wiki.techinc.nl/includes/GitInfo.php
Seb35 125f83234e Improve GitInfo for reading packed refs
GitInfo only reads branches in files /refs/heads/*; it should also
read those in /.git/packed-refs.

There are 4 tests in this commit to test this new "feature" and add some
code coverage to other methods. Given this class tests Git behaviour and
MediaWiki itself is versioned with Git, the test data are created during
the tests and removed at the end to avoid interference with Git as CVS.

Bug: T155747
Change-Id: Icccdf3ec797788582f836e2d8e267a1d714d50dc
2017-10-02 03:47:33 +00:00

408 lines
11 KiB
PHP

<?php
/**
* A class to help return information about a git repo MediaWiki may be inside
* This is used by Special:Version and is also useful for the LocalSettings.php
* of anyone working on large branches in git to setup config that show up only
* when specific branches are currently checked out.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
class GitInfo {
/**
* Singleton for the repo at $IP
*/
protected static $repo = null;
/**
* Location of the .git directory
*/
protected $basedir;
/**
* Path to JSON cache file for pre-computed git information.
*/
protected $cacheFile;
/**
* Cached git information.
*/
protected $cache = [];
/**
* @var array|false Map of repo URLs to viewer URLs. Access via static method getViewers().
*/
private static $viewers = false;
/**
* @param string $repoDir The root directory of the repo where .git can be found
* @param bool $usePrecomputed Use precomputed information if available
* @see precomputeValues
*/
public function __construct( $repoDir, $usePrecomputed = true ) {
$this->cacheFile = self::getCacheFilePath( $repoDir );
wfDebugLog( 'gitinfo',
"Computed cacheFile={$this->cacheFile} for {$repoDir}"
);
if ( $usePrecomputed &&
$this->cacheFile !== null &&
is_readable( $this->cacheFile )
) {
$this->cache = FormatJson::decode(
file_get_contents( $this->cacheFile ),
true
);
wfDebugLog( 'gitinfo', "Loaded git data from cache for {$repoDir}" );
}
if ( !$this->cacheIsComplete() ) {
wfDebugLog( 'gitinfo', "Cache incomplete for {$repoDir}" );
$this->basedir = $repoDir . DIRECTORY_SEPARATOR . '.git';
if ( is_readable( $this->basedir ) && !is_dir( $this->basedir ) ) {
$GITfile = file_get_contents( $this->basedir );
if ( strlen( $GITfile ) > 8 &&
substr( $GITfile, 0, 8 ) === 'gitdir: '
) {
$path = rtrim( substr( $GITfile, 8 ), "\r\n" );
if ( $path[0] === '/' || substr( $path, 1, 1 ) === ':' ) {
// Path from GITfile is absolute
$this->basedir = $path;
} else {
$this->basedir = $repoDir . DIRECTORY_SEPARATOR . $path;
}
}
}
}
}
/**
* Compute the path to the cache file for a given directory.
*
* @param string $repoDir The root directory of the repo where .git can be found
* @return string Path to GitInfo cache file in $wgGitInfoCacheDirectory or
* fallback in the extension directory itself
* @since 1.24
*/
protected static function getCacheFilePath( $repoDir ) {
global $IP, $wgGitInfoCacheDirectory;
if ( $wgGitInfoCacheDirectory ) {
// Convert both $IP and $repoDir to canonical paths to protect against
// $IP having changed between the settings files and runtime.
