Fixed couple of "leaks" when gc is disabled (#979)

kafka/protocol/legacy.py

@@ -133,21 +133,26 @@ class KafkaProtocol(object):
         if acks not in (1, 0, -1):
             raise ValueError('ProduceRequest acks (%s) must be 1, 0, -1' % acks)
 
+        topics = []
+        for topic, topic_payloads in group_by_topic_and_partition(payloads).items():
+            topic_msgs = []
+            for partition, payload in topic_payloads.items():
+                partition_msgs = []
+                for msg in payload.messages:
+                    m = kafka.protocol.message.Message(
+                          msg.value, key=msg.key,
+                          magic=msg.magic, attributes=msg.attributes
+                    )
+                    partition_msgs.append((0, m.encode()))
+                topic_msgs.append((partition, partition_msgs))
+            topics.append((topic, topic_msgs))
+
+
         return kafka.protocol.produce.ProduceRequest[0](
             required_acks=acks,
             timeout=timeout,
-            topics=[(
-                topic,
-                [(
-                    partition,
-                    [(0,
-                      kafka.protocol.message.Message(
-                          msg.value, key=msg.key,
-                          magic=msg.magic, attributes=msg.attributes
-                      ).encode())
-                    for msg in payload.messages])
-                for partition, payload in topic_payloads.items()])
-            for topic, topic_payloads in group_by_topic_and_partition(payloads).items()])
+            topics=topics
+        )
 
     @classmethod
     def decode_produce_response(cls, response):

kafka/protocol/message.py

@@ -10,7 +10,7 @@ from .struct import Struct
 from .types import (
     Int8, Int32, Int64, Bytes, Schema, AbstractType
 )
-from ..util import crc32
+from ..util import crc32, WeakMethod
 
 
 class Message(Struct):
@@ -52,7 +52,7 @@ class Message(Struct):
         self.attributes = attributes
         self.key = key
         self.value = value
-        self.encode = self._encode_self
+        self.encode = WeakMethod(self._encode_self)
 
     @property
     def timestamp_type(self):

kafka/protocol/struct.py

@@ -5,6 +5,8 @@ from io import BytesIO
 from .abstract import AbstractType
 from .types import Schema
 
+from ..util import WeakMethod
+
 
 class Struct(AbstractType):
     SCHEMA = Schema()
@@ -19,7 +21,9 @@ class Struct(AbstractType):
             self.__dict__.update(kwargs)
 
         # overloading encode() to support both class and instance
-        self.encode = self._encode_self
+        # Without WeakMethod() this creates circular ref, which
+        # causes instances to "leak" to garbage
+        self.encode = WeakMethod(self._encode_self)
 
     @classmethod
     def encode(cls, item):  # pylint: disable=E0202

kafka/vendor/six.py

@@ -70,7 +70,9 @@ else:
         else:
             # 64-bit
             MAXSIZE = int((1 << 63) - 1)
-        del X
+
+        # Don't del it here, cause with gc disabled this "leaks" to garbage
+        # del X
 
 
 def _add_doc(func, doc):