3 Copyright (c) 2003 Danilo Segan <danilo@kvota.net>.
4 Copyright (c) 2005 Nico Kaiser <nico@siriux.net>
6 This file is part of PHP-gettext.
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.
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.
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
25 * Provides a simple gettext replacement that works independently from
26 * the system's gettext abilities.
27 * It can read MO files and use them for translating strings.
28 * The files are passed to gettext_reader as a Stream (see streams.php)
30 * This version has the ability to cache all strings and translations to
31 * speed up the string lookup.
32 * While the cache is enabled by default, it can be switched off with the
33 * second parameter in the constructor (e.g. whenusing very large MO files
34 * that you don't want to keep in memory)
36 class gettext_reader {
38 var $error = 0; // public variable that holds error code (0 if no error)
41 var $BYTEORDER = 0; // 0: low endian, 1: big endian
43 var $short_circuit = false;
44 var $enable_cache = false;
45 var $originals = NULL; // offset of original table
46 var $translations = NULL; // offset of translation table
47 var $pluralheader = NULL; // cache header field for plural forms
48 var $total = 0; // total string count
49 var $table_originals = NULL; // table for original strings (offsets)
50 var $table_translations = NULL; // table for translated strings (offsets)
51 var $cache_translations = NULL; // original -> translation mapping
58 * Reads a 32bit Integer from the Stream
61 * @return Integer from the Stream
64 $stream = $this->STREAM->read(4);
65 if ($this->BYTEORDER == 0) {
67 $unpacked = unpack('V',$stream);
68 return array_shift($unpacked);
71 $unpacked = unpack('N',$stream);
72 return array_shift($unpacked);
77 * Reads an array of Integers from the Stream
79 * @param int count How many elements should be read
80 * @return Array of Integers
82 function readintarray($count) {
83 if ($this->BYTEORDER == 0) {
85 return unpack('V'.$count, $this->STREAM->read(4 * $count));
88 return unpack('N'.$count, $this->STREAM->read(4 * $count));
95 * @param object Reader the StreamReader object
96 * @param boolean enable_cache Enable or disable caching of strings (default on)
98 function gettext_reader($Reader, $enable_cache = true) {
99 // If there isn't a StreamReader, turn on short circuit mode.
101 $this->short_circuit = true;
105 // Caching can be turned off
106 $this->enable_cache = $enable_cache;
108 // $MAGIC1 = (int)0x950412de; //bug in PHP 5
109 $MAGIC1 = (int) - 1794895138;
110 // $MAGIC2 = (int)0xde120495; //bug
111 $MAGIC2 = (int) - 569244523;
113 $this->STREAM = $Reader;
114 $magic = $this->readint();
115 if ($magic == $MAGIC1) {
116 $this->BYTEORDER = 0;
117 } elseif ($magic == $MAGIC2) {
118 $this->BYTEORDER = 1;
120 $this->error = 1; // not MO file
124 // FIXME: Do we care about revision? We should.
