Ticket #10165: mo.php

<?php


/**
 * Improved MO file reader for Wordpress.
 *
 * @author Thomas Urban <thomas.urban@toxa.de>
 */


require_once dirname(__FILE__) . '/translations.php';


class MO extends Translations
{

        protected $nplurals = 2;



        public function __construct( $headers = array(), $hash = array() )
        {

                $this->headers = $headers;
                $this->entries = $hash;

                if ( $this->headers['Plural-Forms'] )
                {

                        $temp = strtok( $this->headers['Plural-Forms'], ';' );
                        if ( preg_match( '/^nplurals=(\d+)$/i', trim( $temp ), $matches ) )
                                $this->nplurals = intval( $matches[1] );

                }
        }


        /**
         * Reads provided MO file.
         *
         * @param string $filename name of MO file to read
         * @return MOX
         */

        public function import_from_file( $filename )
        {

                /*
                 * check cache for existing record first
                 */

                // currently defunct due to internal WP_Object_Cache not saving anything
                $set = wp_cache_get( $filename, 'l10n' );
                if ( is_array( $set ) )
                {

                        list( $this->headers, $this->entries ) = $set;

                        return true;

                }



                /**
                 * read header from file
                 */

                $file = fopen( $filename, 'r' );
                if ( !$file )
                        return false;

                $header = fread( $file, 28 );
                if ( strlen( $header ) != 28 )
                        return false;

                // detect endianess
                $endian = unpack( 'Nendian', substr( $header, 0, 4 ) );
                if ( $endian['endian'] == intval( hexdec( '950412de' ) ) )
                        $endian = 'N';
                else if ( $endian['endian'] == intval( hexdec( 'de120495' ) ) )
                        $endian = 'V';
                else
                        return false;

                // parse header
                $header = unpack( "{$endian}Hrevision/{$endian}Hcount/{$endian}HposOriginals/{$endian}HposTranslations/{$endian}HsizeHash/{$endian}HposHash", substr( $header, 4 ) );
                if ( !is_array( $header ) )
                        return false;

                extract( $header );

                // support revision 0 of MO format specs, only
                if ( $Hrevision != 0 )
                        return false;



                /*
                 * read index tables on originals and translations
                 */

                // seek to data blocks
                fseek( $file, $HposOriginals, SEEK_SET );

                // read originals' indices
                $HsizeOriginals = $HposTranslations - $HposOriginals;
                if ( $HsizeOriginals != $Hcount * 8 )
                        return false;

                $originals = fread( $file, $HsizeOriginals );
                if ( strlen( $originals ) != $HsizeOriginals )
                        return false;

                // read translations' indices
                $HsizeTranslations = $HposHash - $HposTranslations;
                if ( $HsizeTranslations != $Hcount * 8 )
                        return false;

                $translations = fread( $file, $HsizeTranslations );
                if ( strlen( $translations ) != $HsizeTranslations )
                        return false;

                // transform raw data into set of indices
                $originals    = str_split( $originals, 8 );
                $translations = str_split( $translations, 8 );



                /*
                 * read set of strings to separate string
                 */

                // skip hash table
                $HposStrings = $HposHash + $HsizeHash * 4;

                fseek( $file, $HposStrings, SEEK_SET );

                // read strings expected in rest of file
                $strings = '';
                while ( !feof( $file ) )
                        $strings .= fread( $file, 4096 );

                fclose( $file );



                // collect hash records
                $hash = $header = array();

                for ( $i = 0; $i < $Hcount; $i++ )
                {

                        // parse index records on original and related translation
                        $o = unpack( "{$endian}length/{$endian}pos", $originals[$i] );
                        $t = unpack( "{$endian}length/{$endian}pos", $translations[$i] );

                        if ( !$o || !$t )
                                return false;

                        // adjust offset due to reading strings to separate space before
                        $o['pos'] -= $HposStrings;
                        $t['pos'] -= $HposStrings;

                        // extract original and translations
                        $original    = substr( $strings, $o['pos'], $o['length'] );
                        $translation = substr( $strings, $t['pos'], $t['length'] );



                        if ( $original === '' )
                        {
                                // got header --> store separately

                                $header = array();

                                foreach ( explode( "\n", $translation ) as $line )
                                {

