From 498a871c7008efa25c26df3792e6691f1cc812c6 Mon Sep 17 00:00:00 2001
From: Jake Howard <git@theorangeone.net>
Date: Fri, 7 Dec 2018 20:35:34 +0000
Subject: [PATCH] Add basic client-server implementation

---
 ipc_unix/client.py   | 10 ++++++++++
 ipc_unix/server.py   | 40 ++++++++++++++++++++++++++++++++++++++++
 ipc_unix/utils.py    | 11 +++++++++++
 tests/__init__.py    | 14 ++++++++++++++
 tests/test_server.py | 40 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 115 insertions(+)
 create mode 100644 ipc_unix/client.py
 create mode 100644 ipc_unix/server.py
 create mode 100644 ipc_unix/utils.py
 create mode 100644 tests/__init__.py
 create mode 100644 tests/test_server.py

diff --git a/ipc_unix/client.py b/ipc_unix/client.py
new file mode 100644
index 0000000..8325380
--- /dev/null
+++ b/ipc_unix/client.py
@@ -0,0 +1,10 @@
+import socket
+from ipc_unix.utils import read_payload
+import ujson
+
+
+def send_to(socket_path, data):
+    with socket.socket(socket.AF_UNIX, type=socket.SOCK_STREAM) as sock:
+        sock.connect(socket_path)
+        sock.sendall(ujson.dumps(data).encode() + b"\n")
+        return read_payload(sock)
diff --git a/ipc_unix/server.py b/ipc_unix/server.py
new file mode 100644
index 0000000..55807e9
--- /dev/null
+++ b/ipc_unix/server.py
@@ -0,0 +1,40 @@
+import socketserver
+import threading
+import ujson
+from ipc_unix.utils import read_payload
+
+
+class RequestHandler(socketserver.BaseRequestHandler):
+    def handle_request(self, request):
+        raise NotImplementedError("Failed to override `handle_request`")
+
+    def handle(self):
+        data = read_payload(self.request)
+        response = self.handle_request(data)
+        self.request.sendall(ujson.dumps(response).encode())
+
+
+class Server:
+    def __init__(self, socket_path):
+        class InstanceRequestHandler(RequestHandler):
+            handle_request = self.handle_request
+
+        self.server = socketserver.UnixStreamServer(socket_path, InstanceRequestHandler)
+
+    def serve_forever(self):
+        self.server.serve_forever()
+
+    def serve_in_thread(self):
+        thread = threading.Thread(target=self.serve_forever)
+        thread.start()
+        return thread
+
+    def shutdown(self):
+        self.server.shutdown()
+
+    def close(self):
+        self.shutdown()
+        self.server.server_close()
+
+    def handle_request(self, request):
+        raise NotImplementedError("Must override `handle_request`")
diff --git a/ipc_unix/utils.py b/ipc_unix/utils.py
new file mode 100644
index 0000000..6ba2124
--- /dev/null
+++ b/ipc_unix/utils.py
@@ -0,0 +1,11 @@
+import ujson
+
+
+def read_payload(payload):
+    data = b""
+    while b"\n" not in data:
+        message = payload.recv(4096)
+        if message == b"":
+            break
+        data += message
+    return ujson.loads(data)
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..9f60e21
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1,14 @@
+from ipc_unix import server
+import tempfile
+import os
+
+
+class EchoServer(server.Server):
+    def handle_request(self, request):
+        return request
+
+
+def get_random_path():
+    _, temp_file_path = tempfile.mkstemp()
+    os.remove(temp_file_path)
+    return temp_file_path
diff --git a/tests/test_server.py b/tests/test_server.py
new file mode 100644
index 0000000..c1882a6
--- /dev/null
+++ b/tests/test_server.py
@@ -0,0 +1,40 @@
+from unittest import TestCase
+from tests import EchoServer, get_random_path
+from ipc_unix import client
+from functools import partial
+
+
+class BasicServerTestCase(TestCase):
+    def setUp(self):
+        self.socket_path = get_random_path()
+        self.server = EchoServer(self.socket_path)
+        self.server.serve_in_thread()
+        self.send_to_client = partial(client.send_to, self.socket_path)
+
+    def tearDown(self):
+        self.server.shutdown()
+
+    def test_sending_dict(self):
+        data = {"foo": "bar"}
+        response = self.send_to_client(data)
+        self.assertEqual(response, data)
+
+    def test_sending_array(self):
+        data = ["foo", "bar"]
+        response = self.send_to_client(data)
+        self.assertEqual(response, data)
+
+    def test_sending_full_buffer(self):
+        data = ["foo"] * 4096  # Pad out the buffer
+        response = self.send_to_client(data)
+        self.assertEqual(response, data)
+
+    def test_sending_empty_payload(self):
+        response = self.send_to_client("")
+        self.assertEqual(response, "")
+
+    def test_multiple_send_to_same_server(self):
+        data = {"foo": "bar"}
+        for _ in range(10):
+            response = self.send_to_client(data)
+            self.assertEqual(response, data)