proxmox-mirrors/libgit2
1
0
Fork 0
mirror of https://git.proxmox.com/git/libgit2 synced 2025-05-29 13:52:17 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge pull request #1093 from libgit2/contributing

Browse Source 
Create contributing guidelines
This commit is contained in:
Vicent Martí 2012-11-23 15:18:30 -08:00
commit 28de452a4b
3 changed files with 210 additions and 107 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
CONTRIBUTING.md Normal file
View File

@ -0,0 +1,47 @@
# Welcome to libgit2!
We're making it easy to do interesting things with git, and we'd love to have
your help.
## Discussion & Chat
We hang out in the #libgit2 channel on irc.freenode.net.
## Reporting Bugs
First, know which version of libgit2 your problem is in. Compile and test
against the `development` branch to avoid re-reporting an issue that's already
been fixed.
It's *incredibly* helpful to be able to reproduce the problem. Please include
a bit of code and/or a zipped repository (if possible). Note that some of the
developers are employees of GitHub, so if your repository is private, find us
on IRC and we'll figure out a way to help you.
## Pull Requests
Life will be a lot easier for you if you create a named branch for your
contribution, rather than just using your fork's `development`.
It's helpful if you include a nice description of your change with your PR; if
someone has to read the whole diff to figure out why you're contributing in the
first place, you're less likely to get feedback and have your change merged in.
## Porting Code From Other Open-Source Projects
The most common case here is porting code from core Git. Git is a GPL project,
which means that in order to port code to this project, we need the explicit
permission of the author. Check the
[`git.git-authors`](https://github.com/libgit2/libgit2/blob/development/git.git-authors)
file for authors who have already consented; feel free to add someone if you've
obtained their consent.
Other licenses have other requirements; check the license of the library you're
porting code *from* to see what you need to do.
## Styleguide
We like to keep the source code consistent and easy to read. Maintaining this
takes some discipline, but it's been more than worth it. Take a look at the
[conventions file](https://github.com/libgit2/libgit2/blob/development/CONVENTIONS.md).

107
CONVENTIONS
View File

@ -1,107 +0,0 @@
libgit2 conventions
===================
Namespace Prefixes
------------------
All types and functions start with 'git_'.
All #define macros start with 'GIT_'.
Type Definitions
----------------
Most types should be opaque, e.g.:
----
typedef struct git_odb git_odb;
----
with allocation functions returning an "instance" created within
the library, and not within the application. This allows the type
to grow (or shrink) in size without rebuilding client code.
Public Exported Function Definitions
------------------------------------
All exported functions must be declared as:
----
GIT_EXTERN(result_type) git_modulename_functionname(arg_list);
----
Semi-Private Exported Functions
-------------------------------
Functions whose modulename is followed by two underscores,
for example 'git_odb__read_packed', are semi-private functions.
They are primarily intended for use within the library itself,
and may disappear or change their signature in a future release.
Calling Conventions
-------------------
Functions should prefer to return a 'int' to indicate success or
failure and supply any output through the first argument (or first
few arguments if multiple outputs are supplied).
int status codes are 0 for GIT_OK and < 0 for an error.
This permits common POSIX result testing:
----
if (git_odb_open(&odb, path))
abort("odb open failed");
----
Functions returning a pointer may return NULL instead of an int
if there is only one type of failure (GIT_ENOMEM).
Functions returning a pointer may also return NULL if the common
case needed by the application is strictly success/failure and a
(possibly slower) function exists that the caller can use to get
more detailed information. Parsing common data structures from
on-disk formats is a good example of this pattern; in general a
"corrupt" entity can be treated as though it does not exist but
a more sophisticated "fsck" support function can report how the
entity is malformed.
Documentation Fomatting
-----------------------
All comments should conform to Doxygen "javadoc" style conventions
for formatting the public API documentation.
Public Header Format
--------------------
All public headers defining types, functions or macros must use
the following form, where ${filename} is the name of the file,
after replacing non-identifier characters with '_'.
----
#ifndef INCLUDE_git_${filename}_h__
#define INCLUDE_git_${filename}_h__
#include "git/common.h"
/**
* @file git/${filename}.h
* @brief Git some description
* @defgroup git_${filename} some description routines
* @ingroup Git
* @{
*/
GIT_BEGIN_DECL
... definitions ...
/** @} */
GIT_END_DECL
#endif
----

