http: Steal download helper from Stream extension

mopidy/internal/http.py

@@ -1,9 +1,14 @@
 from __future__ import absolute_import, unicode_literals
 
+import logging
+import time
+
 import requests
 
 from mopidy import httpclient
 
+logger = logging.getLogger(__name__)
+
 
 def get_requests_session(proxy_config, user_agent):
     proxy = httpclient.format_proxy(proxy_config)
@@ -14,3 +19,30 @@ def get_requests_session(proxy_config, user_agent):
     session.headers.update({'user-agent': full_user_agent})
 
     return session
+
+
+def download(session, uri, timeout=1.0, chunk_size=4096):
+    try:
+        response = session.get(uri, stream=True, timeout=timeout)
+    except requests.exceptions.Timeout:
+        logger.warning('Download of %r failed due to connection timeout after '
+                       '%.3fs', uri, timeout)
+        return None
+    except requests.exceptions.InvalidSchema:
+        logger.warning('%s has an unsupported schema.', uri)
+        return None
+
+    content = []
+    deadline = time.time() + timeout
+    for chunk in response.iter_content(chunk_size):
+        content.append(chunk)
+        if time.time() > deadline:
+            logger.warning('Download of %r failed due to download taking more '
+                           'than %.3fs', uri, timeout)
+            return None
+
+    if not response.ok:
+        logger.warning('Problem downloading %r: %s', uri, response.reason)
+        return None
+
+    return b''.join(content)