULTS.get(arch)) is not None:
return _entry_to_mask(entry)
entry = _resolve_swa_entry_from_transformers(arch)
if entry is not None:
_persist(entry)
return _entry_to_mask(entry)
# Tier 3: live HF fetch (result persistently cached)
if allow_network:
for repo_id in source_repo_candidates:
if not repo_id:
continue
entry = _fetch_swa_entry_from_hf(repo_id)
if entry is not None:
_persist(entry)
return _entry_to_mask(entry)
return None
def _hf_repo_from_url(url: Optional[str]) -> Optional[str]:
"""Strip `https://huggingface.co/owner/name(/...)` -> `owner/name`."""
if not url or "huggingface.co/" not in url:
return None
tail = url.split("huggingface.co/", 1)[1].rstrip("/")
parts = tail.split("/")
if len(parts) < 2:
return None
return f"{parts[0]}/{parts[1]}"
# Lazy import to avoid pulling transformers in at module level.
def _extract_model_size_b(model_id: str):
from utils.models import extract_model_size_b
return extract_model_size_b(model_id)
_TOOL_TEMPLATE_MARKERS = (
"{%- if tools %}",
"{%- if tools -%}",
"{% if tools %}",
"{% if tools -%}",
'"role" == "tool"',
"'role' == 'tool'",
'message.role == "tool"',
"message.role == 'tool'",
)
def detect_reasoning_flags(
chat_template: Optional[str],
model_identifier: Optional[str] = None,
*,
log_source: Optional[str] = None,
) -> dict:
"""Classify a chat template's reasoning and tool-calling capabilities.
Returns the same five keys as the GGUF sniffer: ``supports_reasoning``,
``reasoning_style`` (``"enable_thinking"`` | ``"reasoning_effort"``),
``reasoning_always_on``, ``supports_preserve_thinking``,
``supports_tools``. Used by both the llama-server backend at load time
and the safetensors/transformers paths in ``routes/inference`` so they
agree on what the frontend sees.
"""
flags = {
"supports_reasoning": False,
"reasoning_style": "enable_thinking",
"reasoning_always_on": False,
"supports_preserve_thinking": False,
"supports_tools": False,
}
if not chat_template:
return flags
tpl = chat_template
prefix = f"{log_source}: " if log_source else ""
if "enable_thinking" in tpl:
flags["supports_reasoning"] = True
flags["reasoning_style"] = "enable_thinking"
logger.info(f"{prefix}model supports reasoning (enable_thinking)")
elif "reasoning_effort" in tpl:
# gpt-oss / Harmony use reasoning_effort
# ("low" | "medium" | "high"), not a boolean.
flags["supports_reasoning"] = True
flags["reasoning_style"] = "reasoning_effort"
logger.info(f"{prefix}model supports reasoning (reasoning_effort)")
elif "thinking" in tpl:
# DeepSeek uses 'thinking', not 'enable_thinking'
normalized_id = (model_identifier or "").lower()
if "deepseek" in normalized_id:
flags["supports_reasoning"] = True
logger.info(f"{prefix}model supports reasoning (DeepSeek thinking)")
# Hardcoded <think> tags or reasoning_content in the template mean
# thinking is always on (no toggle).
if not flags["supports_reasoning"]:
if ("<think>" in tpl and "</think>" in tpl) or "reasoning_content" in tpl:
flags["supports_reasoning"] = True
flags["reasoning_always_on"] = True
logger.info(f"{prefix}model always reasons (<think> tags in template)")
# preserve_thinking: independent kwarg on some Qwen templates that
# keeps historical <think> blocks in prior assistant turns.
if "preserve_thinking" in tpl:
flags["supports_preserve_thinking"] = True
logger.info(f"{prefix}model supports preserve_thinking")
if any(marker in tpl for marker in _TOOL_TEMPLATE_MARKERS):
flags["supports_tools"] = True
logger.info(f"{prefix}model supports tool calling")
return flags
def _is_mtp_model_name(model_identifier: Optional[str], gguf_path: Optional[str] = None) -> bool:
"""Name-based MTP detector. Fallback for the metadata signal."""
for cand in (model_identifier, Path(gguf_path).name if gguf_path else None):
if cand and "-mtp" in cand.lower():
return True
return False
def _extra_args_set_spec_type(extra_args: Optional[Iterable[str]]) -> bool:
"""User passed --spec-type / --spec-default? llama-server takes one
--spec-type (comma-separated to chain), so suppress auto-emit."""
if not extra_args:
return False
for raw in extra_args:
tok = str(raw)
if not tok.startswith("--"):
continue
flag = tok.split("=", 1)[0]
if flag in ("--spec-type", "--spec-default"):
return True
return False
def _build_ngram_mod_flags(
caps: Optional[dict],
n_match: int = 24,
n_min: int = 48,
n_max: int = 64,
) -> list[str]:
"""Emit the right ngram-mod knob flags for the running llama-server.
Post-rename builds expose ``--spec-ngram-mod-n-{match,min,max}``;
pre-rename builds expose legacy ``--spec-ngram-size-n`` /
``--draft-min`` / ``--draft-max``. ``caps`` comes from
``probe_server_capabilities``; ``ngram_mod_flavor`` says which set is
real (vs a removal-stub). Returns ``[]`` when neither is available so
the caller can drop ngram-mod entirely.
"""
flavor = caps.get("ngram_mod_flavor") if caps else None
if flavor == "new":
return [
"--spec-ngram-mod-n-match",
str(n_match),
"--spec-ngram-mod-n-min",
str(n_min),
"--spec-ngram-mod-n-max",
str(n_max),
]
if flavor == "legacy":
# Pre-rename llama.cpp: same knobs lived under --spec-ngram-size-n
# (lookup length) and generic --draft-min / --draft-max (N range).
return [
"--spec-ngram-size-n",
str(n_match),
"--draft-min",
str(n_min),
"--draft-max",
str(n_max),
]
return []
# Canonical Speculative Decoding modes exposed by the Studio chat UI.
# Dropdown renders five (auto, mtp, ngram, mtp+ngram, off); the load API
# also accepts legacy values the original Switch and external callers emit
# (default, draft-mtp, ngram-mod, ngram-simple).
_CANONICAL_SPEC_MODES = {"auto", "mtp", "ngram", "mtp+ngram", "off", "ngram-simple"}
_LEGACY_SPEC_MODE_MAP = {
"default": "auto",
"draft-mtp": "mtp",
"ngram-mod": "ngram",
}
def _canonicalize_spec_mode(value):
"""Map any accepted ``speculative_type`` input onto a canonical mode.
Returns ``auto``, ``mtp``, ``ngram``, ``mtp+ngram``, ``off``,
``ngram-simple``, or ``None`` (callers treat ``None`` as ``auto``).
Unknown strings collapse to ``auto`` so a stale UI value or typo falls
back to the safe platform-aware path.
"""
if value is None:
return None
if not isinstance(value, str):
return None
stripped = value.strip().lower()
if not stripped:
return None
if stripped in _CANONICAL_SPEC_MODES:
return stripped
if stripped in _LEGACY_SPEC_MODE_MAP:
return _LEGACY_SPEC_MODE_MAP[stripped]
# Old persisted state emits llama.cpp comma-chains e.g.
# "ngram-mod,draft-mtp"; collapse the most common one explicitly.
pieces = [p.strip() for p in stripped.split(",") if p.strip()]
has_mtp = any(p in ("mtp", "draft-mtp") for p in pieces)
has_ngram = any(p in ("ngram", "ngram-mod") for p in pieces)
if has_mtp and has_ngram:
return "mtp+ngram"
if has_mtp:
return "mtp"
if has_ngram:
return "ngram"
return "auto"
def _backfill_usage_from_timings(usage, timings):
"""Synthesize ``usage`` from llama-server's ``timings`` when the
OpenAI-style usage block is missing or reports zero tokens.
The Studio chat UI computes generation t/s from
``meta.usage.completion_tokens / totalStreamTime``. llama-server always
populates ``timings.predicted_n`` (true decoded count) and
``timings.prompt_n``, but the final SSE chunk's ``usage`` can be absent
or zero on some server builds / streaming configs, making the UI fall
back to wall-clock t/s and dilute speculative-decoding speedups.
"""
if not timings:
return usage
if usage and usage.get("completion_tokens"):
return usage
predicted_n = timings.get("predicted_n")
prompt_n = timings.get("prompt_n")
if predicted_n is None and prompt_n is None:
return usage
out = dict(usage or {})
if not out.get("completion_tokens") and predicted_n is not None:
out["completion_tokens"] = predicted_n
if not out.get("prompt_tokens") and prompt_n is not None:
out["prompt_tokens"] = prompt_n
out["total_tokens"] = int(out.get("prompt_tokens") or 0) + int(
out.get("completion_tokens") or 0
)
return out
class LlamaCppBackend:
"""Manages a llama-server subprocess for GGUF model inference.
Lifecycle:
1. load_model() — start llama-server with the GGUF file
2. generate_chat_completion() — proxy to /v1/chat/completions, stream back
3. unload_model() — terminate the subprocess
"""
def __init__(self):
self._process: Optional[subprocess.Popen] = None
self._port: Optional[int] = None
self._model_identifier: Optional[str] = None
self._gguf_path: Optional[str] = None
self._hf_repo: Optional[str] = None
self._hf_variant: Optional[str] = None
self._is_vision: bool = False
self._healthy = False
# Set by _classify_gpu_offload after _wait_for_health.
self._gpu_offload_active: Optional[bool] = None
self._context_length: Optional[int] = None
self._effective_context_length: Optional[int] = None
self._max_context_length: Optional[int] = None
self._chat_template: Optional[str] = None
self._chat_template_override: Optional[str] = None
self._supports_reasoning: bool = False
self._reasoning_always_on: bool = False
self._reasoning_style: str = "enable_thinking"
self._supports_preserve_thinking: bool = False
self._supports_tools: bool = False
self._cache_type_kv: Optional[str] = None
self._reasoning_default: bool = True
self._speculative_type: Optional[str] = None
# Canonical UI-facing mode the user requested
# (auto/mtp/ngram/mtp+ngram/off/ngram-simple). Round-tripped through the
# status API so the dropdown reflects the picked mode, not the resolved
# flag set (auto on a 27B MTP GGUF resolves to draft-mtp but reads "Auto").
self._requested_spec_mode: Optional[str] = None
# User --spec-draft-n-max override (None = platform default).
self._spec_draft_n_max: Optional[int] = None
# KV-cache estimation fields (populated by _read_gguf_metadata)
self._n_layers: Optional[int] = None
self._n_kv_heads: Optional[int] = None
self._n_kv_heads_by_layer: Optional[list[int]] = None
self._n_heads: Optional[int] = None
self._embedding_length: Optional[int] = None
# Architecture-aware KV fields for 5-path estimation
self._kv_key_length: Optional[int] = None
self._kv_value_length: Optional[int] = None
self._sliding_window: Optional[int] = None
self._sliding_window_pattern: Optional[list[bool]] = None
self._full_attention_interval: Optional[int] = None
self._kv_lora_rank: Optional[int] = None
self._key_length_mla: Optional[int] = None
self._kv_key_length_swa: Optional[int] = None
self._kv_value_length_swa: Optional[int] = None
self._ssm_inner_size: Optional[int] = None
self._ssm_state_size: Optional[int] = None
# Last N layers reuse earlier layers' KV and don't allocate their own
# cache (Gemma 3n / Gemma 4: <arch>.attention.shared_kv_layers).
self._shared_kv_layers: Optional[int] = None
# MTP head count (llama.cpp #22673); >0 enables --spec-type draft-mtp.
self._nextn_predict_layers: Optional[int] = None
self._lock = threading.Lock()
# Wraps load_model() end-to-end so concurrent loads serialise and never
# coexist as two llama-server processes (#5401).
self._serial_load_lock = threading.Lock()
# Last extra_args / requested n_ctx, preserved across unload so the chat
# UI's /unload+/load Apply path can inherit them (#5401).
# ``_extra_args_source`` records the (model_identifier, hf_variant) the
# stored args came from so the route can refuse cross-model inheritance.
self._extra_args: Optional[List[str]] = None
self._extra_args_source: Optional[tuple[str, Optional[str]]] = None
self._requested_n_ctx: int = 0
self._stdout_lines: list[str] = []
self._stdout_thread: Optional[threading.Thread] = None
# llama-server tee log (see _drain_stdout / _kill_process).
self._llama_log_fh = None
self._llama_log_path: Optional[Path] = None
self._cancel_event = threading.Event()
self._api_key: Optional[str] = None
# True once a probe has completed; cleared on transient failure.
self._is_audio: bool = False
self._audio_type: Optional[str] = None
self._audio_probed: bool = False
# Audio INPUT capability (distinct from _is_audio, which is TTS output).
self._has_audio_input: bool = False
self._mmproj_has_audio: bool = False # clip.has_audio_encoder, set at load
# Monotonic timestamp set in _kill_process; read by load_model
# to decide whether to wait for the VRAM reclaim to finish.
self._last_kill_monotonic: float = 0.0
self._kill_orphaned_servers()
atexit.register(self._cleanup)
# ── Properties ────────────────────────────────────────────────
@property
def is_loaded(self) -> bool:
return self._process is not None and self._healthy
@property
def is_active(self) -> bool:
"""True if a llama-server process exists (loading or loaded)."""
return self._process is not None
@property
def base_url(self) -> str:
return f"http://127.0.0.1:{self._port}"
@property
def model_identifier(self) -> Optional[str]:
return self._model_identifier
@property
def is_vision(self) -> bool:
return self._is_vision
@property
def hf_variant(self) -> Optional[str]:
return self._hf_variant
@property
def extra_args(self) -> Optional[List[str]]:
"""Extra llama-server flags from the last load (a copy). None =
never set, [] = explicitly cleared. Used by the route for
inheritance."""
return list(self._extra_args) if self._extra_args is not None else None
@property
def requested_n_ctx(self) -> int:
"""n_ctx the last load was invoked with (not the effective cap).
0 means Auto. Used by the route to detect Auto-vs-explicit flips."""
return self._requested_n_ctx
@property
def extra_args_source(self) -> Optional[tuple[str, Optional[str]]]:
"""(model_identifier, hf_variant) the stored extra_args came from.
``None`` if no extras have ever been recorded. Used by the route
to refuse cross-model inheritance (#5401)."""
return self._extra_args_source
@property
def context_length(self) -> Optional[int]:
"""Return the effective context length the server is running at."""
return self._effective_context_length or self._context_length
@property
def max_context_length(self) -> Optional[int]:
"""Return the largest context that fits on this hardware at load time.
The UI's "safe zone" warning threshold: the ``_fit_context_to_vram``
binary-search cap for the best GPU subset, or the 4096 fallback if the
weights exceed 90% of every subset. The slider ceiling is
``native_context_length``; dragging above this triggers the warning.
"""
return self._max_context_length or self._context_length
@property
def native_context_length(self) -> Optional[int]:
"""Return the model's native context length from GGUF metadata."""
return self._context_length
def load_progress(self) -> Optional[dict]:
"""Return live model-load progress, or None if not loading.
During warm-up llama-server mmaps weight shards into page cache before
pushing layers to VRAM, a window where status only reports ``loading``
and the UI spinner looks stuck for minutes on large MoEs. Samples
``/proc/<pid>/status VmRSS`` against the sum of GGUF shard sizes for a
real progress bar. Returns ``None`` when no load is in flight.
Shape::
{
"phase": "mmap" | "ready",
"bytes_loaded": int, # VmRSS of the llama-server
"bytes_total": int, # sum of shard file sizes
"fraction": float, # bytes_loaded / bytes_total, 0..1
}
Linux-only; returns ``None`` where ``/proc/<pid>/status`` is unavailable.
"""
proc = self._process
if proc is None:
return None
pid = proc.pid
if pid is None:
return None
# Sum shard sizes (primary + any extras alongside).
bytes_total = 0
gguf_path = self._gguf_path
if gguf_path:
primary = Path(gguf_path)
try:
if primary.is_file():
bytes_total += primary.stat().st_size
except OSError:
pass
# Extra shards share the primary's prefix before the shard index.
try:
parent = primary.parent
stem = primary.name
m = _SHARD_RE.match(stem)
prefix = m.group(1) if m else None
if prefix and parent.is_dir():
for sibling in parent.iterdir():
if (
sibling.is_file()
and sibling.name.startswith(prefix)
and sibling.name != stem
and sibling.suffix == ".gguf"
):
try:
bytes_total += sibling.stat().st_size
except OSError:
pass
except OSError:
pass
# Read VmRSS from /proc/<pid>/status (kilobytes on Linux).
bytes_loaded = 0
try:
with open(f"/proc/{pid}/status", "r", encoding = "utf-8") as f:
for line in f:
if line.startswith("VmRSS:"):
kb = int(line.split()[1])
bytes_loaded = kb * 1024
break
except (FileNotFoundError, PermissionError, ValueError, OSError):
return None
phase = "ready" if self._healthy else "mmap"
fraction = 0.0
if bytes_total > 0:
fraction = min(1.0, bytes_loaded / bytes_total)
return {
"phase": phase,
"bytes_loaded": bytes_loaded,
"bytes_total": bytes_total,
"fraction": round(fraction, 4),
}
@property
def chat_template(self) -> Optional[str]:
return self._chat_template
@property
def chat_template_override(self) -> Optional[str]:
return self._chat_template_override
@property
def supports_reasoning(self) -> bool:
return self._supports_reasoning
@property
def reasoning_always_on(self) -> bool:
return self._reasoning_always_on
@property
def reasoning_style(self) -> str:
return self._reasoning_style
@property
def supports_preserve_thinking(self) -> bool:
return self._supports_preserve_thinking
@property
def reasoning_default(self) -> bool:
return self._reasoning_default
def _reasoning_kwargs(self, enable_thinking: bool) -> dict:
if self._reasoning_style == "reasoning_effort":
return {"reasoning_effort": "high" if enable_thinking else "low"}
return {"enable_thinking": enable_thinking}
def _request_reasoning_kwargs(
self,
enable_thinking: Optional[bool],
reasoning_effort: Optional[str] = None,
preserve_thinking: Optional[bool] = None,
) -> Optional[dict]:
"""Build chat_template_kwargs from per-request reasoning fields.
Merges the active model's reasoning style (``enable_thinking`` or
``reasoning_effort``) plus the independent ``preserve_thinking``
kwarg when the template supports it.
"""
kwargs: dict = {}
# Always-on reasoning models hardcode <think> tags and don't consume
# enable_thinking / reasoning_effort -- skip.
if self._supports_reasoning and not self._reasoning_always_on:
if self._reasoning_style == "reasoning_effort":
if reasoning_effort in ("low", "medium", "high"):
kwargs["reasoning_effort"] = reasoning_effort
elif enable_thinking is not None:
kwargs["reasoning_effort"] = "high" if enable_thinking else "low"
else:
if enable_thinking is not None:
kwargs["enable_thinking"] = enable_thinking
if self._supports_preserve_thinking and preserve_thinking is not None:
kwargs["preserve_thinking"] = preserve_thinking
return kwargs or None
@property
def supports_tools(self) -> bool:
return self._supports_tools
@property
def cache_type_kv(self) -> Optional[str]:
return self._cache_type_kv
@property
def speculative_type(self) -> Optional[str]:
return self._speculative_type
@property
def requested_spec_mode(self) -> Optional[str]:
"""Canonical UI-facing mode the user requested (see field doc)."""
return self._requested_spec_mode
@property
def spec_draft_n_max(self) -> Optional[int]:
"""User --spec-draft-n-max override active on the load, or None when
the platform default (6 GPU / 3 CPU) is in effect."""
return self._spec_draft_n_max
# ── Binary discovery ──────────────────────────────────────────
@staticmethod
def _find_llama_server_binary() -> Optional[str]:
"""
Locate the llama-server binary.
