application/FileUtils.php

   1 <?php
   2
   3 use Shaarli\Exceptions\IOException;
   4
   5 require_once 'exceptions/IOException.php';
   6
   7 /**
   8  * Class FileUtils
   9  *
  10  * Utility class for file manipulation.
  11  */
  12 class FileUtils
  13 {
  14     /**
  15      * @var string
  16      */
  17     protected static $phpPrefix = '<?php /* ';
  18
  19     /**
  20      * @var string
  21      */
  22     protected static $phpSuffix = ' */ ?>';
  23
  24     /**
  25      * Write data into a file (Shaarli database format).
  26      * The data is stored in a PHP file, as a comment, in compressed base64 format.
  27      *
  28      * The file will be created if it doesn't exist.
  29      *
  30      * @param string $file    File path.
  31      * @param mixed  $content Content to write.
  32      *
  33      * @return int|bool Number of bytes written or false if it fails.
  34      *
  35      * @throws IOException The destination file can't be written.
  36      */
  37     public static function writeFlatDB($file, $content)
  38     {
  39         if (is_file($file) && !is_writeable($file)) {
  40             // The datastore exists but is not writeable
  41             throw new IOException($file);
  42         } elseif (!is_file($file) && !is_writeable(dirname($file))) {
  43             // The datastore does not exist and its parent directory is not writeable
  44             throw new IOException(dirname($file));
  45         }
  46
  47         return file_put_contents(
  48             $file,
  49             self::$phpPrefix.base64_encode(gzdeflate(serialize($content))).self::$phpSuffix
  50         );
  51     }
  52
  53     /**
  54      * Read data from a file containing Shaarli database format content.
  55      *
  56      * If the file isn't readable or doesn't exist, default data will be returned.
  57      *
  58      * @param string $file    File path.
  59      * @param mixed  $default The default value to return if the file isn't readable.
  60      *
  61      * @return mixed The content unserialized, or default if the file isn't readable, or false if it fails.
  62      */
  63     public static function readFlatDB($file, $default = null)
  64     {
  65         // Note that gzinflate is faster than gzuncompress.
  66         // See: http://www.php.net/manual/en/function.gzdeflate.php#96439
  67         if (! is_readable($file)) {
  68             return $default;
  69         }
  70
  71         $data = file_get_contents($file);
  72         if ($data == '') {
  73             return $default;
  74         }
  75
  76         return unserialize(
  77             gzinflate(
  78                 base64_decode(
  79                     substr($data, strlen(self::$phpPrefix), -strlen(self::$phpSuffix))
  80                 )
  81             )
  82         );
  83     }
  84 }