Support large downloads in send_file (fixes #3)

microdot-asyncio/microdot_asyncio.py

@@ -59,7 +59,17 @@ class Response(BaseResponse):
 
         # body
         if self.body:
-            await stream.awrite(self.body)
+            if hasattr(self.body, 'read'):
+                while True:
+                    buf = self.body.read(self.send_file_buffer_size)
+                    if len(buf):
+                        await stream.awrite(buf)
+                    if len(buf) < self.send_file_buffer_size:
+                        break
+                if hasattr(self.body, 'close'):
+                    self.body.close()
+            else:
+                await stream.awrite(self.body)
 
 
 class Microdot(BaseMicrodot):

microdot/microdot.py

@@ -154,6 +154,7 @@ class Response():
         'png': 'image/png',
         'txt': 'text/plain',
     }
+    send_file_buffer_size = 1024
 
     def __init__(self, body='', status_code=200, headers=None):
         self.status_code = status_code
@@ -163,10 +164,9 @@ class Response():
             self.headers['Content-Type'] = 'application/json'
         elif isinstance(body, str):
             self.body = body.encode()
-        elif isinstance(body, bytes):
-            self.body = body
         else:
-            self.body = str(body).encode()
+            # this applies to bytes or file-like objects
+            self.body = body
 
     def set_cookie(self, cookie, value, path=None, domain=None, expires=None,
                    max_age=None, secure=False, http_only=False):
@@ -190,7 +190,8 @@ class Response():
             self.headers['Set-Cookie'] = [http_cookie]
 
     def complete(self):
-        if 'Content-Length' not in self.headers:
+        if isinstance(self.body, bytes) and \
+                'Content-Length' not in self.headers:
             self.headers['Content-Length'] = str(len(self.body))
         if 'Content-Type' not in self.headers:
             self.headers['Content-Type'] = 'text/plain'
@@ -213,7 +214,17 @@ class Response():
 
         # body
         if self.body:
-            stream.write(self.body)
+            if hasattr(self.body, 'read'):
+                while True:
+                    buf = self.body.read(self.send_file_buffer_size)
+                    if len(buf):
+                        stream.write(buf)
+                    if len(buf) < self.send_file_buffer_size:
+                        break
+                if hasattr(self.body, 'close'):
+                    self.body.close()
+            else:
+                stream.write(self.body)
 
     @classmethod
     def redirect(cls, location, status_code=302):
@@ -227,11 +238,9 @@ class Response():
                 content_type = Response.types_map[ext]
             else:
                 content_type = 'application/octet-stream'
-        with open(filename) as f:
-            body = f.read()
-            return cls(body=body, status_code=status_code,
-                       headers={'Content-Type': content_type,
-                                'Content-Length': str(len(body))})
+        f = open(filename, 'rb')
+        return cls(body=f, status_code=status_code,
+                   headers={'Content-Type': content_type})
 
 
 class URLPattern():

tests/microdot/test_response.py

@@ -92,7 +92,7 @@ class TestResponse(unittest.TestCase):
         res = Response(123)
         self.assertEqual(res.status_code, 200)
         self.assertEqual(res.headers, {})
-        self.assertEqual(res.body, b'123')
+        self.assertEqual(res.body, 123)
 
     def test_create_with_status_code(self):
         res = Response('not found', 404)
@@ -161,11 +161,9 @@ class TestResponse(unittest.TestCase):
             res = Response.send_file('tests/files/' + file)
             self.assertEqual(res.status_code, 200)
             self.assertEqual(res.headers['Content-Type'], content_type)
-            self.assertEqual(res.headers['Content-Length'], '4')
-            self.assertEqual(res.body, b'foo\n')
+            self.assertEqual(res.body.read(), b'foo\n')
         res = Response.send_file('tests/files/test.txt',
                                  content_type='text/html')
         self.assertEqual(res.status_code, 200)
         self.assertEqual(res.headers['Content-Type'], 'text/html')
-        self.assertEqual(res.headers['Content-Length'], '4')
-        self.assertEqual(res.body, b'foo\n')
+        self.assertEqual(res.body.read(), b'foo\n')