Search order:
1. LLAMA_SERVER_PATH environment variable (direct path to binary)
1b. UNSLOTH_LLAMA_CPP_PATH env var (custom llama.cpp install dir)
2. ~/.unsloth/llama.cpp/llama-server (make build, root dir)
3. ~/.unsloth/llama.cpp/build/bin/llama-server (cmake build, Linux)
4. ~/.unsloth/llama.cpp/build/bin/Release/llama-server.exe (cmake build, Windows)
5. ./llama.cpp/llama-server (legacy: make build, root dir)
6. ./llama.cpp/build/bin/llama-server (legacy: cmake in-tree build)
7. llama-server on PATH (system install)
8. ./bin/llama-server (legacy: extracted binary)
"""
binary_name = "llama-server.exe" if sys.platform == "win32" else "llama-server"
# 1. Env var: direct path to binary
env_path = os.environ.get("LLAMA_SERVER_PATH")
if env_path and Path(env_path).is_file():
return env_path
# 1b. UNSLOTH_LLAMA_CPP_PATH: custom llama.cpp install dir
custom_llama_cpp = os.environ.get("UNSLOTH_LLAMA_CPP_PATH")
if custom_llama_cpp:
custom_dir = Path(custom_llama_cpp)
# Root dir (make builds)
root_bin = custom_dir / binary_name
if root_bin.is_file():
return str(root_bin)
# build/bin/ (cmake on Linux)
cmake_bin = custom_dir / "build" / "bin" / binary_name
if cmake_bin.is_file():
return str(cmake_bin)
# build/bin/Release/ (cmake on Windows)
if sys.platform == "win32":
win_bin = custom_dir / "build" / "bin" / "Release" / binary_name
if win_bin.is_file():
return str(win_bin)
# 2-4. Match installer layout: env-mode -> $STUDIO_HOME/llama.cpp;
# default/HOME-redirect -> ~/.unsloth/llama.cpp (sibling of studio).
legacy_llama = Path.home() / ".unsloth" / "llama.cpp"
try:
from utils.paths.storage_roots import studio_root as _sr # noqa: WPS433
_resolved_sr = _sr()
_legacy_studio = Path.home() / ".unsloth" / "studio"
try:
_is_legacy = _resolved_sr.resolve() == _legacy_studio.resolve()
except (OSError, ValueError):
_is_legacy = _resolved_sr == _legacy_studio
if _is_legacy:
search_roots = [legacy_llama]
else:
# _kill_orphaned_servers excludes the legacy root in custom
# mode; discovery must match so we never spawn a server we
# then refuse to clean up. UNSLOTH_LLAMA_CPP_PATH (handled
# earlier) is the explicit way to share a build across roots.
search_roots = [_resolved_sr / "llama.cpp"]
except (ImportError, OSError, ValueError):
search_roots = [legacy_llama]
_seen_roots: set[str] = set()
_unique_roots: list[Path] = []
for r in search_roots:
k = str(r)
if k not in _seen_roots:
_seen_roots.add(k)
_unique_roots.append(r)
for unsloth_home in _unique_roots:
home_root = unsloth_home / binary_name
if home_root.is_file():
return str(home_root)
home_linux = unsloth_home / "build" / "bin" / binary_name
if home_linux.is_file():
return str(home_linux)
if sys.platform == "win32":
home_win = unsloth_home / "build" / "bin" / "Release" / binary_name
if home_win.is_file():
return str(home_win)
# 5-6. Legacy: in-tree build (older setup.sh / setup.ps1)
project_root = Path(__file__).resolve().parents[4]
# Root dir (make builds)
root_path = project_root / "llama.cpp" / binary_name
if root_path.is_file():
return str(root_path)
# build/bin/ (cmake builds)
build_path = project_root / "llama.cpp" / "build" / "bin" / binary_name
if build_path.is_file():
return str(build_path)
if sys.platform == "win32":
win_path = project_root / "llama.cpp" / "build" / "bin" / "Release" / binary_name
if win_path.is_file():
return str(win_path)
# 7. System PATH
system_path = shutil.which("llama-server")
if system_path:
return system_path
# 8. Legacy: extracted to bin/
bin_path = project_root / "bin" / binary_name
if bin_path.is_file():
return str(bin_path)
return None
# ── llama-server capability probe ─────────────────────────────
# Cached on (path, mtime); `unsloth studio update` bumps mtime.
_capability_cache: dict[tuple[str, int], dict[str, object]] = {}
@classmethod
def probe_server_capabilities(cls, binary: Optional[str] = None) -> dict[str, object]:
"""Parse `llama-server --help` for feature flags. Returns
{found, mtp_token, supports_mtp, ngram_mod_flavor,
supports_ngram_mod, spec_draft_n_max_flag}.
``ngram_mod_flavor``: ``"new"`` when the post-rename
``--spec-ngram-mod-n-match / -n-min / -n-max`` are real args;
``"legacy"`` when only the pre-rename
``--spec-ngram-size-n / --draft-min / --draft-max`` are real (the
rename ships stub removal entries for legacy names, told apart by
the "argument has been removed" description); ``None`` if neither
set is usable.
``spec_draft_n_max_flag``: the flag the binary accepts --
``--spec-draft-n-max`` post-rename, ``--draft-max`` on legacy.
``None`` means n_max cannot be set.
"""
bin_path = binary or cls._find_llama_server_binary()
if not bin_path or not Path(bin_path).is_file():
return {
"found": False,
"mtp_token": None,
"supports_mtp": False,
"ngram_mod_flavor": None,
"supports_ngram_mod": False,
"spec_draft_n_max_flag": None,
}
try:
mtime = int(Path(bin_path).stat().st_mtime)
except OSError:
mtime = 0
cache_key = (bin_path, mtime)
cached = cls._capability_cache.get(cache_key)
if cached is not None:
return cached
mtp_token: Optional[str] = None
ngram_mod_flavor: Optional[str] = None
spec_draft_n_max_flag: Optional[str] = None
try:
result = subprocess.run(
[bin_path, "--help"],
capture_output = True,
text = True,
timeout = 10,
check = False,
)
help_text = (result.stdout or "") + "\n" + (result.stderr or "")
# Split into per-flag blocks (each --flag line + its indented
# continuation), so the "argument has been removed" description
# sits with its flag.
blocks: dict[str, str] = {}
current_flags: list[str] = []
current_desc: list[str] = []
for line in help_text.splitlines():
stripped = line.strip()
if stripped.startswith("-") and not line.startswith(" "):
# New flag line; flush previous.
if current_flags:
desc = " ".join(current_desc)
for f in current_flags:
blocks[f] = desc
current_flags = []
current_desc = [stripped]
# Extract long-form flag tokens from the DECLARATION
# prefix only (comma-separated aliases). Stop at the
# first non-flag token so flag references inside
# descriptions are ignored.
for tok in re.split(r"[,\s]+", stripped):
if tok.startswith("--") and re.match(r"--[A-Za-z][A-Za-z0-9_-]*$", tok):
current_flags.append(tok)
elif tok.startswith("-") and len(tok) > 1:
# short alias like -fa; keep scanning aliases.
continue
else:
# First non-flag token marks end of decl.
break
else:
current_desc.append(stripped)
if current_flags:
desc = " ".join(current_desc)
for f in current_flags:
blocks[f] = desc
def _is_real(flag: str) -> bool:
"""True if the flag exists AND is not a removal stub."""
desc = blocks.get(flag)
if desc is None:
return False
return "argument has been removed" not in desc
# MTP token from the --spec-type line.
spec_line = ""
for line in help_text.splitlines():
if "--spec-type" in line:
spec_line = line
break
# PR #22673 used draft-mtp; later renamed to mtp.
if "draft-mtp" in spec_line:
mtp_token = "draft-mtp"
elif re.search(r"[|,\[]mtp[|,\]]", spec_line):
mtp_token = "mtp"
# ngram-mod flag flavor. Post-rename builds advertise both new
# args (real) and legacy ones (stubs); pre-rename builds only
# have legacy ones as real.
new_ngram_real = (
_is_real("--spec-ngram-mod-n-match")
and _is_real("--spec-ngram-mod-n-min")
and _is_real("--spec-ngram-mod-n-max")
)
legacy_ngram_real = (
_is_real("--spec-ngram-size-n")
and _is_real("--draft-max")
and _is_real("--draft-min")
)
if new_ngram_real:
ngram_mod_flavor = "new"
elif legacy_ngram_real:
ngram_mod_flavor = "legacy"
# n_max flag: prefer post-rename, fall back to legacy.
if _is_real("--spec-draft-n-max"):
spec_draft_n_max_flag = "--spec-draft-n-max"
elif _is_real("--draft-max"):
spec_draft_n_max_flag = "--draft-max"
except (OSError, subprocess.SubprocessError) as exc:
logger.debug(f"llama-server --help probe failed: {exc}")
info = {
"found": True,
"mtp_token": mtp_token,
"supports_mtp": mtp_token is not None,
"ngram_mod_flavor": ngram_mod_flavor,
"supports_ngram_mod": ngram_mod_flavor is not None,
"spec_draft_n_max_flag": spec_draft_n_max_flag,
}
cls._capability_cache[cache_key] = info
return info
# ── GPU allocation ────────────────────────────────────────────
@staticmethod
def _get_gguf_size_bytes(model_path: str) -> int:
"""Total GGUF size in bytes, including split shards."""
main = Path(model_path)
total = main.stat().st_size
# Check for split shards (e.g. model-00001-of-00003.gguf)
m = _SHARD_FULL_RE.match(main.name)
if m:
prefix, _, num_total = m.group(1), m.group(2), m.group(3)
sibling_pat = re.compile(
r"^" + re.escape(prefix) + r"-\d{5}-of-" + re.escape(num_total) + r"\.gguf$"
)
for sibling in main.parent.iterdir():
if sibling != main and sibling_pat.match(sibling.name):
total += sibling.stat().st_size
return total
@staticmethod
def _amd_apu_wants_unified_memory() -> bool:
"""True only for AMD unified-memory APUs (gfx1150/gfx1151), where
GGML_CUDA_ENABLE_UNIFIED_MEMORY lets llama.cpp use shared system RAM.
False elsewhere (the env hurts discrete GPUs). ROCm reuses torch.cuda.*;
gcnArchName suffix is stripped."""
try:
import torch
if getattr(torch.version, "hip", None) is None:
return False
if not (hasattr(torch, "cuda") and torch.cuda.is_available()):
return False
for _i in range(torch.cuda.device_count()):
try:
_arch = getattr(torch.cuda.get_device_properties(_i), "gcnArchName", "") or ""
except Exception:
continue
if _arch.split(":")[0].strip().lower() in {"gfx1150", "gfx1151"}:
return True
except Exception:
return False
return False
@staticmethod
def _get_gpu_free_memory() -> list[tuple[int, int]]:
"""Query free memory per GPU.
Order:
1. ``nvidia-smi`` (NVIDIA CUDA hosts) -- respects
``CUDA_VISIBLE_DEVICES``.
2. ``torch.cuda.mem_get_info`` -- universal fallback that works
on AMD ROCm too (HIP runtime reuses the ``torch.cuda.*``
namespace). Covers the AMD case for issue #5106 (nvidia-smi
probe returned [] on AMD) and NVIDIA hosts missing
``nvidia-smi`` from PATH.
Returns list of (gpu_index, free_mib) sorted by index; empty if no
supported GPU is reachable.
"""
# ── NVIDIA via nvidia-smi ────────────────────────────────────
try:
result = subprocess.run(
[
"nvidia-smi",
"--query-gpu=index,memory.free",
"--format=csv,noheader,nounits",
],
capture_output = True,
text = True,
timeout = 10,
env = child_env_without_native_path_secret(),
**_windows_hidden_subprocess_kwargs(),
)
if result.returncode == 0:
allowed: Optional[set[int]] = None
cvd = os.environ.get("CUDA_VISIBLE_DEVICES")
if cvd is not None:
try:
# `if x.strip()` filters trailing-comma masks ("0,1,").
# Empty mask (CVD="") yields an empty set -> all GPUs
# filtered out, per codebase convention.
allowed = set(int(x.strip()) for x in cvd.split(",") if x.strip())
except ValueError:
pass
gpus: list[tuple[int, int]] = []
for line in result.stdout.strip().splitlines():
parts = line.split(",")
if len(parts) == 2:
idx = int(parts[0].strip())
free_mib = int(parts[1].strip())
if allowed is not None and idx not in allowed:
continue
gpus.append((idx, free_mib))
# Match the docstring's sort-by-id guarantee (driver order isn't).
gpus.sort(key = lambda g: g[0])
if gpus:
return gpus
except Exception as e:
logger.debug(f"nvidia-smi probe failed: {e}")
# ── Torch fallback (covers AMD ROCm and missing nvidia-smi) ──
try:
import torch
if not hasattr(torch, "cuda") or not torch.cuda.is_available():
return []
if not hasattr(torch.cuda, "mem_get_info"):
return []
# torch.cuda enumerates GPUs RELATIVE to the visibility mask. We
# feed these IDs back into the subprocess as CVD, so visible ordinals
# must be translated to physical indices first; otherwise CVD=2,3
# gets rewritten to 0,1 and targets the wrong GPUs.
physical_ids: Optional[list[int]] = None
# Match utils/hardware/hardware.py::_get_parent_visible_gpu_spec:
# treat an empty mask (HIP_VISIBLE_DEVICES="") as "no GPUs" rather
# than falling through. ``or`` would coerce "" to the wrong source.
if getattr(torch.version, "hip", None) is not None:
hip_v = os.environ.get("HIP_VISIBLE_DEVICES")
rocr_v = os.environ.get("ROCR_VISIBLE_DEVICES")
cvd = (
hip_v
if hip_v is not None
else rocr_v
if rocr_v is not None
else os.environ.get("CUDA_VISIBLE_DEVICES")
)
else:
cvd = os.environ.get("CUDA_VISIBLE_DEVICES")
if cvd is not None:
try:
# Empty mask (CVD="") yields an empty list -> no GPUs,
# consistent with the nvidia-smi path.
physical_ids = [int(x.strip()) for x in cvd.split(",") if x.strip()]
except ValueError:
physical_ids = None
gpus = []
for ordinal in range(torch.cuda.device_count()):
free_bytes, _total_bytes = torch.cuda.mem_get_info(ordinal)
idx = (
physical_ids[ordinal]
if physical_ids is not None and ordinal < len(physical_ids)
else ordinal
)
gpus.append((idx, free_bytes // (1024 * 1024)))
# Match the nvidia-smi path's docstring guarantee of sorted-by-id.
return sorted(gpus, key = lambda g: g[0])
except Exception as e:
logger.debug(f"torch GPU probe failed: {e}")
return []
# Skip the wait when the last kill is older than this; the driver has
# already reclaimed the prior process's allocations.
_VRAM_SETTLE_WINDOW_S: float = 15.0
@staticmethod
def _wait_for_vram_settle(
max_wait: float = 2.0,
interval: float = 0.25,
tolerance_mib: int = 256,
since_kill: float = 0.0,
) -> None:
"""Poll ``_get_gpu_free_memory`` until free VRAM stabilises.
The driver reclaims a dead process's allocations asynchronously, so
sampling free memory in the kill-to-spawn window reads artificially low
and pushes GPU selection toward needless CPU offload (the Apply-reload
OOM bare-shell launches never see).
Short-circuits on cold start, stale kill (older than
``_VRAM_SETTLE_WINDOW_S``), CPU-only hosts, probe exceptions, and GPU-set
changes. ``max_wait`` bounds wall-clock time so a wedged ``nvidia-smi``
can't extend the reload.
"""
now = time.monotonic()
if since_kill <= 0.0:
return
if now - since_kill > LlamaCppBackend._VRAM_SETTLE_WINDOW_S:
return
deadline = now + max_wait
def _probe_or_none():
if time.monotonic() >= deadline:
return None
try:
return LlamaCppBackend._get_gpu_free_memory()
except Exception:
return None
prev = _probe_or_none()
if prev is None or not prev:
return
while time.monotonic() < deadline:
remaining = deadline - time.monotonic()
if remaining <= 0:
return
# Clip the nap so a near-zero ``max_wait`` is respected.
time.sleep(min(interval, remaining))
curr = _probe_or_none()
if curr is None or not curr or len(curr) != len(prev):
return
prev_map = dict(prev)
stable = True
for idx, free in curr:
if idx not in prev_map:
stable = False
break
prev_free = prev_map[idx]
# Adaptive: 2% of the larger sample dominates the 256 MiB floor.
per_gpu_tol = max(tolerance_mib, int(max(free, prev_free) * 0.02))
if abs(free - prev_free) >= per_gpu_tol:
stable = False
break
if stable:
return
prev = curr
# Free-VRAM fraction at which Studio pins the GPU directly instead of
# deferring to ``--fit on``. 5% headroom covers CUDA context + compute
# buffers; 0.90 dropped 91-94% fits to CPU offload (#5106).
_GPU_PIN_VRAM_FRACTION = 0.95
@staticmethod
def _windows_pip_nvidia_dll_dirs(prefix: str) -> list[str]:
"""Return DLL dirs from pip-installed CUDA wheels under
``<prefix>/Lib/site-packages/`` so llama-server.exe can load
``cudart64_X.dll`` / ``cublas64_X.dll`` without a system CUDA toolkit.
Mirrors the Linux ``nvidia/cu*/lib`` LD_LIBRARY_PATH block, covering the
Windows wheel layouts seen in the wild:
* ``nvidia/<pkg>/bin`` -- legacy modular wheels.
* ``nvidia/<pkg>/bin/x86_64`` and ``.../bin/x64`` -- CUDA 13 layout
for unsuffixed packages (#5106).
* ``nvidia/<pkg>/Library/bin`` (and arch subdirs) -- conda repacks.
* ``torch/lib`` -- PyTorch's CUDA-bundled wheel can ship
``cudart64_*.dll`` here; mirrors install_llama_prebuilt.py.
Walks with ``Path.iterdir`` not ``glob.glob`` so it's safe against
Windows paths containing ``[`` or ``]`` (valid in usernames)."""
site_packages = Path(prefix) / "Lib" / "site-packages"
out: list[str] = []
seen: set[str] = set()
def _add(path: Path) -> None:
if not path.is_dir():
return
key = os.path.normcase(os.path.abspath(str(path)))
if key in seen:
return
seen.add(key)
out.append(str(path))
nvidia_root = site_packages / "nvidia"
if nvidia_root.is_dir():
for pkg_dir in nvidia_root.iterdir():
if not pkg_dir.is_dir():
continue
# Arch-specific subdirs first so the explicit cudart64_X.dll
# location wins over an empty sibling ``bin``.
for sub in (
pkg_dir / "bin" / "x86_64",
pkg_dir / "bin" / "x64",
pkg_dir / "bin",
pkg_dir / "Library" / "bin" / "x86_64",
pkg_dir / "Library" / "bin" / "x64",
pkg_dir / "Library" / "bin",
):
_add(sub)
_add(site_packages / "torch" / "lib")
return out
@staticmethod
def _build_windows_path_dirs(binary_dir: str, prefix: str, cuda_path: str) -> list[str]:
"""Ordered PATH entries prepended so llama-server.exe resolves cudart /
cublas DLLs: binary_dir, pip nvidia wheels, CUDA_PATH/bin, .../bin/x64.
Extracted so test_windows_gpu_detection_mock tests the real logic. #5106."""
path_dirs = [binary_dir]
path_dirs.extend(LlamaCppBackend._windows_pip_nvidia_dll_dirs(prefix))
if cuda_path:
cuda_bin = os.path.join(cuda_path, "bin")
if os.path.isdir(cuda_bin):
path_dirs.append(cuda_bin)
cuda_bin_x64 = os.path.join(cuda_path, "bin", "x64")
if os.path.isdir(cuda_bin_x64):
path_dirs.append(cuda_bin_x64)
return path_dirs
@staticmethod
def _select_gpus(
model_size_bytes: int, gpus: list[tuple[int, int]]
) -> tuple[Optional[list[int]], bool]:
"""Pick GPU(s) for a model from estimated VRAM and free memory.
``model_size_bytes`` should include weights and estimated KV cache.
``_GPU_PIN_VRAM_FRACTION`` provides headroom for compute buffers,
CUDA context, and other runtime overhead.
Returns (gpu_indices, use_fit):
- ([1], False) fits on 1 GPU at the headroom threshold
- ([1, 2], False) needs 2 GPUs
- (None, True) too large, let --fit handle it
"""
if not gpus:
return None, True
model_size_mib = model_size_bytes / (1024 * 1024)
usable_fraction = LlamaCppBackend._GPU_PIN_VRAM_FRACTION
# Sort GPUs by free memory descending
ranked = sorted(gpus, key = lambda g: g[1], reverse = True)
# Try 1 GPU at the usable-VRAM threshold.
if ranked[0][1] * usable_fraction >= model_size_mib:
return [ranked[0][0]], False
# Try N GPUs (accumulate free memory from most-free)
cumulative = 0
selected = []
for idx, free_mib in ranked:
selected.append(idx)
cumulative += free_mib * usable_fraction
if cumulative >= model_size_mib:
return sorted(selected), False
# Too large even for all GPUs; let --fit handle it
logger.debug(
"Model does not fit in available GPU memory, falling back to --fit",
model_size_mib = round(model_size_mib, 2),
ranked_gpus = ranked,
)
return None, True
# ── KV cache VRAM estimation ─────────────────────────────────────
def _can_estimate_kv(self) -> bool:
"""True if we have enough GGUF metadata to estimate KV cache size."""
if self._n_layers is None:
return False
# MLA: kv_lora_rank suffices (K-only cache).
if self._kv_lora_rank is not None:
return True
# New-style: need explicit key AND value dimensions.
if self._kv_key_length is not None and self._kv_value_length is not None:
return True
# Legacy: need embedding_length + a head count (scalar or per-layer).
return self._embedding_length is not None and (
self._n_kv_heads is not None
or self._n_heads is not None
or self._n_kv_heads_by_layer is not None
)
def _kv_heads_for_layer(self, layer_idx: int, fallback: int) -> int:
if self._n_kv_heads_by_layer is not None and layer_idx < len(self._n_kv_heads_by_layer):
return self._n_kv_heads_by_layer[layer_idx]
return fallback
def _estimate_kv_cache_bytes(
self,
n_ctx: int,
cache_type_kv: Optional[str] = None,
*,
swa_full: bool = False,
n_parallel: int = 1,
kv_unified: bool = True,
ctx_checkpoints: int = 0,
) -> int:
"""Estimate KV cache VRAM for a given context length.
