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1 | <?php | |
2 | /** | |
3 | * Data storage for links. | |
4 | * | |
5 | * This object behaves like an associative array. | |
6 | * | |
7 | * Example: | |
8 | * $myLinks = new LinkDB(); | |
9 | * echo $myLinks['20110826_161819']['title']; | |
10 | * foreach ($myLinks as $link) | |
11 | * echo $link['title'].' at url '.$link['url'].'; description:'.$link['description']; | |
12 | * | |
13 | * Available keys: | |
14 | * - description: description of the entry | |
15 | * - linkdate: date of the creation of this entry, in the form YYYYMMDD_HHMMSS | |
16 | * (e.g.'20110914_192317') | |
17 | * - private: Is this link private? 0=no, other value=yes | |
18 | * - tags: tags attached to this entry (separated by spaces) | |
19 | * - title Title of the link | |
20 | * - url URL of the link. Can be absolute or relative. | |
21 | * Relative URLs are permalinks (e.g.'?m-ukcw') | |
22 | * | |
23 | * Implements 3 interfaces: | |
24 | * - ArrayAccess: behaves like an associative array; | |
25 | * - Countable: there is a count() method; | |
26 | * - Iterator: usable in foreach () loops. | |
27 | */ | |
28 | class LinkDB implements Iterator, Countable, ArrayAccess | |
29 | { | |
30 | // Links are stored as a PHP serialized string | |
31 | private $datastore; | |
32 | ||
33 | // Datastore PHP prefix | |
34 | protected static $phpPrefix = '<?php /* '; | |
35 | ||
36 | // Datastore PHP suffix | |
37 | protected static $phpSuffix = ' */ ?>'; | |
38 | ||
39 | // List of links (associative array) | |
40 | // - key: link date (e.g. "20110823_124546"), | |
41 | // - value: associative array (keys: title, description...) | |
42 | private $links; | |
43 | ||
44 | // List of all recorded URLs (key=url, value=linkdate) | |
45 | // for fast reserve search (url-->linkdate) | |
46 | private $urls; | |
47 | ||
48 | // List of linkdate keys (for the Iterator interface implementation) | |
49 | private $keys; | |
50 | ||
51 | // Position in the $this->keys array (for the Iterator interface) | |
52 | private $position; | |
53 | ||
54 | // Is the user logged in? (used to filter private links) | |
55 | private $loggedIn; | |
56 | ||
57 | // Hide public links | |
58 | private $hidePublicLinks; | |
59 | ||
60 | /** | |
61 | * Creates a new LinkDB | |
62 | * | |
63 | * Checks if the datastore exists; else, attempts to create a dummy one. | |
64 | * | |
65 | * @param $isLoggedIn is the user logged in? | |
66 | */ | |
67 | function __construct($datastore, $isLoggedIn, $hidePublicLinks) | |
68 | { | |
69 | $this->datastore = $datastore; | |
70 | $this->loggedIn = $isLoggedIn; | |
71 | $this->hidePublicLinks = $hidePublicLinks; | |
72 | $this->checkDB(); | |
73 | $this->readdb(); | |
74 | } | |
75 | ||
76 | /** | |
77 | * Countable - Counts elements of an object | |
78 | */ | |
79 | public function count() | |
80 | { | |
81 | return count($this->links); | |
82 | } | |
83 | ||
84 | /** | |
85 | * ArrayAccess - Assigns a value to the specified offset | |
86 | */ | |
87 | public function offsetSet($offset, $value) | |
88 | { | |
89 | // TODO: use exceptions instead of "die" | |
90 | if (!$this->loggedIn) { | |
91 | die('You are not authorized to add a link.'); | |
92 | } | |
93 | if (empty($value['linkdate']) || empty($value['url'])) { | |
94 | die('Internal Error: A link should always have a linkdate and URL.'); | |
95 | } | |
96 | if (empty($offset)) { | |
97 | die('You must specify a key.'); | |
98 | } | |
99 | $this->links[$offset] = $value; | |
100 | $this->urls[$value['url']]=$offset; | |
101 | } | |
102 | ||
103 | /** | |
104 | * ArrayAccess - Whether or not an offset exists | |