                                        $sep = strpos( $line, ':' );
                                        if ( $sep !== false )
                                                $header[trim(substr( $line, 0, $sep ))] = trim( substr( $line, $sep + 1 ));

                                }
                        }
                        else
                        {

                                // detect context in original
                                $sep = strpos( $original, "\04" );
                                if ( $sep !== false )
                                {
                                        $context  = substr( $original, 0, $sep );
                                        $original = substr( $original, $sep + 1 );
                                }
                                else
                                        $context  = null;


                                $original     = explode( "\00", $original );
                                $translation  = explode( "\00", $translation );

                                $singularFrom = array_shift( $original );
                                $singularTo   = array_shift( $translation );

                                if ( count( $original ) && ( count( $original ) == count( $translation ) ) )
                                        $plurals = array_combine( $original, $translation );
                                else
                                        $plurals = array();


                                $record = array(
                                                                'context'     => $context,
                                                                'singular'    => $singularFrom,
                                                                'translation' => $singularTo,
                                                                'plurals'     => $plurals,
                                                                );

                                $key = is_null( $context ) ? $singularFrom
                                                                                   : "$context\04$singularFrom";


                                $hash[$key] = $record;

                        }
                }


                $this->headers = $header;
                $this->entries = $hash;



                /*
                 * write result to cache
                 */

                // currently defunct due to internal WP_Object_Cache not saving anything
                wp_cache_set( $filename, array( $header, $hash ), 'l10n' );



                return true;

        }


        /**
         * Retrieves translation of single entry.
         *
         * The provided entry is constructed manually and thus providing proper
         * key for lookup. The method returns a matching entry from internal pool
         * of translations.
         *
         * NOTE! Passing by reference is required as long as parent class is using
         *       it (obviously due to keeping things compatible with PHP4).
         *
         * @param Translate_Entry $entry entry to look up
         * @return Translate_Entry resulting entry
         */

        public function translate_entry( &$entry )
        {

                if ( !isset( $this->entries[$entry->key()] ) )
                        return false;

                if ( is_array( $this->entries[$entry->key()] ) )
                {
                        // convert entry to instance of Translate_Entry on demand

                        // use internally managed record
                        $args = $this->entries[$entry->key()];

                        // add structures required by Translation_Entry
                        $args['translations'] = array( $args['translation'] );
                        if ( count( $args['plurals'] ) )
                                $args['translations'] = array_merge( $args['translations'], array_values( $args['plurals'] ) );

                        if ( count( $args['plurals'] ) )
                                $args['plural'] = array_shift( array_keys( $args['plurals'] ) );

                        // temporarily transform entry
                        return new Translation_Entry( $args );

                }

                if ( $this->entries[$entry->key()] instanceof Translation_Entry )
                        return $this->entries[$entry->key()];

                return false;

        }


        public function translate( $singular, $context = null )
        {

                $key = $this->key( $singular, $context );

                if ( isset( $this->entries[$key] ) )
                        if ( is_string( $this->entries[$key]['translation'] ) )
                                return $this->entries[$key]['translation'];

                return $singular;

        }


        public function translate_plural( $singular, $plural, $count, $context = null )
        {

                $key = $this->key( $singular, $context );

                $translated = $this->entries[$key];
                if ( is_array( $translated ) )
                {

                        $index              = $this->select_plural_form( $count );
                        $total_plural_forms = $this->get_plural_forms_count();

                        if ( ( $index >= 0 ) && ( $index < $total_plural_forms ) )
                        {

                                if ( ( $index == 0 ) && is_string( $translated['translation'] ) )
                                        return $translated['translation'];

                                if ( count( $translated['plurals'] ) == $total_plural_forms - 1 )
                                {
                                        $plurals = array_values( $translated['plurals'] );
                                        return $plurals[$index-1];
                                }
                        }


                        return ( $count == 1 ) ? $singular : $plural;

                }


                // keep class compatible with old-style entry class
                return parent::translate_plural( $singular, $plural, $count, $context );

        }


        public function key( $singular, $context = null )
        {
                return is_null( $context ) ? $singular : "$context\04$singular";
        }


        public function get_plural_forms_count()
        {
                return $this->nplurals;
        }


        public function select_plural_form( $count )
        {
                return $this->gettext_select_plural_form( $count );
        }
}


?>