Wordpress 2.5.1
[autoinstalls/wordpress.git] / wp-includes / gettext.php
1 <?php
2 /**
3  * PHP-Gettext External Library: gettext_reader class
4  *
5  * @package External
6  * @subpackage PHP-gettext
7  *
8  * @internal
9          Copyright (c) 2003 Danilo Segan <danilo@kvota.net>.
10          Copyright (c) 2005 Nico Kaiser <nico@siriux.net>
11
12          This file is part of PHP-gettext.
13
14          PHP-gettext is free software; you can redistribute it and/or modify
15          it under the terms of the GNU General Public License as published by
16          the Free Software Foundation; either version 2 of the License, or
17          (at your option) any later version.
18
19          PHP-gettext is distributed in the hope that it will be useful,
20          but WITHOUT ANY WARRANTY; without even the implied warranty of
21          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22          GNU General Public License for more details.
23
24          You should have received a copy of the GNU General Public License
25          along with PHP-gettext; if not, write to the Free Software
26          Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
27
28 */
29
30 /**
31  * Provides a simple gettext replacement that works independently from
32  * the system's gettext abilities.
33  * It can read MO files and use them for translating strings.
34  * The files are passed to gettext_reader as a Stream (see streams.php)
35  *
36  * This version has the ability to cache all strings and translations to
37  * speed up the string lookup.
38  * While the cache is enabled by default, it can be switched off with the
39  * second parameter in the constructor (e.g. whenusing very large MO files
40  * that you don't want to keep in memory)
41  */
42 class gettext_reader {
43         //public:
44          var $error = 0; // public variable that holds error code (0 if no error)
45
46          //private:
47         var $BYTEORDER = 0;        // 0: low endian, 1: big endian
48         var $STREAM = NULL;
49         var $short_circuit = false;
50         var $enable_cache = false;
51         var $originals = NULL;      // offset of original table
52         var $translations = NULL;    // offset of translation table
53         var $pluralheader = NULL;    // cache header field for plural forms
54         var $select_string_function = NULL; // cache function, which chooses plural forms
55         var $total = 0;          // total string count
56         var $table_originals = NULL;  // table for original strings (offsets)
57         var $table_translations = NULL;  // table for translated strings (offsets)
58         var $cache_translations = NULL;  // original -> translation mapping
59
60
61         /* Methods */
62
63
64         /**
65          * Reads a 32bit Integer from the Stream
66          *
67          * @access private
68          * @return Integer from the Stream
69          */
70         function readint() {
71                 if ($this->BYTEORDER == 0) {
72                         // low endian
73                         $low_end = unpack('V', $this->STREAM->read(4));
74                         return array_shift($low_end);
75                 } else {
76                         // big endian
77                         $big_end = unpack('N', $this->STREAM->read(4));
78                         return array_shift($big_end);
79                 }
80         }
81
82         /**
83          * Reads an array of Integers from the Stream
84          *
85          * @param int count How many elements should be read
86          * @return Array of Integers
87          */
88         function readintarray($count) {
89         if ($this->BYTEORDER == 0) {
90                         // low endian
91                         return unpack('V'.$count, $this->STREAM->read(4 * $count));
92                 } else {
93                         // big endian
94                         return unpack('N'.$count, $this->STREAM->read(4 * $count));
95                 }
96         }
97
98         /**
99          * Constructor
100          *
101          * @param object Reader the StreamReader object
102          * @param boolean enable_cache Enable or disable caching of strings (default on)
103          */
104         function gettext_reader($Reader, $enable_cache = true) {
105                 // If there isn't a StreamReader, turn on short circuit mode.
106                 if (! $Reader || isset($Reader->error) ) {
107                         $this->short_circuit = true;
108                         return;
109                 }
110
111                 // Caching can be turned off
112                 $this->enable_cache = $enable_cache;
113
114                 // $MAGIC1 = (int)0x950412de; //bug in PHP 5.0.2, see https://savannah.nongnu.org/bugs/?func=detailitem&item_id=10565
115                 $MAGIC1 = (int) - 1794895138;
116                 // $MAGIC2 = (int)0xde120495; //bug
117                 $MAGIC2 = (int) - 569244523;
118                 // 64-bit fix
119                 $MAGIC3 = (int) 2500072158;
120
121                 $this->STREAM = $Reader;
122                 $magic = $this->readint();
123                 if ($magic == $MAGIC1 || $magic == $MAGIC3) { // to make sure it works for 64-bit platforms
124                         $this->BYTEORDER = 0;
125                 } elseif ($magic == ($MAGIC2 & 0xFFFFFFFF)) {
126                         $this->BYTEORDER = 1;
127                 } else {
128                         $this->error = 1; // not MO file
129                         return false;
130                 }
131
132                 // FIXME: Do we care about revision? We should.
