class/l10n/gettext.class.php

   1 <?php
   2
   3 /**
   4  * Copyright (c) 2003 Danilo Segan <danilo@kvota.net>.
   5  *
   6  * This file is part of PHP-gettext.
   7  *
   8  * PHP-gettext is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * PHP-gettext is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with PHP-gettext; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  * @copyright 2004-2022 The SquirrelMail Project Team
  23  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  24  * @version $Id$
  25  * @package squirrelmail
  26  * @subpackage i18n
  27  */
  28
  29 /**
  30  * Class that uses parsed translation input objects
  31  * @package squirrelmail
  32  * @subpackage i18n
  33  */
  34 class gettext_reader {
  35     /**
  36      * holds error code (0 if no error)
  37      * @var integer
  38      * @access public
  39      */
  40     var $error = 0;
  41     /**
  42      * specifies the byte order: 0 low endian, 1 big endian
  43      * @var integer
  44      * @access private
  45      */
  46     var $BYTEORDER = 0;
  47     /**
  48      * input object data
  49      * @var object
  50      * @access private
  51      */
  52     var $STREAM = NULL;
  53
  54     /**
  55      *
  56      */
  57     function readint() {
  58         // Reads 4 byte value from $FD and puts it in int
  59         // $BYTEORDER specifies the byte order: 0 low endian, 1 big endian
  60         for ($i=0; $i<4; $i++) {
  61             $byte[$i]=ord($this->STREAM->read(1));
  62         }
  63         //print sprintf("pos: %d\n",$this->STREAM->currentpos());
  64         if ($this->BYTEORDER == 0)
  65             return (int)(($byte[0]) | ($byte[1]<<8) | ($byte[2]<<16) | ($byte[3]<<24));
  66         else
  67             return (int)(($byte[3]) | ($byte[2]<<8) | ($byte[1]<<16) | ($byte[0]<<24));
  68     }
  69
  70     /**
  71      * Constructor (PHP5 style, required in some future version of PHP)
  72      * constructor that requires StreamReader object
  73      * @param object $Reader
  74      * @return boolean false, if some error with stream
  75 TODO: Constructors should not return anything.
  76      */
  77     function __construct($Reader) {
  78         $MAGIC1 = (int) ((222) | (18<<8) | (4<<16) | (149<<24));
  79         $MAGIC2 = (int) ((149) | (4<<8) | (18<<16) | (222<<24));
  80
  81         $this->STREAM = $Reader;
  82         if ($this->STREAM->error>0) {
  83             $this->error=1;
  84             return false;
  85         }
  86         $magic = $this->readint();
  87         if ($magic == $MAGIC1) {
  88             $this->BYTEORDER = 0;
  89         } elseif ($magic == $MAGIC2) {
  90             $this->BYTEORDER = 1;
  91         } else {
  92             $this->error = 1; // not MO file
  93             return false;
  94         }
  95
  96         // FIXME: Do we care about revision? We should.
  97         $revision = $this->readint();
  98
  99         $total = $this->readint();
 100         $originals = $this->readint();
 101         $translations = $this->readint();
 102
 103         $this->total = $total;
 104         $this->originals = $originals;
 105         $this->translations = $translations;
 106
 107         // Here we store already found translations
 108         $this->_HASHED = array();
 109     }
 110
 111     /**
 112      * Constructor (PHP4 style, kept for compatibility reasons)
