Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Previously, when we send all given buffer in data_source_callback, we
return NGHTTP2_ERR_DEFERRED, and nghttp2 library removes this stream
temporarily for writing. This itself is good. If this is the sole
stream in the session, nghttp2_session_want_write() returns zero,
which means that libcurl does not check writeability of the underlying
socket. This leads to very slow upload, because it seems curl only
upload 16k something per 1 second. To fix this, if we still have data
to send, call nghttp2_session_resume_data after nghttp2_session_send.
This makes nghttp2_session_want_write() returns nonzero (if connection
window still opens), and as a result, socket writeability is checked,
and upload speed becomes normal.