CURLMOPT_PIPELINING(3)

1CURLMOPT_PIPELINING(3)     curl_multi_setopt options    CURLMOPT_PIPELINING(3)
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NAME

6       CURLMOPT_PIPELINING - enable HTTP pipelining and multiplexing
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLMcode  curl_multi_setopt(CURLM  *handle,  CURLMOPT_PIPELINING, long
12       bitmask);
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DESCRIPTION

15       Pass in the bitmask parameter to instruct libcurl to enable HTTP  pipe‐
16       lining and/or HTTP/2 multiplexing for this multi handle.
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18       When  enabled, libcurl will attempt to use those protocol features when
19       doing parallel requests to the same hosts.
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21       For pipelining, this means that if you add a second  request  that  can
22       use  an already existing connection, the second request will be "piped"
23       on the same connection rather than being executed in parallel.
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25       For multiplexing, this means that  follow-up  requests  can  re-use  an
26       existing  connection  and send the new request multiplexed over that at
27       the same time as other transfers are already using that single  connec‐
28       tion.
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30       There  are  several other related options that are interesting to tweak
31       and adjust to alter how libcurl spreads out requests on different  con‐
32       nections or not etc.
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34       Before  7.43.0,  this  option  was set to 1 and 0 to enable and disable
35       HTTP/1.1 pipelining.
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37       Starting in 7.43.0, bitmask's second bit also has a  meaning,  and  you
38       can  ask for pipelining and multiplexing independently of each other by
39       toggling the correct bits.
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41       CURLPIPE_NOTHING
42       Default, which means doing no attempts at pipelining or multiplexing.
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44       CURLPIPE_HTTP1
45        If this bit is set, libcurl will try to pipeline HTTP/1.1 requests  on
46        connections that are already established and in use to hosts.
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48        This bit is deprecated and has no effect since version 7.62.0.
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50       CURLPIPE_MULTIPLEX
51         If  this  bit  is set, libcurl will try to multiplex the new transfer
52         over an existing connection if possible. This requires HTTP/2.
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DEFAULT

55       Since 7.62.0, CURLPIPE_MULTIPLEX is enabled by default.
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57       Before that, default was CURLPIPE_NOTHING.
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PROTOCOLS

60       HTTP(S)
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EXAMPLE

63       CURLM *m = curl_multi_init();
64       /* try HTTP/2 multiplexing */
65       curl_multi_setopt(m, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
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AVAILABILITY

68       Added in 7.16.0. Multiplex support bit added in 7.43.0. HTTP/1 Pipelin‐
69       ing support was disabled in 7.62.0.
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RETURN VALUE

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