includes/GitInfo.php

   1 <?php
   2 /**
   3  * A class to help return information about a git repo MediaWiki may be inside
   4  * This is used by Special:Version and is also useful for the LocalSettings.php
   5  * of anyone working on large branches in git to setup config that show up only
   6  * when specific branches are currently checked out.
   7  *
   8  * @file
   9  */
  10
  11 class GitInfo {
  12
  13         /**
  14          * Singleton for the repo at $IP
  15          */
  16         protected static $repo = null;
  17
  18         /**
  19          * Location of the .git directory
  20          */
  21         protected $basedir;
  22
  23         /**
  24          * @param $dir The root directory of the repo where the .git dir can be found
  25          */
  26         public function __construct( $dir ) {
  27                 $this->basedir = "{$dir}/.git/";
  28         }
  29
  30         /**
  31          * Return a singleton for the repo at $IP
  32          * @return GitInfo
  33          */
  34         public static function repo() {
  35                 global $IP;
  36                 if ( is_null( self::$repo ) ) {
  37                         self::$repo = new self( $IP );
  38                 }
  39                 return self::$repo;
  40         }
  41
  42         /**
  43          * Check if a string looks like a hex encoded SHA1 hash
  44          *
  45          * @param $str The string to check
  46          * @return bool Whether or not the string looks like a SHA1
  47          */
  48         public static function isSHA1( $str ) {
  49                 return !!preg_match( '/^[0-9A-Z]{40}$/i', $str );
  50         }
  51
  52         /**
  53          * Return the HEAD of the repo (without any opening "ref: ")
  54          * @return string The HEAD
  55          */
  56         public function getHead() {
  57                 $HEADfile = "{$this->basedir}/HEAD";
  58
  59                 if ( !is_readable( $HEADfile ) ) {
  60                         return false;
  61                 }
  62
  63                 $HEAD = file_get_contents( $HEADfile );
  64
  65                 if ( preg_match( "/ref: (.*)/", $HEAD, $m ) ) {
  66                         return rtrim( $m[1] );
  67                 } else {
  68                         return $HEAD;
  69                 }
  70         }
  71
  72         /**
  73          * Return the SHA1 for the current HEAD of the repo
  74          * @return string A SHA1 or false
  75          */
  76         public function getHeadSHA1() {
  77                 $HEAD = $this->getHead();
  78
  79                 // If detached HEAD may be a SHA1
  80                 if ( self::isSHA1( $HEAD ) ) {
  81                         return $HEAD;
  82                 }
  83
  84                 // If not a SHA1 it may be a ref:
  85                 $REFfile = "{$this->basedir}{$HEAD}";
  86                 if ( !is_readable( $REFfile ) ) {
  87                         return false;
  88                 }
  89
  90                 $sha1 = rtrim( file_get_contents( $REFfile ) );
  91
  92                 return $sha1;
  93         }
  94
  95         /**
  96          * Return the name of the current branch, or HEAD if not found
  97          * @return string The branch name, HEAD, or false
  98          */
  99         public function getCurrentBranch() {
 100                 $HEAD = $this->getHead();
 101                 if ( $HEAD && preg_match( "#^refs/heads/(.*)$#", $HEAD, $m ) ) {
 102                         return $m[1];
 103                 } else {
 104                         return $HEAD;
 105                 }
 106         }
 107
 108         /**
 109          * @see self::getHeadSHA1
 110          */
 111         public static function headSHA1() {
 112                 return self::repo()->getHeadSHA1();
 113         }
 114
 115         /**
 116          * @see self::getCurrentBranch
 117          */
 118         public static function currentBranch() {
 119                 return self::repo()->getCurrentBranch();
 120         }
 121
 122 }