[GitHub] [pulsar] merlimat commented on a change in pull request #8283: [C++] Client is allocating buffer bigger than needed

[GitBox <gi...@apache.org>]

merlimat commented on a change in pull request #8283:
URL: https://github.com/apache/pulsar/pull/8283#discussion_r506752681



##########
File path: pulsar-client-cpp/lib/Commands.cc
##########
@@ -675,7 +675,7 @@ uint64_t Commands::serializeSingleMessageInBatchWithPayload(const Message& msg,
                   << batchPayLoad.writableBytes() << "] can't accomodate new payload [" << requiredSpace
                   << "] - expanding the batchPayload buffer");
         SharedBuffer buffer = SharedBuffer::allocate(batchPayLoad.readableBytes() +
-                                                     std::max(requiredSpace, maxMessageSizeInBytes));
+                                                     std::min(requiredSpace, maxMessageSizeInBytes));

Review comment:
       The `SharedBuffer` class doesn't automatically expand on writes (since it could be just wrapping a memory pointer instead of owning the underlying array). Logically, the `max()` was wrong here, though it could just use `requiredSpace` directly instead because the size check (<maxMessageSize) would have been done before, I guess.




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org