$realIP = realpath( $IP );
$repoName = realpath( $repoDir );
if ( $repoName === false ) {
// Unit tests use fake path names
$repoName = $repoDir;
}
if ( strpos( $repoName, $realIP ) === 0 ) {
// Strip $IP from path
$repoName = substr( $repoName, strlen( $realIP ) );
}
// Transform path to git repo to something we can safely embed in
// a filename
$repoName = strtr( $repoName, DIRECTORY_SEPARATOR, '-' );
$fileName = 'info' . $repoName . '.json';
$cachePath = "{$wgGitInfoCacheDirectory}/{$fileName}";
if ( is_readable( $cachePath ) ) {
return $cachePath;
}
}
return "$repoDir/gitinfo.json";
}
/**
* Get the singleton for the repo at $IP
*
* @return GitInfo
*/
public static function repo() {
if ( is_null( self::$repo ) ) {
global $IP;
self::$repo = new self( $IP );
}
return self::$repo;
}
/**
* Check if a string looks like a hex encoded SHA1 hash
*
* @param string $str The string to check
* @return bool Whether or not the string looks like a SHA1
*/
public static function isSHA1( $str ) {
return !!preg_match( '/^[0-9A-F]{40}$/i', $str );
}
/**
* Get the HEAD of the repo (without any opening "ref: ")
*
* @return string|bool The HEAD (git reference or SHA1) or false
*/
public function getHead() {
if ( !isset( $this->cache['head'] ) ) {
$headFile = "{$this->basedir}/HEAD";
$head = false;
if ( is_readable( $headFile ) ) {
$head = file_get_contents( $headFile );
if ( preg_match( "/ref: (.*)/", $head, $m ) ) {
$head = rtrim( $m[1] );
} else {
$head = rtrim( $head );
}
}
$this->cache['head'] = $head;
}
return $this->cache['head'];
}
/**
* Get the SHA1 for the current HEAD of the repo
*
* @return string|bool A SHA1 or false
*/
public function getHeadSHA1() {
if ( !isset( $this->cache['headSHA1'] ) ) {
$head = $this->getHead();
$sha1 = false;
// If detached HEAD may be a SHA1
if ( self::isSHA1( $head ) ) {
$sha1 = $head;
} else {
// If not a SHA1 it may be a ref:
$refFile = "{$this->basedir}/{$head}";
$packedRefs = "{$this->basedir}/packed-refs";
$headRegex = preg_quote( $head, '/' );
if ( is_readable( $refFile ) ) {
$sha1 = rtrim( file_get_contents( $refFile ) );
} elseif ( is_readable( $packedRefs ) &&
preg_match( "/^([0-9A-Fa-f]{40}) $headRegex$/m", file_get_contents( $packedRefs ), $matches )
) {
$sha1 = $matches[1];
}
}
$this->cache['headSHA1'] = $sha1;
}
return $this->cache['headSHA1'];
}
/**
* Get the commit date of HEAD entry of the git code repository
*
* @since 1.22
* @return int|bool Commit date (UNIX timestamp) or false
*/
public function getHeadCommitDate() {
global $wgGitBin;
if ( !isset( $this->cache['headCommitDate'] ) ) {
$date = false;
if ( is_file( $wgGitBin ) &&
is_executable( $wgGitBin ) &&
$this->getHead() !== false
) {
$environment = [ "GIT_DIR" => $this->basedir ];
$cmd = wfEscapeShellArg( $wgGitBin ) .
" show -s --format=format:%ct HEAD";
$retc = false;
$commitDate = wfShellExec( $cmd, $retc, $environment );
if ( $retc === 0 ) {
$date = (int)$commitDate;
}
}
$this->cache['headCommitDate'] = $date;
}
return $this->cache['headCommitDate'];
}
/**
* Get the name of the current branch, or HEAD if not found
*
* @return string|bool The branch name, HEAD, or false
*/
public function getCurrentBranch() {
if ( !isset( $this->cache['branch'] ) ) {
$branch = $this->getHead();
if ( $branch &&
preg_match( "#^refs/heads/(.*)$#", $branch, $m )
) {
$branch = $m[1];
}
$this->cache['branch'] = $branch;
}
return $this->cache['branch'];
}
/**
* Get an URL to a web viewer link to the HEAD revision.
