Move remaining LoadBalancer classes to Rdbms

[mediawiki.git] / includes / utils / AutoloadGenerator.php

<?php

/**
 * Accepts a list of files and directories to search for
 * php files and generates $wgAutoloadLocalClasses or $wgAutoloadClasses
 * lines for all detected classes. These lines are written out
 * to an autoload.php file in the projects provided basedir.
 *
 * Usage:
 *
 *     $gen = new AutoloadGenerator( __DIR__ );
 *     $gen->readDir( __DIR__ . '/includes' );
 *     $gen->readFile( __DIR__ . '/foo.php' )
 *     $gen->getAutoload();
 */
class AutoloadGenerator {
        const FILETYPE_JSON = 'json';
        const FILETYPE_PHP = 'php';

        /**
         * @var string Root path of the project being scanned for classes
         */
        protected $basepath;

        /**
         * @var ClassCollector Helper class extracts class names from php files
         */
        protected $collector;

        /**
         * @var array Map of file shortpath to list of FQCN detected within file
         */
        protected $classes = [];

        /**
         * @var string The global variable to write output to
         */
        protected $variableName = 'wgAutoloadClasses';

        /**
         * @var array Map of FQCN to relative path(from self::$basepath)
         */
        protected $overrides = [];

        /**
         * @param string $basepath Root path of the project being scanned for classes
         * @param array|string $flags
         *
         *  local - If this flag is set $wgAutoloadLocalClasses will be build instead
         *          of $wgAutoloadClasses
         */
        public function __construct( $basepath, $flags = [] ) {
                if ( !is_array( $flags ) ) {
                        $flags = [ $flags ];
                }
                $this->basepath = self::normalizePathSeparator( realpath( $basepath ) );
                $this->collector = new ClassCollector;
                if ( in_array( 'local', $flags ) ) {
                        $this->variableName = 'wgAutoloadLocalClasses';
                }
        }

        /**
         * Force a class to be autoloaded from a specific path, regardless of where
         * or if it was detected.
         *
         * @param string $fqcn FQCN to force the location of
         * @param string $inputPath Full path to the file containing the class
         * @throws Exception
         */
        public function forceClassPath( $fqcn, $inputPath ) {
                $path = self::normalizePathSeparator( realpath( $inputPath ) );
                if ( !$path ) {
                        throw new \Exception( "Invalid path: $inputPath" );
                }
                $len = strlen( $this->basepath );
                if ( substr( $path, 0, $len ) !== $this->basepath ) {
                        throw new \Exception( "Path is not within basepath: $inputPath" );
                }
                $shortpath = substr( $path, $len );
                $this->overrides[$fqcn] = $shortpath;
        }

        /**
         * @param string $inputPath Path to a php file to find classes within
         * @throws Exception
         */
        public function readFile( $inputPath ) {
                // NOTE: do NOT expand $inputPath using realpath(). It is perfectly
                // reasonable for LocalSettings.php and similiar files to be symlinks
                // to files that are outside of $this->basepath.
                $inputPath = self::normalizePathSeparator( $inputPath );
                $len = strlen( $this->basepath );
                if ( substr( $inputPath, 0, $len ) !== $this->basepath ) {
                        throw new \Exception( "Path is not within basepath: $inputPath" );
                }
                $result = $this->collector->getClasses(
                        file_get_contents( $inputPath )
                );
                if ( $result ) {
                        $shortpath = substr( $inputPath, $len );
                        $this->classes[$shortpath] = $result;
                }
        }

        /**
         * @param string $dir Path to a directory to recursively search
         *  for php files with either .php or .inc extensions
         */
        public function readDir( $dir ) {
                $it = new RecursiveDirectoryIterator(
                        self::normalizePathSeparator( realpath( $dir ) ) );
                $it = new RecursiveIteratorIterator( $it );

                foreach ( $it as $path => $file ) {
                        $ext = pathinfo( $path, PATHINFO_EXTENSION );
                        // some older files in mw use .inc
                        if ( $ext === 'php' || $ext === 'inc' ) {
                                $this->readFile( $path );
                        }
                }
        }

        /**
         * Updates the AutoloadClasses field at the given
         * filename.
         *
         * @param string $filename Filename of JSON
         *  extension/skin registration file
         * @return string Updated Json of the file given as the $filename parameter
         */
        protected function generateJsonAutoload( $filename ) {
                $key = 'AutoloadClasses';
                $json = FormatJson::decode( file_get_contents( $filename ), true );
                unset( $json[$key] );
                // Inverting the key-value pairs so that they become of the
                // format class-name : path when they get converted into json.
                foreach ( $this->classes as $path => $contained ) {
                        foreach ( $contained as $fqcn ) {

