We use a custom memory layout for our SharedBuffer objects, which reserve a few bytes at the beginning of each contiguous memory region for metadata (e.g., the capacity of the buffer). As a result, we cannot have SharedBuffer own the memory allocated by gRPC to read from a server stream. This requires an additional heap allocation and memory copy on the critical path.

We can avoid the copy by either changing the layout of the byte-array sent through gRPC streams, or modify SharedBuffer to accepts raw buffers.