application/legacy/LegacyLinkDB.php

   1 <?php
   2
   3 namespace Shaarli\Legacy;
   4
   5 use ArrayAccess;
   6 use Countable;
   7 use DateTime;
   8 use Iterator;
   9 use Shaarli\Bookmark\Exception\BookmarkNotFoundException;
  10 use Shaarli\Exceptions\IOException;
  11 use Shaarli\Helper\FileUtils;
  12 use Shaarli\Render\PageCacheManager;
  13
  14 /**
  15  * Data storage for bookmarks.
  16  *
  17  * This object behaves like an associative array.
  18  *
  19  * Example:
  20  *    $myLinks = new LinkDB();
  21  *    echo $myLinks[350]['title'];
  22  *    foreach ($myLinks as $link)
  23  *       echo $link['title'].' at url '.$link['url'].'; description:'.$link['description'];
  24  *
  25  * Available keys:
  26  *  - id:       primary key, incremental integer identifier (persistent)
  27  *  - description: description of the entry
  28  *  - created:  creation date of this entry, DateTime object.
  29  *  - updated:  last modification date of this entry, DateTime object.
  30  *  - private:  Is this link private? 0=no, other value=yes
  31  *  - tags:     tags attached to this entry (separated by spaces)
  32  *  - title     Title of the link
  33  *  - url       URL of the link. Used for displayable bookmarks.
  34  *              Can be absolute or relative in the database but the relative bookmarks
  35  *              will be converted to absolute ones in templates.
  36  *  - real_url  Raw URL in stored in the DB (absolute or relative).
  37  *  - shorturl  Permalink smallhash
  38  *
  39  * Implements 3 interfaces:
  40  *  - ArrayAccess: behaves like an associative array;
  41  *  - Countable:   there is a count() method;
  42  *  - Iterator:    usable in foreach () loops.
  43  *
  44  * ID mechanism:
  45  *   ArrayAccess is implemented in a way that will allow to access a link
  46  *   with the unique identifier ID directly with $link[ID].
  47  *   Note that it's not the real key of the link array attribute.
  48  *   This mechanism is in place to have persistent link IDs,
  49  *   even though the internal array is reordered by date.
  50  *   Example:
  51  *     - DB: link #1 (2010-01-01) link #2 (2016-01-01)
  52  *     - Order: #2 #1
  53  *     - Import bookmarks containing: link #3 (2013-01-01)
  54  *     - New DB: link #1 (2010-01-01) link #2 (2016-01-01) link #3 (2013-01-01)
  55  *     - Real order: #2 #3 #1
  56  *
  57  * @deprecated
  58  */
  59 class LegacyLinkDB implements Iterator, Countable, ArrayAccess
  60 {
  61     // Links are stored as a PHP serialized string
  62     private $datastore;
  63
  64     // Link date storage format
  65     const LINK_DATE_FORMAT = 'Ymd_His';
  66
  67     // List of bookmarks (associative array)
  68     //  - key:   link date (e.g. "20110823_124546"),
  69     //  - value: associative array (keys: title, description...)
  70     private $links;
  71
  72     // List of all recorded URLs (key=url, value=link offset)
  73     // for fast reserve search (url-->link offset)
  74     private $urls;
  75
  76     /**
  77      * @var array List of all bookmarks IDS mapped with their array offset.
  78      *            Map: id->offset.
  79      */
  80     protected $ids;
  81
  82     // List of offset keys (for the Iterator interface implementation)
  83     private $keys;
  84
  85     // Position in the $this->keys array (for the Iterator interface)
  86     private $position;
  87
  88     // Is the user logged in? (used to filter private bookmarks)
  89     private $loggedIn;
  90
  91     // Hide public bookmarks
  92     private $hidePublicLinks;
  93
  94     /**
  95      * Creates a new LinkDB
  96      *
  97      * Checks if the datastore exists; else, attempts to create a dummy one.
  98      *
  99      * @param string  $datastore        datastore file path.
 100      * @param boolean $isLoggedIn       is the user logged in?
 101      * @param boolean $hidePublicLinks  if true all bookmarks are private.
