1 files changed, 391 insertions, 0 deletions

diff --git a/bitbake/lib/bb/asyncrpc/serv.py b/bitbake/lib/bb/asyncrpc/serv.py
new file mode 100644
index 0000000000..a66117acad
--- /dev/null
+++ b/bitbake/lib/bb/asyncrpc/serv.py
@@ -0,0 +1,391 @@
+#
+# Copyright BitBake Contributors
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
+import abc
+import asyncio
+import json
+import os
+import signal
+import socket
+import sys
+import multiprocessing
+import logging
+from .connection import StreamConnection, WebsocketConnection
+from .exceptions import ClientError, ServerError, ConnectionClosedError, InvokeError
+
+
+class ClientLoggerAdapter(logging.LoggerAdapter):
+    def process(self, msg, kwargs):
+        return f"[Client {self.extra['address']}] {msg}", kwargs
+
+
+class AsyncServerConnection(object):
+    # If a handler returns this object (e.g. `return self.NO_RESPONSE`), no
+    # return message will be automatically be sent back to the client
+    NO_RESPONSE = object()
+
+    def __init__(self, socket, proto_name, logger):
+        self.socket = socket
+        self.proto_name = proto_name
+        self.handlers = {
+            "ping": self.handle_ping,
+        }
+        self.logger = ClientLoggerAdapter(
+            logger,
+            {
+                "address": socket.address,
+            },
+        )
+        self.client_headers = {}
+
+    async def close(self):
+        await self.socket.close()
+
+    async def handle_headers(self, headers):
+        return {}
+
+    async def process_requests(self):
+        try:
+            self.logger.info("Client %r connected" % (self.socket.address,))
+
+            # Read protocol and version
+            client_protocol = await self.socket.recv()
+            if not client_protocol:
+                return
+
+            (client_proto_name, client_proto_version) = client_protocol.split()
+            if client_proto_name != self.proto_name:
+                self.logger.debug("Rejecting invalid protocol %s" % (self.proto_name))
+                return
+
+            self.proto_version = tuple(int(v) for v in client_proto_version.split("."))
+            if not self.validate_proto_version():
+                self.logger.debug(
+                    "Rejecting invalid protocol version %s" % (client_proto_version)
+                )
+                return
+
+            # Read headers
+            self.client_headers = {}
+            while True:
+                header = await self.socket.recv()
+                if not header:
+                    # Empty line. End of headers
+                    break
+                tag, value = header.split(":", 1)
+                self.client_headers[tag.lower()] = value.strip()
+
+            if self.client_headers.get("needs-headers", "false") == "true":
+                for k, v in (await self.handle_headers(self.client_headers)).items():
+                    await self.socket.send("%s: %s" % (k, v))
+                await self.socket.send("")
+
+            # Handle messages
+            while True:
+                d = await self.socket.recv_message()
+                if d is None:
+                    break
+                try:
+                    response = await self.dispatch_message(d)
+                except InvokeError as e:
+                    await self.socket.send_message(
+                        {"invoke-error": {"message": str(e)}}
+                    )
+                    break
+
+                if response is not self.NO_RESPONSE:
+                    await self.socket.send_message(response)
+
+        except ConnectionClosedError as e:
+            self.logger.info(str(e))
+        except (ClientError, ConnectionError) as e:
+            self.logger.error(str(e))
+        finally:
+            await self.close()
+
+    async def dispatch_message(self, msg):
+        for k in self.handlers.keys():
+            if k in msg:
+                self.logger.debug("Handling %s" % k)
+                return await self.handlers[k](msg[k])
+
+        raise ClientError("Unrecognized command %r" % msg)
+
+    async def handle_ping(self, request):
+        return {"alive": True}
+
+
+class StreamServer(object):
+    def __init__(self, handler, logger):
+        self.handler = handler
+        self.logger = logger
+        self.closed = False
+
+    async def handle_stream_client(self, reader, writer):
+        # writer.transport.set_write_buffer_limits(0)
+        socket = StreamConnection(reader, writer, -1)
+        if self.closed:
+            await socket.close()
+            return
+
+        await self.handler(socket)
+
+    async def stop(self):
+        self.closed = True
+
+
+class TCPStreamServer(StreamServer):
+    def __init__(self, host, port, handler, logger):
+        super().__init__(handler, logger)
+        self.host = host
+        self.port = port
+
+    def start(self, loop):
+        self.server = loop.run_until_complete(
+            asyncio.start_server(self.handle_stream_client, self.host, self.port)
+        )
+
+        for s in self.server.sockets:
+            self.logger.debug("Listening on %r" % (s.getsockname(),))
+            # Newer python does this automatically. Do it manually here for
+            # maximum compatibility
+            s.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
+            s.setsockopt(socket.SOL_TCP, socket.TCP_QUICKACK, 1)
+
+            # 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 = "[%s]:%d" % (name[0], name[1])
+        else:
+            self.address = "%s:%d" % (name[0], name[1])
+
+        return [self.server.wait_closed()]