5-path architecture-aware estimation:
1. MLA -- compressed KV latent + RoPE, K-only (no separate V)
2. Hybrid -- only attention layers need KV (Mamba layers don't)
3. SWA -- sliding-window layers cache min(ctx, window) tokens
4. GQA -- standard full KV with explicit key/value dimensions
5. Legacy -- fallback using embed // n_heads
Server-flag knobs (mirror llama-server's CLI):
swa_full -- ``--swa-full``: force SWA layers to cache full
``n_ctx`` (collapses path 3 to path 4 for them).
n_parallel -- ``--parallel`` slots: non-SWA layers stay constant
(cells split across slots), SWA layers scale linearly.
kv_unified -- ``--kv-unified`` (default on): no-op for memory math;
kept for API forward-compat.
ctx_checkpoints -- ``--ctx-checkpoints`` (PR #15293): N SWA snapshots
per slot, one sliding-window of state per SWA layer.
Returns 0 if metadata is insufficient.
"""
if not self._can_estimate_kv() or n_ctx <= 0:
return 0
n_layers = self._n_layers # type: ignore[assignment]
# Gemma 3n / Gemma 4 reuse earlier KV in the last ``shared_kv_layers``
# blocks (no cache). Floor at 1 so a bad GGUF can't zero out KV.
shared = self._shared_kv_layers or 0
n_layers_kv = max(1, n_layers - shared)
n_kv = self._n_kv_heads or self._n_heads or 1 # type: ignore[assignment]
# Bytes per element depends on KV cache quantization
bpe = {
"f32": 4.0,
"f16": 2.0,
"bf16": 2.0,
"q8_0": 34 / 32,
"q5_1": 0.75,
"q5_0": 0.6875,
"q4_1": 0.625,
"q4_0": 0.5625,
"iq4_nl": 0.5625,
}.get(cache_type_kv or "f16", 2.0)
slots = max(1, n_parallel)
# Path 1: MLA (DeepSeek-V2/V3, GLM-4.7, GLM-5, Kimi-K2.5)
# One compressed KV latent per token/layer (shared across heads); V is
# reconstructed from it, no separate V cache. key_length = kv_lora_rank
# + rope_dim. MLA GGUFs set head_count_kv=1; default to 1 if absent to
# avoid falling back to n_heads (e.g. 128 for DeepSeek-V3) which 128x's.
if self._kv_lora_rank is not None:
n_kv_mla = self._n_kv_heads or 1
rope_dim = self._key_length_mla or 64
key_len = self._kv_key_length or (self._kv_lora_rank + rope_dim)
return int(n_layers_kv * n_ctx * n_kv_mla * key_len * bpe)
key_len = self._kv_key_length
val_len = self._kv_value_length
# Path 2: Hybrid Mamba/Attention (Qwen3.5-27B, Qwen3.5-35B-A3B)
# Only 1 in N layers is attention; the rest are Mamba (no KV cache).
if self._ssm_inner_size is not None and self._full_attention_interval is not None:
fai = self._full_attention_interval
n_attn = -(-n_layers // fai) if fai > 0 else n_layers # ceiling division
if key_len is not None and val_len is not None:
return int(n_attn * n_ctx * n_kv * (key_len + val_len) * bpe)
head_dim = self._embedding_length // self._n_heads if self._n_heads else 128 # type: ignore[operator]
return int(n_attn * n_ctx * n_kv * 2 * head_dim * bpe)
# Path 3: Sliding window (Gemma 2/3/3n/4, gpt-oss, Cohere2 ...).
# Pattern filled by the resolver at parse time; if absent, falls through
# to the legacy 1/4-global heuristic below. Per-layer-type --parallel N
# accounting (verified against llama-server):
# * non-SWA layers: total cells = n_ctx split across slots -> CONSTANT.
# * SWA layers: per-slot cells = 2*sliding_window (capped at n_ctx
# and per_slot_ctx) -> grows LINEARLY in slots.
# --swa-full forces full n_ctx for SWA layers; --ctx-checkpoints N adds
# N snapshots per SWA layer per slot.
if (
self._sliding_window is not None
and self._sliding_window > 0
and key_len is not None
and val_len is not None
):
swa = self._sliding_window
per_slot_ctx = max(1, n_ctx // slots)
# --swa-full caches full context like non-SWA (per-slot cells =
# per_slot_ctx, collapsing to constant n_ctx total); otherwise SWA
# caches 2*sliding_window per slot, clamped at per-slot ctx.
swa_cells_per_slot = per_slot_ctx if swa_full else min(n_ctx, 2 * swa, per_slot_ctx)
key_len_swa = self._kv_key_length_swa or key_len
val_len_swa = self._kv_value_length_swa or val_len
if self._sliding_window_pattern is not None:
global_bytes = 0.0 # constant across slots
swa_bytes_per_slot = 0.0 # multiplied by slots
checkpoint_extra_per_slot = 0.0
# Only layers that allocate their own KV; trailing shared layers
# reuse earlier caches.
for layer_idx in range(n_layers_kv):
layer_n_kv = self._kv_heads_for_layer(layer_idx, n_kv)
is_swa = (
layer_idx < len(self._sliding_window_pattern)
and self._sliding_window_pattern[layer_idx]
)
if is_swa:
swa_bytes_per_slot += (
swa_cells_per_slot * layer_n_kv * (key_len_swa + val_len_swa) * bpe
)
if ctx_checkpoints > 0 and not swa_full:
checkpoint_extra_per_slot += (
ctx_checkpoints
* swa
* layer_n_kv
* (key_len_swa + val_len_swa)
* bpe
)
else:
global_bytes += n_ctx * layer_n_kv * (key_len + val_len) * bpe
return int(global_bytes + slots * (swa_bytes_per_slot + checkpoint_extra_per_slot))
n_global = max(1, n_layers_kv // 4)
n_swa = n_layers_kv - n_global
kv_per_token = n_kv * (key_len + val_len) * bpe
kv_per_token_swa = n_kv * (key_len_swa + val_len_swa) * bpe
global_bytes = n_global * n_ctx * kv_per_token
swa_bytes_per_slot = n_swa * swa_cells_per_slot * kv_per_token_swa
checkpoint_extra_per_slot = (
ctx_checkpoints * n_swa * swa * kv_per_token_swa
if ctx_checkpoints > 0 and not swa_full
else 0.0
)
return int(global_bytes + slots * (swa_bytes_per_slot + checkpoint_extra_per_slot))
# Path 4: Standard GQA with explicit key/value dimensions
if key_len is not None and val_len is not None:
return int(n_layers_kv * n_ctx * n_kv * (key_len + val_len) * bpe)
# Path 5: Legacy fallback (old GGUFs without explicit dimensions)
head_dim = self._embedding_length // self._n_heads if self._n_heads else 128 # type: ignore[operator]
return int(2 * n_kv * head_dim * n_layers_kv * n_ctx * bpe)
def _fit_context_to_vram(
self,
requested_ctx: int,
available_mib: int,
model_size_bytes: int,
cache_type_kv: Optional[str] = None,
min_ctx: int = 4096,
*,
swa_full: bool = False,
n_parallel: int = 1,
kv_unified: bool = True,
ctx_checkpoints: int = 0,
kv_on_gpu: bool = True,
mtp_engaged: bool = False,
) -> int:
"""Return the largest context length that fits in GPU VRAM.
Uses 90% of available VRAM as the ctx-fit budget -- tighter than
``_GPU_PIN_VRAM_FRACTION`` on purpose (over-promising context OOMs at
runtime). If the weights alone don't fit, returns ``requested_ctx``.
``kv_on_gpu`` mirrors ``--kv-offload`` (default on); when False the KV
cache lives in CPU RAM and the requested context is honored verbatim.
Other keyword args mirror ``_estimate_kv_cache_bytes``.
``mtp_engaged`` reserves extra VRAM for the MTP draft model's KV cache +
compute buffers, else tight tiers (e.g. 32 GB) spill to a slower path.
"""
if not self._can_estimate_kv():
logger.debug(
"Skipping context fit because KV cache metadata is unavailable",
requested_ctx = requested_ctx,
available_mib = available_mib,
)
return requested_ctx
# KV lives off-GPU: no VRAM accounting needed for the cache itself.
if not kv_on_gpu:
return requested_ctx
kv_kwargs = dict(
swa_full = swa_full,
n_parallel = n_parallel,
kv_unified = kv_unified,
ctx_checkpoints = ctx_checkpoints,
)
# MTP needs a tighter budget; drop from 0.90 to 0.85.
budget_frac = 0.85 if mtp_engaged else 0.90
budget_bytes = available_mib * 1024 * 1024 * budget_frac
model_footprint = model_size_bytes
# Already fits?
kv = self._estimate_kv_cache_bytes(requested_ctx, cache_type_kv, **kv_kwargs)
if model_footprint + kv <= budget_bytes:
return requested_ctx
# Weights alone exceed budget -- reducing ctx can't help; --fit handles it.
if model_footprint >= budget_bytes:
logger.debug(
"Model footprint exceeds GPU budget before KV cache",
requested_ctx = requested_ctx,
available_mib = available_mib,
model_size_gb = round(model_footprint / (1024**3), 2),
)
return requested_ctx
# Binary search for max context that fits
remaining = budget_bytes - model_footprint
effective_min = min(min_ctx, requested_ctx)
lo, hi = effective_min, requested_ctx
best = effective_min
while lo <= hi:
mid = (lo + hi) // 2
kv = self._estimate_kv_cache_bytes(mid, cache_type_kv, **kv_kwargs)
if kv <= remaining:
best = mid
lo = mid + 1
else:
hi = mid - 1
# Round down to nearest 256 for alignment, never above requested_ctx
best = (best // 256) * 256
best = max(effective_min, best)
best = min(best, requested_ctx)
return best
# ── Variant fallback ────────────────────────────────────────────
@staticmethod
def _find_smallest_fitting_variant(
hf_repo: str,
free_bytes: int,
hf_token: Optional[str] = None,
) -> Optional[tuple[str, int]]:
"""Find the smallest GGUF variant (including all shards) that fits.
Groups split shards by variant prefix and sums their sizes (e.g.
UD-Q4_K_XL with 9 shards of 50 GB each = 450 GB total).
Returns (first_shard_filename, total_size_bytes) or None.
"""
try:
from huggingface_hub import get_paths_info, list_repo_files
files = list_repo_files(hf_repo, token = hf_token)
gguf_files = [f for f in files if f.endswith(".gguf") and "mmproj" not in f.lower()]
if not gguf_files:
return None
# Sizes for all GGUF files
path_infos = list(get_paths_info(hf_repo, gguf_files, token = hf_token))
size_map = {p.path: (p.size or 0) for p in path_infos}
# Group by variant: shards share a prefix before -NNNNN-of-NNNNN
variants: dict[str, list[str]] = {}
for f in gguf_files:
m = _SHARD_RE.match(f)
key = m.group(1) if m else f
variants.setdefault(key, []).append(f)
# Sum shard sizes per variant, track the first shard (for download)
variant_sizes: list[tuple[str, int, list[str]]] = []
for key, shard_files in variants.items():
total = sum(size_map.get(f, 0) for f in shard_files)
first = sorted(shard_files)[0]
variant_sizes.append((first, total, shard_files))
# Smallest that fits
variant_sizes.sort(key = lambda x: x[1])
for first_file, total_size, _ in variant_sizes:
if total_size > 0 and total_size <= free_bytes:
return first_file, total_size
return None
except Exception:
return None
# ── Port allocation ───────────────────────────────────────────
@staticmethod
def _find_free_port() -> int:
"""Find an available TCP port."""
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind(("127.0.0.1", 0))
return s.getsockname()[1]
# ── Stdout drain (prevents pipe deadlock on Windows) ─────────
def _drain_stdout(self):
"""Read subprocess stdout lines in a background thread.
Prevents a pipe-buffer deadlock on Windows (~4 KB buffer): without
draining, llama-server blocks on writes and never becomes healthy.
Each line is also teed to ``self._llama_log_fh`` when set, so a
post-mortem has the full output even if the crash predates the
drain-thread join in ``_wait_for_health``.
"""
try:
for line in self._process.stdout:
line = line.rstrip()
if line:
self._stdout_lines.append(line)
logger.debug(f"[llama-server] {line}")
fh = getattr(self, "_llama_log_fh", None)
if fh is not None:
try:
fh.write(line + "\n")
fh.flush()
except (ValueError, OSError):
# Log file closed under us; tee silently.
pass
except (ValueError, OSError):
# Pipe closed -- process terminating.
pass
# GGUF KV type sizes for fast skipping
_GGUF_TYPE_SIZE = {
0: 1,
1: 1,
2: 2,
3: 2,
4: 4,
5: 4,
6: 4,
7: 1,
10: 8,
11: 8,
12: 8,
}
@staticmethod
def _gguf_skip_value(f, vtype: int) -> None:
"""Skip a GGUF KV value without reading it."""
sz = LlamaCppBackend._GGUF_TYPE_SIZE.get(vtype)
if sz is not None:
f.seek(sz, 1)
elif vtype == 8: # STRING
slen = struct.unpack("<Q", f.read(8))[0]
f.seek(slen, 1)
elif vtype == 9: # ARRAY
atype = struct.unpack("<I", f.read(4))[0]
alen = struct.unpack("<Q", f.read(8))[0]
elem_sz = LlamaCppBackend._GGUF_TYPE_SIZE.get(atype)
if elem_sz is not None:
f.seek(elem_sz * alen, 1)
elif atype == 8:
for _ in range(alen):
slen = struct.unpack("<Q", f.read(8))[0]
f.seek(slen, 1)
else:
for _ in range(alen):
LlamaCppBackend._gguf_skip_value(f, atype)
@staticmethod
def _gguf_read_array_value(f, atype: int, alen: int) -> Optional[list]:
if atype == 4: # UINT32
return [struct.unpack("<I", f.read(4))[0] for _ in range(alen)]
if atype == 5: # INT32
return [struct.unpack("<i", f.read(4))[0] for _ in range(alen)]
if atype == 7: # BOOL
return [struct.unpack("<?", f.read(1))[0] for _ in range(alen)]
for _ in range(alen):
LlamaCppBackend._gguf_skip_value(f, atype)
return None
def _read_gguf_metadata(self, gguf_path: str) -> None:
"""Read context_length, architecture params, and chat_template from a GGUF header.
Parses only the KV pairs we need (~30ms even for multi-GB files).
For split GGUFs, metadata is always in shard 1.
"""
# Reset metadata so stale flags (e.g. _supports_reasoning) don't
# carry over when switching models.
self._context_length = None
self._chat_template = None
self._supports_reasoning = False
self._reasoning_always_on = False
self._reasoning_style = "enable_thinking"
self._reasoning_default = True
self._supports_preserve_thinking = False
self._supports_tools = False
self._n_layers = None
self._n_kv_heads = None
self._n_kv_heads_by_layer = None
self._n_heads = None
self._embedding_length = None
self._kv_key_length = None
self._kv_value_length = None
self._sliding_window = None
self._sliding_window_pattern = None
self._full_attention_interval = None
self._kv_lora_rank = None
self._key_length_mla = None
self._kv_key_length_swa = None
self._kv_value_length_swa = None
self._ssm_inner_size = None
self._ssm_state_size = None
self._shared_kv_layers = None
self._nextn_predict_layers = None
try:
WANTED = {
"general.architecture",
"tokenizer.chat_template",
# Source-repo hints for the SWA resolver's HF fallback.
"general.source.huggingface.repository",
"general.source.url",
"general.source.repo_url",
"general.base_model.0.repo_url",
"general.base_model.0.organization",
"general.base_model.0.name",
"general.basename",
"general.organization",
"general.size_label",
"general.finetune",
}
# Arch-specific keys added dynamically once we know the arch.
arch_keys: dict[str, str] = {} # gguf_key -> attribute name
arch = None
sliding_window_pattern_period: Optional[int] = None
general: dict[str, str] = {}
with open(gguf_path, "rb") as f:
magic = struct.unpack("<I", f.read(4))[0]
if magic != 0x46554747: # b"GGUF" as little-endian u32
return
_version = struct.unpack("<I", f.read(4))[0]
_tensor_count, kv_count = struct.unpack("<QQ", f.read(16))
for _ in range(kv_count):
# Tolerate truncated input (e.g. a partial header from an
# HTTP byte-range fetch): bail out so the resolver
# fallback runs on whatever we parsed.
try:
key_len_bytes = f.read(8)
if len(key_len_bytes) < 8:
break
key_len = struct.unpack("<Q", key_len_bytes)[0]
key_bytes = f.read(key_len)
if len(key_bytes) < key_len:
break
key = key_bytes.decode("utf-8")
vtype_bytes = f.read(4)
if len(vtype_bytes) < 4:
break
vtype = struct.unpack("<I", vtype_bytes)[0]
except (struct.error, UnicodeDecodeError):
break
try:
if key in WANTED or key in arch_keys:
if vtype == 8: # STRING
slen = struct.unpack("<Q", f.read(8))[0]
val_s = f.read(slen).decode("utf-8")
if key.startswith("general.") and key != "general.architecture":
general[key] = val_s
if key == "general.architecture":
arch = val_s
arch_keys = {
f"{arch}.context_length": "context_length",
f"{arch}.block_count": "n_layers",
f"{arch}.attention.head_count_kv": "n_kv_heads",
f"{arch}.attention.head_count": "n_heads",
f"{arch}.embedding_length": "embedding_length",
f"{arch}.attention.key_length": "kv_key_length",
f"{arch}.attention.value_length": "kv_value_length",
f"{arch}.attention.sliding_window": "sliding_window",
f"{arch}.attention.sliding_window_pattern": "sliding_window_pattern",
f"{arch}.full_attention_interval": "full_attention_interval",
f"{arch}.attention.kv_lora_rank": "kv_lora_rank",
f"{arch}.attention.key_length_mla": "key_length_mla",
f"{arch}.attention.key_length_swa": "kv_key_length_swa",
f"{arch}.attention.value_length_swa": "kv_value_length_swa",
f"{arch}.attention.shared_kv_layers": "shared_kv_layers",
f"{arch}.ssm.inner_size": "ssm_inner_size",
f"{arch}.ssm.state_size": "ssm_state_size",
f"{arch}.nextn_predict_layers": "nextn_predict_layers",
}
elif key == "tokenizer.chat_template":
self._chat_template = val_s
elif vtype in (4, 10): # UINT32 or UINT64
val_i = (
struct.unpack("<I", f.read(4))[0]
if vtype == 4
else struct.unpack("<Q", f.read(8))[0]
)
attr = arch_keys.get(key)
if attr:
if attr == "sliding_window_pattern":
sliding_window_pattern_period = val_i
else:
setattr(self, f"_{attr}", val_i)
elif vtype == 9: # ARRAY
atype = struct.unpack("<I", f.read(4))[0]
alen = struct.unpack("<Q", f.read(8))[0]
val_a = self._gguf_read_array_value(f, atype, alen)
attr = arch_keys.get(key)
if attr == "n_kv_heads" and val_a is not None:
self._n_kv_heads_by_layer = [int(x) for x in val_a]
if self._n_kv_heads is None and val_a:
self._n_kv_heads = max(int(x) for x in val_a)
elif attr == "sliding_window_pattern" and val_a is not None:
self._sliding_window_pattern = [bool(x) for x in val_a]
sliding_window_pattern_period = None
else:
self._gguf_skip_value(f, vtype)
else:
self._gguf_skip_value(f, vtype)
except (struct.error, UnicodeDecodeError):
# Truncated input (e.g. HTTP byte-range header
# fetch); break so the resolver fallback runs on
# what we have.
break
# Expand a scalar period straight from the GGUF first.
if (
self._sliding_window_pattern is None
and sliding_window_pattern_period
and self._n_layers
):
self._sliding_window_pattern = [
(i + 1) % sliding_window_pattern_period != 0 for i in range(self._n_layers)
]
# Otherwise hand off to the resolver (cache / bootstrap /
# transformers / HF); see `_resolve_swa_pattern`.
if self._sliding_window_pattern is None and self._sliding_window and self._n_layers:
hf_repo_candidates = (
general.get("general.source.huggingface.repository"),
_hf_repo_from_url(general.get("general.source.url")),
_hf_repo_from_url(general.get("general.source.repo_url")),
_hf_repo_from_url(general.get("general.base_model.0.repo_url")),
(
f"{general['general.base_model.0.organization']}/"
f"{general['general.base_model.0.name']}".replace(" ", "-")
if general.get("general.base_model.0.organization")
and general.get("general.base_model.0.name")
else None
),
(
f"{general['general.organization']}/"
f"{general['general.basename']}".replace(" ", "-")
if general.get("general.organization") and general.get("general.basename")
else None
),
)
self._sliding_window_pattern = _resolve_swa_pattern(
arch,
self._n_layers,
hf_repo_candidates,
)
if self._context_length:
logger.info(f"GGUF metadata: context_length={self._context_length}")
if self._chat_template:
logger.info(f"GGUF metadata: chat_template={len(self._chat_template)} chars")
# Detect thinking/reasoning support from chat template.
flags = detect_reasoning_flags(
self._chat_template,
self._model_identifier,
log_source = "GGUF metadata",
)
self._supports_reasoning = flags["supports_reasoning"]
self._reasoning_style = flags["reasoning_style"]
self._reasoning_always_on = flags["reasoning_always_on"]
self._supports_preserve_thinking = flags["supports_preserve_thinking"]
self._supports_tools = flags["supports_tools"]
except Exception as e:
logger.warning(f"Failed to read GGUF metadata: {e}")
# ── HF download (no lock held) ───────────────────────────────
def _download_gguf(
self,
*,
hf_repo: str,
hf_variant: Optional[str] = None,
hf_token: Optional[str] = None,
) -> str:
"""Download GGUF file(s) from HuggingFace. Returns local path.
Runs WITHOUT self._lock so unload_model() can set _cancel_event at
any time; checks it between each shard download.
"""
try:
from huggingface_hub import hf_hub_download
except ImportError:
raise RuntimeError(
"huggingface_hub is required for HF model loading. "
"Install it with: pip install huggingface_hub"
)
# Resolve the filename from the variant
gguf_filename = None
gguf_extra_shards: list[str] = []
if hf_variant:
try:
from huggingface_hub import list_repo_files
files = list_repo_files(hf_repo, token = hf_token)
variant_lower = hf_variant.lower()
boundary = re.compile(
r"(?<![a-zA-Z0-9])" + re.escape(variant_lower) + r"(?![a-zA-Z0-9])"
)
gguf_files = sorted(
f for f in files if f.endswith(".gguf") and boundary.search(f.lower())
)
if gguf_files:
gguf_filename = gguf_files[0]
m = _SHARD_FULL_RE.match(gguf_filename)
if m:
prefix = m.group(1)
total = m.group(3)
sibling_pat = re.compile(
r"^" + re.escape(prefix) + r"-\d{5}-of-" + re.escape(total) + r"\.gguf$"
)
gguf_extra_shards = [f for f in gguf_files[1:] if sibling_pat.match(f)]
except Exception as e:
logger.warning(f"Could not list repo files: {e}")
# Offline: resolve variant -> filename from the local HF cache.
# The heuristic below assumes filenames echo the repo name, which
# breaks for e.g. Qwen3.6-27B-MTP-GGUF (no "MTP" in file). Match
# against the rel path (not just basename) so subdir layouts like
# ``BF16/foo.gguf`` are findable.
if not gguf_filename:
try:
from utils.models.model_config import _iter_hf_cache_snapshots
boundary = re.compile(
r"(?<![a-zA-Z0-9])" + re.escape(hf_variant.lower()) + r"(?![a-zA-Z0-9])"
)
for snap in _iter_hf_cache_snapshots(hf_repo):
matches = sorted(
p.relative_to(snap).as_posix()
for p in snap.rglob("*.gguf")
if "mmproj" not in p.name.lower()
and boundary.search(p.relative_to(snap).as_posix().lower())
)
if not matches:
continue
gguf_filename = matches[0]
m = _SHARD_FULL_RE.match(Path(gguf_filename).name)
if m:
prefix = m.group(1)
total = m.group(3)
sibling_pat = re.compile(
r"^"
+ re.escape(prefix)
+ r"-\d{5}-of-"
+ re.escape(total)
+ r"\.gguf$"
)
gguf_extra_shards = [
f for f in matches[1:] if sibling_pat.match(Path(f).name)
]
logger.info(
"Resolved variant %s -> %s from local HF cache",
hf_variant,
gguf_filename,
)
break
except Exception as e:
logger.debug(f"Offline cache lookup for variant failed: {e}")
if not gguf_filename:
repo_name = hf_repo.split("/")[-1].replace("-GGUF", "")
gguf_filename = f"{repo_name}-{hf_variant}.gguf"
# Check disk space; fall back to a smaller variant if needed
all_gguf_files = [gguf_filename] + gguf_extra_shards
try:
from huggingface_hub import get_paths_info, try_to_load_from_cache
path_infos = list(get_paths_info(hf_repo, all_gguf_files, token = hf_token))
total_bytes = sum((p.size or 0) for p in path_infos)
# Subtract bytes already in the HF cache so we only preflight
# against what we must download. Without this, re-loading a
# cached large model (e.g. MiniMax-M2.7-GGUF at 131 GB) fails
# cold whenever free disk is below the full weight footprint,
# even though nothing needs downloading.
already_cached_bytes = 0
for p in path_infos:
if not p.size:
continue
try:
cached_path = try_to_load_from_cache(hf_repo, p.path)
except Exception:
cached_path = None
if isinstance(cached_path, str) and os.path.exists(cached_path):
try:
on_disk = os.path.getsize(cached_path)
except OSError:
on_disk = 0
# Satisfied only when the full blob is present.
if on_disk >= p.size:
already_cached_bytes += p.size
total_download_bytes = max(0, total_bytes - already_cached_bytes)
if total_download_bytes > 0:
cache_dir = os.environ.get(
"HF_HUB_CACHE",
str(Path.home() / ".cache" / "huggingface" / "hub"),
)
Path(cache_dir).mkdir(parents = True, exist_ok = True)
free_bytes = shutil.disk_usage(cache_dir).free
total_gb = total_download_bytes / (1024**3)
free_gb = free_bytes / (1024**3)
cached_gb = already_cached_bytes / (1024**3)
logger.info(
f"GGUF download: {total_gb:.1f} GB needed "
f"({cached_gb:.1f} GB already cached), "
f"{free_gb:.1f} GB free on disk"
)
if total_download_bytes > free_bytes:
smaller = self._find_smallest_fitting_variant(
hf_repo,
free_bytes,
hf_token,
)
if smaller:
fallback_file, fallback_size = smaller
logger.info(
f"Selected variant too large ({total_gb:.1f} GB), "
f"falling back to {fallback_file} ({fallback_size / (1024**3):.1f} GB)"
)
gguf_filename = fallback_file
_m = _SHARD_RE.match(gguf_filename)
_prefix = _m.group(1) if _m else None
if _prefix:
gguf_extra_shards = sorted(
f
for f in all_gguf_files
if f.startswith(_prefix)
and f != gguf_filename
and "mmproj" not in f.lower()
)
else:
gguf_extra_shards = []
else:
raise RuntimeError(
f"Not enough disk space to download any variant. "
f"Only {free_gb:.1f} GB free in {cache_dir}"
)
except RuntimeError:
raise
except Exception as e:
logger.warning(f"Could not check disk space: {e}")
gguf_label = f"{hf_repo}/{gguf_filename}" + (
f" (+{len(gguf_extra_shards)} shards)" if gguf_extra_shards else ""
)
logger.info(f"Resolving GGUF: {gguf_label}")
try:
if self._cancel_event.is_set():
raise RuntimeError("Cancelled")
dl_start = time.monotonic()
local_path = hf_hub_download(
repo_id = hf_repo,
filename = gguf_filename,
token = hf_token,
)
for shard in gguf_extra_shards:
if self._cancel_event.is_set():
raise RuntimeError("Cancelled")
logger.info(f"Resolving GGUF shard: {shard}")
hf_hub_download(
repo_id = hf_repo,
filename = shard,
token = hf_token,
)
except RuntimeError as e:
if "Cancelled" in str(e):
raise
raise RuntimeError(
f"Failed to download GGUF file '{gguf_filename}' from {hf_repo}: {e}"
)
except Exception as e:
raise RuntimeError(
f"Failed to download GGUF file '{gguf_filename}' from {hf_repo}: {e}"
)
dl_elapsed = time.monotonic() - dl_start
if dl_elapsed < 2.0:
logger.info(f"GGUF resolved from cache: {local_path}")
else:
logger.info(f"GGUF downloaded in {dl_elapsed:.1f}s: {local_path}")
return local_path
def _download_mmproj(
self,
*,
hf_repo: str,
hf_token: Optional[str] = None,
) -> Optional[str]:
"""Download the mmproj (vision projection) file from a GGUF repo.
Prefers mmproj-F16.gguf, else any mmproj*.gguf. Returns the local
path, or None if none exists.
"""
def _pick_mmproj(candidates: list[str]) -> Optional[str]:
mmproj_files = sorted(
f
for f in candidates
if f.lower().endswith(".gguf") and "mmproj" in Path(f).name.lower()
)
if not mmproj_files:
return None
for f in mmproj_files:
if f.lower().endswith("-f16.gguf"):
return f
return mmproj_files[0]
target: Optional[str] = None
try:
from huggingface_hub import list_repo_files
target = _pick_mmproj(list_repo_files(hf_repo, token = hf_token))
except Exception as e:
logger.debug(f"Could not list repo files for mmproj: {e}")
# Offline: resolve mmproj from the local HF cache snapshot, same as
# _download_gguf's offline fallback above.
if target is None:
try:
from utils.models.model_config import _iter_hf_cache_snapshots
for snap in _iter_hf_cache_snapshots(hf_repo):
rel_files = [p.relative_to(snap).as_posix() for p in snap.rglob("*.gguf")]
target = _pick_mmproj(rel_files)
if target is not None:
logger.info("Resolved mmproj %s from local HF cache", target)
break
except Exception as e:
logger.debug(f"Offline cache lookup for mmproj failed: {e}")
if target is None:
return None
try:
from huggingface_hub import hf_hub_download
logger.info(f"Downloading mmproj: {hf_repo}/{target}")
local_path = hf_hub_download(
repo_id = hf_repo,
filename = target,
token = hf_token,
)
return local_path
except Exception as e:
logger.warning(f"Could not download mmproj: {e}")
return None
def _resolve_launch_mmproj_path(
self, *, model_path: str, mmproj_path: Optional[str]
) -> Optional[str]:
"""Return mmproj_path iff it exists on disk AND matches the model family.
None if mmproj_path is None, missing, or family-mismatched.
"""
if not mmproj_path:
return None
mmproj = Path(mmproj_path)
if not mmproj.is_file():
logger.warning(f"mmproj file not found: {mmproj_path}")
return None
from utils.models.model_config import mmproj_matches_model_family
if not mmproj_matches_model_family(model_path, str(mmproj)):
logger.warning(
f"mmproj does not match model family: model={Path(model_path).name} "
f"mmproj={mmproj.name}"
)
return None
return str(mmproj)
# ── Lifecycle ─────────────────────────────────────────────────
# GGUF ``general.architecture`` values for diffusion / image models.
# llama.cpp has no such architectures, so loading one as a chat model dies
# with "unknown model architecture: '<arch>'". These match the patched
# stable-diffusion.cpp / ComfyUI-GGUF enums. Unsloth publishes FLUX and
# Qwen-Image GGUFs under
# https://huggingface.co/collections/unsloth/unsloth-diffusion-ggufs.
# Matched exactly (not a substring) so a chat arch containing "wan"/"sd1"
# (e.g. "taiwan") isn't misrouted to Images.
_DIFFUSION_ARCHES = frozenset(
(
"qwen_image",
"flux",
"sd1",
"sdxl",
"sd3",
"aura",
"hidream",
"cosmos",
"ltxv",
"hyvid",
"wan",
"lumina2",
)
)
@staticmethod
def _classify_llama_start_failure(
output: str, gguf_path: Optional[str], model_identifier: Optional[str]
) -> str:
"""Explain *why* llama-server failed to start, from its output.
Several distinct failures otherwise collapse into the same opaque
"invalid GGUF or out of memory" message. Worst case: a diffusion GGUF
loaded as a chat model -- valid file, plenty of memory, but llama.cpp
has no such architecture, so the user is told to free memory that was
never the problem (#5842). Pick the most specific message we can.
"""
lowered = (output or "").lower()
# Detect Ollama source up front so the arch branch can keep the
# Ollama hint instead of the generic "unsupported arch" message.
gguf = gguf_path or ""
is_ollama = (
".studio_links" in gguf
or os.sep + "ollama_links" + os.sep in gguf
or os.sep + ".cache" + os.sep + "ollama" + os.sep in gguf
or (model_identifier or "").startswith("ollama/")
)
# "unknown model architecture: '<arch>'": diffusion -> Images page,
# Ollama -> Ollama hint, else a precise "unsupported" message. Exact
# match so chat archs aren't misrouted.
arch_match = re.search(r"unknown model architecture:\s*'([^']+)'", lowered)
if arch_match:
arch = arch_match.group(1)
if arch in LlamaCppBackend._DIFFUSION_ARCHES:
return (
f"'{arch}' is a diffusion (image-generation) GGUF, which "
"llama-server cannot run as a chat/completion model. Use "
"Studio's Images page to generate with local diffusion "
"GGUFs such as FLUX and Qwen-Image."
)
if is_ollama:
return (
"Some Ollama models do not work with llama.cpp. Try a "
"different model, or use this model directly through "
"Ollama instead."
)
return (
f"llama.cpp does not support this GGUF's model architecture "
f"('{arch}'). The file is valid, but this model type cannot "
"be run with llama-server."
)
# Other Ollama compat failures that don't name an arch. Only when
# the output shows a GGUF compat issue, not OOM / missing binaries.
if is_ollama:
gguf_compat_hints = (
"key not found",
"unknown model architecture",
"failed to load model",
)
if any(h in lowered for h in gguf_compat_hints):
return (
"Some Ollama models do not work with llama.cpp. Try a "
"different model, or use this model directly through "
"Ollama instead."
)
# Fallback: genuinely unknown failure (OOM, missing binary ...).
return (
"llama-server failed to start. "
"Check that the GGUF file is valid and you have enough memory."
)
def load_model(
self,
*,
# Local mode: pass a path to a .gguf file
gguf_path: Optional[str] = None,
# Vision projection (mmproj) for local vision models
mmproj_path: Optional[str] = None,
# HF mode: let llama-server download via -hf "repo:quant"
hf_repo: Optional[str] = None,
hf_variant: Optional[str] = None,
hf_token: Optional[str] = None,
# Common
model_identifier: str,
is_vision: bool = False,
n_ctx: int = 4096,
chat_template_override: Optional[str] = None,
cache_type_kv: Optional[str] = None,
speculative_type: Optional[str] = None,
spec_draft_n_max: Optional[int] = None,
n_threads: Optional[int] = None,
n_gpu_layers: Optional[int] = None, # caller compat, unused
n_parallel: int = 1,
extra_args: Optional[List[str]] = None,
) -> bool:
"""Start llama-server with a GGUF model.
Two modes:
- Local: ``gguf_path="/path/to/model.gguf"`` → uses ``-m``
- HF: ``hf_repo="...-GGUF", hf_variant="Q4_K_M"`` → uses ``-hf``
Returns True if the server started and the health check passed.
"""
# Serialise the whole load so concurrent /load calls never leave two
# llama-server processes alive (#5401 / #5161). Doesn't block /unload.
with self._serial_load_lock:
# Duplicate /load that raced past the route check: do nothing if the
# live server already satisfies this request.
if self._already_in_target_state(
gguf_path = gguf_path,
model_identifier = model_identifier,
hf_variant = hf_variant,
n_ctx = n_ctx,
cache_type_kv = cache_type_kv,
speculative_type = speculative_type,
spec_draft_n_max = spec_draft_n_max,
chat_template_override = chat_template_override,
extra_args = extra_args,
is_vision = is_vision,
):
logger.info(
f"load_model: backend already in target state for "
f"'{model_identifier}', skipping reload"
)
# Retry probe only if a prior attempt didn't finish.
if not self._audio_probed:
try:
detected = self._detect_audio_type_strict()
self._audio_probed = True
except Exception as exc:
logger.debug("Fast-path audio probe failed: %s", exc)
detected = None
if detected in ("snac", "bicodec", "dac"):
with self._lock:
if not self._healthy:
return False
try:
self.init_audio_codec(detected)
self._is_audio = True
self._audio_type = detected
except Exception as exc:
logger.warning(
"Failed to init audio codec '%s': %s",
detected,
exc,
)
self._audio_probed = False
return False
elif detected:
# csm / whisper / audio_vlm: track type but keep
# _is_audio False -- GGUF TTS routing only fires for
# snac/bicodec/dac.
with self._lock:
if not self._healthy:
return False
self._audio_type = detected
# Re-derive after a retried probe (_mmproj_has_audio persists).
from utils.models.model_config import is_audio_input_type
self._has_audio_input = bool(is_audio_input_type(self._audio_type)) or bool(
self._mmproj_has_audio
)
if not self._healthy:
return False
return True
self._cancel_event.clear()
# ── Phase 1: kill old process (under lock, fast) ──────────
with self._lock:
self._kill_process()
binary = self._find_llama_server_binary()
if not binary:
raise RuntimeError(
"llama-server binary not found. "
"Run setup.sh to build it, install llama.cpp, "
"or set LLAMA_SERVER_PATH environment variable."
)
# ── Phase 2: download (NO lock held, so cancel can proceed) ──
# Scope HF_HUB_OFFLINE to the download block only when DNS is
# dead; cleanup runs even on exception so a transient hiccup
# can't quarantine future loads.
if hf_repo:
with _hf_offline_if_dns_dead():
model_path = self._download_gguf(
hf_repo = hf_repo,
hf_variant = hf_variant,
hf_token = hf_token,
)
# Auto-download mmproj for vision models
if is_vision and not mmproj_path:
mmproj_path = self._download_mmproj(
hf_repo = hf_repo,
hf_token = hf_token,
)
elif gguf_path:
if not Path(gguf_path).is_file():
raise FileNotFoundError(f"GGUF file not found: {gguf_path}")
model_path = gguf_path
else:
raise ValueError("Either gguf_path or hf_repo must be provided")
# Set identifier early so _read_gguf_metadata can use it (DeepSeek).
self._model_identifier = model_identifier
# Read GGUF metadata (context_length, chat_template); header-only.
self._read_gguf_metadata(model_path)
if self._cancel_event.is_set():
logger.info("Load cancelled after download phase")
return False
# Outside ``self._lock`` so /unload, /cancel, /status aren't
# blocked. ``unload_model`` also records the kill, so the
# frontend /unload+/load Apply path engages the wait here even
# without an in-process kill.
self._wait_for_vram_settle(since_kill = self._last_kill_monotonic)
# ── Phase 3: start llama-server (under lock) ──────────────
with self._lock:
# Re-check cancel inside lock
if self._cancel_event.is_set():
logger.info("Load cancelled before server start")
return False
self._port = self._find_free_port()
# Select GPU(s) from model size + estimated KV cache. Seed
# safe defaults before probing so the except path has valid
# state to publish.
ctx_override = parse_ctx_override(extra_args)
requested_ctx = resolve_requested_ctx(extra_args, n_ctx)
cache_override = parse_cache_override(extra_args)
cache_type_kv = resolve_cache_type_kv(extra_args, cache_type_kv)
if ctx_override is not None and ctx_override > 0:
logger.info(f"User --ctx-size {ctx_override} honored; skipping auto-reduce")
if cache_override is not None:
logger.info(f"User --cache-type-k/-v {cache_override} honored for KV estimate")
effective_ctx = requested_ctx if requested_ctx > 0 else (self._context_length or 0)
max_available_ctx = self._context_length or effective_ctx
gpus: list[tuple[int, int]] = []
try:
model_size = self._get_gguf_size_bytes(model_path)
gpus = self._get_gpu_free_memory()
# Resolve effective context: 0 means let llama-server use
# the model's native length. Only expand to a known native
# length if metadata exists; else keep 0 as a sentinel.
if requested_ctx > 0:
effective_ctx = requested_ctx
elif self._context_length is not None:
effective_ctx = self._context_length
else:
effective_ctx = 0
original_ctx = effective_ctx
# Default UI ceiling to the native context length;
# GPU/VRAM-fit logic below may shrink it on limited HW.
max_available_ctx = self._context_length or effective_ctx
# Will MTP engage on this load? If so, auto-fit reserves
# extra VRAM for the draft model. Mirrors
# _build_speculative_flags' resolver: forced mtp / mtp+ngram
# always engage; auto only on an MTP GGUF >= 3B; ngram /
# ngram-simple / off never engage MTP.
_mtp_canonical = _canonicalize_spec_mode(speculative_type)
_mtp_effective = _mtp_canonical or "auto"
_mtp_size_for_fit = _extract_model_size_b(model_identifier)
_mtp_sub_3b_for_fit = _mtp_size_for_fit is not None and _mtp_size_for_fit < 3.0
_mtp_will_engage = bool(
not _extra_args_set_spec_type(extra_args)
and (
_mtp_effective in ("mtp", "mtp+ngram")
or (
_mtp_effective == "auto"
and (
bool(self._nextn_predict_layers)
or _is_mtp_model_name(model_identifier, model_path)
)
and not _mtp_sub_3b_for_fit
)
)
)
