http2: small clean up in OnStreamRead

PR-URL: #30351 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: David Carlier <[email protected]> Reviewed-By: James M Snell <[email protected]>

Author: lundibundi

src/node_http2.cc

@@ -1907,14 +1907,10 @@ void Http2Session::OnStreamRead(ssize_t nread, const uv_buf_t& buf_){
 // call in OnStreamAfterWrite() immediately provides data. If that does
 // happen, we concatenate the data we received with the already-stored
 // pending input data, slicing off the already processed part.
- AllocatedBuffer new_buf = env()->AllocateManaged(
- stream_buf_.len - stream_buf_offset_ + nread);
-memcpy(new_buf.data(),
- stream_buf_.base + stream_buf_offset_,
- stream_buf_.len - stream_buf_offset_);
-memcpy(new_buf.data() + stream_buf_.len - stream_buf_offset_,
- buf.data(),
- nread);
+size_t pending_len = stream_buf_.len - stream_buf_offset_;
+ AllocatedBuffer new_buf = env()->AllocateManaged(pending_len + nread);
+memcpy(new_buf.data(), stream_buf_.base + stream_buf_offset_, pending_len);
+memcpy(new_buf.data() + pending_len, buf.data(), nread);
  buf = std::move(new_buf);
  nread = buf.size();
  stream_buf_offset_ = 0;