105 | */ | |
106 | public function offsetExists($offset) | |
107 | { | |
108 | return array_key_exists($offset, $this->links); | |
109 | } | |
110 | ||
111 | /** | |
112 | * ArrayAccess - Unsets an offset | |
113 | */ | |
114 | public function offsetUnset($offset) | |
115 | { | |
116 | if (!$this->loggedIn) { | |
117 | // TODO: raise an exception | |
118 | die('You are not authorized to delete a link.'); | |
119 | } | |
120 | $url = $this->links[$offset]['url']; | |
121 | unset($this->urls[$url]); | |
122 | unset($this->links[$offset]); | |
123 | } | |
124 | ||
125 | /** | |
126 | * ArrayAccess - Returns the value at specified offset | |
127 | */ | |
128 | public function offsetGet($offset) | |
129 | { | |
130 | return isset($this->links[$offset]) ? $this->links[$offset] : null; | |
131 | } | |
132 | ||
133 | /** | |
134 | * Iterator - Returns the current element | |
135 | */ | |
136 | function current() | |
137 | { | |
138 | return $this->links[$this->keys[$this->position]]; | |
139 | } | |
140 | ||
141 | /** | |
142 | * Iterator - Returns the key of the current element | |
143 | */ | |
144 | function key() | |
145 | { | |
146 | return $this->keys[$this->position]; | |
147 | } | |
148 | ||
149 | /** | |
150 | * Iterator - Moves forward to next element | |
151 | */ | |
152 | function next() | |
153 | { | |
154 | ++$this->position; | |
155 | } | |
156 | ||
157 | /** | |
158 | * Iterator - Rewinds the Iterator to the first element | |
159 | * | |
160 | * Entries are sorted by date (latest first) | |
161 | */ | |
162 | function rewind() | |
163 | { | |
164 | $this->keys = array_keys($this->links); | |
165 | rsort($this->keys); | |
166 | $this->position = 0; | |
167 | } | |
168 | ||
169 | /** | |
170 | * Iterator - Checks if current position is valid | |
171 | */ | |
172 | function valid() | |
173 | { | |
174 | return isset($this->keys[$this->position]); | |
175 | } | |
176 | ||
177 | /** | |
178 | * Checks if the DB directory and file exist | |
179 | * | |
180 | * If no DB file is found, creates a dummy DB. | |
181 | */ | |
182 | private function checkDB() | |
183 | { | |
184 | if (file_exists($this->datastore)) { | |
185 | return; | |
186 | } | |
187 | ||
188 | // Create a dummy database for example | |
189 | $this->links = array(); | |
190 | $link = array( | |
191 | 'title'=>' Shaarli: the personal, minimalist, super-fast, no-database delicious clone', | |
192 | 'url'=>'https://github.com/shaarli/Shaarli/wiki', | |
193 | 'description'=>'Welcome to Shaarli! This is your first public bookmark. To edit or delete me, you must first login. | |
194 | ||
195 | To learn how to use Shaarli, consult the link "Help/documentation" at the bottom of this page. | |
196 | ||
197 | You use the community supported version of the original Shaarli project, by Sebastien Sauvage.', | |
198 | 'private'=>0, | |
199 | 'linkdate'=> date('Ymd_His'), | |
200 | 'tags'=>'opensource software' | |
201 | ); | |
202 | $this->links[$link['linkdate']] = $link; | |
203 | ||
204 | $link = array( | |
205 | 'title'=>'My secret stuff... - Pastebin.com', | |
206 | 'url'=>'http://sebsauvage.net/paste/?8434b27936c09649#bR7XsXhoTiLcqCpQbmOpBi3rq2zzQUC5hBI7ZT1O3x8=', | |
207 | 'description'=>'Shhhh! I\'m a private link only YOU can see. You can delete me too.', | |
208 | 'private'=>1, | |
209 | 'linkdate'=> date('Ymd_His', strtotime('-1 minute')), | |
210 | 'tags'=>'secretstuff' | |
211 | ); | |
212 | $this->links[$link['linkdate']] = $link; | |
213 | ||
214 | // Write database to disk | |
215 | // TODO: raise an exception if the file is not write-able | |
216 | file_put_contents( | |
