bitbake: hashserv: Add websocket connection implementation

Adds support to the hash equivalence client and server to communicate
over websockets. Since websockets are message orientated instead of
stream orientated, and new connection class is needed to handle them.

Note that websocket support does require the 3rd party websockets python
module be installed on the host, but it should not be required unless
websockets are actually being used.

(Bitbake rev: 56dd2fdbfb6350a9eef43a12aa529c8637887a7e)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/asyncrpc/client.py

@@ -10,7 +10,7 @@ import json
 import os
 import socket
 import sys
-from .connection import StreamConnection, DEFAULT_MAX_CHUNK
+from .connection import StreamConnection, WebsocketConnection, DEFAULT_MAX_CHUNK
 from .exceptions import ConnectionClosedError
 
 
@@ -47,6 +47,15 @@ class AsyncClient(object):
 
         self._connect_sock = connect_sock
 
+    async def connect_websocket(self, uri):
+        import websockets
+
+        async def connect_sock():
+            websocket = await websockets.connect(uri, ping_interval=None)
+            return WebsocketConnection(websocket, self.timeout)
+
+        self._connect_sock = connect_sock
+
     async def setup_connection(self):
         # Send headers
         await self.socket.send("%s %s" % (self.proto_name, self.proto_version))

bitbake/lib/bb/asyncrpc/connection.py

@@ -93,3 +93,47 @@ class StreamConnection(object):
         if self.writer is not None:
             self.writer.close()
             self.writer = None
+
+
+class WebsocketConnection(object):
+    def __init__(self, socket, timeout):
+        self.socket = socket
+        self.timeout = timeout
+
+    @property
+    def address(self):
+        return ":".join(str(s) for s in self.socket.remote_address)
+
+    async def send_message(self, msg):
+        await self.send(json.dumps(msg))
+
+    async def recv_message(self):
+        m = await self.recv()
+        return json.loads(m)
+
+    async def send(self, msg):
+        import websockets.exceptions
+
+        try:
+            await self.socket.send(msg)
+        except websockets.exceptions.ConnectionClosed:
+            raise ConnectionClosedError("Connection closed")
+
+    async def recv(self):
+        import websockets.exceptions
+
+        try:
+            if self.timeout < 0:
+                return await self.socket.recv()
+
+            try:
+                return await asyncio.wait_for(self.socket.recv(), self.timeout)
+            except asyncio.TimeoutError:
+                raise ConnectionError("Timed out waiting for data")
+        except websockets.exceptions.ConnectionClosed:
+            raise ConnectionClosedError("Connection closed")
+
+    async def close(self):
+        if self.socket is not None:
+            await self.socket.close()
+            self.socket = None

bitbake/lib/bb/asyncrpc/serv.py

@@ -12,7 +12,7 @@ import signal
 import socket
 import sys
 import multiprocessing
-from .connection import StreamConnection
+from .connection import StreamConnection, WebsocketConnection
 from .exceptions import ClientError, ServerError, ConnectionClosedError
 
 
@@ -178,6 +178,54 @@ class UnixStreamServer(StreamServer):
         os.unlink(self.path)
 
 
+class WebsocketsServer(object):
+    def __init__(self, host, port, handler, logger):
+        self.host = host
+        self.port = port
+        self.handler = handler
+        self.logger = logger
+
+    def start(self, loop):
+        import websockets.server
+
+        self.server = loop.run_until_complete(
+            websockets.server.serve(
+                self.client_handler,
+                self.host,
+                self.port,
+                ping_interval=None,
+            )
+        )
+
+        for s in self.server.sockets:
+            self.logger.debug("Listening on %r" % (s.getsockname(),))
+
+            # Enable keep alives. This prevents broken client connections
+            # from persisting on the server for long periods of time.
+            s.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
+            s.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, 30)
+            s.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, 15)
+            s.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, 4)
+
+        name = self.server.sockets[0].getsockname()
+        if self.server.sockets[0].family == socket.AF_INET6:
+            self.address = "ws://[%s]:%d" % (name[0], name[1])
+        else:
+            self.address = "ws://%s:%d" % (name[0], name[1])
+
+        return [self.server.wait_closed()]
+
+    async def stop(self):
+        self.server.close()
+
+    def cleanup(self):
+        pass
+
+    async def client_handler(self, websocket):
+        socket = WebsocketConnection(websocket, -1)
+        await self.handler(socket)
+
+
 class AsyncServer(object):
     def __init__(self, logger):
         self.logger = logger
@@ -190,6 +238,9 @@ class AsyncServer(object):
     def start_unix_server(self, path):
         self.server = UnixStreamServer(path, self._client_handler, self.logger)
 
+    def start_websocket_server(self, host, port):
+        self.server = WebsocketsServer(host, port, self._client_handler, self.logger)
+
     async def _client_handler(self, socket):
         try:
             client = self.accept_client(socket)