# Auto-cap context to fit GPU VRAM and select GPUs. Two
# policies by whether the user set n_ctx:
# Explicit n_ctx: honor it. Try the full context with
# _select_gpus (as many GPUs as needed); cap only if it
# doesn't fit on any combination.
# Auto n_ctx=0 (native): prefer fewer GPUs with reduced
# context, since multi-GPU is slower.
gpu_indices, use_fit = None, True
explicit_ctx = requested_ctx > 0
if gpus and self._can_estimate_kv() and effective_ctx > 0:
# Largest hardware-aware cap from the native context
# across all usable GPU subsets (for UI bounds),
# independent of the requested context.
native_ctx_for_cap = self._context_length or effective_ctx
if native_ctx_for_cap > 0:
ranked_for_cap = sorted(gpus, key = lambda g: g[1], reverse = True)
best_cap = 0
for n_gpus in range(1, len(ranked_for_cap) + 1):
subset = ranked_for_cap[:n_gpus]
pool_mib = sum(free for _, free in subset)
capped = self._fit_context_to_vram(
native_ctx_for_cap,
pool_mib,
model_size,
cache_type_kv,
n_parallel = n_parallel,
mtp_engaged = _mtp_will_engage,
)
kv = self._estimate_kv_cache_bytes(
capped, cache_type_kv, n_parallel = n_parallel
)
total_mib = (model_size + kv) / (1024 * 1024)
if total_mib <= pool_mib * 0.90:
best_cap = max(best_cap, capped)
if best_cap > 0:
max_available_ctx = best_cap
else:
# Weights exceed 90% of every GPU subset, so no
# context fits. Anchor the UI "safe zone" at 4096
# so the slider warns above the fallback.
max_available_ctx = min(4096, native_ctx_for_cap)
if explicit_ctx:
# Honor the requested context verbatim. If it fits,
# pin GPUs and skip --fit; else ship -c <ctx> --fit
# on and let llama-server flex -ngl (CPU offload).
requested_total = model_size + self._estimate_kv_cache_bytes(
effective_ctx, cache_type_kv, n_parallel = n_parallel
)
gpu_indices, use_fit = self._select_gpus(requested_total, gpus)
# No silent shrink: effective_ctx stays == requested_ctx.
else:
# Auto context: prefer fewer GPUs, cap to fit. Same
# headroom threshold as _select_gpus (#5106).
ranked = sorted(gpus, key = lambda g: g[1], reverse = True)
pin_fraction = self._GPU_PIN_VRAM_FRACTION
for n_gpus in range(1, len(ranked) + 1):
subset = ranked[:n_gpus]
pool_mib = sum(free for _, free in subset)
capped = self._fit_context_to_vram(
effective_ctx,
pool_mib,
model_size,
cache_type_kv,
n_parallel = n_parallel,
mtp_engaged = _mtp_will_engage,
)
kv = self._estimate_kv_cache_bytes(
capped, cache_type_kv, n_parallel = n_parallel
)
total_mib = (model_size + kv) / (1024 * 1024)
if total_mib <= pool_mib * pin_fraction:
effective_ctx = capped
gpu_indices = sorted(idx for idx, _ in subset)
use_fit = False
break
else:
# Native ctx doesn't fit. Drop to 4096 and
# re-check before --fit on: a model overflowing
# at 131k may pin fine with a 4096 KV (#5106).
effective_ctx = min(4096, effective_ctx)
if effective_ctx > 0:
for n_gpus in range(1, len(ranked) + 1):
subset = ranked[:n_gpus]
pool_mib = sum(free for _, free in subset)
kv = self._estimate_kv_cache_bytes(
effective_ctx,
cache_type_kv,
n_parallel = n_parallel,
)
total_mib = (model_size + kv) / (1024 * 1024)
if total_mib <= pool_mib * pin_fraction:
gpu_indices = sorted(idx for idx, _ in subset)
use_fit = False
break
elif gpus:
# Can't estimate KV -- file-size-only check; keep the
# ceiling at native context (already the default).
logger.debug(
"Falling back to file-size-only GPU selection",
model_size_gb = round(model_size / (1024**3), 2),
)
gpu_indices, use_fit = self._select_gpus(model_size, gpus)
if use_fit and not explicit_ctx:
# Weights don't fit on any subset; default UI to 4096
# so the slider isn't on an unusable native ctx.
effective_ctx = min(4096, effective_ctx) if effective_ctx > 0 else 4096
if effective_ctx < original_ctx:
kv_est = self._estimate_kv_cache_bytes(
effective_ctx, cache_type_kv, n_parallel = n_parallel
)
logger.info(
f"Context auto-reduced: {original_ctx} -> {effective_ctx} "
f"(model: {model_size / (1024**3):.1f} GB, "
f"est. KV cache: {kv_est / (1024**3):.1f} GB)"
)
kv_cache_bytes = self._estimate_kv_cache_bytes(
effective_ctx, cache_type_kv, n_parallel = n_parallel
)
logger.info(
f"GGUF size: {model_size / (1024**3):.1f} GB, "
f"est. KV cache: {kv_cache_bytes / (1024**3):.1f} GB, "
f"context: {effective_ctx}, "
f"GPUs free: {gpus}, selected: {gpu_indices}, fit: {use_fit}"
)
except Exception as e:
logger.warning(f"GPU selection failed ({e}), using --fit on")
gpu_indices, use_fit = None, True
effective_ctx = requested_ctx # fall back to original
launch_mmproj_path = self._resolve_launch_mmproj_path(
model_path = model_path,
mmproj_path = mmproj_path,
)
# Need both a resolved mmproj AND the config vision flag; a stray
# mmproj passing the family-name heuristic must not flip a non-VLM
# GGUF into vision mode.
effective_is_vision = bool(launch_mmproj_path) and bool(is_vision)
if is_vision and not effective_is_vision:
logger.warning(
"Vision-capable GGUF loaded without a usable mmproj; "
"image input will be disabled for this session"
)
# Audio input straight from the mmproj (clip.has_audio_encoder),
# independent of token names.
self._mmproj_has_audio = False
if launch_mmproj_path:
try:
from utils.models.gguf_metadata import (
read_mmproj_audio_capability,
)
self._mmproj_has_audio = bool(
read_mmproj_audio_capability(launch_mmproj_path)
)
except Exception as e:
logger.debug(f"mmproj audio-capability read failed: {e}")
cmd = [
binary,
"-m",
model_path,
"--port",
str(self._port),
"-c",
str(effective_ctx) if effective_ctx > 0 else "0",
"--parallel",
str(n_parallel),
"--flash-attn",
"on", # Force flash attention for speed
# Error out at n_ctx instead of silently rotating the KV cache; frontend catches it and points the user at "Context Length".
"--no-context-shift",
]
if use_fit:
cmd.extend(["--fit", "on"])
elif gpu_indices is not None:
# Fits on selected GPU(s) -- offload all layers
cmd.extend(["-ngl", "-1"])
# -1 = llama.cpp auto-detect (physical cores). Pass explicitly
# so we don't inherit llama-server's internal default, which
# has varied (hardware concurrency incl. hyperthreads on some
# builds).
cmd.extend(["--threads", str(n_threads if n_threads is not None else -1)])
# Enable Jinja chat template rendering
cmd.extend(["--jinja"])
# KV cache data type
_valid_cache_types = {
"f16",
"bf16",
"q8_0",
"q4_0",
"q4_1",
"q5_0",
"q5_1",
"iq4_nl",
"f32",
}
if cache_type_kv and cache_type_kv in _valid_cache_types:
cmd.extend(
[
"--cache-type-k",
cache_type_kv,
"--cache-type-v",
cache_type_kv,
]
)
self._cache_type_kv = cache_type_kv
logger.info(f"KV cache type: {cache_type_kv}")
else:
self._cache_type_kv = None
# Speculative decoding. See _build_speculative_flags for the
# mode resolution, benchmarks, and llama.cpp references.
spec_flags = self._build_speculative_flags(
speculative_type = speculative_type,
spec_draft_n_max = spec_draft_n_max,
extra_args = extra_args,
model_identifier = model_identifier,
model_path = model_path,
gpus = bool(gpus),
binary = binary,
)
cmd.extend(spec_flags)
# Apply custom chat template override if provided.
self._chat_template_override = chat_template_override
if chat_template_override:
import tempfile
flags = detect_reasoning_flags(
chat_template_override,
self._model_identifier,
log_source = "GGUF chat template override",
)
self._supports_reasoning = flags["supports_reasoning"]
self._reasoning_style = flags["reasoning_style"]
self._reasoning_always_on = flags["reasoning_always_on"]
self._supports_preserve_thinking = flags["supports_preserve_thinking"]
self._supports_tools = flags["supports_tools"]
self._chat_template_file = tempfile.NamedTemporaryFile(
mode = "w",
suffix = ".jinja",
delete = False,
prefix = "unsloth_chat_template_",
)
self._chat_template_file.write(chat_template_override)
self._chat_template_file.close()
cmd.extend(["--chat-template-file", self._chat_template_file.name])
logger.info(f"Using custom chat template file: {self._chat_template_file.name}")
# Default thinking mode for reasoning models. Qwen3.5/3.6 below
# 9B disable thinking by default; 9B+ enable it. Always-on
# templates ignore the kwarg, so skip.
if self._supports_reasoning and not self._reasoning_always_on:
thinking_default = True
mid = (model_identifier or "").lower()
if "qwen3.5" in mid or "qwen3.6" in mid:
size_val = _extract_model_size_b(mid)
if size_val is not None and size_val < 9:
thinking_default = False
self._reasoning_default = thinking_default
reasoning_kw = self._reasoning_kwargs(thinking_default)
cmd.extend(
[
"--chat-template-kwargs",
json.dumps(reasoning_kw),
]
)
logger.info(f"Reasoning model: {reasoning_kw} by default")
if launch_mmproj_path and effective_is_vision:
cmd.extend(["--mmproj", launch_mmproj_path])
logger.info(f"Using mmproj for vision: {launch_mmproj_path}")
# Option C: --api-key for direct client access when enabled
import os as _os
import secrets as _secrets
if _os.getenv("UNSLOTH_DIRECT_STREAM", "0") == "1":
self._api_key = _secrets.token_urlsafe(32)
cmd.extend(["--api-key", self._api_key])
logger.info("llama-server started with --api-key for direct streaming")
else:
self._api_key = None
# User pass-through args go last so llama.cpp's last-wins parsing
# lets the user override Studio's auto-set flags. Already
# validated by the route via validate_extra_args().
if extra_args:
cmd.extend(str(a) for a in extra_args)
logger.info(f"Appending user extra args to llama-server: {list(extra_args)}")
_log_cmd = list(cmd)
if "--api-key" in _log_cmd:
_ki = _log_cmd.index("--api-key") + 1
if _ki < len(_log_cmd):
_log_cmd[_ki] = "<redacted>"
logger.info(f"Starting llama-server: {' '.join(_log_cmd)}")
# Library paths so llama-server finds its shared libs and CUDA DLLs.
import os
import sys
env = child_env_without_native_path_secret()
binary_dir = str(Path(binary).parent)
# AMD unified-memory APUs (gfx1150/gfx1151): let llama.cpp use
# shared system RAM. setdefault so a user value wins.
if self._amd_apu_wants_unified_memory():
env.setdefault("GGML_CUDA_ENABLE_UNIFIED_MEMORY", "1")
logger.info("AMD unified-memory APU: set GGML_CUDA_ENABLE_UNIFIED_MEMORY=1")
if sys.platform == "win32":
# Ordering: see _build_windows_path_dirs. #5106.
path_dirs = self._build_windows_path_dirs(
binary_dir,
sys.prefix,
os.environ.get("CUDA_PATH", ""),
)
existing_path = env.get("PATH", "")
env["PATH"] = ";".join(path_dirs) + ";" + existing_path
# ROCm: the prebuilt bundles rocblas.dll but NOT the Tensile
# kernel files (rocblas/library/*.dat + *.hsaco); the DLL
# searches <binary_dir>/rocblas/library/ which doesn't exist
# -> silent crash on the first GEMM. ROCBLAS_TENSILE_LIBPATH
# repoints that search at the ROCm install.
_hip_path = os.environ.get("HIP_PATH", os.environ.get("ROCM_PATH", ""))
if _hip_path:
_rocblas_lib = os.path.join(_hip_path, "bin", "rocblas", "library")
if os.path.isdir(_rocblas_lib):
env.setdefault("ROCBLAS_TENSILE_LIBPATH", _rocblas_lib)
else:
# Linux: LD_LIBRARY_PATH for shared libs next to the binary
# plus CUDA runtime libs (libcudart, libcublas, etc.)
import platform
lib_dirs = [binary_dir]
_arch = platform.machine() # x86_64, aarch64, etc.
# Pip-installed nvidia CUDA runtime libs. The prebuilt
# binary links libcudart.so.13 / libcublas.so.13 which live
# here, not in /usr/local/cuda.
import glob as _glob
for _nv_pattern in [
os.path.join(
sys.prefix,
"lib",
"python*",
"site-packages",
"nvidia",
"cu*",
"lib",
),
os.path.join(
sys.prefix,
"lib",
"python*",
"site-packages",
"nvidia",
"cudnn",
"lib",
),
os.path.join(
sys.prefix,
"lib",
"python*",
"site-packages",
"nvidia",
"nvjitlink",
"lib",
),
]:
for _nv_dir in _glob.glob(_nv_pattern):
if os.path.isdir(_nv_dir):
lib_dirs.append(_nv_dir)
for cuda_lib in [
"/usr/local/cuda/lib64",
f"/usr/local/cuda/targets/{_arch}-linux/lib",
# Fallback CUDA compat paths (e.g. binary built with
# CUDA 12 where default /usr/local/cuda is CUDA 13+).
"/usr/local/cuda-12/lib64",
"/usr/local/cuda-12.8/lib64",
f"/usr/local/cuda-12/targets/{_arch}-linux/lib",
f"/usr/local/cuda-12.8/targets/{_arch}-linux/lib",
]:
if os.path.isdir(cuda_lib):
lib_dirs.append(cuda_lib)
existing_ld = env.get("LD_LIBRARY_PATH", "")
new_ld = ":".join(lib_dirs)
env["LD_LIBRARY_PATH"] = f"{new_ld}:{existing_ld}" if existing_ld else new_ld
# Pin to selected GPU(s). On ROCm, narrowing only
# CUDA_VISIBLE_DEVICES leaves an AMD child seeing the full
# HIP/ROCR set, so set those too.
if gpu_indices is not None:
pinned = ",".join(str(i) for i in gpu_indices)
env["CUDA_VISIBLE_DEVICES"] = pinned
try:
import torch as _torch
if getattr(_torch.version, "hip", None) is not None:
env["HIP_VISIBLE_DEVICES"] = pinned
env["ROCR_VISIBLE_DEVICES"] = pinned
except Exception as e:
logger.debug("Failed to set ROCm visibility env vars for child: %s", e)
# Defensive kill: drop an orphan Popen a concurrent load may
# have stored before we overwrite the reference (#5161).
self._kill_process()
self._stdout_lines = []
# Tee llama-server output to a dedicated log file so a
# post-mortem has the full trail even when the parent only kept
# the last 50 lines. Path is under the studio home.
self._llama_log_fh = None
try:
log_dir = _swa_cache_path().parent / "logs" / "llama-server"
log_dir.mkdir(parents = True, exist_ok = True)
self._llama_log_path = (
log_dir / f"llama-{int(time.time())}-port-{self._port}.log"
)
self._llama_log_fh = open(
self._llama_log_path,
"w",
encoding = "utf-8",
buffering = 1,
)
logger.info(f"llama-server stdout/stderr -> {self._llama_log_path}")
except OSError as e:
# Best-effort; never block the load on logging.
logger.debug(f"Could not open llama-server log file: {e}")
self._llama_log_path = None
self._process = subprocess.Popen(
cmd,
stdout = subprocess.PIPE,
stderr = subprocess.STDOUT,
text = True,
env = env,
**_windows_hidden_subprocess_kwargs(),
)
# Background thread to drain stdout (prevents pipe deadlock)
self._stdout_thread = threading.Thread(
target = self._drain_stdout, daemon = True, name = "llama-stdout"
)
self._stdout_thread.start()
# Store the resolved on-disk path, not the caller's kwarg: in
# HF mode gguf_path is None and ``model_path`` is what
# llama-server mmap's, which downstream consumers need.
self._gguf_path = model_path
self._hf_repo = hf_repo
# For local GGUF files, extract variant from filename if absent
if hf_variant:
self._hf_variant = hf_variant
elif gguf_path:
try:
from utils.models.model_config import _extract_quant_label
self._hf_variant = _extract_quant_label(gguf_path)
except Exception:
self._hf_variant = None
else:
self._hf_variant = None
self._is_vision = effective_is_vision
self._model_identifier = model_identifier
# Store the effective (possibly capped) context separately; do
# NOT overwrite _context_length (the native length for display).
self._effective_context_length = (
effective_ctx if effective_ctx > 0 else self._context_length
)
self._max_context_length = (
max_available_ctx if max_available_ctx > 0 else self._effective_context_length
)
# Wait for llama-server to become healthy.
if not self._wait_for_health(timeout = 600.0):
self._kill_process()
raise RuntimeError(
self._classify_llama_start_failure(
"\n".join(self._stdout_lines[-50:]),
gguf_path,
self._model_identifier,
)
)
self._healthy = True
# Commit caller intent only after _healthy=True so a failed start
# can't poison the next inheritance check. None keeps prior, []
# clears, list sets. Source records hf_variant for the route's
# same_source check.
if extra_args is not None:
self._extra_args = list(extra_args)
self._extra_args_source = (model_identifier, hf_variant)
self._requested_n_ctx = int(n_ctx)
# Catch silent CPU fallback when GPU was intended (#5106).
self._gpu_offload_active = self._classify_gpu_offload(
gpu_indices is not None or use_fit, gpus or []
)
if self._gpu_offload_active is False:
logger.warning(
"llama-server appears to have loaded the model entirely "
"on CPU even though Studio detected at least one GPU. "
"This usually means the prebuilt binary's GPU backend "
"failed to load -- on Windows, cudart64_X.dll / "
"cublas64_X.dll could not be resolved. Reinstall the "
"Studio llama.cpp prebuilt or install a matching CUDA "
"toolkit (issue unslothai/unsloth#5106).",
)
logger.info(
f"llama-server ready on port {self._port} " f"for model '{model_identifier}'"
)
# Probe outside _lock (interruptible by /unload); init inside.
self._is_audio = False
self._audio_type = None
self._audio_probed = False
self._has_audio_input = False
try:
detected = self._detect_audio_type_strict()
self._audio_probed = True
except Exception as exc:
logger.debug("Audio probe failed: %s", exc)
detected = None
if detected in ("snac", "bicodec", "dac"):
with self._lock:
if not self._healthy:
return False
try:
self.init_audio_codec(detected)
self._is_audio = True
self._audio_type = detected
except Exception as exc:
# Surface as HTTP 500 (matches pre-PR contract).
logger.warning(
"Failed to init audio codec '%s': %s",
detected,
exc,
)
self._audio_probed = False
return False
elif detected:
# csm / whisper / audio_vlm: track type but keep _is_audio
# False -- GGUF TTS routing only fires for snac/bicodec/dac.
with self._lock:
if not self._healthy:
return False
self._audio_type = detected
# Audio input = token probe (audio_vlm/whisper) OR mmproj encoder.
from utils.models.model_config import is_audio_input_type
self._has_audio_input = bool(is_audio_input_type(self._audio_type)) or bool(
self._mmproj_has_audio
)
if not self._healthy:
return False
return True
def _build_speculative_flags(
self,
*,
speculative_type: Optional[str],
spec_draft_n_max: Optional[int],
extra_args: Optional[List[str]],
model_identifier: str,
model_path: Optional[str],
gpus: bool,
binary: Optional[str],
) -> List[str]:
"""Return the llama-server flag list for the requested spec mode.
Side effects: sets ``self._speculative_type`` (resolved internal
emit), ``self._requested_spec_mode`` (canonical UI mode for the
status round-trip), and ``self._spec_draft_n_max`` (user override
only; None when the platform default applies).
Speculative decoding (n-gram self-speculation, zero VRAM):
ngram-mod uses a ~16 MB shared hash pool, constant memory /
complexity, variable draft lengths. Helps most when the model
repeats existing text (code refactor, summarisation, reasoning);
for low-repetition chat, overhead is ~5 ms.
Benchmarks from upstream llama.cpp speculative-decoding PRs:
Scenario | Without | With | Speedup
gpt-oss-120b code refactor | 181 t/s | 446 t/s | 2.5x
Qwen3-235B offloaded | 12 t/s | 21 t/s | 1.8x
gpt-oss-120b repeat (92% accept)| 181 t/s | 814 t/s | 4.5x
Refs: https://github.com/ggml-org/llama.cpp/blob/master/docs/speculative.md
https://github.com/ggml-org/llama.cpp/pull/19164
https://github.com/ggml-org/llama.cpp/pull/18471
MTP guide: unsloth.ai/docs/models/qwen3.6#mtp-guide
Sub-3B dense MTP regresses vs spec-off: the draft head's per-token
cost exceeds the acceptance savings at this scale. Q4_K_XL clean
bench (each prompt once after an unrelated warmup) on B200 + x86 CPU:
0.8B GPU: draft-mtp n=2 = 0.58x vs OFF; ngram-only = 1.10x
2B GPU: draft-mtp n=2 = 0.82x vs OFF; OFF or ngram = 1.00x
0.8B CPU: chained n=2 = 0.86x vs OFF; ngram-only = 1.19x
2B CPU: chained n=2 = 0.83x vs OFF; ngram-only = 1.01x
4B+ GPU/CPU: spec on is a net win (1.08x-1.46x).
Auto falls back to ngram-mod (zero-VRAM, near-zero idle cost on
diverse content); forced MTP variants engage anyway and just log a
warning per the user's choice.
