Merge pull request #13 from dbrgn/last_update

Last update

Cargo.lock

@@ -10,6 +10,7 @@ dependencies = [
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "tar 0.3.2 (git+https://github.com/dbrgn/tar-rs?branch=pax_header)",
+ "time 0.1.34 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -253,6 +254,16 @@ dependencies = [
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "time"
+version = "0.1.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "url"
 version = "0.2.38"

Cargo.toml

@@ -15,3 +15,4 @@ curl = "^0.2"
 env_logger = { version = "^0.3", optional = true }
 rustc-serialize = "^0.3"
 docopt = "^0.6"
+time = "^0.1"

src/main.rs

@@ -8,6 +8,7 @@ extern crate flate2;
 extern crate tar;
 extern crate curl;
 extern crate rustc_serialize;
+extern crate time;
 
 use std::io::BufReader;
 use std::fs::File;
@@ -59,7 +60,8 @@ To render a local file (for testing):
 
     $ tldr --render /path/to/file.md
 ";
-const ARCHIVE_URL: &'static str = "https://github.com/tldr-pages/tldr/archive/master.tar.gz";
+const ARCHIVE_URL: &'static str = "http://localhost:8001/master.tar.gz";
+const MAX_CACHE_AGE: i64 = 2592000; // 30 days
 
 
 #[derive(Debug, RustcDecodable)]
@@ -110,6 +112,9 @@ fn main() {
         process::exit(0);
     }
 
+    // Initialize updater
+    let dl = Updater::new(ARCHIVE_URL);
+
     // Clear cache, pass through
     if args.flag_clear_cache {
         println!("Flag --clear-cache not yet implemented.");
@@ -118,7 +123,6 @@ fn main() {
 
     // Update cache, pass through
     if args.flag_update {
-        let dl = Updater::new(ARCHIVE_URL);
         dl.update().unwrap_or_else(|e| {
             match e {
                 TldrError::UpdateError(msg) => println!("Could not update cache: {}", msg),
@@ -156,6 +160,19 @@ fn main() {
 
     // Show command from cache
     if let Some(command) = args.arg_command {
+        if !args.flag_update {
+            match dl.last_update() {
+                Some(ago) if ago > MAX_CACHE_AGE => {
+                    println!("Cache wasn't updated in {} days.", MAX_CACHE_AGE / 24 / 3600);
+                    println!("You should probably run `tldr --update` soon."); 
+                },
+                None => {
+                    println!("Cache not found. Please run `tldr --update`.");
+                    process::exit(1);
+                },
+                _ => {},
+            }
+        }
         println!("Page rendering from cache not yet implemented.");
         process::exit(1);
     }

src/updater.rs

@@ -1,10 +1,14 @@
 use std::io::Read;
 use std::fs;
 use std::env;
+use std::path::PathBuf;
+
+#[cfg(unix)] use std::os::unix::fs::MetadataExt;
 
 use flate2::read::GzDecoder;
 use tar::Archive;
 use curl::http;
+use time;
 
 use error::TldrError::{self, UpdateError};
 
@@ -22,6 +26,12 @@ impl Updater {
         }
     }
 
+    /// Return the path to the cache directory.
+    fn get_cache_dir(&self) -> Result<PathBuf, TldrError> {
+        let home_dir = try!(env::home_dir().ok_or(UpdateError("Could not determine home directory".into())));
+        Ok(home_dir.join(".cache").join("tldr-rs"))
+    }
+
     /// Download the archive
     fn download(&self) -> Result<http::Response, TldrError> {
         let resp = try!(
@@ -48,8 +58,7 @@ impl Updater {
         let mut archive = try!(self.decompress(response.get_body()));
 
         // Determine paths
-        let home_dir = try!(env::home_dir().ok_or(UpdateError("Could not determine home directory".into())));
-        let cache_dir = home_dir.join(".cache").join("tldr-rs");
+        let cache_dir = try!(self.get_cache_dir());
 
         // Extract archive
         try!(archive.unpack(&cache_dir).map_err(|e| {
@@ -65,4 +74,17 @@ impl Updater {
         Ok(())
     }
 
+    /// Return the number of seconds since the cache directory was last modified.
+    #[cfg(unix)]
+    pub fn last_update(&self) -> Option<i64> {
+        if let Ok(cache_dir) = self.get_cache_dir() {
+            if let Ok(metadata) = fs::metadata(cache_dir) {
+                let mtime = metadata.mtime();
+                let now = time::now_utc().to_timespec();
+                return Some(now.sec - mtime)
+            };
+        };
+        None
+    }
+
 }