CASID: richer dataset card (paper info, usage, verification), add verify script

scripts/verify_download.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""Verify a downloaded CASID release against release_file_hashes.csv.
+
+Checks, for every row in the manifest:
+  1. the file exists
+  2. its size matches
+  3. its MD5 matches (full read)
+
+Usage:
+  python verify_download.py --root CASID-dataset [--workers 8]
+"""
+import argparse
+import csv
+import hashlib
+import os
+import sys
+from multiprocessing import Pool
+
+CHUNK = 1 << 20
+
+
+def check(task):
+    root, rel, size, md5 = task
+    path = os.path.join(root, rel)
+    if not os.path.isfile(path):
+        return rel, "MISSING"
+    if os.path.getsize(path) != int(size):
+        return rel, "SIZE_MISMATCH"
+    h = hashlib.md5()
+    try:
+        with open(path, "rb") as f:
+            for chunk in iter(lambda: f.read(CHUNK), b""):
+                h.update(chunk)
+    except OSError as e:
+        return rel, "READ_ERROR(%s)" % e
+    return rel, "OK" if h.hexdigest() == md5 else "MD5_MISMATCH"
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--root", required=True, help="downloaded dataset root")
+    ap.add_argument("--workers", type=int, default=8)
+    args = ap.parse_args()
+
+    manifest = os.path.join(args.root, "release_file_hashes.csv")
+    if not os.path.isfile(manifest):
+        sys.exit("ERROR: %s not found (download incomplete?)" % manifest)
+
+    tasks = []
+    with open(manifest) as f:
+        for row in csv.reader(f):
+            if row and row[0] != "path":
+                tasks.append((args.root, row[0], row[1], row[2]))
+    print("verifying %d files ..." % len(tasks))
+
+    n_ok = n_bad = 0
+    bad = []
+    with Pool(args.workers) as pool:
+        for rel, status in pool.imap_unordered(check, tasks, chunksize=8):
+            if status == "OK":
+                n_ok += 1
+            else:
+                n_bad += 1
+                bad.append((rel, status))
+            if (n_ok + n_bad) % 500 == 0:
+                print("  %d/%d" % (n_ok + n_bad, len(tasks)), flush=True)
+
+    print("RESULT: %d OK, %d bad (total %d)" % (n_ok, n_bad, len(tasks)))
+    for rel, status in bad[:20]:
+        print("  %s: %s" % (status, rel))
+    if n_bad:
+        sys.exit(1)
+    print("ALL FILES VERIFIED ✔")
+
+
+if __name__ == "__main__":
+    main()