 113      * constructor that requires StreamReader object
 114      * @param object $Reader
 115      * @return boolean false, if some error with stream
 116 TODO: Constructors should not return anything.
 117      */
 118     function gettext_reader($Reader) {
 119         return self::__construct($Reader);
 120     }
 121
 122     /**
 123      * @param boolean $translations do translation have to be loaded
 124      */
 125     function load_tables($translations=false) {
 126         // if tables are loaded do not load them again
 127         if (!isset($this->ORIGINALS)) {
 128             $this->ORIGINALS = array();
 129             $this->STREAM->seekto($this->originals);
 130             for ($i=0; $i<$this->total; $i++) {
 131                 $len = $this->readint();
 132                 $ofs = $this->readint();
 133                 $this->ORIGINALS[] = array($len,$ofs);
 134             }
 135         }
 136
 137         // similar for translations
 138         if ($translations and !isset($this->TRANSLATIONS)) {
 139             $this->TRANSLATIONS = array();
 140             $this->STREAM->seekto($this->translations);
 141             for ($i=0; $i<$this->total; $i++) {
 142                 $len = $this->readint();
 143                 $ofs = $this->readint();
 144                 $this->TRANSLATIONS[] = array($len,$ofs);
 145             }
 146         }
 147     }
 148
 149     /**
 150      * get a string with particular number
 151      * @param integer $num
 152      * @return string untranslated string
 153      */
 154     function get_string_number($num) {
 155         // TODO: Add simple hashing [check array, add if not already there]
 156         $this->load_tables();
 157         $meta = $this->ORIGINALS[$num];
 158         $length = $meta[0];
 159         $offset = $meta[1];
 160         $this->STREAM->seekto($offset);
 161         $data = $this->STREAM->read($length);
 162         return (string)$data;
 163     }
 164
 165     /**
 166      * get translated string with particular number
 167      * @param integer $num
 168      * @return string translated string
 169      */
 170     function get_translation_number($num) {
 171         // get a string with particular number
 172         // TODO: Add simple hashing [check array, add if not already there]
 173         $this->load_tables(true);
 174         $meta = $this->TRANSLATIONS[$num];
 175         $length = $meta[0];
 176         $offset = $meta[1];
 177         $this->STREAM->seekto($offset);
 178         $data = $this->STREAM->read($length);
 179         return (string)$data;
 180     }
 181
 182     /**
 183      * binary search for string
 184      * @param string $string
 185      * @param integer $start
 186      * @param integer $end
 187      */
 188     function find_string($string, $start,$end) {
 189         //print "start: $start, end: $end\n";
 190         // Simple hashing to improve speed
 191         if (isset($this->_HASHED[$string])) return $this->_HASHED[$string];
 192
 193         if (abs($start-$end)<=1) {
 194             // we're done, if it's not it, bye bye
 195             $txt = $this->get_string_number($start);
 196             if ($string == $txt) {
 197                 $this->_HASHED[$string] = $start;
 198                 return $start;
 199             } else
 200                 return -1;
 201         } elseif ($start>$end) {
 202             return $this->find_string($string,$end,$start);
 203         }  else {
 204             $half = (int)(($start+$end)/2);
 205             $tst = $this->get_string_number($half);
 206             $cmp = strcmp($string,$tst);
 207             if ($cmp == 0) {
 208                 $this->_HASHED[$string] = $half;
 209                 return $half;
 210             } elseif ($cmp<0)
 211                 return $this->find_string($string,$start,$half);
 212             else
 213                 return $this->find_string($string,$half,$end);
 214         }
 215     }
 216
 217     /**
 218      * translate string
 219      * @param string $string English string
 220      * @return string translated string
 221      */
 222     function translate($string) {
 223         if ($this->error > 0) return $string;
 224         $num = $this->find_string($string, 0, $this->total);
 225         if ($num == -1)
 226             return $string;
 227         else
 228             return $this->get_translation_number($num);
 229     }
 230
 231     /**
 232      * extract plural forms header
 233      * @return string plural-forms header string
 234      */
 235     function get_plural_forms() {
 236         // lets assume message number 0 is header
 237         // this is true, right?
 238
 239         // cache header field for plural forms
 240         if (isset($this->pluralheader) && is_string($this->pluralheader))
 241             return $this->pluralheader;
 242         else {
 243             $header = $this->get_translation_number(0);
 244
 245             if (preg_match('/plural-forms: (.*)\n/i',$header,$regs)) {
 246                 $expr = $regs[1];
 247             } else {
 248                 $expr = "nplurals=2; plural=n == 1 ? 0 : 1;";
 249             }
 250             $this->pluralheader = $expr;
 251             return $expr;
 252         }
 253     }
 254
 255     /**
 256      * find out the appropriate form number
 257      * @param integer $n count
 258      * @return integer
 259      */
 260     function select_string($n) {
 261         $string = $this->get_plural_forms();
 262         $string = str_replace('nplurals',"\$total",$string);
 263         $string = str_replace("n",$n,$string);
 264         $string = str_replace('plural',"\$plural",$string);
 265
 266         $total = 0;
 267         $plural = 0;
 268
 269         eval("$string");
 270         if ($plural>=$total) $plural = 0;
 271         return $plural;
 272     }
 273
 274     /**
 275      * translate string with singular/plural forms
 276      * @param string $single English singural form of translation
 277      * @param string $plural English plural form of translation
 278      * @param string $number count
 279      * @return string
 280      */
 281     function ngettext($single, $plural, $number) {
 282         if ($this->error > 0) {
 283             $result=-1;
 284         } else {
 285             // find out the appropriate form
 286             $select = $this->select_string($number);
 287
 288             // this should contains all strings separated by NULLs
 289             $result = $this->find_string($single.chr(0).$plural,0,$this->total);
 290         }
 291         if ($result == -1) {
 292             if ($number != 1) return $plural;
 293             else return $single;
 294         } else {
 295             $result = $this->get_translation_number($result);
 296
 297             // lets try to parse all the NUL staff
 298             //$result = "proba0".chr(0)."proba1".chr(0)."proba2";
 299             $list = explode (chr(0), $result);
 300             return $list[$select];
 301         }
 302     }
 303 }