application/bookmark/BookmarkIO.php

   1 <?php
   2
   3 namespace Shaarli\Bookmark;
   4
   5 use malkusch\lock\mutex\Mutex;
   6 use malkusch\lock\mutex\NoMutex;
   7 use Shaarli\Bookmark\Exception\DatastoreNotInitializedException;
   8 use Shaarli\Bookmark\Exception\EmptyDataStoreException;
   9 use Shaarli\Bookmark\Exception\NotWritableDataStoreException;
  10 use Shaarli\Config\ConfigManager;
  11
  12 /**
  13  * Class BookmarkIO
  14  *
  15  * This class performs read/write operation to the file data store.
  16  * Used by BookmarkFileService.
  17  *
  18  * @package Shaarli\Bookmark
  19  */
  20 class BookmarkIO
  21 {
  22     /**
  23      * @var string Datastore file path
  24      */
  25     protected $datastore;
  26
  27     /**
  28      * @var ConfigManager instance
  29      */
  30     protected $conf;
  31
  32
  33     /** @var Mutex */
  34     protected $mutex;
  35
  36     /**
  37      * string Datastore PHP prefix
  38      */
  39     protected static $phpPrefix = '<?php /* ';
  40     /**
  41      * string Datastore PHP suffix
  42      */
  43     protected static $phpSuffix = ' */ ?>';
  44
  45     /**
  46      * LinksIO constructor.
  47      *
  48      * @param ConfigManager $conf instance
  49      */
  50     public function __construct(ConfigManager $conf, Mutex $mutex = null)
  51     {
  52         if ($mutex === null) {
  53             // This should only happen with legacy classes
  54             $mutex = new NoMutex();
  55         }
  56         $this->conf = $conf;
  57         $this->datastore = $conf->get('resource.datastore');
  58         $this->mutex = $mutex;
  59     }
  60
  61     /**
  62      * Reads database from disk to memory
  63      *
  64      * @return BookmarkArray instance
  65      *
  66      * @throws NotWritableDataStoreException    Data couldn't be loaded
  67      * @throws EmptyDataStoreException          Datastore file exists but does not contain any bookmark
  68      * @throws DatastoreNotInitializedException File does not exists
  69      */
  70     public function read()
  71     {
  72         if (! file_exists($this->datastore)) {
  73             throw new DatastoreNotInitializedException();
  74         }
  75
  76         if (!is_writable($this->datastore)) {
  77             throw new NotWritableDataStoreException($this->datastore);
  78         }
  79
  80         $content = null;
  81         $this->mutex->synchronized(function () use (&$content) {
  82             $content = file_get_contents($this->datastore);
  83         });
  84
  85         // Note that gzinflate is faster than gzuncompress.
  86         // See: http://www.php.net/manual/en/function.gzdeflate.php#96439
  87         $links = unserialize(gzinflate(base64_decode(
  88             substr($content, strlen(self::$phpPrefix), -strlen(self::$phpSuffix))
  89         )));
  90
  91         if (empty($links)) {
  92             if (filesize($this->datastore) > 100) {
  93                 throw new NotWritableDataStoreException($this->datastore);
  94             }
  95             throw new EmptyDataStoreException();
  96         }
  97
  98         return $links;
  99     }
 100
 101     /**
 102      * Saves the database from memory to disk
 103      *
 104      * @param BookmarkArray $links instance.
 105      *
 106      * @throws NotWritableDataStoreException the datastore is not writable
 107      */
 108     public function write($links)
 109     {
 110         if (is_file($this->datastore) && !is_writeable($this->datastore)) {
 111             // The datastore exists but is not writeable
 112             throw new NotWritableDataStoreException($this->datastore);
 113         } else if (!is_file($this->datastore) && !is_writeable(dirname($this->datastore))) {
 114             // The datastore does not exist and its parent directory is not writeable
 115             throw new NotWritableDataStoreException(dirname($this->datastore));
 116         }
 117
 118         $data = self::$phpPrefix.base64_encode(gzdeflate(serialize($links))).self::$phpSuffix;
 119
 120         $this->mutex->synchronized(function () use ($data) {
 121             file_put_contents(
 122                 $this->datastore,
 123                 $data
 124             );
 125         });
 126     }
 127 }