Send heartbeat frames more often

The AMQP protocol is saying that we should send "two"
"heartbeat frames" during the "heartbeat timeout" (see [1] and rabbit
implement this in [2]).

The "two" value is the "rate" parameter in the current implementation.

The current implementation was sending only one frame during the
"heartbeat timeout", which is wrong.

[1] https://www.amqp.org/specification/0-9-1/amqp-org-download
[2] https://www.rabbitmq.com/heartbeats.html#heartbeats-interval

Signed-off-by: Arnaud Morin <arnaud.morin@ovhcloud.com>

Author: arnaudmorin

amqp/connection.py

@@ -724,13 +724,18 @@ def heartbeat_tick(self, rate=2):
             once per second.
 
         Keyword Arguments:
-            rate (int): Previously used, but ignored now.
+            rate (int): Number of heartbeat frames to send during the heartbeat
+                        timeout
         """
         AMQP_HEARTBEAT_LOGGER.debug('heartbeat_tick : for connection %s',
                                     self._connection_id)
         if not self.heartbeat:
             return
 
+        # If rate is wrong, let's use 2 as default
+        if rate <= 0:
+            rate = 2
+
         # treat actual data exchange in either direction as a heartbeat
         sent_now = self.bytes_sent
         recv_now = self.bytes_recv
@@ -755,7 +760,7 @@ def heartbeat_tick(self, rate=2):
         self.prev_sent, self.prev_recv = sent_now, recv_now
 
         # send a heartbeat if it's time to do so
-        if now > self.last_heartbeat_sent + self.heartbeat:
+        if now > self.last_heartbeat_sent + self.heartbeat / rate:
             AMQP_HEARTBEAT_LOGGER.debug(
                 'heartbeat_tick: sending heartbeat for connection %s',
                 self._connection_id)

t/unit/test_connection.py

@@ -1,10 +1,10 @@
 import re
 import socket
 import warnings
-from array import array
 from unittest.mock import Mock, call, patch
 
 import pytest
+import time
 
 from amqp import Connection, spec
 from amqp.connection import SSLError
@@ -514,6 +514,38 @@ def test_heartbeat_tick(self):
         with pytest.raises(ConnectionError):
             self.conn.heartbeat_tick()
 
+    def _test_heartbeat_rate_tick(self, rate):
+        # Doing 22 calls,
+        # First one is setting the variables
+        # All nexts may send heartbeats, depending on rate
+        for i in range(1, 22):
+            self.conn.heartbeat_tick(rate)
+            time.sleep(0.1)
+
+    def test_heartbeat_check_rate_default(self):
+        # Heartbeat set to 2 secs
+        self.conn.heartbeat = 2
+        # Default rate is 2 --> should send frames every sec
+        self._test_heartbeat_rate_tick(2)
+        # Verify that we wrote 2 frames
+        assert self.conn.frame_writer.call_count == 2
+
+    def test_heartbeat_check_rate_four(self):
+        # Heartbeat set to 2 secs
+        self.conn.heartbeat = 2
+        # Rate 4 --> should send frames every 0.5sec
+        self._test_heartbeat_rate_tick(4)
+        # Verify that we wrote 4 frames
+        assert self.conn.frame_writer.call_count == 4
+
+    def test_heartbeat_check_rate_wrong(self):
+        # Heartbeat set to 2 secs
+        self.conn.heartbeat = 2
+        # Default rate is 2 --> should send frames every sec
+        self._test_heartbeat_rate_tick(-42)
+        # Verify that we wrote 2 frames
+        assert self.conn.frame_writer.call_count == 2
+
     def test_server_capabilities(self):
         self.conn.server_properties['capabilities'] = {'foo': 1}
         assert self.conn.server_capabilities == {'foo': 1}