                                // Using substr to remove the leading '/'
                                $json[$key][$fqcn] = substr( $path, 1 );
                        }
                }
                foreach ( $this->overrides as $path => $fqcn ) {

                        // Using substr to remove the leading '/'
                        $json[$key][$fqcn] = substr( $path, 1 );
                }

                // Sorting the list of autoload classes.
                ksort( $json[$key] );

                // Return the whole JSON file
                return FormatJson::encode( $json, true ) . "\n";
        }

        /**
         * Generates a PHP file setting up autoload information.
         *
         * @param {string} $commandName Command name to include in comment
         * @param {string} $filename of PHP file to put autoload information in.
         * @return string
         */
        protected function generatePHPAutoload( $commandName, $filename ) {
                // No existing JSON file found; update/generate PHP file
                $content = [];

                // We need to generate a line each rather than exporting the
                // full array so __DIR__ can be prepended to all the paths
                $format = "%s => __DIR__ . %s,";
                foreach ( $this->classes as $path => $contained ) {
                        $exportedPath = var_export( $path, true );
                        foreach ( $contained as $fqcn ) {
                                $content[$fqcn] = sprintf(
                                        $format,
                                        var_export( $fqcn, true ),
                                        $exportedPath
                                );
                        }
                }

                foreach ( $this->overrides as $fqcn => $path ) {
                        $content[$fqcn] = sprintf(
                                $format,
                                var_export( $fqcn, true ),
                                var_export( $path, true )
                        );
                }

                // sort for stable output
                ksort( $content );

                // extensions using this generator are appending to the existing
                // autoload.
                if ( $this->variableName === 'wgAutoloadClasses' ) {
                        $op = '+=';
                } else {
                        $op = '=';
                }

                $output = implode( "\n\t", $content );
                return
                        <<<EOD
<?php
// This file is generated by $commandName, do not adjust manually
// @codingStandardsIgnoreFile
global \${$this->variableName};

\${$this->variableName} {$op} [
        {$output}
];

EOD;

        }

        /**
         * Returns all known classes as a string, which can be used to put into a target
         * file (e.g. extension.json, skin.json or autoload.php)
         *
         * @param string $commandName Value used in file comment to direct
         *  developers towards the appropriate way to update the autoload.
         * @return string
         */
        public function getAutoload( $commandName = 'AutoloadGenerator' ) {

                // We need to check whether an extenson.json or skin.json exists or not, and
                // incase it doesn't, update the autoload.php file.

                $fileinfo = $this->getTargetFileinfo();

                if ( $fileinfo['type'] === self::FILETYPE_JSON ) {
                        return $this->generateJsonAutoload( $fileinfo['filename'] );
                } else {
                        return $this->generatePHPAutoload( $commandName, $fileinfo['filename'] );
                }
        }

        /**
         * Returns the filename of the extension.json of skin.json, if there's any, or
         * otherwise the path to the autoload.php file in an array as the "filename"
         * key and with the type (AutoloadGenerator::FILETYPE_JSON or AutoloadGenerator::FILETYPE_PHP)
         * of the file as the "type" key.
         *
         * @return array
         */
        public function getTargetFileinfo() {
                $fileinfo = [
                        'filename' => $this->basepath . '/autoload.php',
                        'type' => self::FILETYPE_PHP
                ];
                if ( file_exists( $this->basepath . '/extension.json' ) ) {
                        $fileinfo = [
                                'filename' => $this->basepath . '/extension.json',
                                'type' => self::FILETYPE_JSON
                        ];
                } elseif ( file_exists( $this->basepath . '/skin.json' ) ) {
                        $fileinfo = [
                                'filename' => $this->basepath . '/skin.json',
                                'type' => self::FILETYPE_JSON
                        ];
                }

                return $fileinfo;
        }

        /**
         * Ensure that Unix-style path separators ("/") are used in the path.
         *
         * @param string $path
         * @return string
         */
        protected static function normalizePathSeparator( $path ) {
                return str_replace( '\\', '/', $path );
        }

        /**
         * Initialize the source files and directories which are used for the MediaWiki default
         * autoloader in {mw-base-dir}/autoload.php including:
         *  * includes/
         *  * languages/
         *  * maintenance/
         *  * mw-config/
         *  * /*.php
         */
        public function initMediaWikiDefault() {
                foreach ( [ 'includes', 'languages', 'maintenance', 'mw-config' ] as $dir ) {
                        $this->readDir( $this->basepath . '/' . $dir );
                }
                foreach ( glob( $this->basepath . '/*.php' ) as $file ) {
                        $this->readFile( $file );
                }
        }
}

/**
 * Reads PHP code and returns the FQCN of every class defined within it.
 */
class ClassCollector {

