Introducing a number of options to the multi interface that
allows for multiple pipelines to the same host, in order to
optimize the balance between the penalty for opening new
connections and the potential pipelining latency.
Two new options for limiting the number of connections:
CURLMOPT_MAX_HOST_CONNECTIONS - Limits the number of running connections
to the same host. When adding a handle that exceeds this limit,
that handle will be put in a pending state until another handle is
finished, so we can reuse the connection.
CURLMOPT_MAX_TOTAL_CONNECTIONS - Limits the number of connections in total.
When adding a handle that exceeds this limit,
that handle will be put in a pending state until another handle is
finished. The free connection will then be reused, if possible, or
closed if the pending handle can't reuse it.
Several new options for pipelining:
CURLMOPT_MAX_PIPELINE_LENGTH - Limits the pipeling length. If a
pipeline is "full" when a connection is to be reused, a new connection
will be opened if the CURLMOPT_MAX_xxx_CONNECTIONS limits allow it.
If not, the handle will be put in a pending state until a connection is
ready (either free or a pipe got shorter).
CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE - A pipelined connection will not
be reused if it is currently processing a transfer with a content
length that is larger than this.
CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE - A pipelined connection will not
be reused if it is currently processing a chunk larger than this.
CURLMOPT_PIPELINING_SITE_BL - A blacklist of hosts that don't allow
pipelining.
CURLMOPT_PIPELINING_SERVER_BL - A blacklist of server types that don't allow
pipelining.
See the curl_multi_setopt() man page for details.
Updated the POP3 sub-section to refer to message ID rather than mailbox.
Added an IMAP sub-section with example URLs depicting the specification
of mailbox, uid and section.
* Elaborates on default values of some curl_easy_setopt() options.
* Reminds the user to cast variadic arguments to curl_easy_setopt() to
'void *' where curl internally interprets them as such.
* Clarifies the working of the CURLOPT_SEEKFUNCTION option for
curl_easy_setopt().
* Fixes typo 'forth' → 'fourth'.
* Elaborates on CURL_SOCKET_TIMEOUT.
* Adds some missing periods.
* Notes that the return value of curl_version() must not be passed to
free().
* Adds several links to documentation of library functions which were
missing.
* Marks documentation of deprecated library functions "(deprecated)".
* Removes spurious .html suffixes.
Schannel and darwinssl use the certificates built into the
OS to do vert verification instead of bundles. darwinssl
is thread-safe. Corrected typos in the NSS docs.
After a research team wrote a document[1] that found several live source
codes out there in the wild that misused the CURLOPT_SSL_VERIFYHOST
option thinking it was a boolean, this change now bans 1 as a value and
will make libcurl return error for it.
1 was never a sensible value to use in production but was introduced
back in the days to help debugging. It was always documented clearly
this way.
1 was never supported by all SSL backends in libcurl, so this cleanup
makes the treatment of it unified.
The report's list of mistakes for this option were all PHP code and
while there's a binding layer between libcurl and PHP, the PHP team has
decided that they have an as thin layer as possible on top of libcurl so
they will not alter or specifically filter a 'TRUE' value for this
particular option. I sympathize with that position.
[1] = http://daniel.haxx.se/blog/2012/10/25/libcurl-claimed-to-be-dangerous/
This is a minor change in behavior after having been pointed out by Mark
Tully and discussed on the list. Initially this case would internally
call poll() with no sockets and a timeout which would equal a sleep for
that specified time.
Bug: http://curl.haxx.se/mail/lib-2012-10/0076.html
Reported by: Mark Tully
"Currently you can only share DNS and/or COOKIE data" is incorrect since
also SSL sessions can be shared.
Bug: http://curl.haxx.se/bug/view.cgi?id=3562261
Reported by: Joe Mason
- For all *FUNCTION options, they now all show the complete prototype in
the description. Previously some of them would just refer to a
typedef'ed function pointer in the curl.h header.
- I made the phrasing of that "Pass a pointer to a function that matches
the following prototype" the same for all *FUNCTION option descriptions.
- I removed some uses of 'should'. I think I sometimes over-use this
word as in many places I actually mean MUST or otherwise more specific
and not-so-optional synonyms.
Setting bit 2 for this value was documented as having a constant value
defined as CURL_REDIR_POST_303 yet referenced a 302 request.
Additionally corrected the meaning of CURL_REDIR_POST_ALL for all three
bits and fixed problems with the bolding of keywords in this section.
Standardised how RFCs are referenced so that the website may autolink to
the correct documentation on ietf.org. Additionally removed the one link
to RFC3986 on curl.haxx.se.
