70 строки
2.7 KiB
Plaintext
70 строки
2.7 KiB
Plaintext
_ _ ____ _
|
|
___| | | | _ \| |
|
|
/ __| | | | |_) | |
|
|
| (__| |_| | _ <| |___
|
|
\___|\___/|_| \_\_____|
|
|
|
|
libcurl's binary interface
|
|
|
|
ABI - Application Binary Interface
|
|
|
|
First, allow me to define the word for this context: ABI describes the
|
|
low-level interface between an application program and a library. Calling
|
|
conventions, function arguments, return values, struct sizes/defines and
|
|
more.
|
|
|
|
For a longer description, see
|
|
http://en.wikipedia.org/wiki/Application_binary_interface
|
|
|
|
Upgrades
|
|
|
|
In the vast majority of all cases, a typical libcurl upgrade does not break
|
|
the ABI at all. Your application can remain using libcurl just as before,
|
|
only with less bugs and possibly with added new features. You need to read
|
|
the release notes, and if they mention an ABI break/soname bump, you may
|
|
have to verify that your application still builds fine and uses libcurl as
|
|
it now is defined to work.
|
|
|
|
Version Numbers
|
|
|
|
In libcurl land, you really can't tell by the libcurl version number if that
|
|
libcurl is binary compatible or not with another libcurl version.
|
|
|
|
Soname Bumps
|
|
|
|
Whenever there are changes done to the library that will cause an ABI
|
|
breakage, that may require your application to get attention or possibly be
|
|
changed to adhere to new things, we will bump the soname. Then the library
|
|
will get a different output name and thus can in fact be installed in
|
|
parallel with an older installed lib (on most systems). Thus, old
|
|
applications built against the previous ABI version will remain working and
|
|
using the older lib, while newer applications build and use the newer one.
|
|
|
|
During the first seven years of libcurl releases, there have only been four
|
|
ABI breakages.
|
|
|
|
Downgrades
|
|
|
|
Going to an older libcurl version from one you're currently using can be a
|
|
tricky thing. Mostly we add features and options to newer libcurls as that
|
|
won't break ABI or hamper existing applications. This has the implication
|
|
that going backwards may get you in a situation where you pick a libcurl
|
|
that doesn't support the options your application needs. Or possibly you
|
|
even downgrade so far so you cross an ABI break border and thus a different
|
|
soname, and then your application may need to adapt to the modified ABI.
|
|
|
|
History
|
|
|
|
The previous major library soname number bumps (breaking backwards
|
|
compatibility) have happened the following times:
|
|
|
|
0 - libcurl 7.1, August 2000
|
|
|
|
1 - libcurl 7.5 December 2000
|
|
|
|
2 - libcurl 7.7 March 2001
|
|
|
|
3 - libcurl 7.12.0 June 2004
|
|
|
|
4 - libcurl 7.16.0 October 2006
|