+
+    async def stop(self):
+        await super().stop()
+        self.server.close()
+
+    def cleanup(self):
+        pass
+
+
+class UnixStreamServer(StreamServer):
+    def __init__(self, path, handler, logger):
+        super().__init__(handler, logger)
+        self.path = path
+
+    def start(self, loop):
+        cwd = os.getcwd()
+        try:
+            # Work around path length limits in AF_UNIX
+            os.chdir(os.path.dirname(self.path))
+            self.server = loop.run_until_complete(
+                asyncio.start_unix_server(
+                    self.handle_stream_client, os.path.basename(self.path)
+                )
+            )
+        finally:
+            os.chdir(cwd)
+
+        self.logger.debug("Listening on %r" % self.path)
+        self.address = "unix://%s" % os.path.abspath(self.path)
+        return [self.server.wait_closed()]
+
+    async def stop(self):
+        await super().stop()
+        self.server.close()
+
+    def cleanup(self):
+        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
+        self.loop = None
+        self.run_tasks = []
+
+    def start_tcp_server(self, host, port):
+        self.server = TCPStreamServer(host, port, self._client_handler, self.logger)
+
+    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):
+        address = socket.address
+        try:
+            client = self.accept_client(socket)
+            await client.process_requests()
+        except Exception as e:
+            import traceback
+
+            self.logger.error(
+                "Error from client %s: %s" % (address, str(e)), exc_info=True
+            )
+            traceback.print_exc()
+        finally:
+            self.logger.debug("Client %s disconnected", address)
+            await socket.close()
+
+    @abc.abstractmethod
+    def accept_client(self, socket):
+        pass
+
+    async def stop(self):
+        self.logger.debug("Stopping server")
+        await self.server.stop()
+
+    def start(self):
+        tasks = self.server.start(self.loop)
+        self.address = self.server.address
+        return tasks
+
+    def signal_handler(self):
+        self.logger.debug("Got exit signal")
+        self.loop.create_task(self.stop())
+
+    def _serve_forever(self, tasks):
+        try:
+            self.loop.add_signal_handler(signal.SIGTERM, self.signal_handler)
+            self.loop.add_signal_handler(signal.SIGINT, self.signal_handler)
+            self.loop.add_signal_handler(signal.SIGQUIT, self.signal_handler)
+            signal.pthread_sigmask(signal.SIG_UNBLOCK, [signal.SIGTERM])
+
+            self.loop.run_until_complete(asyncio.gather(*tasks))
+
+            self.logger.debug("Server shutting down")
+        finally:
+            self.server.cleanup()
+
+    def serve_forever(self):
+        """
+        Serve requests in the current process
+        """
+        self._create_loop()
+        tasks = self.start()
+        self._serve_forever(tasks)
+        self.loop.close()
+
+    def _create_loop(self):
+        # Create loop and override any loop that may have existed in
+        # a parent process.  It is possible that the usecases of
+        # serve_forever might be constrained enough to allow using
+        # get_event_loop here, but better safe than sorry for now.
+        self.loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(self.loop)
+
+    def serve_as_process(self, *, prefunc=None, args=(), log_level=None):
+        """
+        Serve requests in a child process
+        """
+
+        def run(queue):
+            # Create loop and override any loop that may have existed
+            # in a parent process.  Without doing this and instead
+            # using get_event_loop, at the very minimum the hashserv
+            # unit tests will hang when running the second test.
+            # This happens since get_event_loop in the spawned server
+            # process for the second testcase ends up with the loop
+            # from the hashserv client created in the unit test process
+            # when running the first testcase.  The problem is somewhat
+            # more general, though, as any potential use of asyncio in
+            # Cooker could create a loop that needs to replaced in this
+            # new process.
+            self._create_loop()
+            try:
+                self.address = None
+                tasks = self.start()
+            finally:
+                # Always put the server address to wake up the parent task
+                queue.put(self.address)
+                queue.close()
+
+            if prefunc is not None:
+                prefunc(self, *args)
+
+            if log_level is not None:
+                self.logger.setLevel(log_level)
+
+            self._serve_forever(tasks)
+
+            if sys.version_info >= (3, 6):
+                self.loop.run_until_complete(self.loop.shutdown_asyncgens())
+            self.loop.close()
+
+        queue = multiprocessing.Queue()
+
+        # Temporarily block SIGTERM. The server process will inherit this
+        # block which will ensure it doesn't receive the SIGTERM until the
+        # handler is ready for it
+        mask = signal.pthread_sigmask(signal.SIG_BLOCK, [signal.SIGTERM])
+        try:
+            self.process = multiprocessing.Process(target=run, args=(queue,))
+            self.process.start()
+
+            self.address = queue.get()
+            queue.close()
+            queue.join_thread()
+
+            return self.process
+        finally:
+            signal.pthread_sigmask(signal.SIG_SETMASK, mask)