        /**
         * @var string Current namespace
         */
        protected $namespace = '';

        /**
         * @var array List of FQCN detected in this pass
         */
        protected $classes;

        /**
         * @var array Token from token_get_all() that started an expect sequence
         */
        protected $startToken;

        /**
         * @var array List of tokens that are members of the current expect sequence
         */
        protected $tokens;

        /**
         * @var array Class alias with target/name fields
         */
        protected $alias;

        /**
         * @var string $code PHP code (including <?php) to detect class names from
         * @return array List of FQCN detected within the tokens
         */
        public function getClasses( $code ) {
                $this->namespace = '';
                $this->classes = [];
                $this->startToken = null;
                $this->alias = null;
                $this->tokens = [];

                foreach ( token_get_all( $code ) as $token ) {
                        if ( $this->startToken === null ) {
                                $this->tryBeginExpect( $token );
                        } else {
                                $this->tryEndExpect( $token );
                        }
                }

                return $this->classes;
        }

        /**
         * Determine if $token begins the next expect sequence.
         *
         * @param array $token
         */
        protected function tryBeginExpect( $token ) {
                if ( is_string( $token ) ) {
                        return;
                }
                // Note: When changing class name discovery logic,
                // AutoLoaderTest.php may also need to be updated.
                switch ( $token[0] ) {
                case T_NAMESPACE:
                case T_CLASS:
                case T_INTERFACE:
                case T_TRAIT:
                case T_DOUBLE_COLON:
                        $this->startToken = $token;
                        break;
                case T_STRING:
                        if ( $token[1] === 'class_alias' ) {
                                $this->startToken = $token;
                                $this->alias = [];
                        }
                }
        }

        /**
         * Accepts the next token in an expect sequence
         *
         * @param array
         */
        protected function tryEndExpect( $token ) {
                switch ( $this->startToken[0] ) {
                case T_DOUBLE_COLON:
                        // Skip over T_CLASS after T_DOUBLE_COLON because this is something like
                        // "self::static" which accesses the class name. It doens't define a new class.
                        $this->startToken = null;
                        break;
                case T_NAMESPACE:
                        if ( $token === ';' || $token === '{' ) {
                                $this->namespace = $this->implodeTokens() . '\\';
                        } else {
                                $this->tokens[] = $token;
                        }
                        break;

                case T_STRING:
                        if ( $this->alias !== null ) {
                                // Flow 1 - Two string literals:
                                // - T_STRING  class_alias
                                // - '('
                                // - T_CONSTANT_ENCAPSED_STRING 'TargetClass'
                                // - ','
                                // - T_WHITESPACE
                                // - T_CONSTANT_ENCAPSED_STRING 'AliasName'
                                // - ')'
                                // Flow 2 - Use of ::class syntax for first parameter
                                // - T_STRING  class_alias
                                // - '('
                                // - T_STRING TargetClass
                                // - T_DOUBLE_COLON ::
                                // - T_CLASS class
                                // - ','
                                // - T_WHITESPACE
                                // - T_CONSTANT_ENCAPSED_STRING 'AliasName'
                                // - ')'
                                if ( $token === '(' ) {
                                        // Start of a function call to class_alias()
                                        $this->alias = [ 'target' => false, 'name' => false ];
                                } elseif ( $token === ',' ) {
                                        // Record that we're past the first parameter
                                        if ( $this->alias['target'] === false ) {
                                                $this->alias['target'] = true;
                                        }
                                } elseif ( is_array( $token ) && $token[0] === T_CONSTANT_ENCAPSED_STRING ) {
                                        if ( $this->alias['target'] === true ) {
                                                // We already saw a first argument, this must be the second.
                                                // Strip quotes from the string literal.
                                                $this->alias['name'] = substr( $token[1], 1, -1 );
                                        }
                                } elseif ( $token === ')' ) {
                                        // End of function call
                                        $this->classes[] = $this->alias['name'];
                                        $this->alias = null;
                                        $this->startToken = null;
                                }
                        }
                        break;

                case T_CLASS:
                case T_INTERFACE:
                case T_TRAIT:
                        $this->tokens[] = $token;
                        if ( is_array( $token ) && $token[0] === T_STRING ) {
                                $this->classes[] = $this->namespace . $this->implodeTokens();
                        }
                }
        }

        /**
         * Returns the string representation of the tokens within the
         * current expect sequence and resets the sequence.
         *
         * @return string
         */
        protected function implodeTokens() {
                $content = [];
                foreach ( $this->tokens as $token ) {
                        $content[] = is_string( $token ) ? $token : $token[1];
                }

                $this->tokens = [];
                $this->startToken = null;

                return trim( implode( '', $content ), " \n\t" );
        }
}