<?php /** * Data storage for links. * * This object behaves like an associative array. * * Example: * $myLinks = new LinkDB(); * echo $myLinks[350]['title']; * foreach ($myLinks as $link) * echo $link['title'].' at url '.$link['url'].'; description:'.$link['description']; * * Available keys: * - id: primary key, incremental integer identifier (persistent) * - description: description of the entry * - created: creation date of this entry, DateTime object. * - updated: last modification date of this entry, DateTime object. * - private: Is this link private? 0=no, other value=yes * - tags: tags attached to this entry (separated by spaces) * - title Title of the link * - url URL of the link. Used for displayable links (no redirector, relative, etc.). * Can be absolute or relative. * Relative URLs are permalinks (e.g.'?m-ukcw') * - real_url Absolute processed URL. * - shorturl Permalink smallhash * * Implements 3 interfaces: * - ArrayAccess: behaves like an associative array; * - Countable: there is a count() method; * - Iterator: usable in foreach () loops. * * ID mechanism: * ArrayAccess is implemented in a way that will allow to access a link * with the unique identifier ID directly with $link[ID]. * Note that it's not the real key of the link array attribute. * This mechanism is in place to have persistent link IDs, * even though the internal array is reordered by date. * Example: * - DB: link #1 (2010-01-01) link #2 (2016-01-01) * - Order: #2 #1 * - Import links containing: link #3 (2013-01-01) * - New DB: link #1 (2010-01-01) link #2 (2016-01-01) link #3 (2013-01-01) * - Real order: #2 #3 #1 */ class LinkDB implements Iterator, Countable, ArrayAccess { // Links are stored as a PHP serialized string private $datastore; // Link date storage format const LINK_DATE_FORMAT = 'Ymd_His'; // Datastore PHP prefix protected static $phpPrefix = '<?php /* '; // Datastore PHP suffix protected static $phpSuffix = ' */ ?>'; // List of links (associative array) // - key: link date (e.g. "20110823_124546"), // - value: associative array (keys: title, description...) private $links; // List of all recorded URLs (key=url, value=link offset) // for fast reserve search (url-->link offset) private $urls; /** * @var array List of all links IDS mapped with their array offset. * Map: id->offset. */ protected $ids; // List of offset keys (for the Iterator interface implementation) private $keys; // Position in the $this->keys array (for the Iterator interface) private $position; // Is the user logged in? (used to filter private links) private $loggedIn; // Hide public links private $hidePublicLinks; // link redirector set in user settings. private $redirector; /** * Set this to `true` to urlencode link behind redirector link, `false` to leave it untouched. * * Example: * anonym.to needs clean URL while dereferer.org needs urlencoded URL. * * @var boolean $redirectorEncode parameter: true or false */ private $redirectorEncode; /** * Creates a new LinkDB * * Checks if the datastore exists; else, attempts to create a dummy one. * * @param string $datastore datastore file path. * @param boolean $isLoggedIn is the user logged in? * @param boolean $hidePublicLinks if true all links are private. * @param string $redirector link redirector set in user settings. * @param boolean $redirectorEncode Enable urlencode on redirected urls (default: true). */ public function __construct( $datastore, $isLoggedIn, $hidePublicLinks, $redirector = '', $redirectorEncode = true ) { $this->datastore = $datastore; $this->loggedIn = $isLoggedIn; $this->hidePublicLinks = $hidePublicLinks; $this->redirector = $redirector; $this->redirectorEncode = $redirectorEncode === true; $this->check(); $this->read(); } /** * Countable - Counts elements of an object */ public function count() { return count($this->links); } /** * ArrayAccess - Assigns a value to the specified offset */ public function offsetSet($offset, $value) { // TODO: use exceptions instead of "die" if (!$this->loggedIn) { die('You are not authorized to add a link.'); } if (!isset($value['id']) || empty($value['url'])) { die('Internal Error: A link should always have an id and URL.'); } if ((! empty($offset) && ! is_int($offset)) || ! is_int($value['id'])) { die('You must specify an integer as a key.'); } if (! empty($offset) && $offset !== $value['id']) { die('Array offset and link ID must be equal.'); } // If the link exists, we reuse the real offset, otherwise new entry $existing = $this->getLinkOffset($offset); if ($existing !== null) { $offset = $existing; } else { $offset = count($this->links); } $this->links[$offset] = $value; $this->urls[$value['url']] = $offset; $this->ids[$value['id']] = $offset; } /** * ArrayAccess - Whether or not an offset exists */ public function offsetExists($offset) { return array_key_exists($this->getLinkOffset($offset), $this->links); } /** * ArrayAccess - Unsets an offset */ public function offsetUnset($offset) { if (!