implemented the memcache protocol

vaurien/handlers/dummy.py

@@ -6,6 +6,8 @@
 
 RE_LEN = re.compile('Content-Length: (\d+)', re.M | re.I)
 RE_KEEPALIVE = re.compile('Connection: Keep-Alive')
+RE_MEMCACHE_COMMAND = re.compile('(.*)\r\n')
+
 EOH = '\r\n\r\n'
 
 
@@ -36,6 +38,70 @@ class Dummy(BaseHandler):
                'buffer': ("Buffer size", int, 2048),
                'protocol': ("Protocol used", str, 'unknown')}
 
+    def _memcache(self, client_sock, backend_sock, to_backend):
+        buffer_size = self.option('buffer')
+
+        # Sending the query
+        buffer = self._get_data(client_sock, backend_sock, to_backend)
+        if not buffer:
+            if not to_backend:
+                # We want to close the socket if the backend sock is empty
+                if not self.option('reuse_socket'):
+                    backend_sock.close()
+                    backend_sock._closed = True
+            return
+
+        # sending the first packet
+        dest = to_backend and backend_sock or client_sock
+        source = to_backend and client_sock or backend_sock
+        dest.sendall(buffer)
+
+        # finding the command sent.
+        cmd = RE_MEMCACHE_COMMAND.search(buffer)
+
+        if cmd is None:
+            # wat ?
+            if not to_backend:
+                # We want to close the socket if the backend sock is empty
+                if not self.option('reuse_socket'):
+                    backend_sock.close()
+                    backend_sock._closed = True
+            return
+
+        # looking at the command
+        cmd = cmd.groups()[0]
+
+        if cmd in ('set', 'add', 'replace', 'append'):
+            cmd_size = len(cmd) + len('\r\n')
+            data_size = int(cmd.split()[-1])
+            total_size = cmd_size + data_size
+
+            # grabbing more data if needed
+            left_to_read = total_size - len(buffer)
+            if left_to_read > 0:
+                for chunk in chunked(left_to_read, buffer_size):
+                    data = source.recv(chunk)
+                    buffer += data
+                    dest.sendall(data)
+
+        # Receiving the response now
+        buffer = dest.recv(buffer_size)
+        source.sendall(buffer)
+
+        if buffer.startswith('VALUE'):
+            # we're getting back a value.
+            EOW = 'END\r\n'
+        else:
+            EOW = '\r\n'
+
+        while not buffer.endswith(EOW):
+            data = dest.recv(buffer_size)
+            buffer += data
+            source.sendall(data)
+
+        # we're done
+        return True    # keeping connected
+
     def _http(self, client_sock, backend_sock, to_backend):
         buffer_size = self.option('buffer')
 
@@ -100,7 +166,8 @@ def _http(self, client_sock, backend_sock, to_backend):
     def __call__(self, client_sock, backend_sock, to_backend):
         if self.option('protocol') == 'http':
             return self._http(client_sock, backend_sock, to_backend)
-
+        elif self.option('protocol') == 'memcache':
+            return self._memcache(client_sock, backend_sock, to_backend)
 
         data = self._get_data(client_sock, backend_sock, to_backend)
         if data: