feat: add favorite task templates and optimize evidence exports

apps/admin_console/services/export_cache.py

@@ -0,0 +1,66 @@
+"""Per-object export coordination and content-aware artifact reuse."""
+
+from contextlib import contextmanager, ExitStack
+import hashlib
+import json
+from pathlib import Path
+import threading
+from weakref import WeakValueDictionary
+
+_guard = threading.Lock()
+_locks: WeakValueDictionary = WeakValueDictionary()
+TERMINAL = {"completed", "success", "failed", "cancelled", "interrupted", "skipped"}
+
+
+@contextmanager
+def export_lock(*keys: str):
+    # Retain strong references until every lock is released. Unrelated exports
+    # run concurrently; nested session exports can reacquire their own RLock.
+    with _guard:
+        locks = []
+        for key in sorted(set(keys)):
+            lock = _locks.get(key)
+            if lock is None:
+                lock = threading.RLock()
+                _locks[key] = lock
+            locks.append(lock)
+    with ExitStack() as stack:
+        for lock in locks:
+            stack.enter_context(lock)
+        yield
+
+
+def fingerprint(report: dict, files=(), extra=None) -> str:
+    metadata = []
+    for path, name in files:
+        stat = path.stat()
+        metadata.append((name, str(path), stat.st_size, stat.st_mtime_ns))
+    payload = json.dumps([2, report, metadata, extra], sort_keys=True, default=str)
+    return hashlib.sha256(payload.encode()).hexdigest()
+
+
+def reusable(path: Path, signature: str, status: str) -> bool:
+    if status not in TERMINAL or not path.is_file():
+        return False
+    try:
+        return path.with_suffix(path.suffix + ".fingerprint").read_text() == signature
+    except OSError:
+        return False
+
+
+def remember(path: Path, signature: str) -> None:
+    marker = path.with_suffix(path.suffix + ".fingerprint")
+    temporary = marker.with_suffix(".tmp")
+    temporary.write_text(signature, encoding="ascii")
+    temporary.replace(marker)
+
+
+def compression(path: Path) -> int:
+    import zipfile
+
+    return (
+        zipfile.ZIP_STORED
+        if path.suffix.lower()
+        in {".mp4", ".mkv", ".webm", ".docx", ".xlsx", ".png", ".jpg", ".jpeg", ".zip"}
+        else zipfile.ZIP_DEFLATED
+    )