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          * Map of repo URLs to viewer URLs.
  25          * Key is a pattern passed to preg_match() and preg_replace(),
  26          * without the delimiters (which are #) and must match the whole URL.
  27          * The value is the replacement for the key (it can contain $1, etc.)
  28          * %h will be replaced by the short SHA-1 (7 first chars) and %H by the
  29          * full SHA-1 of the HEAD revision.
  30          */
  31         protected $viewers = array(
  32                 'https://gerrit.wikimedia.org/r/p/(.*)' => 'https://gerrit.wikimedia.org/r/gitweb?p=$1;h=%H',
  33                 'ssh://(?:[a-z0-9_]+@)?gerrit.wikimedia.org:29418/(.*)' => 'https://gerrit.wikimedia.org/r/gitweb?p=$1;h=%H',
  34         );
  35
  36         /**
  37          * @param $dir The root directory of the repo where the .git dir can be found
  38          */
  39         public function __construct( $dir ) {
  40                 $this->basedir = "{$dir}/.git/";
  41         }
  42
  43         /**
  44          * Return a singleton for the repo at $IP
  45          * @return GitInfo
  46          */
  47         public static function repo() {
  48                 global $IP;
  49                 if ( is_null( self::$repo ) ) {
  50                         self::$repo = new self( $IP );
  51                 }
  52                 return self::$repo;
  53         }
  54
  55         /**
  56          * Check if a string looks like a hex encoded SHA1 hash
  57          *
  58          * @param $str The string to check
  59          * @return bool Whether or not the string looks like a SHA1
  60          */
  61         public static function isSHA1( $str ) {
  62                 return !!preg_match( '/^[0-9A-F]{40}$/i', $str );
  63         }
  64
  65         /**
  66          * Return the HEAD of the repo (without any opening "ref: ")
  67          * @return string The HEAD
  68          */
  69         public function getHead() {
  70                 $HEADfile = "{$this->basedir}/HEAD";
  71
  72                 if ( !is_readable( $HEADfile ) ) {
  73                         return false;
  74                 }
  75
  76                 $HEAD = file_get_contents( $HEADfile );
  77
  78                 if ( preg_match( "/ref: (.*)/", $HEAD, $m ) ) {
  79                         return rtrim( $m[1] );
  80                 } else {
  81                         return $HEAD;
  82                 }
  83         }
  84
  85         /**
  86          * Return the SHA1 for the current HEAD of the repo
  87          * @return string A SHA1 or false
  88          */
  89         public function getHeadSHA1() {
  90                 $HEAD = $this->getHead();
  91
  92                 // If detached HEAD may be a SHA1
  93                 if ( self::isSHA1( $HEAD ) ) {
  94                         return $HEAD;
  95                 }
  96
  97                 // If not a SHA1 it may be a ref:
  98                 $REFfile = "{$this->basedir}{$HEAD}";
  99                 if ( !is_readable( $REFfile ) ) {
 100                         return false;
 101                 }
 102
 103                 $sha1 = rtrim( file_get_contents( $REFfile ) );
 104
 105                 return $sha1;
 106         }
 107
 108         /**
 109          * Return the name of the current branch, or HEAD if not found
 110          * @return string The branch name, HEAD, or false
 111          */
 112         public function getCurrentBranch() {
 113                 $HEAD = $this->getHead();
 114                 if ( $HEAD && preg_match( "#^refs/heads/(.*)$#", $HEAD, $m ) ) {
 115                         return $m[1];
 116                 } else {
 117                         return $HEAD;
 118                 }
 119         }
 120
 121         /**
 122          * Get an URL to a web viewer link to the HEAD revision.
 123          *
 124          * @return string|false string if an URL is available or false otherwise.
 125          */
 126         public function getHeadViewUrl() {
 127                 $config = "{$this->basedir}/config";
 128                 if ( !is_readable( $config ) ) {
 129                         return false;
 130                 }
 131
 132                 $configArray = parse_ini_file( $config, true );
 133                 $remote = false;
 134
 135                 // Use the "origin" remote repo if available or any other repo if not.
 136                 if ( isset( $configArray['remote origin'] ) ) {
 137                         $remote = $configArray['remote origin'];
 138                 } else {
 139                         foreach( $configArray as $sectionName => $sectionConf ) {
 140                                 if ( substr( $sectionName, 0, 6 ) == 'remote' ) {
 141                                         $remote = $sectionConf;
 142                                 }
 143                         }
 144                 }
 145
 146                 if ( $remote === false || !isset( $remote['url'] ) ) {
 147                         return false;
 148                 }
 149
 150                 $url = $remote['url'];
 151                 if ( substr( $url, -4 ) !== '.git' ) {
 152                         $url .= '.git';
 153                 }
 154                 foreach( $this->viewers as $repo => $viewer ) {
 155                         $m = array();
 156                         $pattern = '#^' . $repo . '$#';
 157                         if ( preg_match( $pattern, $url ) ) {
 158                                 $viewerUrl = preg_replace( $pattern, $viewer, $url );
 159                                 $headSHA1 = $this->getHeadSHA1();
 160                                 $replacements = array(
 161                                         '%h' => substr( $headSHA1, 0, 7 ),
 162                                         '%H' => $headSHA1
 163                                 );
 164                                 return strtr( $viewerUrl, $replacements );
 165                         }
 166                 }
 167                 return false;
 168         }
 169
 170         /**
 171          * @see self::getHeadSHA1
 172          */
 173         public static function headSHA1() {
 174                 return self::repo()->getHeadSHA1();
 175         }
 176
 177         /**
 178          * @see self::getCurrentBranch
 179          */
 180         public static function currentBranch() {
 181                 return self::repo()->getCurrentBranch();
 182         }
 183
 184         /**
 185          * @see self::getHeadViewUrl()
 186          */
 187         public static function headViewUrl() {
 188                 return self::repo()->getHeadViewUrl();
 189         }
 190 }