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- <?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';
- // 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 (($offset !== null && ! is_int($offset)) || ! is_int($value['id'])) {
- die('You must specify an integer as a key.');
- }
- if ($offset !== null && $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;
- }
- $this->links = FileUtils::readFlatDB($this->datastore, []);
- $toremove = array();
- foreach ($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]);
- }
- $this->reorder();
- }
- /**
- * Saves the database from memory to disk
- *
- * @throws IOException the datastore is not writable
- */
- private function write()
- {
- FileUtils::writeFlatDB($this->datastore, $this->links);
- }
- /**
- * 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 tags appearing in the links with the given tags
- * @param $filteringTags: tags selecting the links to consider
- * @param $visibility: process only all/private/public links
- * @return: a tag=>linksCount array
- */
- public function linksCountPerTag($filteringTags = [], $visibility = 'all')
- {
- $links = empty($filteringTags) ? $this->links : $this->filterSearch(['searchtags' => $filteringTags], false, $visibility);
- $tags = array();
- $caseMapping = array();
- foreach ($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;
- }
- }
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