Connection URL parsing

chat.py

@@ -7,19 +7,15 @@ import syndicate.mini.core as S
 Present = S.Record.makeConstructor('Present', 'who')
 Says = S.Record.makeConstructor('Says', 'who what')
 
-if len(sys.argv) == 4:
-    conn = S.TcpConnection(sys.argv[1], int(sys.argv[2]), sys.argv[3])
-elif len(sys.argv) == 3:
-    if sys.argv[1].startswith('ws:') or sys.argv[1].startswith('wss:'):
-        conn = S.WebsocketConnection(sys.argv[1], sys.argv[2])
-    else:
-        conn = S.UnixSocketConnection(sys.argv[1], sys.argv[2])
-elif len(sys.argv) == 1:
-    conn = S.WebsocketConnection('ws://localhost:8000/', 'chat')
+if len(sys.argv) == 1:
+    conn_url = 'ws://localhost:8000/#chat'
+elif len(sys.argv) == 2:
+    conn_url = sys.argv[1]
 else:
     sys.stderr.write(
-        'Usage: chat.py [ HOST PORT SCOPE | WEBSOCKETURL SCOPE | UNIXSOCKETPATH SCOPE ]\n')
+        'Usage: chat.py [ tcp://HOST[:PORT]#SCOPE | ws://HOST[:PORT]#SCOPE | unix:PATH#SCOPE ]\n')
     sys.exit(1)
+conn = S.Connection.from_url(conn_url)
 
 _print = print
 def print(*items):

ovlinfo.py

@@ -6,7 +6,7 @@ import syndicate.mini.core as S
 
 OverlayLink = S.Record.makeConstructor('OverlayLink', 'downNode upNode')
 
-conn = S.WebsocketConnection(sys.argv[1], sys.argv[2])
+conn = S.Connection.from_url(sys.argv[1])
 
 uplinks = {}
 def add_uplink(turn, src, tgt):

setup.py

@@ -5,7 +5,7 @@ except ImportError:
 
 setup(
     name="mini-syndicate",
-    version="0.0.1",
+    version="0.0.2",
     author="Tony Garnock-Jones",
     author_email="tonyg@leastfixedpoint.com",
     license="GNU General Public License v3 or later (GPLv3+)",

syndicate/mini/core.py

@@ -2,10 +2,13 @@ import asyncio
 import secrets
 import logging
 import websockets
+import re
+from urllib.parse import urlparse, urlunparse
 
 log = logging.getLogger(__name__)
 
 import syndicate.mini.protocol as protocol
+import syndicate.mini.url as url
 
 from syndicate.mini.protocol import Capture, Discard, Observe
 CAPTURE = Capture(Discard())
@@ -203,6 +206,10 @@ class Connection(object):
     def _disconnect(self):
         raise Exception('subclassresponsibility')
 
+    @classmethod
+    def from_url(cls, s):
+        return url.connection_from_url(s)
+
 class _StreamConnection(Connection, asyncio.Protocol):
     def __init__(self, scope):
         super().__init__(scope)
@@ -260,6 +267,7 @@ class _StreamConnection(Connection, asyncio.Protocol):
             self.stop_signal = None
             self.decoder = None
 
+@url.schema('tcp')
 class TcpConnection(_StreamConnection):
     def __init__(self, host, port, scope):
         super().__init__(scope)
@@ -269,6 +277,19 @@ class TcpConnection(_StreamConnection):
     async def _create_connection(self, loop):
         return await loop.create_connection(lambda: self, self.host, self.port)
 
+    @classmethod
+    def default_port(cls):
+        return 21369
+
+    @classmethod
+    def from_url(cls, s):
+        u = urlparse(s)
+        host, port = url._hostport(u.netloc, cls.default_port())
+        if not host: return
+        scope = u.fragment
+        return cls(host, port, scope)
+
+@url.schema('unix')
 class UnixSocketConnection(_StreamConnection):
     def __init__(self, path, scope):
         super().__init__(scope)
@@ -277,6 +298,13 @@ class UnixSocketConnection(_StreamConnection):
     async def _create_connection(self, loop):
         return await loop.create_unix_connection(lambda: self, self.path)
 
+    @classmethod
+    def from_url(cls, s):
+        u = urlparse(s)
+        return cls(u.path, u.fragment)
+
+@url.schema('ws')
+@url.schema('wss')
 class WebsocketConnection(Connection):
     def __init__(self, url, scope):
         super().__init__(scope)
@@ -328,3 +356,8 @@ class WebsocketConnection(Connection):
         self.loop = None
         self.ws = None
         return True
+
+    @classmethod
+    def from_url(cls, s):
+        u = urlparse(s)
+        return cls(urlunparse(u._replace(fragment='')), u.fragment)

syndicate/mini/url.py

@@ -0,0 +1,33 @@
+# URLs denoting Syndicate servers.
+
+class InvalidSyndicateUrl(ValueError): pass
+
+schemas = {}
+
+def schema(schema_name):
+    def k(factory_class):
+        schemas[schema_name] = factory_class
+        return factory_class
+    return k
+
+def _bad_url(u):
+    raise InvalidSyndicateUrl('Invalid Syndicate server URL', u)
+
+def connection_from_url(u):
+    pieces = u.split(':', 1)
+    if len(pieces) != 2: _bad_url(u)
+    schema_name, _rest = pieces
+    if schema_name not in schemas: _bad_url(u)
+    conn = schemas[schema_name].from_url(u)
+    if not conn: _bad_url(u)
+    return conn
+
+def _hostport(s, default_port):
+    try:
+        i = s.rindex(':')
+    except ValueError:
+        i = None
+    if i is not None:
+        return (s[:i], int(s[i+1:]))
+    else:
+        return (s, default_port)