 102      */
 103     public function __construct(
 104         $datastore,
 105         $isLoggedIn,
 106         $hidePublicLinks
 107     ) {
 108
 109         $this->datastore = $datastore;
 110         $this->loggedIn = $isLoggedIn;
 111         $this->hidePublicLinks = $hidePublicLinks;
 112         $this->check();
 113         $this->read();
 114     }
 115
 116     /**
 117      * Countable - Counts elements of an object
 118      */
 119     public function count()
 120     {
 121         return count($this->links);
 122     }
 123
 124     /**
 125      * ArrayAccess - Assigns a value to the specified offset
 126      */
 127     public function offsetSet($offset, $value)
 128     {
 129         // TODO: use exceptions instead of "die"
 130         if (!$this->loggedIn) {
 131             die(t('You are not authorized to add a link.'));
 132         }
 133         if (!isset($value['id']) || empty($value['url'])) {
 134             die(t('Internal Error: A link should always have an id and URL.'));
 135         }
 136         if (($offset !== null && !is_int($offset)) || !is_int($value['id'])) {
 137             die(t('You must specify an integer as a key.'));
 138         }
 139         if ($offset !== null && $offset !== $value['id']) {
 140             die(t('Array offset and link ID must be equal.'));
 141         }
 142
 143         // If the link exists, we reuse the real offset, otherwise new entry
 144         $existing = $this->getLinkOffset($offset);
 145         if ($existing !== null) {
 146             $offset = $existing;
 147         } else {
 148             $offset = count($this->links);
 149         }
 150         $this->links[$offset] = $value;
 151         $this->urls[$value['url']] = $offset;
 152         $this->ids[$value['id']] = $offset;
 153     }
 154
 155     /**
 156      * ArrayAccess - Whether or not an offset exists
 157      */
 158     public function offsetExists($offset)
 159     {
 160         return array_key_exists($this->getLinkOffset($offset), $this->links);
 161     }
 162
 163     /**
 164      * ArrayAccess - Unsets an offset
 165      */
 166     public function offsetUnset($offset)
 167     {
 168         if (!$this->loggedIn) {
 169             // TODO: raise an exception
 170             die('You are not authorized to delete a link.');
 171         }
 172         $realOffset = $this->getLinkOffset($offset);
 173         $url = $this->links[$realOffset]['url'];
 174         unset($this->urls[$url]);
 175         unset($this->ids[$realOffset]);
 176         unset($this->links[$realOffset]);
 177     }
 178
 179     /**
 180      * ArrayAccess - Returns the value at specified offset
 181      */
 182     public function offsetGet($offset)
 183     {
 184         $realOffset = $this->getLinkOffset($offset);
 185         return isset($this->links[$realOffset]) ? $this->links[$realOffset] : null;
 186     }
 187
 188     /**
 189      * Iterator - Returns the current element
 190      */
 191     public function current()
 192     {
 193         return $this[$this->keys[$this->position]];
 194     }
 195
 196     /**
 197      * Iterator - Returns the key of the current element
 198      */
 199     public function key()
 200     {
 201         return $this->keys[$this->position];
 202     }
 203
 204     /**
 205      * Iterator - Moves forward to next element
 206      */
 207     public function next()
 208     {
 209         ++$this->position;
 210     }
 211
 212     /**
 213      * Iterator - Rewinds the Iterator to the first element
 214      *
 215      * Entries are sorted by date (latest first)
 216      */
 217     public function rewind()
 218     {
 219         $this->keys = array_keys($this->ids);
 220         $this->position = 0;
 221     }
 222
 223     /**
 224      * Iterator - Checks if current position is valid
 225      */
 226     public function valid()
 227     {
 228         return isset($this->keys[$this->position]);
 229     }
 230
 231     /**
 232      * Checks if the DB directory and file exist
 233      *
 234      * If no DB file is found, creates a dummy DB.
 235      */
 236     private function check()
 237     {
 238         if (file_exists($this->datastore)) {
 239             return;
 240         }
 241
 242         // Create a dummy database for example
 243         $this->links = [];
 244         $link = [
 245             'id' => 1,
 246             'title' => t('The personal, minimalist, super-fast, database free, bookmarking service'),
 247             'url' => 'https://shaarli.readthedocs.io',
 248             'description' => t(
 249                 'Welcome to Shaarli! This is your first public bookmark. '
 250                 . 'To edit or delete me, you must first login.
