diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 21ededc5ae..23ce0af277 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -28,6 +28,7 @@ class Codes(object):
UNKNOWN = "M_UNKNOWN"
NOT_FOUND = "M_NOT_FOUND"
UNKNOWN_TOKEN = "M_UNKNOWN_TOKEN"
+ LIMIT_EXCEEDED = "M_LIMIT_EXCEEDED"
class CodeMessageException(Exception):
@@ -39,10 +40,13 @@ class CodeMessageException(Exception):
self.code = code
self.msg = msg
+ def error_dict(self):
+ return cs_error(self.msg)
+
class SynapseError(CodeMessageException):
"""A base error which can be caught for all synapse events."""
- def __init__(self, code, msg, errcode=""):
+ def __init__(self, code, msg, errcode=Codes.UNKNOWN):
"""Constructs a synapse error.
Args:
@@ -53,6 +57,11 @@ class SynapseError(CodeMessageException):
super(SynapseError, self).__init__(code, msg)
self.errcode = errcode
+ def error_dict(self):
+ return cs_error(
+ self.msg,
+ self.errcode,
+ )
class RoomError(SynapseError):
"""An error raised when a room event fails."""
@@ -91,13 +100,25 @@ class StoreError(SynapseError):
pass
-def cs_exception(exception):
- if isinstance(exception, SynapseError):
+class LimitExceededError(SynapseError):
+ """A client has sent too many requests and is being throttled.
+ """
+ def __init__(self, code=429, msg="Too Many Requests", retry_after_ms=None,
+ errcode=Codes.LIMIT_EXCEEDED):
+ super(LimitExceededError, self).__init__(code, msg, errcode)
+ self.retry_after_ms = retry_after_ms
+
+ def error_dict(self):
return cs_error(
- exception.msg,
- Codes.UNKNOWN if not exception.errcode else exception.errcode)
- elif isinstance(exception, CodeMessageException):
- return cs_error(exception.msg)
+ self.msg,
+ self.errcode,
+ retry_after_ms=self.retry_after_ms,
+ )
+
+
+def cs_exception(exception):
+ if isinstance(exception, CodeMessageException):
+ return exception.error_dict()
else:
logging.error("Unknown exception type: %s", type(exception))
diff --git a/synapse/api/ratelimiting.py b/synapse/api/ratelimiting.py
new file mode 100644
index 0000000000..ab26c2376a
--- /dev/null
+++ b/synapse/api/ratelimiting.py
@@ -0,0 +1,65 @@
+import collections
+
+
+class Ratelimiter(object):
+ """
+ Ratelimit message sending by user.
+ """
+
+ def __init__(self):
+ self.message_counts = collections.OrderedDict()
+
+ def send_message(self, user_id, time_now_s, msg_rate_hz, burst_count):
+ """Can the user send a message?
+ Args:
+ user_id: The user sending a message.
+ time_now_s: The time now.
+ msg_rate_hz: The long term number of messages a user can send in a
+ second.
+ burst_count: How many messages the user can send before being
+ limited.
+ Returns:
+ A pair of a bool indicating if they can send a message now and a
+ time in seconds of when they can next send a message.
+ """
+ self.prune_message_counts(time_now_s)
+ message_count, time_start, _ignored = self.message_counts.pop(
+ user_id, (0., time_now_s, None),
+ )
+ time_delta = time_now_s - time_start
+ sent_count = message_count - time_delta * msg_rate_hz
+ if sent_count < 0:
+ allowed = True
+ time_start = time_now_s
+ messagecount = 1.
+ elif sent_count > burst_count - 1.:
+ allowed = False
+ else:
+ allowed = True
+ message_count += 1
+
+ self.message_counts[user_id] = (
+ message_count, time_start, msg_rate_hz
+ )
+
+ if msg_rate_hz > 0:
+ time_allowed = (
+ time_start + (message_count - burst_count + 1) / msg_rate_hz
+ )
+ if time_allowed < time_now_s:
+ time_allowed = time_now_s
+ else:
+ time_allowed = -1
+
+ return allowed, time_allowed
+
+ def prune_message_counts(self, time_now_s):
+ for user_id in self.message_counts.keys():
+ message_count, time_start, msg_rate_hz = (
+ self.message_counts[user_id]
+ )
+ time_delta = time_now_s - time_start
+ if message_count - time_delta * msg_rate_hz > 0:
+ break
+ else:
+ del self.message_counts[user_id]
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