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 bitmask);
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DESCRIPTION

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

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

58       HTTP(S)
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EXAMPLE

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

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

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