 251
 252 To learn how to use Shaarli, consult the link "Documentation" at the bottom of this page.
 253
 254 You use the community supported version of the original Shaarli project, by Sebastien Sauvage.'
 255             ),
 256             'private' => 0,
 257             'created' => new DateTime(),
 258             'tags' => 'opensource software',
 259             'sticky' => false,
 260         ];
 261         $link['shorturl'] = link_small_hash($link['created'], $link['id']);
 262         $this->links[1] = $link;
 263
 264         $link = [
 265             'id' => 0,
 266             'title' => t('My secret stuff... - Pastebin.com'),
 267             'url' => 'http://sebsauvage.net/paste/?8434b27936c09649#bR7XsXhoTiLcqCpQbmOpBi3rq2zzQUC5hBI7ZT1O3x8=',
 268             'description' => t('Shhhh! I\'m a private link only YOU can see. You can delete me too.'),
 269             'private' => 1,
 270             'created' => new DateTime('1 minute ago'),
 271             'tags' => 'secretstuff',
 272             'sticky' => false,
 273         ];
 274         $link['shorturl'] = link_small_hash($link['created'], $link['id']);
 275         $this->links[0] = $link;
 276
 277         // Write database to disk
 278         $this->write();
 279     }
 280
 281     /**
 282      * Reads database from disk to memory
 283      */
 284     private function read()
 285     {
 286         // Public bookmarks are hidden and user not logged in => nothing to show
 287         if ($this->hidePublicLinks && !$this->loggedIn) {
 288             $this->links = [];
 289             return;
 290         }
 291
 292         $this->urls = [];
 293         $this->ids = [];
 294         $this->links = FileUtils::readFlatDB($this->datastore, []);
 295
 296         $toremove = [];
 297         foreach ($this->links as $key => &$link) {
 298             if (!$this->loggedIn && $link['private'] != 0) {
 299                 // Transition for not upgraded databases.
 300                 unset($this->links[$key]);
 301                 continue;
 302             }
 303
 304             // Sanitize data fields.
 305             sanitizeLink($link);
 306
 307             // Remove private tags if the user is not logged in.
 308             if (!$this->loggedIn) {
 309                 $link['tags'] = preg_replace('/(^|\s+)\.[^($|\s)]+\s*/', ' ', $link['tags']);
 310             }
 311
 312             $link['real_url'] = $link['url'];
 313
 314             $link['sticky'] = isset($link['sticky']) ? $link['sticky'] : false;
 315
 316             // To be able to load bookmarks before running the update, and prepare the update
 317             if (!isset($link['created'])) {
 318                 $link['id'] = $link['linkdate'];
 319                 $link['created'] = DateTime::createFromFormat(self::LINK_DATE_FORMAT, $link['linkdate']);
 320                 if (!empty($link['updated'])) {
 321                     $link['updated'] = DateTime::createFromFormat(self::LINK_DATE_FORMAT, $link['updated']);
 322                 }
 323                 $link['shorturl'] = smallHash($link['linkdate']);
 324             }
 325
 326             $this->urls[$link['url']] = $key;
 327             $this->ids[$link['id']] = $key;
 328         }
 329     }
 330
 331     /**
 332      * Saves the database from memory to disk
 333      *
 334      * @throws IOException the datastore is not writable
 335      */
 336     private function write()
 337     {
 338         $this->reorder();
 339         FileUtils::writeFlatDB($this->datastore, $this->links);
 340     }
 341
 342     /**
 343      * Saves the database from memory to disk
 344      *
 345      * @param string $pageCacheDir page cache directory
 346      */
 347     public function save($pageCacheDir)
 348     {
 349         if (!$this->loggedIn) {
 350             // TODO: raise an Exception instead
 351             die('You are not authorized to change the database.');
 352         }
 353
 354         $this->write();
 355
 356         $pageCacheManager = new PageCacheManager($pageCacheDir, $this->loggedIn);
 357         $pageCacheManager->invalidateCaches();
 358     }
 359
 360     /**
 361      * Returns the link for a given URL, or False if it does not exist.
