curl-w32/docs/libcurl/opts/CURLMOPT_PIPELINING.md

c	SPDX-License-Identifier	Title	Section	Source	See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al.	curl	CURLMOPT_PIPELINING	3	libcurl	CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE (3) CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE (3) CURLMOPT_MAXCONNECTS (3) CURLMOPT_MAX_HOST_CONNECTIONS (3) CURLMOPT_MAX_PIPELINE_LENGTH (3) CURLMOPT_PIPELINING_SITE_BL (3)

NAME

CURLMOPT_PIPELINING - enable HTTP pipelining and multiplexing

SYNOPSIS

#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING, long bitmask);

DESCRIPTION

Pass in the correct value in the bitmask parameter to instruct libcurl to enable multiplexing for this multi handle.

With multiplexing enabled, libcurl attempts to do multiple transfers over the same connection when doing parallel transfers to the same hosts.

CURLPIPE_NOTHING (0)

Default, which means doing no attempts at multiplexing.

CURLPIPE_HTTP1 (1)

This bit is deprecated and has no effect since version 7.62.0.

CURLPIPE_MULTIPLEX (2)

If this bit is set, libcurl tries to multiplex the new transfer over an existing connection if possible. This requires HTTP/2 or HTTP/3.

DEFAULT

Since 7.62.0, CURLPIPE_MULTIPLEX is enabled by default.

Before that, default was CURLPIPE_NOTHING.

PROTOCOLS

HTTP(S)

EXAMPLE

int main(void)
{
  CURLM *m = curl_multi_init();
  /* try HTTP/2 multiplexing */
  curl_multi_setopt(m, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
}

AVAILABILITY

Added in 7.16.0. Multiplex support bit added in 7.43.0. HTTP/1 Pipelining support was disabled in 7.62.0.

RETURN VALUE

Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION if not.