63 lines
1.9 KiB
Markdown
63 lines
1.9 KiB
Markdown
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---
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c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
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SPDX-License-Identifier: curl
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Title: libcurl-share
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Section: 3
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Source: libcurl
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See-also:
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- curl_share_cleanup (3)
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- curl_share_init (3)
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- curl_share_setopt (3)
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- libcurl-easy (3)
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- libcurl-errors (3)
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- libcurl-multi (3)
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---
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# NAME
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libcurl-share - how to use the share interface
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# DESCRIPTION
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This is an overview on how to use the libcurl share interface in your C
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programs. There are specific man pages for each function mentioned in
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here.
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All functions in the share interface are prefixed with curl_share.
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# OBJECTIVES
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The share interface was added to enable sharing of data between curl handles.
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# ONE SET OF DATA - MANY TRANSFERS
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You can have multiple easy handles share data between them. Have them update
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and use the **same** cookie database, DNS cache, TLS session cache and/or
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connection cache! This way, each single transfer takes advantage from data
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updates made by the other transfer(s).
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# SHARE OBJECT
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You create a shared object with curl_share_init(3). It returns a handle
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for a newly created one.
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You tell the shared object what data you want it to share by using
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curl_share_setopt(3).
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Since you can use this share from multiple threads, and libcurl has no
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internal thread synchronization, you must provide mutex callbacks if you are
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using this multi-threaded. You set lock and unlock functions with
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curl_share_setopt(3) too.
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Then, you make an easy handle to use this share, you set the
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CURLOPT_SHARE(3) option with curl_easy_setopt(3), and pass in
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share handle. You can make any number of easy handles share the same share
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handle.
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To make an easy handle stop using that particular share, you set
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CURLOPT_SHARE(3) to NULL for that easy handle. To make a handle stop
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sharing a particular data, you can CURLSHOPT_UNSHARE(3) it.
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When you are done using the share, make sure that no easy handle is still using
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it, and call curl_share_cleanup(3) on the handle.
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