125 $revision = $this->readint();
127 $this->total = $this->readint();
128 $this->originals = $this->readint();
129 $this->translations = $this->readint();
133 * Loads the translation tables from the MO file into the cache
134 * If caching is enabled, also loads all strings into a cache
135 * to speed up translation lookups
139 function load_tables() {
140 if (is_array($this->cache_translations) &&
141 is_array($this->table_originals) &&
142 is_array($this->table_translations))
145 /* get original and translations tables */
146 $this->STREAM->seekto($this->originals);
147 $this->table_originals = $this->readintarray($this->total * 2);
148 $this->STREAM->seekto($this->translations);
149 $this->table_translations = $this->readintarray($this->total * 2);
151 if ($this->enable_cache) {
152 $this->cache_translations = array ();
153 /* read all strings in the cache */
154 for ($i = 0; $i < $this->total; $i++) {
155 $this->STREAM->seekto($this->table_originals[$i * 2 + 2]);
156 $original = $this->STREAM->read($this->table_originals[$i * 2 + 1]);
157 $this->STREAM->seekto($this->table_translations[$i * 2 + 2]);
158 $translation = $this->STREAM->read($this->table_translations[$i * 2 + 1]);
159 $this->cache_translations[$original] = $translation;
165 * Returns a string from the "originals" table
168 * @param int num Offset number of original string
169 * @return string Requested string if found, otherwise ''
171 function get_original_string($num) {
172 $length = $this->table_originals[$num * 2 + 1];
173 $offset = $this->table_originals[$num * 2 + 2];
176 $this->STREAM->seekto($offset);
177 $data = $this->STREAM->read($length);
178 return (string)$data;
182 * Returns a string from the "translations" table
185 * @param int num Offset number of original string
186 * @return string Requested string if found, otherwise ''
188 function get_translation_string($num) {
189 $length = $this->table_translations[$num * 2 + 1];
190 $offset = $this->table_translations[$num * 2 + 2];
193 $this->STREAM->seekto($offset);
194 $data = $this->STREAM->read($length);
195 return (string)$data;
199 * Binary search for string
202 * @param string string
203 * @param int start (internally used in recursive function)
204 * @param int end (internally used in recursive function)
205 * @return int string number (offset in originals table)
207 function find_string($string, $start = -1, $end = -1) {
208 if (($start == -1) or ($end == -1)) {
209 // find_string is called with only one parameter, set start end end
213 if (abs($start - $end) <= 1) {
214 // We're done, now we either found the string, or it doesn't exist
215 $txt = $this->get_original_string($start);
220 } else if ($start > $end) {
221 // start > end -> turn around and start over
222 return $this->find_string($string, $end, $start);
224 // Divide table in two parts
225 $half = (int)(($start + $end) / 2);
226 $cmp = strcmp($string, $this->get_original_string($half));
228 // string is exactly in the middle => return it
231 // The string is in the upper half
232 return $this->find_string($string, $start, $half);
234 // The string is in the lower half
235 return $this->find_string($string, $half, $end);
240 * Translates a string
243 * @param string string to be translated
244 * @return string translated string (or original, if not found)
246 function translate($string) {
247 if ($this->short_circuit)
249 $this->load_tables();
251 if ($this->enable_cache) {
252 // Caching enabled, get translated string from cache
253 if (array_key_exists($string, $this->cache_translations))
254 return $this->cache_translations[$string];
258 // Caching not enabled, try to find string
259 $num = $this->find_string($string);
263 return $this->get_translation_string($num);
268 * Get possible plural forms from MO header
271 * @return string plural form header
273 function get_plural_forms() {
274 // lets assume message number 0 is header
275 // this is true, right?
276 $this->load_tables();
278 // cache header field for plural forms
279 if (! is_string($this->pluralheader)) {
280 if ($this->enable_cache) {
281 $header = $this->cache_translations[""];
283 $header = $this->get_translation_string(0);
285 if (eregi("plural-forms: (.*)\n", $header, $regs))
288 $expr = "nplurals=2; plural=n == 1 ? 0 : 1;";
289 $this->pluralheader = $expr;
291 return $this->pluralheader;
295 * Detects which plural form to take
299 * @return int array index of the right plural form
301 function select_string($n) {
302 $string = $this->get_plural_forms();
303 $string = str_replace('nplurals',"\$total",$string);
304 $string = str_replace("n",$n,$string);
305 $string = str_replace('plural',"\$plural",$string);
311 if ($plural >= $total) $plural = 0;
316 * Plural version of gettext
319 * @param string single
320 * @param string plural
321 * @param string number
322 * @return translated plural form
324 function ngettext($single, $plural, $number) {
325 if ($this->short_circuit) {
332 // find out the appropriate form
333 $select = $this->select_string($number);
335 // this should contains all strings separated by NULLs
336 $key = $single.chr(0).$plural;
339 if ($this->enable_cache) {
340 if (! array_key_exists($key, $this->cache_translations)) {
341 return ($number != 1) ? $plural : $single;
343 $result = $this->cache_translations[$key];
344 $list = explode(chr(0), $result);
345 return $list[$select];
348 $num = $this->find_string($key);
350 return ($number != 1) ? $plural : $single;
352 $result = $this->get_translation_string($num);
353 $list = explode(chr(0), $result);
354 return $list[$select];