217 | $this->datastore, | |
218 | self::$phpPrefix.base64_encode(gzdeflate(serialize($this->links))).self::$phpSuffix | |
219 | ); | |
220 | } | |
221 | ||
222 | /** | |
223 | * Reads database from disk to memory | |
224 | */ | |
225 | private function readdb() | |
226 | { | |
227 | ||
228 | // Public links are hidden and user not logged in => nothing to show | |
229 | if ($this->hidePublicLinks && !$this->loggedIn) { | |
230 | $this->links = array(); | |
231 | return; | |
232 | } | |
233 | ||
234 | // Read data | |
235 | // Note that gzinflate is faster than gzuncompress. | |
236 | // See: http://www.php.net/manual/en/function.gzdeflate.php#96439 | |
237 | $this->links = array(); | |
238 | ||
239 | if (file_exists($this->datastore)) { | |
240 | $this->links = unserialize(gzinflate(base64_decode( | |
241 | substr(file_get_contents($this->datastore), | |
242 | strlen(self::$phpPrefix), -strlen(self::$phpSuffix))))); | |
243 | } | |
244 | ||
245 | // If user is not logged in, filter private links. | |
246 | if (!$this->loggedIn) { | |
247 | $toremove = array(); | |
248 | foreach ($this->links as $link) { | |
249 | if ($link['private'] != 0) { | |
250 | $toremove[] = $link['linkdate']; | |
251 | } | |
252 | } | |
253 | foreach ($toremove as $linkdate) { | |
254 | unset($this->links[$linkdate]); | |
255 | } | |
256 | } | |
257 | ||
258 | // Keep the list of the mapping URLs-->linkdate up-to-date. | |
259 | $this->urls = array(); | |
260 | foreach ($this->links as $link) { | |
261 | $this->urls[$link['url']] = $link['linkdate']; | |
262 | } | |
263 | ||
264 | // Escape links data | |
265 | foreach($this->links as &$link) { | |
266 | sanitizeLink($link); | |
267 | } | |
268 | } | |
269 | ||
270 | /** | |
271 | * Saves the database from memory to disk | |
272 | */ | |
273 | public function savedb() | |
274 | { | |
275 | if (!$this->loggedIn) { | |
276 | // TODO: raise an Exception instead | |
277 | die('You are not authorized to change the database.'); | |
278 | } | |
279 | file_put_contents( | |
280 | $this->datastore, | |
281 | self::$phpPrefix.base64_encode(gzdeflate(serialize($this->links))).self::$phpSuffix | |
282 | ); | |
283 | invalidateCaches(); | |
284 | } | |
285 | ||
286 | /** | |
287 | * Returns the link for a given URL, or False if it does not exist. | |
288 | */ | |
289 | public function getLinkFromUrl($url) | |
290 | { | |
291 | if (isset($this->urls[$url])) { | |
292 | return $this->links[$this->urls[$url]]; | |
293 | } | |
294 | return false; | |
295 | } | |
296 | ||
297 | /** | |
298 | * Returns the list of links corresponding to a full-text search | |
299 | * | |
300 | * Searches: | |
301 | * - in the URLs, title and description; | |
302 | * - are case-insensitive. | |
303 | * | |
304 | * Example: | |
305 | * print_r($mydb->filterFulltext('hollandais')); | |
306 | * | |
307 | * mb_convert_case($val, MB_CASE_LOWER, 'UTF-8') | |
308 | * - allows to perform searches on Unicode text | |
309 | * - see https://github.com/shaarli/Shaarli/issues/75 for examples | |
310 | */ | |
311 | public function filterFulltext($searchterms) | |
312 | { | |
313 | // FIXME: explode(' ',$searchterms) and perform a AND search. | |
314 | // FIXME: accept double-quotes to search for a string "as is"? | |
315 | $filtered = array(); | |
316 | $search = mb_convert_case($searchterms, MB_CASE_LOWER, 'UTF-8'); | |
317 | $keys = array('title', 'description', 'url', 'tags'); | |
318 | ||
319 | foreach ($this->links as $link) { | |
320 | $found = false; | |
321 | ||
322 | foreach ($keys as $key) { | |
323 | if (strpos(mb_convert_case($link[$key], MB_CASE_LOWER, 'UTF-8'), | |
