Add video upload, extraction progress, and reusable analysis sources

clips/blobs.py

@@ -15,6 +15,7 @@ addressing that answers questions about work not yet done.
 """
 import hashlib
 import os
+import tempfile
 from pathlib import Path
 
 from django.conf import settings
@@ -60,6 +61,31 @@ def write(data: bytes) -> tuple[str, int]:
     return digest, len(data)
 
 
+def write_stream(chunks) -> tuple[str, int]:
+    """Store an uploaded file without reading the whole video into memory."""
+    root = Path(settings.BLOB_ROOT)
+    root.mkdir(parents=True, exist_ok=True)
+    digest = hashlib.sha256()
+    size = 0
+    with tempfile.NamedTemporaryFile(dir=root, prefix="upload-", delete=False) as out:
+        temporary = Path(out.name)
+        try:
+            for chunk in chunks:
+                digest.update(chunk)
+                size += len(chunk)
+                out.write(chunk)
+        except BaseException:
+            temporary.unlink(missing_ok=True)
+            raise
+    dest = path_for(digest.hexdigest())
+    dest.parent.mkdir(parents=True, exist_ok=True)
+    if dest.exists():
+        temporary.unlink()
+    else:
+        os.replace(temporary, dest)
+    return digest.hexdigest(), size
+
+
 def adopt(source: Path) -> tuple[str, int]:
     """Store a file already on disk, by hard link where the filesystem allows it.