$this->loggedIn) { // TODO: raise an exception die('You are not authorized to delete a link.'); } $realOffset = $this->getLinkOffset($offset); $url = $this->links[$realOffset]['url']; unset($this->urls[$url]); unset($this->ids[$realOffset]); unset($this->links[$realOffset]); } /** * ArrayAccess - Returns the value at specified offset */ public function offsetGet($offset) { $realOffset = $this->getLinkOffset($offset); return isset($this->links[$realOffset]) ? $this->links[$realOffset] : null; } /** * Iterator - Returns the current element */ public function current() { return $this[$this->keys[$this->position]]; } /** * Iterator - Returns the key of the current element */ public function key() { return $this->keys[$this->position]; } /** * Iterator - Moves forward to next element */ public function next() { ++$this->position; } /** * Iterator - Rewinds the Iterator to the first element * * Entries are sorted by date (latest first) */ public function rewind() { $this->keys = array_keys($this->ids); $this->position = 0; } /** * Iterator - Checks if current position is valid */ public function valid() { return isset($this->keys[$this->position]); } /** * Checks if the DB directory and file exist * * If no DB file is found, creates a dummy DB. */ private function check() { if (file_exists($this->datastore)) { return; } // Create a dummy database for example $this->links = array(); $link = array( 'id' => 1, 'title'=>' Shaarli: the personal, minimalist, super-fast, no-database delicious clone', 'url'=>'https://github.com/shaarli/Shaarli/wiki', 'description'=>'Welcome to Shaarli! This is your first public bookmark. To edit or delete me, you must first login. To learn how to use Shaarli, consult the link "Help/documentation" at the bottom of this page. You use the community supported version of the original Shaarli project, by Sebastien Sauvage.', 'private'=>0, 'created'=> new DateTime(), 'tags'=>'opensource software' ); $link['shorturl'] = link_small_hash($link['created'], $link['id']); $this->links[1] = $link; $link = array( 'id' => 0, 'title'=>'My secret stuff... - Pastebin.com', 'url'=>'http://sebsauvage.net/paste/?8434b27936c09649#bR7XsXhoTiLcqCpQbmOpBi3rq2zzQUC5hBI7ZT1O3x8=', 'description'=>'Shhhh! I\'m a private link only YOU can see. You can delete me too.', 'private'=>1, 'created'=> new DateTime('1 minute ago'), 'tags'=>'secretstuff', ); $link['shorturl'] = link_small_hash($link['created'], $link['id']); $this->links[0] = $link; // Write database to disk $this->write(); } /** * Reads database from disk to memory */ private function read() { // Public links are hidden and user not logged in => nothing to show if ($this->hidePublicLinks && !$this->loggedIn) { $this->links = array(); return; } // Read data // Note that gzinflate is faster than gzuncompress. // See: http://www.php.net/manual/en/function.gzdeflate.php#96439 $this->links = array(); if (file_exists($this->datastore)) { $this->links = unserialize(gzinflate(base64_decode( substr(file_get_contents($this->datastore), strlen(self::$phpPrefix), -strlen(self::$phpSuffix))))); } $toremove = array(); foreach ($this->links as $key => &$link) { if (! $this->loggedIn && $link['private'] != 0) { // Transition for not upgraded databases. $toremove[] = $key; continue; } // Sanitize data fields. sanitizeLink($link); // Remove private tags if the user is not logged in. if (! $this->loggedIn) { $link['tags'] = preg_replace('/(^|\s+)\.[^($|\s)]+\s*/', ' ', $link['tags']); } // Do not use the redirector for internal links (Shaarli note URL starting with a '?'). if (!empty($this->redirector) && !startsWith($link['url'], '?')) { $link['real_url'] = $this->redirector; if ($this->redirectorEncode) { $link['real_url'] .= urlencode(unescape($link['url'])); } else { $link['real_url'] .= $link['url']; } } else { $link['real_url'] = $link['url']; } // To be able to load links before running the update, and prepare the update if (! isset($link['created'])) { $link['id'] = $link['linkdate']; $link['created'] = DateTime::createFromFormat(self::LINK_DATE_FORMAT, $link['linkdate']); if (! empty($link['updated'])) { $link['updated'] = DateTime::createFromFormat(self::LINK_DATE_FORMAT, $link['updated']); } $link['shorturl'] = smallHash($link['linkdate']); } } // If user is not logged in, filter private links. foreach ($toremove as $offset) { unset($this->links[$offset]); } $this->reorder(); } /** * Saves the database from memory to disk * * @throws IOException the datastore is not writable */ private function write() { if (is_file($this->datastore) && !is_writeable($this->datastore)) { // The datastore exists but is not writeable throw new IOException($this->datastore); } else if (!is_file($this->datastore) && !is_writeable(dirname($this->datastore))) { // The datastore does not exist and its parent directory is not writeable throw new IOException(dirname($this->datastore)); } file_put_contents( $this->datastore, self::$phpPrefix.base64_encode(gzdeflate(serialize($this->links))).self::$phpSuffix ); } /** * Saves the database from memory to disk * * @param string $pageCacheDir page cache directory */ public function save($pageCacheDir) { if (!