163
CONVENTIONS.md Normal file
View File

@ -0,0 +1,163 @@
# Libgit2 Conventions
We like to keep the source consistent and readable. Herein are some guidelines
that should help with that.
## Naming Things
All types and functions start with `git_`, and all #define macros start with `GIT_`.
Functions with a single output parameter should name that parameter `out`.
Multiple outputs should be named `foo_out`, `bar_out`, etc.
Parameters of type `git_oid` should be named `id`, or `foo_id`. Calls that
return an OID should be named `git_foo_id`.
Where there is a callback passed in, the `void *` that is passed into it should
be named "payload".
## Typedef
Wherever possible, use `typedef`. If a structure is just a collection of
function pointers, the pointer types don't need to be separately typedef'd, but
loose function pointer types should be.
## Exports
All exported functions must be declared as:
```C
GIT_EXTERN(result_type) git_modulename_functionname(arg_list);
```
## Internals
Functions whose modulename is followed by two underscores,
for example `git_odb__read_packed`, are semi-private functions.
They are primarily intended for use within the library itself,
and may disappear or change their signature in a future release.
## Parameters
Out parameters come first.
Whenever possible, pass argument pointers as `const`. Some structures (such
as `git_repository` and `git_index`) have internal structure that prevents
this.
Callbacks should always take a `void *` payload as their last parameter.
Callback pointers are grouped with their payloads, and come last when passed as
arguments:
```C
int foo(git_repository *repo, git_foo_cb callback, void *payload);
```
## Memory Ownership
Some APIs allocate memory which the caller is responsible for freeing; others
return a pointer into a buffer that's owned by some other object. Make this
explicit in the documentation.
## Return codes
Return an `int` when a public API can fail in multiple ways. These may be
transformed into exception types in some bindings, so returning a semantically
appropriate error code is important. Check
[`errors.h`](https://github.com/libgit2/libgit2/blob/development/include/git2/errors.h)
for the return codes already defined.
Use `giterr_set` to provide extended error information to callers.
If an error is not to be propagated, use `giterr_clear` to prevent callers from
getting the wrong error message later on.
## Opaque Structs
Most types should be opaque, e.g.:
```C
typedef struct git_odb git_odb;
```
...with allocation functions returning an "instance" created within
the library, and not within the application. This allows the type
to grow (or shrink) in size without rebuilding client code.
To preserve ABI compatibility, include an `int version` field in all opaque
structures, and initialize to the latest version in the construction call.
Increment the "latest" version whenever the structure changes, and try to only
append to the end of the structure.
## Option Structures
If a function's parameter count is too high, it may be desirable to package up
the options in a structure. Make them transparent, include a version field,
and provide an initializer constant or constructor. Using these structures
should be this easy:
```C
git_foo_options opts = GIT_FOO_OPTIONS_INIT;
opts.baz = BAZ_OPTION_ONE;
git_foo(&opts);
```
## Enumerations
Typedef all enumerated types. If each option stands alone, use the enum type
for passing them as parameters; if they are flags, pass them as `unsigned int`.
## Code Layout
Try to keep lines less than 80 characters long. Use common sense to wrap most
code lines; public function declarations should use this convention:
```C
GIT_EXTERN(int) git_foo_id(
git_oid **out,
int a,
int b);
```
Public headers are indented with spaces, three to a tab. Internal code is
indented with tabs; set your editor's tab width to 3 for best effect.
## Documentation
All comments should conform to Doxygen "javadoc" style conventions for
formatting the public API documentation. Try to document every parameter, and
keep the comments up to date if you change the parameter list.
## Public Header Template
Use this template when creating a new public header.
```C
#ifndef INCLUDE_git_${filename}_h__
#define INCLUDE_git_${filename}_h__
#include "git/common.h"
/**
* @file git/${filename}.h
* @brief Git some description
* @defgroup git_${filename} some description routines
* @ingroup Git
* @{
*/
GIT_BEGIN_DECL
/* ... definitions ... */
/** @} */
GIT_END_DECL
#endif
```