"""
flags: List[str] = []
# Reset; emit branches re-set on the resolved emission.
self._spec_draft_n_max = None
self._speculative_type = None
# Canonical UI-facing requested mode (legacy values mapped via
# _canonicalize_spec_mode).
canonical_mode = _canonicalize_spec_mode(speculative_type)
is_mtp_model = bool(self._nextn_predict_layers) or (
_is_mtp_model_name(model_identifier, model_path)
)
user_owns_spec_type = _extra_args_set_spec_type(extra_args)
_mtp_size_b = _extract_model_size_b(model_identifier)
_mtp_too_small = _mtp_size_b is not None and _mtp_size_b < 3.0
if user_owns_spec_type:
# User --spec-type wins outright; suppress auto-emit to avoid a
# duplicate spec block.
self._requested_spec_mode = None
return flags
effective_mode = canonical_mode or "auto"
self._requested_spec_mode = effective_mode
def _resolved_draft_n_max() -> int:
# User override wins; else platform default (the B200 / x86
# clean-sweep sweet spot from PR #5582 is n=2 GPU, n=3 CPU;
# past 3 regresses on essay-style low-acceptance prompts).
if spec_draft_n_max is not None:
n = int(spec_draft_n_max)
self._spec_draft_n_max = n
return n
return 2 if gpus else 3
def _emit_mtp(*, chain_ngram: bool) -> bool:
"""Append --spec-type mtp[/draft-mtp][,ngram-mod] + n-max."""
caps = self.probe_server_capabilities(binary)
mtp_token = caps.get("mtp_token") if caps else None
if not mtp_token:
logger.warning(
"Requested MTP speculative decoding but "
"llama-server lacks --spec-type mtp/draft-mtp; "
"run `unsloth studio update`. Loading without "
"speculative decoding."
)
return False
draft_n_max = _resolved_draft_n_max()
n_max_flag = caps.get("spec_draft_n_max_flag") or "--spec-draft-n-max"
if chain_ngram:
ngram_knobs = _build_ngram_mod_flags(caps)
if ngram_knobs:
spec_value = f"ngram-mod,{mtp_token}"
else:
logger.warning(
"llama-server lacks ngram-mod tuning "
"flags; loading MTP only (no ngram chain)"
)
spec_value = mtp_token
flags.extend(
[
"--spec-type",
spec_value,
n_max_flag,
str(draft_n_max),
]
)
flags.extend(ngram_knobs)
else:
flags.extend(
[
"--spec-type",
mtp_token,
n_max_flag,
str(draft_n_max),
]
)
self._speculative_type = "draft-mtp"
chain_label = "chained ngram-mod" if chain_ngram else "MTP-only"
logger.info(f"Spec decoding: {mtp_token} ({chain_label})")
return True
def _emit_ngram_mod() -> bool:
"""Append --spec-type ngram-mod + flag-set knobs."""
ngram_caps = self.probe_server_capabilities(binary)
ngram_knobs = _build_ngram_mod_flags(ngram_caps)
flags.extend(["--spec-type", "ngram-mod"])
if not ngram_knobs:
logger.warning(
"llama-server lacks ngram-mod tuning "
"flags; loading without --spec-ngram-mod-* knobs"
)
flags.extend(ngram_knobs)
self._speculative_type = "ngram-mod"
logger.info("Spec decoding: ngram-mod")
return True
if effective_mode == "off":
return flags # nothing to emit
if effective_mode == "ngram-simple":
flags.extend(["--spec-type", "ngram-simple"])
self._speculative_type = "ngram-simple"
return flags
if effective_mode == "ngram":
_emit_ngram_mod()
return flags
if effective_mode == "mtp":
if _mtp_too_small:
logger.warning(
f"Forcing MTP on a {_mtp_size_b:.1f}B model; "
"the bench shows draft-mtp regresses below 3B. "
"Engaging anyway (user override)."
)
elif not is_mtp_model:
logger.warning(
"Forcing MTP on a non-MTP GGUF; llama-server may "
"fall back to spec-off if no nextn head is present. "
"Engaging anyway (user override)."
)
_emit_mtp(chain_ngram = False)
return flags
if effective_mode == "mtp+ngram":
if _mtp_too_small:
logger.warning(
f"Forcing MTP+Ngram on a {_mtp_size_b:.1f}B model; "
"the bench shows the chain regresses below 3B. "
"Engaging anyway (user override)."
)
elif not is_mtp_model:
logger.warning(
"Forcing MTP+Ngram on a non-MTP GGUF; llama-server "
"may fall back to ngram-only if no nextn head is "
"present. Engaging anyway (user override)."
)
_emit_mtp(chain_ngram = True)
return flags
# effective_mode == "auto": the promotion path. llama.cpp #22673:
# MTP is compatible with mmproj, so there's no vision gate.
if is_mtp_model and not _mtp_too_small:
# GPU: MTP-only. CPU/Mac: chain ngram-mod + MTP.
_emit_mtp(chain_ngram = not gpus)
elif is_mtp_model and _mtp_too_small:
# Sub-3B fallback: drop the MTP draft head, keep ngram-mod when
# the binary supports it.
_small_caps = self.probe_server_capabilities(binary)
if _small_caps.get("supports_ngram_mod"):
logger.info(
f"MTP GGUF detected but model size {_mtp_size_b:.1f}B "
"is below the 3B speedup threshold; using ngram-mod "
"only (zero-VRAM, no draft head). Override via "
"--spec-type or the Studio Speculative Decoding "
"dropdown."
)
_emit_ngram_mod()
else:
logger.info(
f"MTP GGUF detected but model size {_mtp_size_b:.1f}B "
"is below the 3B speedup threshold and the bundled "
"llama-server does not advertise ngram-mod; "
"auto-disabling speculative decoding."
)
else:
# Non-MTP model: let llama-server choose its default strategy.
flags.append("--spec-default")
self._speculative_type = "default"
return flags
def _already_in_target_state(
self,
*,
model_identifier: str,
hf_variant: Optional[str],
n_ctx: int,
cache_type_kv: Optional[str],
speculative_type: Optional[str],
chat_template_override: Optional[str],
extra_args: Optional[List[str]],
is_vision: bool,
gguf_path: Optional[str] = None,
spec_draft_n_max: Optional[int] = None,
) -> bool:
"""True iff the live server already satisfies these load kwargs.
Mirrors ``routes/inference.py:_request_matches_loaded_settings`` but
compares raw kwargs so ``load_model`` can short-circuit a duplicate
/load that raced past the route-level check (#5401).
"""
if not self.is_loaded:
return False
if (self._model_identifier or "").lower() != (model_identifier or "").lower():
return False
# Direct-file loads pass hf_variant=None while the backend stores an
# extracted filename label; compare paths to keep the guard symmetric.
if gguf_path is not None and self._gguf_path:
try:
if Path(self._gguf_path).resolve() != Path(gguf_path).resolve():
return False
except OSError:
return False
elif (self._hf_variant or "").lower() != (hf_variant or "").lower():
return False
if self._requested_n_ctx != int(n_ctx):
return False
def _norm(value):
if value is None:
return None
if isinstance(value, str):
stripped = value.strip().lower()
return stripped or None
return value
if _norm(self._cache_type_kv) != _norm(cache_type_kv):
return False
# Compare on the canonical requested mode. With --spec-type in
# extra_args the backend stores None; mirror that here.
if _extra_args_set_spec_type(extra_args):
req_mode = None
else:
req_mode = _canonicalize_spec_mode(speculative_type) or "auto"
backend_mode = self._requested_spec_mode
if req_mode != backend_mode:
return False
# spec_draft_n_max only matters when an MTP variant is engaged. Compare
# on the resolved spec so an Auto request promoted to draft-mtp still
# bounces a reload when n_max changes.
if (
self._speculative_type == "draft-mtp"
and spec_draft_n_max is not None
and int(spec_draft_n_max) != (self._spec_draft_n_max or 0)
):
return False
if (self._chat_template_override or None) != (chat_template_override or None):
return False
# extra_args=None means "no opinion" (inherit handled at the route
# layer); only an explicit list forces equality.
if extra_args is not None:
current = list(self._extra_args) if self._extra_args is not None else []
if list(extra_args) != current:
return False
return True
def _classify_gpu_offload(
self, expected_gpu: bool, detected_gpus: list[tuple[int, int]]
) -> Optional[bool]:
"""True if a GPU model buffer was allocated, False if only CPU
buffers landed despite GPU intent, None when there's no signal (no
GPU detected, no buffer-size lines, etc.)."""
if not detected_gpus or not expected_gpu:
return None
# llama-server logs one "model buffer size = N MiB" line per backend
# buffer; CUDA/ROCm/Metal/Vulkan/OpenCL/SYCL are GPU, CPU* are not.
gpu_markers = ("CUDA", "ROCm", "Metal", "Vulkan", "OpenCL", "SYCL")
saw_buffer_line = False
saw_gpu_buffer = False
for line in self._stdout_lines:
if "model buffer size" not in line:
continue
saw_buffer_line = True
if any(marker in line for marker in gpu_markers):
saw_gpu_buffer = True
break
if not saw_buffer_line:
return None
return saw_gpu_buffer
def unload_model(self) -> bool:
"""Terminate the subprocess and cancel any in-flight download."""
self._cancel_event.set()
with self._lock:
self._kill_process()
logger.info(f"Unloaded GGUF model: {self._model_identifier}")
self._model_identifier = None
self._gguf_path = None
self._hf_repo = None
self._hf_variant = None
self._is_vision = False
self._is_audio = False
self._audio_type = None
self._audio_probed = False
self._has_audio_input = False
self._mmproj_has_audio = False
self._port = None
self._healthy = False
self._context_length = None
self._effective_context_length = None
self._max_context_length = None
self._chat_template = None
self._chat_template_override = None
self._supports_reasoning = False
self._reasoning_always_on = False
self._reasoning_style = "enable_thinking"
self._reasoning_default = True
self._supports_preserve_thinking = False
self._supports_tools = False
self._cache_type_kv = None
self._speculative_type = None
self._requested_spec_mode = None
self._spec_draft_n_max = None
self._n_layers = None
self._n_kv_heads = None
self._n_kv_heads_by_layer = None
self._n_heads = None
self._embedding_length = None
self._kv_key_length = None
self._kv_value_length = None
self._sliding_window = None
self._sliding_window_pattern = None
self._full_attention_interval = None
self._kv_lora_rank = None
self._key_length_mla = None
self._kv_key_length_swa = None
self._kv_value_length_swa = None
self._ssm_inner_size = None
self._ssm_state_size = None
self._shared_kv_layers = None
self._nextn_predict_layers = None
# Clean up temp chat template file.
if hasattr(self, "_chat_template_file") and self._chat_template_file:
try:
import os
os.unlink(self._chat_template_file.name)
except Exception:
pass
self._chat_template_file = None
# Free audio codec GPU memory.
if LlamaCppBackend._codec_mgr is not None:
LlamaCppBackend._codec_mgr.unload()
LlamaCppBackend._codec_mgr = None
import torch
if torch.cuda.is_available():
torch.cuda.empty_cache()
return True
def _kill_process(self):
"""Terminate the subprocess if running."""
if self._process is None:
return
try:
self._process.terminate()
self._process.wait(timeout = 5)
except subprocess.TimeoutExpired:
logger.warning("llama-server did not exit on SIGTERM, sending SIGKILL")
self._process.kill()
self._process.wait(timeout = 5)
except Exception as e:
logger.warning(f"Error killing llama-server process: {e}")
finally:
self._process = None
# Clear healthy so a /load during the replacement's warm-up can't
# short-circuit against the previous server's health (#5401).
self._healthy = False
# Drives _wait_for_vram_settle in the next load_model; set in finally
# so both in-process and frontend Apply paths record the kill.
self._last_kill_monotonic = time.monotonic()
if self._stdout_thread is not None:
self._stdout_thread.join(timeout = 2)
self._stdout_thread = None
fh = getattr(self, "_llama_log_fh", None)
if fh is not None:
try:
fh.close()
except Exception:
pass
self._llama_log_fh = None
@staticmethod
def _kill_orphaned_servers():
"""Kill orphaned llama-server processes started by studio.
Only kills processes whose resolved binary lives under a known
Studio install dir (or matches an exact env-var override), to avoid
terminating unrelated llama-server instances. Mirrors every location
_find_llama_server_binary() can return, so orphans from any
supported install path are cleaned up.
Uses psutil for cross-platform support (Linux, macOS, Windows);
falls back to pgrep + /proc/<pid>/exe on Linux when psutil is
absent.
"""
try:
# -- Build the ownership allowlist --------------------------------
# exact_binaries -- env var overrides (exact path match).
# install_roots -- Studio-owned dir trees (binary must be under one).
install_roots: list[Path] = []
# Env-mode custom root (mirrors _find_llama_server_binary).
_is_custom_root = False
try:
from utils.paths.storage_roots import studio_root as _sr # noqa: WPS433
_resolved_sr = _sr()
_legacy_studio = Path.home() / ".unsloth" / "studio"
try:
_is_custom_root = _resolved_sr.resolve() != _legacy_studio.resolve()
except (OSError, ValueError):
_is_custom_root = _resolved_sr != _legacy_studio
if _is_custom_root:
install_roots.append(_resolved_sr / "llama.cpp")
except (ImportError, OSError, ValueError):
pass
# Primary install dir (default mode only). Env-mode skips this so a
# custom-root Studio can't kill a default-install Studio's server.
if not _is_custom_root:
install_roots.append(Path.home() / ".unsloth" / "llama.cpp")
# Legacy in-tree build dirs (older setup.sh)
project_root = Path(__file__).resolve().parents[4]
install_roots.append(project_root / "llama.cpp")
# Legacy: extracted binary
install_roots.append(project_root / "bin")
# UNSLOTH_LLAMA_CPP_PATH env var (custom install dir)
custom_dir = os.environ.get("UNSLOTH_LLAMA_CPP_PATH")
if custom_dir:
install_roots.append(Path(custom_dir))
# LLAMA_SERVER_PATH env var (exact binary path)
exact_binaries: list[Path] = []
env_binary = os.environ.get("LLAMA_SERVER_PATH")
if env_binary:
try:
exact_binaries.append(Path(env_binary).resolve())
except OSError:
pass
# Resolve all roots so is_relative_to works reliably.
resolved_roots: list[Path] = []
for root in install_roots:
try:
resolved_roots.append(root.resolve())
except OSError:
pass
my_pid = os.getpid()
# -- Enumerate processes -------------------------------------------
# Prefer psutil (cross-platform); fall back to pgrep + /proc on
# Linux when psutil is absent.
try:
import psutil
has_psutil = True
except ImportError:
has_psutil = False
if has_psutil:
for proc in psutil.process_iter(["pid", "name", "exe"]):
try:
if proc.info["pid"] == my_pid:
continue
name = proc.info.get("name") or ""
if not name.lower().startswith("llama-server"):
continue
exe = proc.info.get("exe")
if not exe:
continue
exe_path = Path(exe).resolve()
# Ownership: exact match OR binary under a known root.
is_ours = exe_path in exact_binaries or any(
exe_path.is_relative_to(root) for root in resolved_roots
)
if not is_ours:
continue
proc.kill()
logger.info(
f"Killed orphaned llama-server process " f"(pid={proc.info['pid']})"
)
except (
psutil.NoSuchProcess,
psutil.AccessDenied,
psutil.ZombieProcess,
):
pass
else:
# -- Fallback: pgrep + /proc/<pid>/exe (Linux only) -----------
if sys.platform != "linux":
return
result = subprocess.run(
["pgrep", "-a", "-f", "llama-server"],
capture_output = True,
text = True,
timeout = 5,
env = child_env_without_native_path_secret(),
)
if result.returncode != 0:
return
for line in result.stdout.strip().splitlines():
parts = line.strip().split(None, 1)
if len(parts) < 2:
continue
pid = int(parts[0])
if pid == my_pid:
continue
# /proc/<pid>/exe symlinks the real binary, avoiding
# cmdline-parsing ambiguities; fall back to the first
# cmdline token when /proc is unavailable.
proc_exe = Path(f"/proc/{pid}/exe")
try:
binary = proc_exe.resolve(strict = True)
except (OSError, ValueError):
cmdline = parts[1]
token = cmdline.split()[0] if cmdline.strip() else ""
if not token:
continue
binary = Path(token).resolve(strict = False)
owned = binary in exact_binaries or any(
binary.is_relative_to(root) for root in resolved_roots
)
if not owned:
continue
try:
os.kill(pid, signal.SIGKILL)
logger.info(f"Killed orphaned llama-server process (pid={pid})")
except ProcessLookupError:
pass
except PermissionError:
pass
except Exception:
logger.warning("Error during orphan server cleanup", exc_info = True)
def _cleanup(self):
"""atexit handler to ensure llama-server is terminated."""
self._kill_process()
def _wait_for_health(
self,
timeout: float = 120.0,
interval: float = 0.5,
) -> bool:
"""Poll llama-server's /health until 200; also detect early exit/crash."""
deadline = time.monotonic() + timeout
url = f"http://127.0.0.1:{self._port}/health"
while time.monotonic() < deadline:
# Process crashed?
if self._process.poll() is not None:
# Let the drain thread collect final output.
if self._stdout_thread is not None:
self._stdout_thread.join(timeout = 2)
output = "\n".join(self._stdout_lines[-50:])
logger.error(
f"llama-server exited with code {self._process.returncode}. "
f"Output: {output[:2000]}"
)
return False
try:
resp = httpx.get(url, timeout = 2.0)
if resp.status_code == 200:
return True
except (
httpx.ConnectError,
httpx.TimeoutException,
# ReadError covers TCP RST mid-read while still binding the port
# (Windows: WinError 10054); the crash branch catches real exits.
httpx.ReadError,
httpx.RemoteProtocolError,
httpx.WriteError,
):
pass
time.sleep(interval)
logger.error(f"llama-server health check timed out after {timeout}s")
return False
# ── Message building (OpenAI format) ──────────────────────────
@staticmethod
def _parse_tool_calls_from_text(content: str, *, allow_incomplete: bool = True) -> list[dict]:
"""Thin wrapper around the shared parser in tool_call_parser
so safetensors and llama_cpp pick up the same fixes."""
return _shared_parse_tool_calls_from_text(
content,
allow_incomplete = allow_incomplete,
)
@staticmethod
def _build_openai_messages(messages: list[dict], image_b64: Optional[str] = None) -> list[dict]:
"""Build OpenAI-format messages, optionally injecting an image_url part
into the last user message for vision models. As-is if no image."""
if not image_b64:
return messages
# Convert the last user message to multimodal content parts
result = [msg.copy() for msg in messages]
last_user_idx = None
for i, msg in enumerate(result):
if msg["role"] == "user":
last_user_idx = i
if last_user_idx is not None:
text_content = result[last_user_idx].get("content", "")
result[last_user_idx]["content"] = [
{"type": "text", "text": text_content},
{
"type": "image_url",
"image_url": {
"url": f"data:image/png;base64,{image_b64}",
},
},
]
return result
# ── Generation (proxy to llama-server) ────────────────────────
@staticmethod
def _iter_text_cancellable(
response: "httpx.Response", cancel_event: Optional[threading.Event] = None
) -> Generator[str, None, None]:
"""Iterate an httpx streaming response with cancel support.
Checks cancel_event between chunks and on ReadTimeout; the
_stream_with_retry watcher also closes the response on cancel.
"""
text_iter = response.iter_text()
while True:
if cancel_event is not None and cancel_event.is_set():
response.close()
return
try:
chunk = next(text_iter)
yield chunk
except StopIteration:
return
except httpx.ReadTimeout:
# No data within the timeout window -- loop back and re-check
# cancel_event.
continue
@staticmethod
@contextlib.contextmanager
def _stream_with_retry(
client: "httpx.Client",
url: str,
payload: dict,
cancel_event: Optional[threading.Event] = None,
headers: Optional[dict] = None,
):
"""Open an httpx streaming POST with cancel support.
Sends once with a long read timeout (120 s) so prefill finishes without
a retry storm (the old 0.5 s timeout caused duplicate POSTs every half
second). A watcher thread cancels by closing the response. httpx can't
interrupt a blocked read before the response exists, so cancel during
the header wait (1-5 s prefill) is deferred until headers arrive.
"""
if cancel_event is not None and cancel_event.is_set():
raise GeneratorExit
# Background watcher: close the response if cancel is requested.
# Only effective after response headers arrive (httpx limitation).
_cancel_closed = threading.Event()
_response_ref: list = [None]
def _cancel_watcher():
while not _cancel_closed.is_set():
if cancel_event.wait(timeout = 0.3):
# Cancel requested. Poll until the response object exists
# so we can close it, or until the main thread finishes
# (_cancel_closed set in finally).
while not _cancel_closed.is_set():
r = _response_ref[0]
if r is not None:
try:
r.close()
return
except Exception as e:
logger.debug(f"Error closing response in cancel watcher: {e}")
# Response not created yet -- wait briefly and retry
_cancel_closed.wait(timeout = 0.1)
return
watcher = None
if cancel_event is not None:
watcher = threading.Thread(target = _cancel_watcher, daemon = True, name = "prefill-cancel")
watcher.start()
try:
# Long read timeout so prefill can finish without a retry storm.
# Cancel during prefill and streaming is handled by the watcher
# thread closing the response, unblocking any httpx read.
prefill_timeout = httpx.Timeout(
connect = 30,
read = 120.0,
write = 10,
pool = 10,
)
with client.stream(
"POST",
url,
json = payload,
timeout = prefill_timeout,
headers = headers,
) as response:
_response_ref[0] = response
if cancel_event is not None and cancel_event.is_set():
raise GeneratorExit
yield response
return
except (httpx.ReadError, httpx.RemoteProtocolError, httpx.CloseError):
# Response was closed by the cancel watcher
if cancel_event is not None and cancel_event.is_set():
raise GeneratorExit
raise
finally:
_cancel_closed.set()
def generate_chat_completion(
self,
messages: list[dict],
image_b64: Optional[str] = None,
temperature: float = 0.6,
top_p: float = 0.95,
top_k: int = 20,
min_p: float = 0.01,
max_tokens: Optional[int] = None,
repetition_penalty: float = 1.0,
presence_penalty: float = 0.0,
stop: Optional[list[str]] = None,
cancel_event: Optional[threading.Event] = None,
enable_thinking: Optional[bool] = None,
reasoning_effort: Optional[str] = None,
preserve_thinking: Optional[bool] = None,
seed: Optional[int] = None,
) -> Generator[str | dict, None, None]:
"""
Send a chat completion to llama-server and stream tokens back.
