Implement rate limiting

README.md

@@ -3,9 +3,9 @@ A Discord Python bot built to be easy to use and scale.
 
 ## TODOS
 
-- rate limits
 - flesh out gateway paths (reconnect/resume)
 - flesh out API client
+- storage/database/config
 - flesh out type methods
 - plugin reload
 - voice support

disco/api/http.py

@@ -2,6 +2,9 @@ import requests
 
 from holster.enum import Enum
 
+from disco.util.logging import LoggingClass
+from disco.api.ratelimit import RateLimiter
+
 HTTPMethod = Enum(
     GET='GET',
     POST='POST',
@@ -21,36 +24,57 @@ class Routes(object):
 
 
 class APIException(Exception):
-    def __init__(self, obj):
-        self.code = obj['code']
-        self.msg = obj['msg']
-
-        super(APIException, self).__init__(self.msg)
+    def __init__(self, msg, status_code=0, content=None):
+        super(APIException, self).__init__(msg)
+        self.status_code = status_code
+        self.content = content
 
 
-class HTTPClient(object):
+class HTTPClient(LoggingClass):
     BASE_URL = 'https://discordapp.com/api'
+    MAX_RETRIES = 5
 
     def __init__(self, token):
+        super(HTTPClient, self).__init__()
+
+        self.limiter = RateLimiter()
         self.headers = {
             'Authorization': 'Bot ' + token,
         }
 
     def __call__(self, route, *args, **kwargs):
-        method, url = route
+        retry = kwargs.pop('retry_number', 0)
 
+        # Merge or set headers
+        if 'headers' in kwargs:
+            kwargs['headers'].update(self.headers)
+        else:
             kwargs['headers'] = self.headers
 
-        r = requests.request(str(method), (self.BASE_URL + url).format(*args), **kwargs)
+        # Compile URL args
+        compiled = (str(route[0]), (self.BASE_URL) + route[1].format(*args))
+
+        # Possibly wait if we're rate limited
+        self.limiter.check(compiled)
+
+        # Make the actual request
+        r = requests.request(compiled[0], compiled[1], **kwargs)
 
-        try:
-            r.raise_for_status()
-        except:
-            print r.json()
-            raise
-            # TODO: rate limits
-            # TODO: check json
-            raise APIException(r.json())
+        # Update rate limiter
+        self.limiter.update(compiled, r)
 
-        # TODO: check json
+        # If we got a success status code, just return the data
+        if r.status_code < 400:
             return r.json()
+        else:
+            if r.status_code == 429:
+                self.log.warning('Request responded w/ 429, retrying (but this should not happen, check your clock sync')
+
+            # If we hit the max retries, throw an error
+            retry += 1
+            if retry > self.MAX_RETRIES:
+                self.log.error('Failing request, hit max retries')
+                raise APIException('Request failed after {} attempts'.format(self.MAX_RETRIES), r.status_code, r.content)
+
+            # Otherwise just recurse and try again
+            return self(route, retry_number=retry, *args, **kwargs)

disco/api/ratelimit.py

@@ -0,0 +1,64 @@
+import time
+import gevent
+
+
+class RouteState(object):
+    def __init__(self, route, request):
+        self.route = route
+        self.remaining = 0
+        self.reset_time = 0
+        self.event = None
+
+        self.update(request)
+
+    @property
+    def chilled(self):
+        return self.event is not None
+
+    def update(self, request):
+        if 'X-RateLimit-Remaining' not in request.headers:
+            return
+
+        self.remaining = int(request.headers.get('X-RateLimit-Remaining'))
+        self.reset_time = int(request.headers.get('X-RateLimit-Reset'))
+
+    def wait(self, timeout=None):
+        self.event.wait(timeout)
+
+    def next_will_ratelimit(self):
+        if self.remaining - 1 < 0 and time.time() <= self.reset_time:
+            return True
+
+        return False
+
+    def cooldown(self):
+        if self.reset_time - time.time() < 0:
+            raise Exception('Cannot cooldown for negative time period; check clock sync')
+
+        self.event = gevent.event.Event()
+        gevent.sleep((self.reset_time - time.time()) + .5)
+        self.event.set()
+        self.event = None
+
+
+class RateLimiter(object):
+    def __init__(self):
+        self.cooldowns = {}
+        self.states = {}
+
+    def check(self, route, timeout=None):
+        if route in self.states:
+            # If we're current waiting, join the club
+            if self.states[route].chilled:
+                return self.states[route].wait(timeout)
+
+            if self.states[route].next_will_ratelimit():
+                self.states[route].cooldown()
+
+        return True
+
+    def update(self, route, request):
+        if route in self.states:
+            self.states[route].update(request)
+        else:
+            self.states[route] = RouteState(route, request)

disco/bot/bot.py

@@ -44,7 +44,6 @@ class Bot(object):
 
     def compute_command_matches_re(self):
         re_str = '|'.join(command.regex for command in self.commands)
-        print re_str
         if re_str:
             self.command_matches_re = re.compile(re_str)
         else:

disco/bot/command.py

@@ -9,7 +9,7 @@ class CommandEvent(object):
     def __init__(self, msg, match):
         self.msg = msg
         self.match = match
-        self.args = self.match.group(1).split(' ')
+        self.args = self.match.group(1).strip().split(' ')
 
 
 class Command(object):

examples/basic_plugin.py

@@ -11,7 +11,13 @@ class BasicPlugin(Plugin):
     @Plugin.command('test')
     def on_test_command(self, event):
         event.msg.reply('HELLO WORLD')
-        print 'wtf'
+
+    @Plugin.command('spam')
+    def on_spam_command(self, event):
+        count = int(event.args[0])
+
+        for i in range(count):
+            event.msg.reply(' '.join(event.args[1:]))
 
 if __name__ == '__main__':
     bot = Bot(disco_main())