Stream block uploads and compress cached mouth crops

clips/blobs.py

@@ -16,11 +16,13 @@ addressing that answers questions about work not yet done.
 import hashlib
 import os
 import tempfile
+import zlib
 from pathlib import Path
 
 from django.conf import settings
 
 CHUNK = 1 << 20
+CROP_MEDIA_TYPE = "application/zlib"
 
 
 def digest_bytes(data: bytes) -> str:
@@ -86,6 +88,20 @@ def write_stream(chunks) -> tuple[str, int]:
     return digest.hexdigest(), size
 
 
+def write_compressed_stream(chunks) -> tuple[str, int]:
+    """Store a losslessly compressed stream; the digest names stored bytes."""
+    compressor = zlib.compressobj()
+
+    def compressed():
+        for chunk in chunks:
+            if part := compressor.compress(chunk):
+                yield part
+        if part := compressor.flush():
+            yield part
+
+    return write_stream(compressed())
+
+
 def adopt(source: Path) -> tuple[str, int]:
     """Store a file already on disk, by hard link where the filesystem allows it.