application/bookmark/BookmarkIO.php

   1 <?php
   2
   3 declare(strict_types=1);
   4
   5 namespace Shaarli\Bookmark;
   6
   7 use malkusch\lock\mutex\Mutex;
   8 use malkusch\lock\mutex\NoMutex;
   9 use Shaarli\Bookmark\Exception\DatastoreNotInitializedException;
  10 use Shaarli\Bookmark\Exception\EmptyDataStoreException;
  11 use Shaarli\Bookmark\Exception\NotWritableDataStoreException;
  12 use Shaarli\Config\ConfigManager;
  13
  14 /**
  15  * Class BookmarkIO
  16  *
  17  * This class performs read/write operation to the file data store.
  18  * Used by BookmarkFileService.
  19  *
  20  * @package Shaarli\Bookmark
  21  */
  22 class BookmarkIO
  23 {
  24     /**
  25      * @var string Datastore file path
  26      */
  27     protected $datastore;
  28
  29     /**
  30      * @var ConfigManager instance
  31      */
  32     protected $conf;
  33
  34
  35     /** @var Mutex */
  36     protected $mutex;
  37
  38     /**
  39      * string Datastore PHP prefix
  40      */
  41     protected static $phpPrefix = '<?php /* ';
  42     /**
  43      * string Datastore PHP suffix
  44      */
  45     protected static $phpSuffix = ' */ ?>';
  46
  47     /**
  48      * LinksIO constructor.
  49      *
  50      * @param ConfigManager $conf instance
  51      */
  52     public function __construct(ConfigManager $conf, Mutex $mutex = null)
  53     {
  54         if ($mutex === null) {
  55             // This should only happen with legacy classes
  56             $mutex = new NoMutex();
  57         }
  58         $this->conf = $conf;
  59         $this->datastore = $conf->get('resource.datastore');
  60         $this->mutex = $mutex;
  61     }
  62
  63     /**
  64      * Reads database from disk to memory
  65      *
  66      * @return Bookmark[]
  67      *
  68      * @throws NotWritableDataStoreException    Data couldn't be loaded
  69      * @throws EmptyDataStoreException          Datastore file exists but does not contain any bookmark
  70      * @throws DatastoreNotInitializedException File does not exists
  71      */
  72     public function read()
  73     {
  74         if (! file_exists($this->datastore)) {
  75             throw new DatastoreNotInitializedException();
  76         }
  77
  78         if (!is_writable($this->datastore)) {
  79             throw new NotWritableDataStoreException($this->datastore);
  80         }
  81
  82         $content = null;
  83         $this->mutex->synchronized(function () use (&$content) {
  84             $content = file_get_contents($this->datastore);
  85         });
  86
  87         // Note that gzinflate is faster than gzuncompress.
  88         // See: http://www.php.net/manual/en/function.gzdeflate.php#96439
  89         $links = unserialize(gzinflate(base64_decode(
  90             substr($content, strlen(self::$phpPrefix), -strlen(self::$phpSuffix))
  91         )));
  92
  93         if (empty($links)) {
  94             if (filesize($this->datastore) > 100) {
  95                 throw new NotWritableDataStoreException($this->datastore);
  96             }
  97             throw new EmptyDataStoreException();
  98         }
  99
 100         return $links;
 101     }
 102
 103     /**
 104      * Saves the database from memory to disk
 105      *
 106      * @param Bookmark[] $links
 107      *
 108      * @throws NotWritableDataStoreException the datastore is not writable
 109      */
 110     public function write($links)
 111     {
 112         if (is_file($this->datastore) && !is_writeable($this->datastore)) {
 113             // The datastore exists but is not writeable
 114             throw new NotWritableDataStoreException($this->datastore);
 115         } elseif (!is_file($this->datastore) && !is_writeable(dirname($this->datastore))) {
 116             // The datastore does not exist and its parent directory is not writeable
 117             throw new NotWritableDataStoreException(dirname($this->datastore));
 118         }
 119
 120         $data = self::$phpPrefix . base64_encode(gzdeflate(serialize($links))) . self::$phpSuffix;
 121
 122         $this->mutex->synchronized(function () use ($data) {
 123             file_put_contents(
 124                 $this->datastore,
 125                 $data
 126             );
 127         });
 128     }
 129 }