*
* @return string|bool String if a URL is available or false otherwise
*/
public function getHeadViewUrl() {
$url = $this->getRemoteUrl();
if ( $url === false ) {
return false;
}
foreach ( self::getViewers() as $repo => $viewer ) {
$pattern = '#^' . $repo . '$#';
if ( preg_match( $pattern, $url, $matches ) ) {
$viewerUrl = preg_replace( $pattern, $viewer, $url );
$headSHA1 = $this->getHeadSHA1();
$replacements = [
'%h' => substr( $headSHA1, 0, 7 ),
'%H' => $headSHA1,
'%r' => urlencode( $matches[1] ),
'%R' => $matches[1],
];
return strtr( $viewerUrl, $replacements );
}
}
return false;
}
/**
* Get the URL of the remote origin.
* @return string|bool String if a URL is available or false otherwise.
*/
protected function getRemoteUrl() {
if ( !isset( $this->cache['remoteURL'] ) ) {
$config = "{$this->basedir}/config";
$url = false;
if ( is_readable( $config ) ) {
MediaWiki\suppressWarnings();
$configArray = parse_ini_file( $config, true );
MediaWiki\restoreWarnings();
$remote = false;
// Use the "origin" remote repo if available or any other repo if not.
if ( isset( $configArray['remote origin'] ) ) {
$remote = $configArray['remote origin'];
} elseif ( is_array( $configArray ) ) {
foreach ( $configArray as $sectionName => $sectionConf ) {
if ( substr( $sectionName, 0, 6 ) == 'remote' ) {
$remote = $sectionConf;
}
}
}
if ( $remote !== false && isset( $remote['url'] ) ) {
$url = $remote['url'];
}
}
$this->cache['remoteURL'] = $url;
}
return $this->cache['remoteURL'];
}
/**
* Check to see if the current cache is fully populated.
*
* Note: This method is public only to make unit testing easier. There's
* really no strong reason that anything other than a test should want to
* call this method.
*
* @return bool True if all expected cache keys exist, false otherwise
*/
public function cacheIsComplete() {
return isset( $this->cache['head'] ) &&
isset( $this->cache['headSHA1'] ) &&
isset( $this->cache['headCommitDate'] ) &&
isset( $this->cache['branch'] ) &&
isset( $this->cache['remoteURL'] );
}
/**
* Precompute and cache git information.
*
* Creates a JSON file in the cache directory associated with this
* GitInfo instance. This cache file will be used by subsequent GitInfo objects referencing
* the same directory to avoid needing to examine the .git directory again.
*
* @since 1.24
*/
public function precomputeValues() {
if ( $this->cacheFile !== null ) {
// Try to completely populate the cache
$this->getHead();
$this->getHeadSHA1();
$this->getHeadCommitDate();
$this->getCurrentBranch();
$this->getRemoteUrl();
if ( !$this->cacheIsComplete() ) {
wfDebugLog( 'gitinfo',
"Failed to compute GitInfo for \"{$this->basedir}\""
);
return;
}
$cacheDir = dirname( $this->cacheFile );
if ( !file_exists( $cacheDir ) &&
!wfMkdirParents( $cacheDir, null, __METHOD__ )
) {
throw new MWException( "Unable to create GitInfo cache \"{$cacheDir}\"" );
}
file_put_contents( $this->cacheFile, FormatJson::encode( $this->cache ) );
}
}
/**
* @see self::getHeadSHA1
* @return string
*/
public static function headSHA1() {
return self::repo()->getHeadSHA1();
}
/**
* @see self::getCurrentBranch
* @return string
*/
public static function currentBranch() {
return self::repo()->getCurrentBranch();
}
/**
* @see self::getHeadViewUrl()
* @return bool|string
*/
public static function headViewUrl() {
return self::repo()->getHeadViewUrl();
}
/**
* Gets the list of repository viewers
* @return array
*/
protected static function getViewers() {
global $wgGitRepositoryViewers;
if ( self::$viewers === false ) {
self::$viewers = $wgGitRepositoryViewers;
Hooks::run( 'GitViewers', [ &self::$viewers ] );
}
return self::$viewers;
}
}