N-th fix od model DL

packages/node/meshnet_node/downloader.py

@@ -8,9 +8,11 @@ test suite never touches the network.
 
 import hashlib
 import json
+import os
 import shutil
 import tarfile
 import tempfile
+import time
 import urllib.parse
 import urllib.request
 from pathlib import Path
@@ -23,6 +25,7 @@ _PEER_TIMEOUT_SECONDS = 2.0
 # they run sequentially before the race and may hit dead endpoints.
 _MODEL_SOURCE_TIMEOUT_SECONDS = 30.0
 _PROGRESS_INTERVAL_BYTES = 512 * 1024 * 1024
+_FILE_RETRY_ATTEMPTS = 3
 
 
 def compute_shard_checksum(shard_dir: Path) -> str:
@@ -111,6 +114,121 @@ def _download_shard_from_peer(
             return False
 
 
+class _TarOnlySource(Exception):
+    """The server ignored ?file= and streamed a tar — no single-file support."""
+
+
+def _fetch_source_file(
+    file_url: str,
+    dest: Path,
+    timeout: float,
+) -> int:
+    """Download one file; skip if *dest* already matches the remote size.
+
+    Returns the file's final size. Raises on any failure, including a
+    short read against the server's Content-Length.
+    """
+    with urllib.request.urlopen(file_url, timeout=timeout) as resp:
+        ctype = resp.getheader("Content-Type") if hasattr(resp, "getheader") else None
+        if isinstance(ctype, str) and "x-tar" in ctype:
+            raise _TarOnlySource(file_url)
+        length = resp.getheader("Content-Length") if hasattr(resp, "getheader") else None
+        expected = int(length) if isinstance(length, str) and length.isdigit() else None
+        if expected is not None and dest.exists() and dest.stat().st_size == expected:
+            return expected  # complete from an earlier attempt/run
+        received = 0
+        with dest.open("wb") as out:
+            while True:
+                chunk = resp.read(1024 * 1024)
+                if not chunk:
+                    break
+                out.write(chunk)
+                received += len(chunk)
+        if expected is not None and received != expected:
+            raise OSError(f"short read: got {received} of {expected} bytes")
+        return received
+
+
+def _reuse_local_file(expected: int, dest: Path, final: Path) -> bool:
+    """Reuse an already-complete copy of a file instead of re-downloading."""
+    if dest.exists() and dest.stat().st_size == expected:
+        return True
+    if final.exists() and final.stat().st_size == expected:
+        try:
+            os.link(final, dest)
+        except OSError:
+            shutil.copy2(final, dest)
+        return True
+    return False
+
+
+def _download_source_files(
+    source: dict,
+    shard_dir: Path,
+    timeout: float,
+    progress: bool,
+    label: str,
+) -> Path | None:
+    """Per-file download from a model source — retries and resumes per file.
+
+    Far more robust than one multi-GB tar stream on flaky links: a dropped
+    connection costs at most one file, and completed files are skipped when
+    the download is retried or the node is restarted.
+    """
+    url = source.get("url")
+    rel_files = [
+        rel for rel in (source.get("files") or [])
+        if isinstance(rel, str) and rel and not rel.startswith("/") and ".." not in Path(rel).parts
+    ]
+    if not isinstance(url, str) or not url or not rel_files:
+        return None
+    sizes = source.get("file_sizes")
+    if not isinstance(sizes, dict):
+        sizes = {}
+    partial_dir = shard_dir.parent / f"{shard_dir.name}.partial"
+    partial_dir.mkdir(parents=True, exist_ok=True)
+    sep = "&" if "?" in url else "?"
+    for index, rel in enumerate(rel_files, start=1):
+        dest = partial_dir / rel
+        dest.parent.mkdir(parents=True, exist_ok=True)
+        known_size = sizes.get(rel)
+        if isinstance(known_size, int) and _reuse_local_file(known_size, dest, shard_dir / rel):
+            if progress:
+                print(
+                    f"  {label}: [{index}/{len(rel_files)}] {rel} "
+                    f"(already complete, {known_size / 1e9:.2f} GB)",
+                    flush=True,
+                )
+            continue
+        file_url = f"{url}{sep}{urllib.parse.urlencode({'file': rel})}"
+        for attempt in range(1, _FILE_RETRY_ATTEMPTS + 1):
+            try:
+                size = _fetch_source_file(file_url, dest, timeout)
+                if progress:
+                    print(
+                        f"  {label}: [{index}/{len(rel_files)}] {rel} ({size / 1e9:.2f} GB)",
+                        flush=True,
+                    )
+                break
+            except _TarOnlySource:
+                if progress:
+                    print(f"  {label}: no single-file support — using tar stream", flush=True)
+                return None
+            except Exception as exc:
+                if progress:
+                    print(
+                        f"  {label}: {rel} attempt {attempt}/{_FILE_RETRY_ATTEMPTS} failed: {exc!r}",
+                        flush=True,
+                    )
+                if attempt == _FILE_RETRY_ATTEMPTS:
+                    return None
+                time.sleep(1.0 * attempt)
+    if shard_dir.exists():
+        shutil.rmtree(shard_dir)
+    shutil.move(str(partial_dir), str(shard_dir))
+    return shard_dir
+
+
 def _download_model_source(
     source: dict,
     shard_dir: Path,
@@ -118,6 +236,13 @@ def _download_model_source(
     progress: bool = False,
     label: str = "model-source",
 ) -> Path | None:
+    # Prefer per-file transfers whenever the source advertises its file list;
+    # fall through to the tar stream if the server lacks single-file support
+    # or per-file transfers keep failing.
+    if source.get("files"):
+        fetched = _download_source_files(source, shard_dir, timeout, progress, label)
+        if fetched is not None:
+            return fetched
     url = source.get("url")
     if not isinstance(url, str) or not url:
         endpoint = source.get("endpoint")

packages/node/meshnet_node/startup.py

@@ -43,7 +43,9 @@ def _full_model_sources(model_sources: list[dict]) -> list[dict]:
             full_sources.append({
                 **source,
                 "url": full_url,
-                "files": [],
+                # full_files (when advertised) enables robust per-file download
+                # of the whole snapshot; empty list falls back to the tar stream.
+                "files": source.get("full_files") or [],
                 "type": f"{source.get('type') or 'model-source'}-full",
             })
     return full_sources