Add output rate limiting

docs/setup/initial_config.rst

@@ -40,7 +40,11 @@ Instance Configuration
             ],
             "force_ipv6": false,
             "force_ipv4": false,
-            "bind": ["1.2.3.4", 5678]
+            "bind": ["1.2.3.4", 5678],
+            "rate_limit": {
+                "rate_max": 5.0,
+                "rate_int":1.1
+            }
         },
         "modules":[
             "PingResponder",
@@ -98,6 +102,11 @@ options:
 
     To bind to an address but no specific port, set the second tuple entry to `null`.
 
+.. cmdoption:: connection.rate_limit
+
+    Set to false to disable rate limiting. Otherwise, a dict containing two floats keyed: `rate_max`: how many messages
+    may be bursted at once, and `rate_int`: after bursting, how many seconds between messages.
+
 .. cmdoption:: modules
 
     A list of modules to load. Modules are loaded in the order they are listed

examples/config.json

@@ -13,7 +13,11 @@
             ["dickson.freenode.net", 6667],
             ["morgan.freenode.net", 6667]
         ],
-        "force_ipv6": false
+        "force_ipv6": false,
+        "rate_limit": {
+            "rate_max": 5.0,
+            "rate_int":1.1
+        }
     },
     "modules":[
         "PingResponder",

pyircbot/common.py

@@ -0,0 +1,41 @@
+from time import time
+from math import floor
+
+
+class burstbucket(object):
+    def __init__(self, maximum, interval):
+        """
+        Burst bucket class for rate limiting
+        :param maximum: maximum value in the bucket
+        :param interval: how often a whole item is added to the bucket
+        """
+        # How many messages can be bursted
+        self.bucket_max = maximum
+        # how often the bucket has 1 item added
+        self.bucket_period = interval
+        # last time the burst bucket was filled
+        self.bucket_lastfill = time()
+
+        self.bucket = self.bucket_max
+
+    def get(self):
+        """
+        Return 0 if no sleeping is necessary to rate limit. Otherwise, return the number of seconds to sleep. This
+        method should be called again by the user after sleeping
+        """
+        # First, update the bucket
+        # Check if $period time has passed since the bucket was filled
+        since_fill = time() - self.bucket_lastfill
+        if since_fill > self.bucket_period:
+            # How many complete points are credited
+            fills = floor(since_fill / self.bucket_period)
+            self.bucket += fills
+            if self.bucket > self.bucket_max:
+                self.bucket = self.bucket_max
+            # Advance the lastfill time appropriately
+            self.bucket_lastfill += self.bucket_period * fills
+
+        if self.bucket >= 1:
+            self.bucket -= 1
+            return 0
+        return self.bucket_period - since_fill

pyircbot/irccore.py

@@ -12,7 +12,7 @@ import logging
 import traceback
 import sys
 from inspect import getargspec
-from time import sleep
+from pyircbot.common import burstbucket
 from collections import namedtuple
 from io import StringIO
 
@@ -23,7 +23,13 @@ ServerPrefix = namedtuple("ServerPrefix", "hostname")
 
 class IRCCore(object):
 
-    def __init__(self, servers):
+    def __init__(self, servers, loop, rate_limit=True, rate_max=5.0, rate_int=1.1):
+        self._loop = loop
+
+        # rate limiting options
+        self.rate_limit = rate_limit
+        self.rate_max = float(rate_max)
+        self.rate_int = float(rate_int)
 
         self.connected = False
         """If we're connected or not"""
@@ -53,6 +59,9 @@ class IRCCore(object):
         # Set up hooks for modules
         self.initHooks()
 
+        self.outputq = asyncio.Queue()
+        self._loop.call_soon(asyncio.ensure_future, self.outputqueue())
+
     async def loop(self, loop):
         while self.alive:
             try:
@@ -88,6 +97,26 @@ class IRCCore(object):
                 logging.info("Reconnecting in 3s...")
                 await asyncio.sleep(3)
 
+    async def outputqueue(self):
+        bucket = burstbucket(self.rate_max, self.rate_int)
+        while True:
+            prio, line = await self.outputq.get()
+            # sleep until the bucket allows us to send
+            if self.rate_limit:
+                while True:
+                    s = bucket.get()
+                    if s == 0:
+                        break
+                    else:
+                        await asyncio.sleep(s, loop=self._loop)
+            self.fire_hook('_SEND', args=None, prefix=None, trailing=None)
+            self.log.debug(">>> {}".format(repr(line)))
+            try:
+                self.writer.write((line + "\r\n").encode("UTF-8"))
+            except Exception as e:  # Probably fine if we drop messages while offline
+                print(e)
+                print(self.trace())
+
     async def kill(self, message="Help! Another thread is killing me :(", forever=True):
         """Send quit message, flush queue, and close the socket
 
@@ -137,9 +166,7 @@ class IRCCore(object):
             self.fire_hook(command, args=args, prefix=prefix, trailing=trailing)
 
     def sendRaw(self, data):
-        self.log.debug(">>> {}".format(repr(data)))
-        self.fire_hook('_SEND', args=None, prefix=None, trailing=None)
-        self.writer.write((data + "\r\n").encode("UTF-8"))
+        asyncio.run_coroutine_threadsafe(self.outputq.put((5, data, )), self._loop)
 
     " Module related code "
     def initHooks(self):

pyircbot/pyircbot.py

@@ -31,6 +31,8 @@ class PyIRCBot(object):
         self.log = logging.getLogger('PyIRCBot')
         """Reference to logger object"""
 
+        self.loop = asyncio.get_event_loop()
+
         """saved copy of the instance config"""
         self.botconfig = botconfig
 
@@ -43,8 +45,14 @@ class PyIRCBot(object):
         """Reference to BotRPC thread"""
         self.rpc = BotRPC(self)
 
+        ratelimit = self.botconfig["connection"].get("rate_limit", None) or dict(rate_max=5.0, rate_int=1.1)
+
         """IRC protocol handler"""
-        self.irc = IRCCore(servers=self.botconfig["connection"]["servers"])
+        self.irc = IRCCore(servers=self.botconfig["connection"]["servers"],
+                           loop=self.loop,
+                           rate_limit=True if ratelimit else False,
+                           rate_max=ratelimit["rate_max"],
+                           rate_int=ratelimit["rate_int"])
         if self.botconfig.get("connection").get("force_ipv6", False):
             self.irc.connection_family = AF_INET6
         elif self.botconfig.get("connection").get("force_ipv4", False):
@@ -72,8 +80,6 @@ class PyIRCBot(object):
         self.irc.addHook("PRIVMSG", self._irchook_internal)
 
     def run(self):
-        self.loop = asyncio.get_event_loop()
-
         self.client = asyncio.ensure_future(self.irc.loop(self.loop), loop=self.loop)
         try:
             self.loop.set_debug(True)