IGNITE-15479 Fix incorrect partial read from socket in sync client - F…

…ixes #50.

pyignite/connection/connection.py

@@ -156,6 +156,9 @@ def _connection_listener(self):
         return self.client._event_listeners
 
 
+DEFAULT_INITIAL_BUF_SIZE = 1024
+
+
 class Connection(BaseConnection):
     """
     This is a `pyignite` class, that represents a connection to Ignite
@@ -348,39 +351,35 @@ def recv(self, flags=None, reconnect=True) -> bytearray:
         if flags is not None:
             kwargs['flags'] = flags
 
-        data = bytearray(1024)
+        data = bytearray(DEFAULT_INITIAL_BUF_SIZE)
         buffer = memoryview(data)
-        bytes_total_received, bytes_to_receive = 0, 0
+        total_rcvd, packet_len = 0, 0
         while True:
             try:
-                bytes_received = self._socket.recv_into(buffer, len(buffer), **kwargs)
-                if bytes_received == 0:
+                bytes_rcvd = self._socket.recv_into(buffer, len(buffer), **kwargs)
+                if bytes_rcvd == 0:
                     raise SocketError('Connection broken.')
-                bytes_total_received += bytes_received
+                total_rcvd += bytes_rcvd
             except connection_errors as e:
                 self.failed = True
                 if reconnect:
                     self._on_connection_lost(e)
                     self.reconnect()
                 raise e
 
-            if bytes_total_received < 4:
-                continue
-            elif bytes_to_receive == 0:
-                response_len = int.from_bytes(data[0:4], PROTOCOL_BYTE_ORDER)
-                bytes_to_receive = response_len
-
-                if response_len + 4 > len(data):
+            if packet_len == 0 and total_rcvd > 4:
+                packet_len = int.from_bytes(data[0:4], PROTOCOL_BYTE_ORDER, signed=True) + 4
+                if packet_len > len(data):
                     buffer.release()
-                    data.extend(bytearray(response_len + 4 - len(data)))
-                    buffer = memoryview(data)[bytes_total_received:]
+                    data.extend(bytearray(packet_len - len(data)))
+                    buffer = memoryview(data)[total_rcvd:]
                     continue
 
-            if bytes_total_received >= bytes_to_receive:
+            if 0 < packet_len <= total_rcvd:
                 buffer.release()
                 break
 
-            buffer = buffer[bytes_received:]
+            buffer = buffer[bytes_rcvd:]
 
         return data
 

tests/common/test_sync_socket.py

@@ -0,0 +1,42 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import secrets
+import socket
+import unittest.mock as mock
+
+import pytest
+
+from pyignite import Client
+from tests.util import get_or_create_cache
+
+old_recv_into = socket.socket.recv_into
+
+
+def patched_recv_into_factory(buf_len):
+    def patched_recv_into(self, buffer, nbytes, **kwargs):
+        return old_recv_into(self, buffer, min(nbytes, buf_len) if buf_len else nbytes, **kwargs)
+    return patched_recv_into
+
+
+@pytest.mark.parametrize('buf_len', [0, 1, 4, 16, 32, 64, 128, 256, 512, 1024])
+def test_get_large_value(buf_len):
+    with mock.patch.object(socket.socket, 'recv_into', new=patched_recv_into_factory(buf_len)):
+        c = Client()
+        with c.connect("127.0.0.1", 10801):
+            with get_or_create_cache(c, 'test') as cache:
+                value = secrets.token_hex((1 << 16) + 1)
+                cache.put(1, value)
+                assert value == cache.get(1)