133                 $revision = $this->readint();
134
135                 $this->total = $this->readint();
136                 $this->originals = $this->readint();
137                 $this->translations = $this->readint();
138         }
139
140         /**
141          * Loads the translation tables from the MO file into the cache
142          * If caching is enabled, also loads all strings into a cache
143          * to speed up translation lookups
144          *
145          * @access private
146          */
147         function load_tables() {
148                 if (is_array($this->cache_translations) &&
149                         is_array($this->table_originals) &&
150                         is_array($this->table_translations))
151                         return;
152
153                 /* get original and translations tables */
154                 $this->STREAM->seekto($this->originals);
155                 $this->table_originals = $this->readintarray($this->total * 2);
156                 $this->STREAM->seekto($this->translations);
157                 $this->table_translations = $this->readintarray($this->total * 2);
158
159                 if ($this->enable_cache) {
160                         $this->cache_translations = array ();
161                         /* read all strings in the cache */
162                         for ($i = 0; $i < $this->total; $i++) {
163                                 $this->STREAM->seekto($this->table_originals[$i * 2 + 2]);
164                                 $original = $this->STREAM->read($this->table_originals[$i * 2 + 1]);
165                                 $this->STREAM->seekto($this->table_translations[$i * 2 + 2]);
166                                 $translation = $this->STREAM->read($this->table_translations[$i * 2 + 1]);
167                                 $this->cache_translations[$original] = $translation;
168                         }
169                 }
170         }
171
172         /**
173          * Returns a string from the "originals" table
174          *
175          * @access private
176          * @param int num Offset number of original string
177          * @return string Requested string if found, otherwise ''
178          */
179         function get_original_string($num) {
180                 $length = $this->table_originals[$num * 2 + 1];
181                 $offset = $this->table_originals[$num * 2 + 2];
182                 if (! $length)
183                         return '';
184                 $this->STREAM->seekto($offset);
185                 $data = $this->STREAM->read($length);
186                 return (string)$data;
187         }
188
189         /**
190          * Returns a string from the "translations" table
191          *
192          * @access private
193          * @param int num Offset number of original string
194          * @return string Requested string if found, otherwise ''
195          */
196         function get_translation_string($num) {
197                 $length = $this->table_translations[$num * 2 + 1];
198                 $offset = $this->table_translations[$num * 2 + 2];
199                 if (! $length)
200                         return '';
201                 $this->STREAM->seekto($offset);
202                 $data = $this->STREAM->read($length);
203                 return (string)$data;
204         }
205
206         /**
207          * Binary search for string
208          *
209          * @access private
210          * @param string string
211          * @param int start (internally used in recursive function)
212          * @param int end (internally used in recursive function)
213          * @return int string number (offset in originals table)
214          */
215         function find_string($string, $start = -1, $end = -1) {
216                 if (($start == -1) or ($end == -1)) {
217                         // find_string is called with only one parameter, set start end end
218                         $start = 0;
219                         $end = $this->total;
220                 }
221                 if (abs($start - $end) <= 1) {
222                         // We're done, now we either found the string, or it doesn't exist
223                         $txt = $this->get_original_string($start);
224                         if ($string == $txt)
225                                 return $start;
226                         else
227                                 return -1;
228                 } else if ($start > $end) {
229                         // start > end -> turn around and start over
230                         return $this->find_string($string, $end, $start);
231                 } else {
232                         // Divide table in two parts
233                         $half = (int)(($start + $end) / 2);
234                         $cmp = strcmp($string, $this->get_original_string($half));
235                         if ($cmp == 0)
236                                 // string is exactly in the middle => return it
237                                 return $half;
238                         else if ($cmp < 0)
239                                 // The string is in the upper half
240                                 return $this->find_string($string, $start, $half);
241                         else
242                                 // The string is in the lower half
243                                 return $this->find_string($string, $half, $end);
244                 }
245         }
246
247         /**
248          * Translates a string
249          *
250          * @access public
251          * @param string string to be translated
252          * @return string translated string (or original, if not found)
253          */
254         function translate($string) {
255                 if ($this->short_circuit)
256                         return $string;
257                 $this->load_tables();
258
259                 if ($this->enable_cache) {
260                         // Caching enabled, get translated string from cache
261                         if (array_key_exists($string, $this->cache_translations))
262                                 return $this->cache_translations[$string];
263                         else
264                                 return $string;
265                 } else {
266                         // Caching not enabled, try to find string
267                         $num = $this->find_string($string);
268                         if ($num == -1)
269                                 return $string;
270                         else
271                                 return $this->get_translation_string($num);
272                 }
273         }
274
275         /**
276          * Get possible plural forms from MO header
277          *
278          * @access private
279          * @return string plural form header
280          */
281         function get_plural_forms() {
282                 // lets assume message number 0 is header
283                 // this is true, right?
