1 files changed, 93 insertions, 0 deletions
diff --git a/python/lib/yamlrpc.py b/python/lib/yamlrpc.py
new file mode 100644
index 0000000..bd61569
--- /dev/null
+++ b/python/lib/yamlrpc.py
@@ -0,0 +1,93 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+#   Copyright (C) 2018
+#   Matthias P. Braendli, matthias.braendli@mpb.li
+#
+#    http://www.opendigitalradio.org
+#
+#   This file is part of ODR-DabMod.
+#
+#   ODR-DabMod is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as
+#   published by the Free Software Foundation, either version 3 of the
+#   License, or (at your option) any later version.
+#
+#   ODR-DabMod is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with ODR-DabMod.  If not, see <http://www.gnu.org/licenses/>.
+
+"""yamlrpc is json-rpc, except that it's yaml and not json."""
+
+# Same as jsonrpc version we're aiming to mirror in YAML
+YAMLRPC_VERSION = "2.0"
+
+import yaml
+import socket
+import struct
+
+def request(request_id: int, method: str, params) -> bytes:
+    r = {
+            'yamlrpc': YAMLRPC_VERSION,
+            'method': method,
+            'params': params,
+            'id': request_id}
+    return yaml.dump(r).encode()
+
+def response_success(request_id: int, result) -> bytes:
+    r = {
+            'yamlrpc': YAMLRPC_VERSION,
+            'result': result,
+            'error': None,
+            'id': request_id}
+    return yaml.dump(r).encode()
+
+def response_error(request_id: int, error) -> bytes:
+    r = {
+            'yamlrpc': YAMLRPC_VERSION,
+            'result': None,
+            'error': error,
+            'id': request_id}
+    return yaml.dump(r).encode()
+
+def notification(method: str, params) -> bytes:
+    r = {
+            'yamlrpc': YAMLRPC_VERSION,
+            'method': method,
+            'params': params}
+    return yaml.dump(r).encode()
+
+class Socket:
+    def __init__(self, bind_port: int):
+        self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        if bind_port > 0:
+            self.socket.bind(('127.0.0.1', bind_port))
+
+    def receive_request(self):
+        data, addr = self.socket.recvfrom(512)
+        y = yaml.load(data.decode())
+
+        if 'yamlrpc' not in y:
+            raise ValueError("Message is not yamlrpc")
+        if y['yamlrpc'] != YAMLRPC_VERSION:
+            raise ValueError("Invalid yamlrpc version")
+
+        # expect a request
+        try:
+            method = y['method']
+            msg_id = y['id']
+            params = y['params']
+        except KeyError:
+            raise ValueError("Incomplete message")
+        return addr, msg_id, method, params
+
+    def send_success_response(self, addr, msg_id: int, result):
+        self.socket.sendto(response_success(msg_id, result), addr)
+
+    def send_error_response(self, addr, msg_id: int, error):
+        self.socket.sendto(response_error(msg_id, error), addr)
+