fix ratelimiting

the new ratelimiting: use ratelimit(ratelimit_class) to push and verify ratelimit buckets defined in common (can be extended during runtime).

common.py

@@ -5,17 +5,20 @@ import os
 import pickle
 import re
 import sys
+import time
 import urllib.request
-
+from collections import namedtuple
+from threading import Lock
 from local_config import conf
 
+RATE_NO_LIMIT = 0x00
 RATE_GLOBAL = 0x01
 RATE_NO_SILENCE = 0x02
 RATE_INTERACTIVE = 0x04
 RATE_CHAT = 0x08
 RATE_URL = 0x10
-
-rate_limit_classes = (RATE_CHAT, RATE_GLOBAL, RATE_NO_SILENCE, RATE_INTERACTIVE, RATE_URL)
+RATE_EVENT = 0x20
+RATE_FUN = 0x40
 
 BUFSIZ = 8192
 EVENTLOOP_DELAY = 0.100  # seconds
@@ -41,22 +44,98 @@ def conf_load():
 		return {}
 
 
+Bucket = namedtuple("BucketConfig", ["history", "period", "max_hist_len"])
+
+buckets = {
+	# everything else
+	RATE_GLOBAL: Bucket(history=[], period=60, max_hist_len=10),
+	# bot writes with no visible stimuli
+	RATE_NO_SILENCE: Bucket(history=[], period=10, max_hist_len=5),
+	# interactive stuff like ping
+	RATE_INTERACTIVE: Bucket(history=[], period=30, max_hist_len=5),
+	# chitty-chat, master volume control
+	RATE_CHAT: Bucket(history=[], period=10, max_hist_len=5),
+	# reacting on URLs
+	RATE_URL: Bucket(history=[], period=10, max_hist_len=5),
+	# triggering events
+	RATE_EVENT: Bucket(history=[], period=60, max_hist_len=10),
+	# bot blames people, produces cake and entertains
+	RATE_FUN: Bucket(history=[], period=180, max_hist_len=5),
+}
+
+rate_limit_classes = buckets.keys()
+
+
+def rate_limit(rate_class=RATE_GLOBAL):
+	"""
+	Remember N timestamps,
+	if N[0] newer than now()-T then do not output, do not append.
+	else pop(0); append()
+
+	:param rate_class: the type of message to verify
+	:return: False if blocked, True if allowed
+	"""
+	if rate_class not in rate_limit_classes:
+		return all(rate_limit(c) for c in rate_limit_classes if c & rate_class)
+
+	now = time.time()
+	bucket = buckets[rate_class]
+	logging.getLogger(__name__).debug("[ratelimit][bucket=%x][time=%s]%s" % (rate_class, now, bucket.history))
+
+	if len(bucket.history) >= bucket.max_hist_len and bucket.history[0] > (now - bucket.period):
+		# print("blocked")
+		return False
+	else:
+		if bucket.history and len(bucket.history) > bucket.max_hist_len:
+			bucket.history.pop(0)
+		bucket.history.append(now)
+		return True
+
+
+def rate_limited(max_per_second):
+	"""
+	very simple flow control context manager
+	:param max_per_second: how many events per second may be executed - more are delayed
+	:return:
+	"""
+	min_interval = 1.0 / float(max_per_second)
+
+	def decorate(func):
+		lasttimecalled = [0.0]
+
+		def ratelimitedfunction(*args, **kargs):
+			elapsed = time.clock() - lasttimecalled[0]
+			lefttowait = min_interval - elapsed
+			if lefttowait > 0:
+				time.sleep(lefttowait)
+			ret = func(*args, **kargs)
+			lasttimecalled[0] = time.clock()
+			return ret
+
+		return ratelimitedfunction
+
+	return decorate
+
+
 def get_version_git():
 	import subprocess
 
 	cmd = ['git', 'log', '--oneline', '--abbrev-commit']
 
-	p = subprocess.Popen(cmd, bufsize=1, stdout=subprocess.PIPE)
-	first_line = p.stdout.readline()
-	line_count = len(p.stdout.readlines()) + 1
+	try:
+		p = subprocess.Popen(cmd, bufsize=1, stdout=subprocess.PIPE)
+		first_line = p.stdout.readline()
+		line_count = len(p.stdout.readlines()) + 1
 
-	if 0 == p.wait():
-		# skip this 1st, 2nd, 3rd stuff and use always [0-9]th
-		return "version (Git, %dth rev) '%s'" % (
-			line_count, str(first_line.strip(), encoding='utf8')
-		)
-	else:
-		return "(unknown version)"
+		if 0 == p.wait():
+			# skip this 1st, 2nd, 3rd stuff and use always [0-9]th
+			return "version (Git, %dth rev) '%s'" % (
+				line_count, str(first_line.strip(), encoding='utf8')
+			)
+		else:
+			return "(unknown version)"
+	except:
+		return "cannot determine version"
 
 
 VERSION = get_version_git()
@@ -120,8 +199,7 @@ def extract_title(url):
 	if result:
 		match = result.groups()[0]
 
-		if not parser:
-			parser = html.parser.HTMLParser()
+		parser = html.parser.HTMLParser()
 		try:
 			expanded_html = parser.unescape(match)
 		except UnicodeDecodeError as e:  # idk why this can happen, but it does