$this->loggedIn) { // TODO: raise an Exception instead die('You are not authorized to change the database.'); } $this->write(); invalidateCaches($pageCacheDir); } /** * Returns the link for a given URL, or False if it does not exist. * * @param string $url URL to search for * * @return mixed the existing link if it exists, else 'false' */ public function getLinkFromUrl($url) { if (isset($this->urls[$url])) { return $this->links[$this->urls[$url]]; } return false; } /** * Returns the shaare corresponding to a smallHash. * * @param string $request QUERY_STRING server parameter. * * @return array $filtered array containing permalink data. * * @throws LinkNotFoundException if the smallhash is malformed or doesn't match any link. */ public function filterHash($request) { $request = substr($request, 0, 6); $linkFilter = new LinkFilter($this->links); return $linkFilter->filter(LinkFilter::$FILTER_HASH, $request); } /** * Returns the list of articles for a given day. * * @param string $request day to filter. Format: YYYYMMDD. * * @return array list of shaare found. */ public function filterDay($request) { $linkFilter = new LinkFilter($this->links); return $linkFilter->filter(LinkFilter::$FILTER_DAY, $request); } /** * Filter links according to search parameters. * * @param array $filterRequest Search request content. Supported keys: * - searchtags: list of tags * - searchterm: term search * @param bool $casesensitive Optional: Perform case sensitive filter * @param string $visibility return only all/private/public links * * @return array filtered links, all links if no suitable filter was provided. */ public function filterSearch($filterRequest = array(), $casesensitive = false, $visibility = 'all') { // Filter link database according to parameters. $searchtags = !empty($filterRequest['searchtags']) ? escape($filterRequest['searchtags']) : ''; $searchterm = !empty($filterRequest['searchterm']) ? escape($filterRequest['searchterm']) : ''; // Search tags + fullsearch. if (! empty($searchtags) && ! empty($searchterm)) { $type = LinkFilter::$FILTER_TAG | LinkFilter::$FILTER_TEXT; $request = array($searchtags, $searchterm); } // Search by tags. elseif (! empty($searchtags)) { $type = LinkFilter::$FILTER_TAG; $request = $searchtags; } // Fulltext search. elseif (! empty($searchterm)) { $type = LinkFilter::$FILTER_TEXT; $request = $searchterm; } // Otherwise, display without filtering. else { $type = ''; $request = ''; } $linkFilter = new LinkFilter($this); return $linkFilter->filter($type, $request, $casesensitive, $visibility); } /** * Returns the list of all tags * Output: associative array key=tags, value=0 */ public function allTags() { $tags = array(); $caseMapping = array(); foreach ($this->links as $link) { foreach (preg_split('/\s+/', $link['tags'], 0, PREG_SPLIT_NO_EMPTY) as $tag) { if (empty($tag)) { continue; } // The first case found will be displayed. if (!isset($caseMapping[strtolower($tag)])) { $caseMapping[strtolower($tag)] = $tag; $tags[$caseMapping[strtolower($tag)]] = 0; } $tags[$caseMapping[strtolower($tag)]]++; } } // Sort tags by usage (most used tag first) arsort($tags); return $tags; } /** * Returns the list of days containing articles (oldest first) * Output: An array containing days (in format YYYYMMDD). */ public function days() { $linkDays = array(); foreach ($this->links as $link) { $linkDays[$link['created']->format('Ymd')] = 0; } $linkDays = array_keys($linkDays); sort($linkDays); return $linkDays; } /** * Reorder links by creation date (newest first). * * Also update the urls and ids mapping arrays. * * @param string $order ASC|DESC */ public function reorder($order = 'DESC') { $order = $order === 'ASC' ? -1 : 1; // Reorder array by dates. usort($this->links, function($a, $b) use ($order) { return $a['created'] < $b['created'] ? 1 * $order : -1 * $order; }); $this->urls = array(); $this->ids = array(); foreach ($this->links as $key => $link) { $this->urls[$link['url']] = $key; $this->ids[$link['id']] = $key; } } /** * Return the next key for link creation. * E.g. If the last ID is 597, the next will be 598. * * @return int next ID. */ public function getNextId() { if (!empty($this->ids)) { return max(array_keys($this->ids)) + 1; } return 0; } /** * Returns a link offset in links array from its unique ID. * * @param int $id Persistent ID of a link. * * @return int Real offset in local array, or null if doesn't exist. */ protected function getLinkOffset($id) { if (isset($this->ids[$id])) { return $this->ids[$id]; } return null; } }