Start to cache actor icon

utils/img.py

@@ -0,0 +1,52 @@
+import base64
+from gzip import GzipFile
+from io import BytesIO
+from typing import Any
+
+import gridfs
+import requests
+from PIL import Image
+
+
+def load(url):
+    """Initializes a `PIL.Image` from the URL."""
+    # TODO(tsileo): user agent
+    resp = requests.get(url, stream=True)
+    resp.raise_for_status()
+    try:
+        image = Image.open(BytesIO(resp.raw.read()))
+    finally:
+        resp.close()
+    return image
+
+
+def to_data_uri(img):
+    out = BytesIO()
+    img.save(out, format=img.format)
+    out.seek(0)
+    data = base64.b64encode(out.read()).decode("utf-8")
+    return f"data:{img.get_format_mimetype()};base64,{data}"
+
+
+class ImageCache(object):
+    def __init__(self, gridfs_db: str) -> None:
+        self.fs = gridfs.GridFS(gridfs_db)
+
+    def cache_actor_icon(self, url: str):
+        if self.fs.find_one({"url": url}):
+            return
+        i = load(url)
+        for size in [50, 80]:
+            t1 = i.copy()
+            t1.thumbnail((size, size))
+            with BytesIO() as buf:
+                f1 = GzipFile(mode='wb', fileobj=buf)
+                t1.save(f1, format=i.format)
+                f1.close()
+                buf.seek(0)
+                self.fs.put(
+                    buf, url=url, size=size, content_type=i.get_format_mimetype()
+                )
+
+    def get_file(self, url: str, size: int) -> Any:
+        return self.fs.find_one({"url": url, "size": size})