 362      *
 363      * @param string $url URL to search for
 364      *
 365      * @return mixed the existing link if it exists, else 'false'
 366      */
 367     public function getLinkFromUrl($url)
 368     {
 369         if (isset($this->urls[$url])) {
 370             return $this->links[$this->urls[$url]];
 371         }
 372         return false;
 373     }
 374
 375     /**
 376      * Returns the shaare corresponding to a smallHash.
 377      *
 378      * @param string $request QUERY_STRING server parameter.
 379      *
 380      * @return array $filtered array containing permalink data.
 381      *
 382      * @throws BookmarkNotFoundException if the smallhash is malformed or doesn't match any link.
 383      */
 384     public function filterHash($request)
 385     {
 386         $request = substr($request, 0, 6);
 387         $linkFilter = new LegacyLinkFilter($this->links);
 388         return $linkFilter->filter(LegacyLinkFilter::$FILTER_HASH, $request);
 389     }
 390
 391     /**
 392      * Returns the list of articles for a given day.
 393      *
 394      * @param string $request day to filter. Format: YYYYMMDD.
 395      *
 396      * @return array list of shaare found.
 397      */
 398     public function filterDay($request)
 399     {
 400         $linkFilter = new LegacyLinkFilter($this->links);
 401         return $linkFilter->filter(LegacyLinkFilter::$FILTER_DAY, $request);
 402     }
 403
 404     /**
 405      * Filter bookmarks according to search parameters.
 406      *
 407      * @param array  $filterRequest  Search request content. Supported keys:
 408      *                                - searchtags: list of tags
 409      *                                - searchterm: term search
 410      * @param bool   $casesensitive  Optional: Perform case sensitive filter
 411      * @param string $visibility     return only all/private/public bookmarks
 412      * @param bool   $untaggedonly   return only untagged bookmarks
 413      *
 414      * @return array filtered bookmarks, all bookmarks if no suitable filter was provided.
 415      */
 416     public function filterSearch(
 417         $filterRequest = [],
 418         $casesensitive = false,
 419         $visibility = 'all',
 420         $untaggedonly = false
 421     ) {
 422
 423         // Filter link database according to parameters.
 424         $searchtags = isset($filterRequest['searchtags']) ? escape($filterRequest['searchtags']) : '';
 425         $searchterm = isset($filterRequest['searchterm']) ? escape($filterRequest['searchterm']) : '';
 426
 427         // Search tags + fullsearch - blank string parameter will return all bookmarks.
 428         $type = LegacyLinkFilter::$FILTER_TAG | LegacyLinkFilter::$FILTER_TEXT; // == "vuotext"
 429         $request = [$searchtags, $searchterm];
 430
 431         $linkFilter = new LegacyLinkFilter($this);
 432         return $linkFilter->filter($type, $request, $casesensitive, $visibility, $untaggedonly);
 433     }
 434
 435     /**
 436      * Returns the list tags appearing in the bookmarks with the given tags
 437      *
 438      * @param array  $filteringTags tags selecting the bookmarks to consider
 439      * @param string $visibility    process only all/private/public bookmarks
 440      *
 441      * @return array tag => linksCount
 442      */
 443     public function linksCountPerTag($filteringTags = [], $visibility = 'all')
 444     {
 445         $links = $this->filterSearch(['searchtags' => $filteringTags], false, $visibility);
 446         $tags = [];
 447         $caseMapping = [];
 448         foreach ($links as $link) {
 449             foreach (preg_split('/\s+/', $link['tags'], 0, PREG_SPLIT_NO_EMPTY) as $tag) {
 450                 if (empty($tag)) {
 451                     continue;
 452                 }
 453                 // The first case found will be displayed.
 454                 if (!isset($caseMapping[strtolower($tag)])) {
 455                     $caseMapping[strtolower($tag)] = $tag;
 456                     $tags[$caseMapping[strtolower($tag)]] = 0;
 457                 }
 458                 $tags[$caseMapping[strtolower($tag)]]++;
 459             }
 460         }
 461
 462         /*
 463          * Formerly used arsort(), which doesn't define the sort behaviour for equal values.