284                 $this->load_tables();
285
286                 // cache header field for plural forms
287                 if (! is_string($this->pluralheader)) {
288                         if ($this->enable_cache) {
289                                 $header = $this->cache_translations[""];
290                         } else {
291                                 $header = $this->get_translation_string(0);
292                         }
293                         $header .= "\n"; //make sure our regex matches
294                         if (eregi("plural-forms: ([^\n]*)\n", $header, $regs))
295                                 $expr = $regs[1];
296                         else
297                                 $expr = "nplurals=2; plural=n == 1 ? 0 : 1;";
298
299                         // add parentheses
300                         // important since PHP's ternary evaluates from left to right
301                         $expr.= ';';
302                         $res= '';
303                         $p= 0;
304                         for ($i= 0; $i < strlen($expr); $i++) {
305                                 $ch= $expr[$i];
306                                 switch ($ch) {
307                                         case '?':
308                                                 $res.= ' ? (';
309                                                 $p++;
310                                                 break;
311                                         case ':':
312                                                 $res.= ') : (';
313                                                 break;
314                                         case ';':
315                                                 $res.= str_repeat( ')', $p) . ';';
316                                                 $p= 0;
317                                                 break;
318                                         default:
319                                                 $res.= $ch;
320                                 }
321                         }
322                         $this->pluralheader = $res;
323                 }
324
325                 return $this->pluralheader;
326         }
327
328         /**
329          * Detects which plural form to take
330          *
331          * @access private
332          * @param n count
333          * @return int array index of the right plural form
334          */
335         function select_string($n) {
336                 if (is_null($this->select_string_function)) {
337                         $string = $this->get_plural_forms();
338                         if (preg_match("/nplurals\s*=\s*(\d+)\s*\;\s*plural\s*=\s*(.*?)\;+/", $string, $matches)) {
339                                 $nplurals = $matches[1];
340                                 $expression = $matches[2];
341                                 $expression = str_replace("n", '$n', $expression);
342                         } else {
343                                 $nplurals = 2;
344                                 $expression = ' $n == 1 ? 0 : 1 ';
345                         }
346                         $func_body = "
347                                 \$plural = ($expression);
348                                 return (\$plural <= $nplurals)? \$plural : \$plural - 1;";
349                         $this->select_string_function = create_function('$n', $func_body);
350                 }
351                 return call_user_func($this->select_string_function, $n);
352         }
353
354         /**
355          * Plural version of gettext
356          *
357          * @access public
358          * @param string single
359          * @param string plural
360          * @param string number
361          * @return translated plural form
362          */
363         function ngettext($single, $plural, $number) {
364                 if ($this->short_circuit) {
365                         if ($number != 1)
366                                 return $plural;
367                         else
368                                 return $single;
369                 }
370
371                 // find out the appropriate form
372                 $select = $this->select_string($number);
373
374                 // this should contains all strings separated by NULLs
375                 $key = $single.chr(0).$plural;
376
377
378                 if ($this->enable_cache) {
379                         if (! array_key_exists($key, $this->cache_translations)) {
380                                 return ($number != 1) ? $plural : $single;
381                         } else {
382                                 $result = $this->cache_translations[$key];
383                                 $list = explode(chr(0), $result);
384                                 return $list[$select];
385                         }
386                 } else {
387                         $num = $this->find_string($key);
388                         if ($num == -1) {
389                                 return ($number != 1) ? $plural : $single;
390                         } else {
391                                 $result = $this->get_translation_string($num);
392                                 $list = explode(chr(0), $result);
393                                 return $list[$select];
394                         }
395                 }
396         }
397
398 }
399
400 ?>