Uses /v1/chat/completions -- llama-server applies the chat template
and handles vision (multimodal image_url parts) natively.
Yields cumulative text (matching InferenceBackend's convention).
"""
if not self.is_loaded:
raise RuntimeError("llama-server is not loaded")
openai_messages = self._build_openai_messages(messages, image_b64)
payload = {
"messages": openai_messages,
"stream": True,
"temperature": temperature,
"top_p": top_p,
"top_k": top_k if top_k >= 0 else 0,
"min_p": min_p,
"repeat_penalty": repetition_penalty,
"presence_penalty": presence_penalty,
}
# Per-request enable_thinking / reasoning_effort / preserve_thinking
_reasoning_kw = self._request_reasoning_kwargs(
enable_thinking, reasoning_effort, preserve_thinking
)
if _reasoning_kw is not None:
payload["chat_template_kwargs"] = _reasoning_kw
# Cap to the effective context length when known, else the floor.
# The wall-clock backstop below stops a stuck model regardless.
payload["max_tokens"] = (
max_tokens
if max_tokens is not None
else (self._effective_context_length or _DEFAULT_MAX_TOKENS_FLOOR)
)
payload["t_max_predict_ms"] = _DEFAULT_T_MAX_PREDICT_MS
if stop:
payload["stop"] = stop
if seed is not None:
payload["seed"] = seed
payload["stream_options"] = {"include_usage": True}
url = f"{self.base_url}/v1/chat/completions"
cumulative = ""
in_thinking = False
_stream_done = False
_metadata_usage = None
_metadata_timings = None
_metadata_finish_reason = None
try:
# _stream_with_retry uses a 120 s read timeout so prefill can
# finish. Cancel during streaming is handled by the watcher
# thread (closes the response on cancel_event).
stream_timeout = httpx.Timeout(connect = 10, read = 0.5, write = 10, pool = 10)
_auth_headers = {"Authorization": f"Bearer {self._api_key}"} if self._api_key else None
with httpx.Client(
timeout = stream_timeout, limits = httpx.Limits(max_keepalive_connections = 0)
) as client:
with self._stream_with_retry(
client,
url,
payload,
cancel_event,
headers = _auth_headers,
) as response:
if response.status_code != 200:
error_body = response.read().decode()
raise RuntimeError(
f"llama-server returned {response.status_code}: {error_body}"
)
buffer = ""
has_content_tokens = False
reasoning_text = ""
for raw_chunk in self._iter_text_cancellable(response, cancel_event):
buffer += raw_chunk
while "\n" in buffer:
line, buffer = buffer.split("\n", 1)
line = line.strip()
if not line:
continue
if line == "data: [DONE]":
if in_thinking:
if has_content_tokens:
# Real thinking + content: close the tag
cumulative += "</think>"
yield cumulative
else:
# Only reasoning_content, no content:
# model put its whole reply in reasoning
# (e.g. Qwen3 always-think). Show it as
# the main response, not a thinking block.
cumulative = reasoning_text
yield cumulative
_stream_done = True
break # exit inner while
if not line.startswith("data: "):
continue
try:
data = json.loads(line[6:])
# Capture server timings/usage from final chunks.
_chunk_timings = data.get("timings")
if _chunk_timings:
_metadata_timings = _chunk_timings
_chunk_usage = data.get("usage")
if _chunk_usage:
_metadata_usage = _chunk_usage
choices = data.get("choices", [])
if choices:
delta = choices[0].get("delta", {})
_fr = choices[0].get("finish_reason")
if _fr:
_metadata_finish_reason = _fr
# Reasoning/thinking tokens: llama-server
# sends these as "reasoning_content"; wrap
# in <think> tags for the frontend parser.
reasoning = delta.get("reasoning_content", "")
if reasoning:
reasoning_text += reasoning
if not in_thinking:
cumulative += "<think>"
in_thinking = True
cumulative += reasoning
yield cumulative
token = delta.get("content", "")
if token:
has_content_tokens = True
if in_thinking:
cumulative += "</think>"
in_thinking = False
cumulative += token
yield cumulative
except json.JSONDecodeError:
logger.debug(f"Skipping malformed SSE line: {line[:100]}")
if _stream_done:
break # exit outer for
if _metadata_usage or _metadata_timings or _metadata_finish_reason:
_metadata_usage = _backfill_usage_from_timings(
_metadata_usage, _metadata_timings
)
yield {
"type": "metadata",
# Never None: a finish-only metadata event (no usage,
# no timings) would otherwise crash consumers that do
# usage.get(...) on the non-streaming paths.
"usage": _metadata_usage or {},
"timings": _metadata_timings,
"finish_reason": _metadata_finish_reason,
}
except httpx.ConnectError:
raise RuntimeError("Lost connection to llama-server")
except Exception as e:
if cancel_event is not None and cancel_event.is_set():
return
raise
# ── Tool-calling agentic loop ──────────────────────────────
def generate_chat_completion_with_tools(
self,
messages: list[dict],
tools: list[dict],
temperature: float = 0.6,
top_p: float = 0.95,
top_k: int = 20,
min_p: float = 0.01,
max_tokens: Optional[int] = None,
repetition_penalty: float = 1.0,
presence_penalty: float = 0.0,
stop: Optional[list[str]] = None,
cancel_event: Optional[threading.Event] = None,
enable_thinking: Optional[bool] = None,
reasoning_effort: Optional[str] = None,
preserve_thinking: Optional[bool] = None,
max_tool_iterations: int = 25,
auto_heal_tool_calls: bool = True,
tool_call_timeout: int = 300,
session_id: Optional[str] = None,
rag_scope: Optional[dict] = None,
seed: Optional[int] = None,
disable_parallel_tool_use: bool = False,
) -> Generator[dict, None, None]:
"""
Agentic loop: let the model call tools, execute them, and continue.
Yields dicts:
{"type": "status", "text": "Searching: ..."/"Reading: ..."} -- tool status updates
{"type": "content", "text": "token"} -- streamed content tokens (cumulative)
{"type": "reasoning", "text": "token"} -- streamed reasoning tokens (cumulative)
"""
from core.inference.tools import build_rag_autoinject, execute_tool
if not self.is_loaded:
raise RuntimeError("llama-server is not loaded")
conversation = list(messages)
# Forced first-pass RAG so a doc question doesn't lose to web_search. Emits
# the same tool card + citations a real call would.
_auto = build_rag_autoinject(conversation, rag_scope)
if _auto:
for _ev in _auto["events"]:
yield _ev
conversation.extend(_auto["messages"])
url = f"{self.base_url}/v1/chat/completions"
_accumulated_completion_tokens = 0
_accumulated_predicted_ms = 0.0
_accumulated_predicted_n = 0
def _strip_tool_markup(
text: str,
*,
final: bool = False,
force: bool = False,
) -> str:
if not (auto_heal_tool_calls or force):
return text
return strip_tool_call_markup(text, final = final)
def _strip_tool_markup_streaming(text: str, *, force: bool = False) -> str:
if not (auto_heal_tool_calls or force):
return text
for pat in _TOOL_ALL_PATS:
text = pat.sub("", text)
return text
tool_controller = ToolLoopController(
tools = tools,
auto_heal_tool_calls = auto_heal_tool_calls,
)
def _tool_succeeded(tool_name: str) -> bool:
key_prefix = f"{tool_name}:"
return any(
record.executed and not record.is_error and record.key.startswith(key_prefix)
for record in tool_controller.history
)
_MAX_BUFFER_CHARS = 32
_append_budget_exhausted_nudge = True
# RAG: cap knowledge-base searches per assistant turn. The controller is
# tool-agnostic, so this gate stays in the loop.
_kb_search_count = 0
# ── Re-prompt on plan-without-action ─────────────────
# When the model describes what it intends to do (forward-looking
# language) without calling a tool, re-prompt once. Only triggers on
# responses signaling intent/planning -- a direct answer like "4" or
# "Hello!" won't match. Pattern compiled at module level
# (_INTENT_SIGNAL).
_reprompt_count = 0
_forced_tool_call_pending = False
# Reserve extra iterations for re-prompts so they don't consume the
# caller's tool-call budget; only when tool iterations are allowed.
_extra = _MAX_REPROMPTS if max_tool_iterations > 0 else 0
for iteration in range(max_tool_iterations + _extra):
if cancel_event is not None and cancel_event.is_set():
return
active_tools = tool_controller.active_tools()
if not active_tools:
_append_budget_exhausted_nudge = False
break
_tool_xml_signals = TOOL_XML_SIGNALS if active_tools else ()
# Build payload -- stream: True so we detect tool signals
# in the first 1-2 chunks without a non-streaming penalty.
payload = {
"messages": conversation,
"stream": True,
"stream_options": {"include_usage": True},
"temperature": temperature,
"top_p": top_p,
"top_k": top_k if top_k >= 0 else 0,
"min_p": min_p,
"repeat_penalty": repetition_penalty,
"presence_penalty": presence_penalty,
"tools": active_tools,
"tool_choice": "auto",
}
_reasoning_kw = self._request_reasoning_kwargs(
enable_thinking, reasoning_effort, preserve_thinking
)
if _reasoning_kw is not None:
payload["chat_template_kwargs"] = _reasoning_kw
payload["max_tokens"] = (
max_tokens
if max_tokens is not None
else (self._effective_context_length or _DEFAULT_MAX_TOKENS_FLOOR)
)
payload["t_max_predict_ms"] = _DEFAULT_T_MAX_PREDICT_MS
if stop:
payload["stop"] = stop
if seed is not None:
payload["seed"] = seed
try:
_auth_headers = (
{"Authorization": f"Bearer {self._api_key}"} if self._api_key else None
)
# ── Speculative buffer state machine ──────────────────
# BUFFERING: accumulate content, check for tool signals
# STREAMING: no tool detected, yield tokens to caller
# DRAINING: tool signal found, silently consume rest
_S_BUFFERING = 0
_S_STREAMING = 1
_S_DRAINING = 2
detect_state = _S_BUFFERING
content_buffer = "" # Raw content held during BUFFERING
content_accum = "" # All content tokens (for tool parsing)
reasoning_accum = ""
cumulative_display = "" # Cumulative yielded text (with <think>)
in_thinking = False
has_content_tokens = False
tool_calls_acc = {} # Structured delta.tool_calls fragments
has_structured_tc = False
_iter_usage = None
_iter_timings = None
_iter_finish_reason = None
_stream_done = False
_last_emitted = ""
provisional_render_html_tool_call_ids = set()
_suppress_visible_output = _forced_tool_call_pending
stream_timeout = httpx.Timeout(
connect = 10,
read = 0.5,
write = 10,
pool = 10,
)
with httpx.Client(
timeout = stream_timeout,
limits = httpx.Limits(max_keepalive_connections = 0),
) as client:
with self._stream_with_retry(
client,
url,
payload,
cancel_event,
headers = _auth_headers,
) as response:
if response.status_code != 200:
error_body = response.read().decode()
raise RuntimeError(
f"llama-server returned {response.status_code}: " f"{error_body}"
)
raw_buf = ""
for raw_chunk in self._iter_text_cancellable(
response,
cancel_event,
):
raw_buf += raw_chunk
while "\n" in raw_buf:
line, raw_buf = raw_buf.split("\n", 1)
line = line.strip()
if not line:
continue
if line == "data: [DONE]":
# Flush thinking state for STREAMING
if detect_state == _S_STREAMING and in_thinking:
if has_content_tokens:
cumulative_display += "</think>"
if not _suppress_visible_output:
yield {
"type": "content",
"text": _strip_tool_markup(
cumulative_display,
final = True,
),
}
else:
cumulative_display = reasoning_accum
if not _suppress_visible_output:
yield {
"type": "content",
"text": cumulative_display,
}
_stream_done = True
break # exit inner while
if not line.startswith("data: "):
continue
try:
chunk_data = json.loads(line[6:])
_ct = chunk_data.get("timings")
if _ct:
_iter_timings = _ct
_cu = chunk_data.get("usage")
if _cu:
_iter_usage = _cu
choices = chunk_data.get("choices", [])
if not choices:
continue
delta = choices[0].get("delta", {})
_fr = choices[0].get("finish_reason")
if _fr:
_iter_finish_reason = _fr
# ── Structured tool_calls ──
tc_deltas = delta.get("tool_calls")
if tc_deltas:
# llama-server can emit visible assistant
# preface content before native structured
# tool_calls. Preserve content_accum as
# the assistant pre-tool text and still
# drain/execute the structured call.
has_structured_tc = True
detect_state = _S_DRAINING
for tc_d in tc_deltas:
idx = tc_d.get("index", 0)
if idx not in tool_calls_acc:
tool_calls_acc[idx] = {
"id": tc_d.get("id", f"call_{idx}"),
"type": "function",
"function": {
"name": "",
"arguments": "",
},
}
elif tc_d.get("id"):
# Update ID if a real one
# arrives on a later delta.
tool_calls_acc[idx]["id"] = tc_d["id"]
func = tc_d.get("function", {})
if func.get("name"):
tool_calls_acc[idx]["function"]["name"] += func[
"name"
]
if func.get("arguments"):
tool_calls_acc[idx]["function"]["arguments"] += (
func["arguments"]
)
current_name = tool_calls_acc[idx]["function"].get(
"name", ""
)
fallback_id = f"call_{idx}"
current_id = tool_calls_acc[idx].get("id", fallback_id)
already_started = (
current_id in provisional_render_html_tool_call_ids
)
has_real_id = current_id != fallback_id
if (
current_name == "render_html"
and not _tool_succeeded("render_html")
and any(
(
(tool.get("function") or {}).get("name")
== "render_html"
)
for tool in active_tools
)
and not already_started
and not provisional_render_html_tool_call_ids
and has_real_id
):
provisional_render_html_tool_call_ids.add(
current_id
)
yield {
"type": "tool_start",
"tool_name": "render_html",
"tool_call_id": current_id,
"arguments": {},
"provenance": tool_event_provenance(
provisional = True,
),
}
continue
# ── Reasoning tokens ──
# Yield only in STREAMING. In BUFFERING and
# DRAINING, accumulate silently so we don't
# corrupt the consumer's prev_text tracker
# (routes/inference.py never resets it
# between tool iterations).
reasoning = delta.get("reasoning_content", "")
if reasoning:
reasoning_accum += reasoning
if detect_state == _S_STREAMING:
if not in_thinking:
cumulative_display += "<think>"
in_thinking = True
cumulative_display += reasoning
if not _suppress_visible_output:
yield {
"type": "content",
"text": cumulative_display,
}
# ── Content tokens ──
token = delta.get("content", "")
if token:
has_content_tokens = True
content_accum += token
if detect_state == _S_DRAINING:
pass # accumulate silently
elif detect_state == _S_STREAMING:
if in_thinking:
cumulative_display += "</think>"
in_thinking = False
cumulative_display += token
cleaned = _strip_tool_markup_streaming(
cumulative_display
)
if len(cleaned) > len(_last_emitted):
_last_emitted = cleaned
if not _suppress_visible_output:
yield {
"type": "content",
"text": cleaned,
}
elif detect_state == _S_BUFFERING:
content_buffer += token
stripped_buf = content_buffer.lstrip()
if not stripped_buf:
continue
# Check tool signal prefixes.
is_prefix = False
is_match = False
for sig in _tool_xml_signals:
if stripped_buf.startswith(sig):
is_match = True
break
if sig.startswith(stripped_buf):
is_prefix = True
break
if is_match:
# Tool signal -- flush any visible
# prefix before DRAINING so the
# route sends it before tool_start.
if reasoning_accum:
cumulative_display += "<think>"
cumulative_display += reasoning_accum
cumulative_display += "</think>"
cumulative_display += content_buffer
cleaned = _strip_tool_markup_streaming(
cumulative_display,
force = True,
)
if len(cleaned) > len(_last_emitted):
_last_emitted = cleaned
if not _suppress_visible_output:
yield {
"type": "content",
"text": cleaned,
}
detect_state = _S_DRAINING
elif (
is_prefix and len(stripped_buf) < _MAX_BUFFER_CHARS
):
pass # keep buffering
else:
# Not a tool -- flush buffer
detect_state = _S_STREAMING
# Flush reasoning accumulated
# during BUFFERING.
if reasoning_accum:
cumulative_display += "<think>"
cumulative_display += reasoning_accum
cumulative_display += "</think>"
cumulative_display += content_buffer
cleaned = _strip_tool_markup(
cumulative_display,
)
if len(cleaned) > len(_last_emitted):
_last_emitted = cleaned
if not _suppress_visible_output:
yield {
"type": "content",
"text": cleaned,
}
except json.JSONDecodeError:
logger.debug(f"Skipping malformed SSE line: {line[:100]}")
if _stream_done:
break # exit outer for
# ── Resolve BUFFERING at stream end ──
if detect_state == _S_BUFFERING:
stripped_buf = content_buffer.lstrip()
if stripped_buf and any(s in stripped_buf for s in _tool_xml_signals):
detect_state = _S_DRAINING
elif content_accum or reasoning_accum:
detect_state = _S_STREAMING
if content_buffer:
# Flush reasoning first.
if reasoning_accum:
cumulative_display += "<think>"
cumulative_display += reasoning_accum
cumulative_display += "</think>"
cumulative_display += content_buffer
if not _suppress_visible_output:
yield {
"type": "content",
"text": _strip_tool_markup(
cumulative_display,
final = True,
),
}
elif reasoning_accum and not has_content_tokens:
# Reasoning-only response: show reasoning as plain
# text, matching the final streaming pass for
# models that put everything in reasoning.
cumulative_display = reasoning_accum
if not _suppress_visible_output:
yield {
"type": "content",
"text": cumulative_display,
}
else:
return
# ── STREAMING path: no tool call ──
if detect_state == _S_STREAMING:
# Safety net: check for XML tool signals in content. The
# route layer resets prev_text on tool_start, so post-tool
# synthesis streams correctly even if content was emitted
# before the tool XML.
_safety_tc = None
if any(s in content_accum for s in _tool_xml_signals):
_safety_tc = self._parse_tool_calls_from_text(
content_accum,
allow_incomplete = auto_heal_tool_calls,
)
if not _safety_tc:
# ── Re-prompt on plan-without-action ──
# If the model described its intent (forward-looking
# language) without calling a tool, nudge it to act.
# Fires at most once per request, only on short
# responses with intent signals -- "4" or "Hello!"
# won't trigger it. Use content if available, else
# fall back to reasoning text (reasoning-only stalls).
_stripped = content_accum.strip()
if not _stripped:
_stripped = reasoning_accum.strip()
_render_html_already_done_intent = _tool_succeeded(
"render_html"
) and re.search(
r"(?i)\brender[_\s-]?html\b",
_stripped,
)
if (
auto_heal_tool_calls
and active_tools
and not _render_html_already_done_intent
and _reprompt_count < _MAX_REPROMPTS
and _is_short_intent_without_action(_stripped)
):
_reprompt_count += 1
logger.info(
f"Re-prompt {_reprompt_count}/{_MAX_REPROMPTS}: "
f"model responded without calling tools "
f"({len(_stripped)} chars)"
)
conversation.append(
{
"role": "assistant",
"content": _stripped,
}
)
available_tool_names = [
(tool.get("function") or {}).get("name")
for tool in active_tools
if isinstance(tool, dict) and isinstance(tool.get("function"), dict)
]
available_tool_names = [name for name in available_tool_names if name]
tool_hint = " or ".join(available_tool_names) or "an available tool"
_forced_tool_call_pending = True
conversation.append(
{
"role": "user",
"content": (
"You have access to enabled tools. If a tool is needed to satisfy "
"the user's request or complete the action you described, call "
f"{tool_hint} now. If no tool is needed, provide the final answer "
"and follow the user's requested format."