324 | $search) !== false) { | |
325 | $found = true; | |
326 | } | |
327 | } | |
328 | ||
329 | if ($found) { | |
330 | $filtered[$link['linkdate']] = $link; | |
331 | } | |
332 | } | |
333 | krsort($filtered); | |
334 | return $filtered; | |
335 | } | |
336 | ||
337 | /** | |
338 | * Returns the list of links associated with a given list of tags | |
339 | * | |
340 | * You can specify one or more tags, separated by space or a comma, e.g. | |
341 | * print_r($mydb->filterTags('linux programming')); | |
342 | */ | |
343 | public function filterTags($tags, $casesensitive=false) | |
344 | { | |
345 | // Same as above, we use UTF-8 conversion to handle various graphemes (i.e. cyrillic, or greek) | |
346 | // FIXME: is $casesensitive ever true? | |
347 | $t = str_replace( | |
348 | ',', ' ', | |
349 | ($casesensitive ? $tags : mb_convert_case($tags, MB_CASE_LOWER, 'UTF-8')) | |
350 | ); | |
351 | ||
352 | $searchtags = explode(' ', $t); | |
353 | $filtered = array(); | |
354 | ||
355 | foreach ($this->links as $l) { | |
356 | $linktags = explode( | |
357 | ' ', | |
358 | ($casesensitive ? $l['tags']:mb_convert_case($l['tags'], MB_CASE_LOWER, 'UTF-8')) | |
359 | ); | |
360 | ||
361 | if (count(array_intersect($linktags, $searchtags)) == count($searchtags)) { | |
362 | $filtered[$l['linkdate']] = $l; | |
363 | } | |
364 | } | |
365 | krsort($filtered); | |
366 | return $filtered; | |
367 | } | |
368 | ||
369 | ||
370 | /** | |
371 | * Returns the list of articles for a given day, chronologically sorted | |
372 | * | |
373 | * Day must be in the form 'YYYYMMDD' (e.g. '20120125'), e.g. | |
374 | * print_r($mydb->filterDay('20120125')); | |
375 | */ | |
376 | public function filterDay($day) | |
377 | { | |
378 | if (! checkDateFormat('Ymd', $day)) { | |
379 | throw new Exception('Invalid date format'); | |
380 | } | |
381 | ||
382 | $filtered = array(); | |
383 | foreach ($this->links as $l) { | |
384 | if (startsWith($l['linkdate'], $day)) { | |
385 | $filtered[$l['linkdate']] = $l; | |
386 | } | |
387 | } | |
388 | ksort($filtered); | |
389 | return $filtered; | |
390 | } | |
391 | ||
392 | /** | |
393 | * Returns the article corresponding to a smallHash | |
394 | */ | |
395 | public function filterSmallHash($smallHash) | |
396 | { | |
397 | $filtered = array(); | |
398 | foreach ($this->links as $l) { | |
399 | if ($smallHash == smallHash($l['linkdate'])) { | |
400 | // Yes, this is ugly and slow | |
401 | $filtered[$l['linkdate']] = $l; | |
402 | return $filtered; | |
403 | } | |
404 | } | |
405 | return $filtered; | |
406 | } | |
407 | ||
408 | /** | |
409 | * Returns the list of all tags | |
410 | * Output: associative array key=tags, value=0 | |
411 | */ | |
412 | public function allTags() | |
413 | { | |
414 | $tags = array(); | |
415 | foreach ($this->links as $link) { | |
416 | foreach (explode(' ', $link['tags']) as $tag) { | |
417 | if (!empty($tag)) { | |
418 | $tags[$tag] = (empty($tags[$tag]) ? 1 : $tags[$tag] + 1); | |
419 | } | |
420 | } | |
421 | } | |
422 | // Sort tags by usage (most used tag first) | |
423 | arsort($tags); | |
424 | return $tags; | |
425 | } | |
426 | ||
427 | /** | |
428 | * Returns the list of days containing articles (oldest first) | |
429 | * Output: An array containing days (in format YYYYMMDD). | |
430 | */ | |
431 | public function days() | |
432 | { | |
433 | $linkDays = array(); | |
434 | foreach (array_keys($this->links) as $day) { | |
435 | $linkDays[substr($day, 0, 8)] = 0; | |
436 | } | |
437 | $linkDays = array_keys($linkDays); | |
438 | sort($linkDays); | |
439 | return $linkDays; | |
440 | } | |
441 | } | |
442 | ?> |