feat: add TCP client and server

src/comms/TcpClient.py

@@ -0,0 +1,29 @@
+from typing import Optional
+import asyncio
+import re
+
+from .StreamConnection import StreamConnection
+from .StreamClient import StreamClient
+
+TCP_URL_REGEX = re.compile(r'^tcp://([^:/]+)(?:\:(\d+))?')
+
+class TcpClient(StreamClient):
+
+    def __init__(self, url: str = 'tcp://127.0.0.1', encoders=None):
+        StreamClient.__init__(self, encoders=encoders)
+        match = TCP_URL_REGEX.match(url)
+        if match:
+            self._url = url
+            self._host = match.group(1)
+            self._port = int(match.group(2)) if match.group(2) else 2000
+        else:
+            raise RuntimeError(f'Invalid URL for TCP: {url}')
+
+    @property
+    def url(self):
+        return self._url
+
+    async def open(self) -> None:
+        reader, writer = await asyncio.open_connection(self._host, self._port)
+        self.connection = StreamConnection(reader, writer)
+        await StreamClient.open(self)

src/comms/TcpServer.py

@@ -0,0 +1,18 @@
+import asyncio
+
+from ..Processor import Processor
+from .StreamMultiServer import StreamMultiServer
+
+class TcpServer(StreamMultiServer):
+
+    def __init__(self, processor: Processor, host: str = '127.0.0.1', port: int = 2000, encoders=None):
+        StreamMultiServer.__init__(self, processor, encoders)
+        self.host = host
+        self.port = port
+
+    @property
+    def url(self):
+        return f'tcp://{self.host}:{self.port}'
+
+    async def open(self) -> None:
+        await asyncio.start_server(self.on_client_connected, self.host, self.port)

tests/comms/TcpClientServerTest.py

@@ -0,0 +1,37 @@
+import pytest
+
+from stencilaschema.comms.JsonEncoder import JsonEncoder
+from stencilaschema.comms.JsonGzipBase64Encoder import JsonGzipBase64Encoder
+from stencilaschema.comms.TcpClient import TcpClient
+from stencilaschema.comms.TcpServer import TcpServer
+
+from helpers.TestProcessor import TestProcessor
+
+@pytest.mark.asyncio
+async def test_client_server():
+    # Create test processor
+    processor = TestProcessor()
+
+    # Start the server and several clients
+    server = TcpServer(processor, encoders=[JsonEncoder(), JsonGzipBase64Encoder()])
+    await server.start()
+    client1 = TcpClient(server.url)
+    await client1.start()
+    client2 = TcpClient(server.url, encoders=[JsonGzipBase64Encoder(), JsonEncoder()])
+    await client2.start()
+    client3 = TcpClient(server.url, encoders=[JsonGzipBase64Encoder()])
+    await client3.start()
+
+    thing1 = {'type': 'Thing', 'name': 'thing1'}
+    thing2 = {'type': 'Thing', 'name': 'thing2'}
+    thing3 = {'type': 'Thing', 'name': 'thing3'}
+
+    assert await client1.execute(thing1) == thing1
+    assert await client2.execute(thing2) == thing2
+    assert await client3.execute(thing3) == thing3
+
+    # Stop everything
+    await client1.stop()
+    await client2.stop()
+    await client3.stop()
+    await server.stop()