 464          * Also, this function doesn't produce the same result between PHP 5.6 and 7.
 465          *
 466          * So we now use array_multisort() to sort tags by DESC occurrences,
 467          * then ASC alphabetically for equal values.
 468          *
 469          * @see https://github.com/shaarli/Shaarli/issues/1142
 470          */
 471         $keys = array_keys($tags);
 472         $tmpTags = array_combine($keys, $keys);
 473         array_multisort($tags, SORT_DESC, $tmpTags, SORT_ASC, $tags);
 474         return $tags;
 475     }
 476
 477     /**
 478      * Rename or delete a tag across all bookmarks.
 479      *
 480      * @param string $from Tag to rename
 481      * @param string $to   New tag. If none is provided, the from tag will be deleted
 482      *
 483      * @return array|bool List of altered bookmarks or false on error
 484      */
 485     public function renameTag($from, $to)
 486     {
 487         if (empty($from)) {
 488             return false;
 489         }
 490         $delete = empty($to);
 491         // True for case-sensitive tag search.
 492         $linksToAlter = $this->filterSearch(['searchtags' => $from], true);
 493         foreach ($linksToAlter as $key => &$value) {
 494             $tags = preg_split('/\s+/', trim($value['tags']));
 495             if (($pos = array_search($from, $tags)) !== false) {
 496                 if ($delete) {
 497                     unset($tags[$pos]); // Remove tag.
 498                 } else {
 499                     $tags[$pos] = trim($to);
 500                 }
 501                 $value['tags'] = trim(implode(' ', array_unique($tags)));
 502                 $this[$value['id']] = $value;
 503             }
 504         }
 505
 506         return $linksToAlter;
 507     }
 508
 509     /**
 510      * Returns the list of days containing articles (oldest first)
 511      * Output: An array containing days (in format YYYYMMDD).
 512      */
 513     public function days()
 514     {
 515         $linkDays = [];
 516         foreach ($this->links as $link) {
 517             $linkDays[$link['created']->format('Ymd')] = 0;
 518         }
 519         $linkDays = array_keys($linkDays);
 520         sort($linkDays);
 521
 522         return $linkDays;
 523     }
 524
 525     /**
 526      * Reorder bookmarks by creation date (newest first).
 527      *
 528      * Also update the urls and ids mapping arrays.
 529      *
 530      * @param string $order ASC|DESC
 531      */
 532     public function reorder($order = 'DESC')
 533     {
 534         $order = $order === 'ASC' ? -1 : 1;
 535         // Reorder array by dates.
 536         usort($this->links, function ($a, $b) use ($order) {
 537             if (isset($a['sticky']) && isset($b['sticky']) && $a['sticky'] !== $b['sticky']) {
 538                 return $a['sticky'] ? -1 : 1;
 539             }
 540             if ($a['created'] == $b['created']) {
 541                 return $a['id'] < $b['id'] ? 1 * $order : -1 * $order;
 542             }
 543             return $a['created'] < $b['created'] ? 1 * $order : -1 * $order;
 544         });
 545
 546         $this->urls = [];
 547         $this->ids = [];
 548         foreach ($this->links as $key => $link) {
 549             $this->urls[$link['url']] = $key;
 550             $this->ids[$link['id']] = $key;
 551         }
 552     }
 553
 554     /**
 555      * Return the next key for link creation.
 556      * E.g. If the last ID is 597, the next will be 598.
 557      *
 558      * @return int next ID.
 559      */
 560     public function getNextId()
 561     {
 562         if (!empty($this->ids)) {
 563             return max(array_keys($this->ids)) + 1;
 564         }
 565         return 0;
 566     }
 567
 568     /**
 569      * Returns a link offset in bookmarks array from its unique ID.
 570      *
 571      * @param int $id Persistent ID of a link.
 572      *
 573      * @return int Real offset in local array, or null if doesn't exist.
 574      */
 575     protected function getLinkOffset($id)
 576     {
 577         if (isset($this->ids[$id])) {
 578             return $this->ids[$id];
 579         }
 580         return null;
 581     }
 582 }