unsloth/studio/backend/utils/models/checkpoints.py
Daniel Han 187144d4e7
Reduce and tighten code comments and docstrings repo-wide (#6095)
Trim and tighten code comments and docstrings across the repository. Comment-only: every changed file verified code-identical to main via AST/token comparison.
2026-06-08 23:09:51 -07:00

135 lines
5.4 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
"""Checkpoint scanning utilities for discovering training runs and checkpoints."""
import json
import structlog
from loggers import get_logger
from pathlib import Path
from typing import List, Optional, Tuple
from utils.paths import outputs_root, resolve_output_dir
logger = get_logger(__name__)
def _read_checkpoint_loss(checkpoint_path: Path) -> Optional[float]:
"""Read loss from the last log_history entry of trainer_state.json, or None."""
trainer_state = checkpoint_path / "trainer_state.json"
if not trainer_state.exists():
return None
try:
with open(trainer_state) as f:
state = json.load(f)
log_history = state.get("log_history", [])
if log_history:
return log_history[-1].get("loss")
except Exception as e:
logger.debug(f"Could not read loss from {trainer_state}: {e}")
return None
def scan_checkpoints(
outputs_dir: str = str(outputs_root()),
) -> List[Tuple[str, List[Tuple[str, str, Optional[float]]], dict]]:
"""Scan outputs folder for training runs and their checkpoints.
Returns:
[(model_name, [(display_name, checkpoint_path, loss), ...], metadata), ...]
metadata keys (optional): base_model, peft_type, lora_rank.
First checkpoint entry is the main adapter; its loss mirrors the last
(highest-step) intermediate checkpoint.
"""
models = []
outputs_path = resolve_output_dir(outputs_dir)
if not outputs_path.exists():
logger.warning(f"Outputs directory not found: {outputs_dir}")
return models
try:
for item in outputs_path.iterdir():
if not item.is_dir():
continue
config_file = item / "config.json"
adapter_config = item / "adapter_config.json"
if not (config_file.exists() or adapter_config.exists()):
continue
# Training metadata from adapter_config.json / config.json
metadata: dict = {}
try:
if adapter_config.exists():
cfg = json.loads(adapter_config.read_text())
metadata["base_model"] = cfg.get("base_model_name_or_path")
metadata["peft_type"] = cfg.get("peft_type")
metadata["lora_rank"] = cfg.get("r")
elif config_file.exists():
cfg = json.loads(config_file.read_text())
metadata["base_model"] = cfg.get("_name_or_path")
# Detect BNB quantization from config.json
if config_file.exists():
if "cfg" not in dir():
cfg = json.loads(config_file.read_text())
quant_cfg = cfg.get("quantization_config")
if (
isinstance(quant_cfg, dict)
and quant_cfg.get("quant_method") == "bitsandbytes"
):
metadata["is_quantized"] = True
logger.info("Detected BNB-quantized model: %s", item.name)
except Exception:
pass
# Fallback: extract base model name from the folder name, e.g.
# "unsloth_Llama-3.2-3B-Instruct_1771227800" → "unsloth/Llama-3.2-3B-Instruct"
if not metadata.get("base_model"):
parts = item.name.rsplit("_", 1)
if len(parts) == 2 and parts[1].isdigit():
name_part = parts[0]
idx = name_part.find("_")
if idx > 0:
metadata["base_model"] = name_part[:idx] + "/" + name_part[idx + 1 :]
else:
metadata["base_model"] = name_part
# Valid training run.
checkpoints = []
# Main adapter placeholder — loss filled from the last checkpoint below.
checkpoints.append((item.name, str(item), None))
# Scan for intermediate checkpoints (checkpoint-N subdirs).
for sub in sorted(item.iterdir()):
if not sub.is_dir() or not sub.name.startswith("checkpoint-"):
continue
sub_config = sub / "config.json"
sub_adapter = sub / "adapter_config.json"
if sub_config.exists() or sub_adapter.exists():
loss = _read_checkpoint_loss(sub)
checkpoints.append((sub.name, str(sub), loss))
# Assign the last checkpoint's loss to the main adapter entry.
if len(checkpoints) > 1:
last_checkpoint_loss = checkpoints[-1][2]
checkpoints[0] = (
checkpoints[0][0],
checkpoints[0][1],
last_checkpoint_loss,
)
models.append((item.name, checkpoints, metadata))
logger.debug(f"Found model: {item.name} with {len(checkpoints)} checkpoint(s)")
# Sort by modification time (newest first)
models.sort(key = lambda x: Path(x[1][0][1]).stat().st_mtime, reverse = True)
logger.info(f"Found {len(models)} training runs in {outputs_dir}")
return models
except Exception as e:
logger.error(f"Error scanning checkpoints: {e}")
return []