Sync up core repo with Parsoid

[mediawiki.git] / includes / GitInfo.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
 */

use MediaWiki\Config\ServiceOptions;
use MediaWiki\HookContainer\HookRunner;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Shell\Shell;
use Psr\Log\LoggerInterface;
use Wikimedia\AtEase\AtEase;

/**
 * @newable
 * @note marked as newable in 1.35 for lack of a better alternative,
 *       but should become a stateless service eventually.
 */
class GitInfo {

        /**
         * Singleton for the repo at $IP
         */
        protected static $repo = null;

        /**
         * Location of the .git directory
         */
        protected $basedir;

        /**
         * Location of the repository
         */
        protected $repoDir;

        /**
         * 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 method getViewers().
         */
        private static $viewers = false;

        /** Configuration options needed */
        private const CONSTRUCTOR_OPTIONS = [
                MainConfigNames::BaseDirectory,
                MainConfigNames::CacheDirectory,
                MainConfigNames::GitBin,
                MainConfigNames::GitInfoCacheDirectory,
                MainConfigNames::GitRepositoryViewers,
        ];

        /** @var LoggerInterface */
        private $logger;

        /** @var ServiceOptions */
        private $options;

        /** @var HookRunner */
        private $hookRunner;

        /**
         * @stable to call
         * @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->repoDir = $repoDir;
                $this->options = new ServiceOptions(
                        self::CONSTRUCTOR_OPTIONS,
                        MediaWikiServices::getInstance()->getMainConfig()
                );
                $this->options->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
                // $this->options must be set before using getCacheFilePath()
                $this->cacheFile = $this->getCacheFilePath( $repoDir );
                $this->logger = LoggerFactory::getInstance( 'gitinfo' );
                $this->logger->debug(
                        "Candidate cacheFile={$this->cacheFile} for {$repoDir}"
                );
                $this->hookRunner = Hooks::runner();
                if ( $usePrecomputed &&
                        $this->cacheFile !== null &&
                        is_readable( $this->cacheFile )
                ) {
                        $this->cache = FormatJson::decode(
                                file_get_contents( $this->cacheFile ),
                                true
                        );
                        $this->logger->debug( "Loaded git data from cache for {$repoDir}" );
                }

                if ( !$this->cacheIsComplete() ) {
                        $this->logger->debug( "Cache incomplete for {$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
         */
        private function getCacheFilePath( $repoDir ) {
                $gitInfoCacheDirectory = $this->options->get( MainConfigNames::GitInfoCacheDirectory );
                if ( $gitInfoCacheDirectory === false ) {
                        $gitInfoCacheDirectory = $this->options->get( MainConfigNames::CacheDirectory ) . '/gitinfo';
                }
                $baseDir = $this->options->get( MainConfigNames::BaseDirectory );
                if ( $gitInfoCacheDirectory ) {
                        // Convert both $IP and $repoDir to canonical paths to protect against
                        // $IP having changed between the settings files and runtime.
                        $realIP = realpath( $baseDir );
                        $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';
                        $cachePath = "{$gitInfoCacheDirectory}/{$fileName}";
                        if ( is_readable( $cachePath ) ) {
                                return $cachePath;
                        }
                }

                return "$repoDir/gitinfo.json";
        }

        /**
         * Get the singleton for the repo at MW_INSTALL_PATH
         *
         * @return GitInfo
         */
        public static function repo() {
                if ( self::$repo === null ) {
                        self::$repo = new self( MW_INSTALL_PATH );
                }
                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( $str ) {
                return (bool)preg_match( '/^[0-9A-F]{40}$/i', $str );
        }

        /**
         * Get the HEAD of the repo (without any opening "ref: ")
         *
         * @return string|false 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|false 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|false Commit date (UNIX timestamp) or false
         */
        public function getHeadCommitDate() {
                $gitBin = $this->options->get( MainConfigNames::GitBin );

                if ( !isset( $this->cache['headCommitDate'] ) ) {
                        $date = false;

                        // Suppress warnings about any open_basedir restrictions affecting $wgGitBin (T74445).
                        $isFile = AtEase::quietCall( 'is_file', $gitBin );
                        if ( $isFile &&
                                is_executable( $gitBin ) &&
                                !Shell::isDisabled() &&
                                $this->getHead() !== false
                        ) {
                                $cmd = [
                                        $gitBin,
                                        'show',
                                        '-s',
                                        '--format=format:%ct',
                                        'HEAD',
                                ];
                                $gitDir = realpath( $this->basedir );
                                $result = Shell::command( $cmd )
                                        ->environment( [ 'GIT_DIR' => $gitDir ] )
                                        ->restrict( Shell::RESTRICT_DEFAULT | Shell::NO_NETWORK )
                                        ->allowPath( $gitDir, $this->repoDir )
                                        ->execute();

                                if ( $result->getExitCode() === 0 ) {
                                        $date = (int)$result->getStdout();
                                }
                        }
                        $this->cache['headCommitDate'] = $date;
                }
                return $this->cache['headCommitDate'];
        }

        /**
         * Get the name of the current branch, or HEAD if not found
         *
         * @return string|false 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|false String if a URL is available or false otherwise
         */
        public function getHeadViewUrl() {
                $url = $this->getRemoteUrl();
                if ( $url === false ) {
                        return false;
                }
                foreach ( $this->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|false 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 ) ) {
                                AtEase::suppressWarnings();
                                $configArray = parse_ini_file( $config, true );
                                AtEase::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() ) {
                                $this->logger->debug(
                                        "Failed to compute GitInfo for \"{$this->basedir}\""
                                );
                                return;
                        }

                        $cacheDir = dirname( $this->cacheFile );
                        if ( !file_exists( $cacheDir ) &&
                                !wfMkdirParents( $cacheDir, null, __METHOD__ )
                        ) {
                                throw new RuntimeException( "Unable to create GitInfo cache \"{$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 string|false
         */
        public static function headViewUrl() {
                return self::repo()->getHeadViewUrl();
        }

        /**
         * Gets the list of repository viewers
         * @return array
         */
        private function getViewers() {
                if ( self::$viewers === false ) {
                        self::$viewers = $this->options->get( MainConfigNames::GitRepositoryViewers );
                        $this->hookRunner->onGitViewers( self::$viewers );
                }

                return self::$viewers;
        }
}