),
}
)
# Accumulate tokens and timing from this iteration.
_fu_r = _backfill_usage_from_timings(_iter_usage, _iter_timings) or {}
_accumulated_completion_tokens += _fu_r.get("completion_tokens", 0)
_it_r = _iter_timings or {}
_accumulated_predicted_ms += _it_r.get("predicted_ms", 0)
_accumulated_predicted_n += _it_r.get("predicted_n", 0)
yield {"type": "status", "text": ""}
continue
if _forced_tool_call_pending:
_forced_tool_call_pending = False
if not _should_suppress_forced_no_tool_output(_stripped):
if cumulative_display:
forced_visible_text = _strip_tool_markup(
cumulative_display,
final = True,
)
elif content_accum:
forced_visible_text = _strip_tool_markup(
content_accum,
final = True,
)
else:
forced_visible_text = reasoning_accum
if forced_visible_text:
yield {
"type": "content",
"text": forced_visible_text,
}
# Content was already streamed. Yield metadata.
yield {"type": "status", "text": ""}
_fu = _backfill_usage_from_timings(_iter_usage, _iter_timings) or {}
_fc = _fu.get("completion_tokens", 0)
_fp = _fu.get("prompt_tokens", 0)
_tc = _fc + _accumulated_completion_tokens
if _iter_usage or _iter_timings or _accumulated_completion_tokens:
_mt = dict(_iter_timings) if _iter_timings else {}
if _accumulated_predicted_ms or _accumulated_predicted_n:
_mt["predicted_ms"] = (
_mt.get("predicted_ms", 0) + _accumulated_predicted_ms
)
_tn = _mt.get("predicted_n", 0) + _accumulated_predicted_n
_mt["predicted_n"] = _tn
_tms = _mt["predicted_ms"]
if _tms > 0:
_mt["predicted_per_second"] = _tn / (_tms / 1000.0)
yield {
"type": "metadata",
"usage": {
"prompt_tokens": _fp,
"completion_tokens": _tc,
"total_tokens": _fp + _tc,
},
"timings": _mt,
"finish_reason": _iter_finish_reason,
}
return
# Safety net caught tool XML -- treat as tool call.
tool_calls = _safety_tc
content_text = _strip_tool_markup(
content_accum,
final = True,
force = True,
)
logger.info(
f"Safety net: parsed {len(tool_calls)} tool call(s) "
f"from streamed content"
)
else:
# ── DRAINING path: assemble tool_calls ──
tool_calls = None
content_text = content_accum
if has_structured_tc:
# Drop incomplete fragments (e.g. from max_tokens
# truncation or disconnect).
tool_calls = [
tool_calls_acc[i]
for i in sorted(tool_calls_acc)
if (tool_calls_acc[i].get("function", {}).get("name", "").strip())
] or None
if not tool_calls and any(s in content_accum for s in _tool_xml_signals):
tool_calls = self._parse_tool_calls_from_text(
content_accum,
allow_incomplete = auto_heal_tool_calls,
)
if tool_calls and not has_structured_tc:
content_text = _strip_tool_markup(
content_text,
final = True,
force = True,
)
if tool_calls:
logger.info(
f"Parsed {len(tool_calls)} tool call(s) from "
f"{'structured delta' if has_structured_tc else 'content text'}"
)
if not tool_calls:
# DRAINING but no tool calls (false positive). Merge
# accumulated metrics from prior tool iterations so
# they aren't silently dropped.
yield {"type": "status", "text": ""}
if content_accum:
# Strip leaked tool-call XML before yielding.
content_accum = _strip_tool_markup(content_accum, final = True)
if content_accum:
yield {"type": "content", "text": content_accum}
_fu = _backfill_usage_from_timings(_iter_usage, _iter_timings) or {}
_fc = _fu.get("completion_tokens", 0)
_fp = _fu.get("prompt_tokens", 0)
_tc = _fc + _accumulated_completion_tokens
if _iter_usage or _iter_timings or _accumulated_completion_tokens:
_mt = dict(_iter_timings) if _iter_timings else {}
if _accumulated_predicted_ms or _accumulated_predicted_n:
_mt["predicted_ms"] = (
_mt.get("predicted_ms", 0) + _accumulated_predicted_ms
)
_tn = _mt.get("predicted_n", 0) + _accumulated_predicted_n
_mt["predicted_n"] = _tn
_tms = _mt["predicted_ms"]
if _tms > 0:
_mt["predicted_per_second"] = _tn / (_tms / 1000.0)
yield {
"type": "metadata",
"usage": {
"prompt_tokens": _fp,
"completion_tokens": _tc,
"total_tokens": _fp + _tc,
},
"timings": _mt,
"finish_reason": _iter_finish_reason,
}
return
# ── Execute tool calls ──
_accumulated_completion_tokens += (
_backfill_usage_from_timings(_iter_usage, _iter_timings) or {}
).get("completion_tokens", 0)
_it = _iter_timings or {}
_accumulated_predicted_ms += _it.get("predicted_ms", 0)
_accumulated_predicted_n += _it.get("predicted_n", 0)
# disable_parallel_tool_use: execute only the first tool call
# this turn. Truncate before building assistant_msg so the
# conversation stays consistent and extra calls are never executed.
if disable_parallel_tool_use and tool_calls and len(tool_calls) > 1:
tool_calls = tool_calls[:1]
assistant_msg: dict = {"role": "assistant", "content": content_text}
assistant_appended = False
for tc in tool_calls or []:
func = tc.get("function", {})
tool_name = func.get("name", "")
provisional_render_html_match = (
tool_name == "render_html"
and tc.get("id") in provisional_render_html_tool_call_ids
)
decision = tool_controller.prepare_call(
tc,
forced = _forced_tool_call_pending,
provisional = provisional_render_html_match,
)
if not decision.should_execute:
if content_text and not assistant_appended:
conversation.append(assistant_msg)
assistant_appended = True
completion = tool_controller.record_noop(decision)
conversation.append(completion.model_message())
if _forced_tool_call_pending:
_forced_tool_call_pending = False
logger.info(
"Suppressed local GGUF tool call as internal no-op: "
f"action={decision.action} tool={decision.tool_name}"
)
break
if not assistant_appended:
assistant_msg["tool_calls"] = [decision.as_assistant_tool_call()]
conversation.append(assistant_msg)
assistant_appended = True
else:
assistant_msg.setdefault("tool_calls", []).append(
decision.as_assistant_tool_call()
)
yield {"type": "status", "text": decision.status_text}
yield decision.tool_start_event()
_effective_timeout = None if tool_call_timeout >= 9999 else tool_call_timeout
# RAG: cap paraphrased KB re-searches that slip past the dup guard.
if (
decision.tool_name == "search_knowledge_base"
and _kb_search_count >= RAG_MAX_SEARCHES_PER_TURN
):
result = RAG_SEARCH_CAP_NUDGE
else:
result = execute_tool(
decision.tool_name,
decision.arguments,
cancel_event = cancel_event,
timeout = _effective_timeout,
session_id = session_id,
rag_scope = rag_scope,
)
if decision.tool_name == "search_knowledge_base":
_kb_search_count += 1
completion = tool_controller.record_result(decision, result)
yield completion.tool_end_event()
conversation.append(completion.tool_message())
if _forced_tool_call_pending:
_forced_tool_call_pending = False
# Clear tool status badge before next generation/final pass.
yield {"type": "status", "text": ""}
if tool_controller.force_final_answer or not tool_controller.active_tools():
_append_budget_exhausted_nudge = False
break
continue
except httpx.ConnectError:
raise RuntimeError("Lost connection to llama-server")
except Exception as e:
if cancel_event is not None and cancel_event.is_set():
return
raise
# ── Tool iteration cap reached -- synthesize final answer ──
# The model used all iterations without a final text response. Nudge
# the final streaming pass to produce a useful answer instead of
# continuing to request tools.
if max_tool_iterations > 0 and _append_budget_exhausted_nudge:
conversation.append(
{
"role": "user",
"content": (
"You have used all available tool calls. Based on "
"everything you have found so far, provide your final "
"answer now. Do not call any more tools."
),
}
)
# Clear status.
yield {"type": "status", "text": ""}
# Final streaming pass with the full conversation context.
stream_payload = {
"messages": conversation,
"stream": True,
"temperature": temperature,
"top_p": top_p,
"top_k": top_k if top_k >= 0 else 0,
"min_p": min_p,
"repeat_penalty": repetition_penalty,
"presence_penalty": presence_penalty,
}
_reasoning_kw = self._request_reasoning_kwargs(
enable_thinking, reasoning_effort, preserve_thinking
)
if _reasoning_kw is not None:
stream_payload["chat_template_kwargs"] = _reasoning_kw
stream_payload["max_tokens"] = (
max_tokens
if max_tokens is not None
else (self._effective_context_length or _DEFAULT_MAX_TOKENS_FLOOR)
)
stream_payload["t_max_predict_ms"] = _DEFAULT_T_MAX_PREDICT_MS
if stop:
stream_payload["stop"] = stop
if seed is not None:
stream_payload["seed"] = seed
stream_payload["stream_options"] = {"include_usage": True}
cumulative = ""
_last_emitted = ""
in_thinking = False
has_content_tokens = False
reasoning_text = ""
_metadata_usage = None
_metadata_timings = None
_metadata_finish_reason = None
_stream_done = False
try:
stream_timeout = httpx.Timeout(connect = 10, read = 0.5, write = 10, pool = 10)
_auth_headers = {"Authorization": f"Bearer {self._api_key}"} if self._api_key else None
with httpx.Client(
timeout = stream_timeout, limits = httpx.Limits(max_keepalive_connections = 0)
) as client:
with self._stream_with_retry(
client,
url,
stream_payload,
cancel_event,
headers = _auth_headers,
) as response:
if response.status_code != 200:
error_body = response.read().decode()
raise RuntimeError(
f"llama-server returned {response.status_code}: {error_body}"
)
buffer = ""
for raw_chunk in self._iter_text_cancellable(response, cancel_event):
buffer += raw_chunk
while "\n" in buffer:
line, buffer = buffer.split("\n", 1)
line = line.strip()
if not line:
continue
if line == "data: [DONE]":
if in_thinking:
if has_content_tokens:
cumulative += "</think>"
yield {
"type": "content",
"text": _strip_tool_markup(cumulative, final = True),
}
else:
cumulative = reasoning_text
yield {"type": "content", "text": cumulative}
_stream_done = True
break # exit inner while
if not line.startswith("data: "):
continue
try:
chunk_data = json.loads(line[6:])
# Capture server timings/usage from final chunks.
_chunk_timings = chunk_data.get("timings")
if _chunk_timings:
_metadata_timings = _chunk_timings
_chunk_usage = chunk_data.get("usage")
if _chunk_usage:
_metadata_usage = _chunk_usage
choices = chunk_data.get("choices", [])
if choices:
delta = choices[0].get("delta", {})
_fr = choices[0].get("finish_reason")
if _fr:
_metadata_finish_reason = _fr
reasoning = delta.get("reasoning_content", "")
if reasoning:
reasoning_text += reasoning
if not in_thinking:
cumulative += "<think>"
in_thinking = True
cumulative += reasoning
yield {"type": "content", "text": cumulative}
token = delta.get("content", "")
if token:
has_content_tokens = True
if in_thinking:
cumulative += "</think>"
in_thinking = False
cumulative += token
cleaned = _strip_tool_markup(cumulative)
# Emit only when cleaned text grows (monotonic).
if len(cleaned) > len(_last_emitted):
_last_emitted = cleaned
yield {"type": "content", "text": cleaned}
except json.JSONDecodeError:
logger.debug(f"Skipping malformed SSE line: {line[:100]}")
if _stream_done:
break # exit outer for
_final_usage = _metadata_usage or {}
_final_completion = _final_usage.get("completion_tokens", 0)
_final_prompt = _final_usage.get("prompt_tokens", 0)
_total_completion = _final_completion + _accumulated_completion_tokens
if _metadata_usage or _metadata_timings or _metadata_finish_reason:
_merged_timings = dict(_metadata_timings) if _metadata_timings else {}
if _accumulated_predicted_ms or _accumulated_predicted_n:
_merged_timings["predicted_ms"] = (
_merged_timings.get("predicted_ms", 0) + _accumulated_predicted_ms
)
_total_predicted_n = (
_merged_timings.get("predicted_n", 0) + _accumulated_predicted_n
)
_merged_timings["predicted_n"] = _total_predicted_n
_total_predicted_ms = _merged_timings["predicted_ms"]
if _total_predicted_ms > 0:
_merged_timings["predicted_per_second"] = _total_predicted_n / (
_total_predicted_ms / 1000.0
)
yield {
"type": "metadata",
"usage": {
"prompt_tokens": _final_prompt,
"completion_tokens": _total_completion,
"total_tokens": _final_prompt + _total_completion,
},
"timings": _merged_timings,
"finish_reason": _metadata_finish_reason,
}
except httpx.ConnectError:
raise RuntimeError("Lost connection to llama-server")
except Exception as e:
if cancel_event is not None and cancel_event.is_set():
return
raise
# ── Prompt token counting ──────────────────────────────────
def count_chat_tokens(
self,
messages,
system = None,
tools = None,
strict: bool = False,
) -> int:
"""Count prompt tokens for a chat request via llama-server.
Non-strict callers keep the historical best-effort behavior and receive
0 when a count cannot be determined. Strict callers (public count_tokens
endpoints) get an exception instead of a successful-looking zero when
tokenizer/template calls fail or a multimodal prompt would fall back to a
text-only approximation.
"""
if not self.is_loaded:
if strict:
raise RuntimeError("llama-server is not loaded")
return 0
def _has_non_text_content(content) -> bool:
if isinstance(content, list):
for block in content:
if isinstance(block, str):
continue
if not isinstance(block, dict):
return True
if block.get("type") == "text" and isinstance(block.get("text"), str):
continue
if isinstance(block.get("text"), str):
continue
return True
return False
def _has_non_text_prompt_parts() -> bool:
if _has_non_text_content(system):
return True
for msg in messages or []:
if isinstance(msg, dict) and _has_non_text_content(msg.get("content", "")):
return True
return False
def _block_text(content) -> str:
if isinstance(content, str):
return content
if isinstance(content, list):
parts = []
for block in content:
if isinstance(block, dict):
if block.get("type") == "text" and isinstance(block.get("text"), str):
parts.append(block["text"])
elif isinstance(block.get("text"), str):
parts.append(block["text"])
elif isinstance(block, str):
parts.append(block)
return "".join(parts)
return ""
# Normalize system into a leading message / plain text.
system_text = ""
if isinstance(system, str):
system_text = system
elif isinstance(system, list):
system_text = _block_text(system)
try:
_auth_headers = {"Authorization": f"Bearer {self._api_key}"} if self._api_key else None
with httpx.Client(timeout = 10, headers = _auth_headers) as client:
def _tokenize(text: str) -> int:
r = client.post(
f"{self.base_url}/tokenize",
json = {"content": text, "add_special": True},
)
if r.status_code != 200:
if strict:
raise RuntimeError("llama-server tokenizer failed")
return 0
tokens = r.json().get("tokens", [])
if not isinstance(tokens, list):
if strict:
raise RuntimeError("llama-server tokenizer returned invalid tokens")
return 0
return len(tokens)
# 1. Try /apply-template to render the real chat prompt.
template_messages = list(messages) if messages else []
if system_text:
template_messages = [
{"role": "system", "content": system_text}
] + template_messages
apply_template_failed = False
try:
# llama-server's /apply-template renders tool declarations
# into the prompt when ``tools`` is supplied, so pass them
# through — otherwise tool-schema tokens go uncounted.
template_body = {"messages": template_messages}
if tools:
template_body["tools"] = tools
resp = client.post(
f"{self.base_url}/apply-template",
json = template_body,
)
if resp.status_code == 200:
prompt = resp.json().get("prompt", "")
if isinstance(prompt, str):
return _tokenize(prompt)
apply_template_failed = True
except Exception:
apply_template_failed = True
if strict and apply_template_failed and _has_non_text_prompt_parts():
raise RuntimeError(
"cannot fall back to text-only token counting for multimodal messages"
)
# 2. Fallback: concatenate plain text and tokenize. Append a
# serialized form of the tools so they still contribute to the
# count when /apply-template is unavailable.
parts = []
if system_text:
parts.append(system_text)
for msg in messages or []:
if isinstance(msg, dict):
parts.append(_block_text(msg.get("content", "")))
if tools:
try:
parts.append(json.dumps(tools, ensure_ascii = False))
except Exception:
pass
return _tokenize("\n".join(p for p in parts if p))
except Exception:
if strict:
raise
return 0
# ── TTS support ────────────────────────────────────────────
def detect_audio_type(self) -> Optional[str]:
"""Detect audio/TTS codec; swallows errors (use _strict to distinguish)."""
try:
return self._detect_audio_type_strict()
except Exception as e:
logger.debug(f"Audio type detection failed: {e}")
return None
def _detect_audio_type_strict(self) -> Optional[str]:
"""Codec name on match, None on non-audio, raises on transport/JSON errors."""
if not self.is_loaded:
return None
_auth_headers = {"Authorization": f"Bearer {self._api_key}"} if self._api_key else None
with httpx.Client(timeout = 10, headers = _auth_headers) as client:
def _detok(tid: int) -> str:
# Non-200 means "marker not in vocab" -- keep probing.
# Transport / JSON errors still raise.
r = client.post(f"{self.base_url}/detokenize", json = {"tokens": [tid]})
if r.status_code != 200:
return ""
return r.json().get("content", "")
def _tok(text: str) -> list[int]:
r = client.post(
f"{self.base_url}/tokenize",
json = {"content": text, "add_special": False},
)
if r.status_code != 200:
return []
return r.json().get("tokens", [])
# Codec-specific tokens (not generic ones that non-audio models may have)
if "<custom_token_" in _detok(128258) and "<custom_token_" in _detok(128259):
return "snac"
if len(_tok("<|AUDIO|>")) == 1 and len(_tok("<|audio_eos|>")) == 1:
return "csm"
if len(_tok("<|startoftranscript|>")) == 1:
return "whisper"
# Gemma 3n: <audio_soft_token>; Gemma 4: <|audio|> (not csm's <|AUDIO|>).
if len(_tok("<audio_soft_token>")) == 1 or len(_tok("<|audio|>")) == 1:
return "audio_vlm"
if len(_tok("<|bicodec_semantic_0|>")) == 1 and len(_tok("<|bicodec_global_0|>")) == 1:
return "bicodec"
if len(_tok("<|c1_0|>")) == 1 and len(_tok("<|c2_0|>")) == 1:
return "dac"
return None
# Prompt format per codec: (template, stop_tokens, needs_token_ids).
# Matches InferenceBackend._generate_snac/bicodec/dac.
_TTS_PROMPTS = {
"snac": (
"<custom_token_3>{text}<|eot_id|><custom_token_4>",
["<custom_token_2>"],
True,
),
"bicodec": (
"<|task_tts|><|start_content|>{text}<|end_content|><|start_global_token|>",
["<|im_end|>", "</s>"],
False,
),
"dac": (
"<|im_start|>\n<|text_start|>{text}<|text_end|>\n<|audio_start|><|global_features_start|>\n",
["<|im_end|>", "<|audio_end|>"],
False,
),
}
_codec_mgr = None # Shared AudioCodecManager instance
def init_audio_codec(self, audio_type: str) -> None:
"""Load the audio codec at model load time (mirrors the non-GGUF path)."""
import torch
from core.inference.audio_codecs import AudioCodecManager
if LlamaCppBackend._codec_mgr is None:
LlamaCppBackend._codec_mgr = AudioCodecManager()
device = "cuda" if torch.cuda.is_available() else "cpu"
model_repo_path = None
# BiCodec needs a repo with BiCodec/ weights -- download canonical SparkTTS
if audio_type == "bicodec":
from huggingface_hub import snapshot_download
import os
repo_path = snapshot_download("unsloth/Spark-TTS-0.5B", local_dir = "Spark-TTS-0.5B")
model_repo_path = os.path.abspath(repo_path)
LlamaCppBackend._codec_mgr.load_codec(audio_type, device, model_repo_path = model_repo_path)
logger.info(f"Loaded audio codec for GGUF TTS: {audio_type}")
def generate_audio_response(
self,
text: str,
audio_type: str,
temperature: float = 0.6,
top_p: float = 0.95,
top_k: int = 50,
min_p: float = 0.0,
max_new_tokens: int = 2048,
repetition_penalty: float = 1.1,
) -> tuple:
"""
Generate TTS audio via llama-server /completion + codec decode.
Returns (wav_bytes, sample_rate).
"""
if audio_type not in self._TTS_PROMPTS:
raise RuntimeError(f"GGUF TTS does not support '{audio_type}' codec.")
tpl, stop, need_ids = self._TTS_PROMPTS[audio_type]
payload: dict = {
"prompt": tpl.format(text = text),
"stream": False,
"n_predict": max_new_tokens,
"temperature": temperature,
"top_p": top_p,
"top_k": top_k if top_k >= 0 else 0,
"min_p": min_p,
"repeat_penalty": repetition_penalty,
}
if stop:
payload["stop"] = stop
if need_ids:
payload["n_probs"] = 1
_auth_headers = {"Authorization": f"Bearer {self._api_key}"} if self._api_key else None
with httpx.Client(timeout = httpx.Timeout(300, connect = 10), headers = _auth_headers) as client:
resp = client.post(f"{self.base_url}/completion", json = payload)
if resp.status_code != 200:
raise RuntimeError(f"llama-server returned {resp.status_code}: {resp.text}")
data = resp.json()
token_ids = (
[p["id"] for p in data.get("completion_probabilities", []) if "id" in p]
if need_ids
else None
)
import torch
device = "cuda" if torch.cuda.is_available() else "cpu"
return LlamaCppBackend._codec_mgr.decode(
audio_type, device, token_ids = token_ids, text = data.get("content", "")
)