session_cache_file.module in Session Cache API 7

session_cache_file.module

Provides a file storage implementation for the Session Cache API. More than anything for demonstration and debugging purporses as it is easy to follow on the file system when the caches are written and expired, i.e. when the underlying files are updated and removed.

See the session_cache/README.txt for more info.

File

session_cache_file/session_cache_file.module

<?php

/**
 * @file
 * session_cache_file.module
 *
 * Provides a file storage implementation for the Session Cache API.
 * More than anything for demonstration and debugging purporses as it is easy
 * to follow on the file system when the caches are written and expired,
 * i.e. when the underlying files are updated and removed.
 *
 * See the session_cache/README.txt for more info.
 */
define('SESSION_CACHE_FILE_STORAGE_FILE', 5);

/**
 * Implements hook_form_FORM_ID_alter().
 */
function session_cache_file_form_session_cache_admin_config_alter(&$form, &$form_state) {
  $form['session_cache_storage_method']['#options'][SESSION_CACHE_FILE_STORAGE_FILE] = t('on the server, as a small file');
}

/**
 * Returns the directory path to where session cache files are stored.
 *
 * @param string $bin
 *   The bin for which the path is to be returned, NULL for the base path.
 *
 * @return boolean|string
 *   The existing or newly created path, or FALSE if there was an error.
 */
function session_cache_file_directory($bin = NULL) {
  $path = variable_get('file_private_path');

  // Typically $path == 'sites/default/files/private'.
  if (empty($path)) {
    drupal_set_message(t('Session Cache File: the <strong>Private file system path</strong> is not set. Please configure it <a href="@url">here</a>.', array(
      '@url' => url('admin/config/media/file-system'),
    )), 'warning', FALSE);
    return FALSE;
  }

  // Use the absolute path as is, if it starts with a slash.
  $path = preg_match('/^\\//', $path) ? $path : DRUPAL_ROOT . "/{$path}";
  $path .= '/session_cache';

  // @todo Use file_prepare_directory(&$path, FILE_CREATE_DIRECTORY)
  if (!file_exists($path) && !@mkdir($path)) {
    drupal_set_message(t('Session cache directory %path could not be created.', array(
      '%path' => $path,
    )), 'error', FALSE);
    return FALSE;
  }
  if (empty($bin)) {
    return $path;
  }
  if (!file_exists("{$path}/{$bin}") && !@mkdir("{$path}/{$bin}")) {
    drupal_set_message(t('Session cache subdirectory %bin could not be created inside %path', array(
      '%bin' => $bin,
      '%path' => $path,
    )), 'error', FALSE);
    return FALSE;
  }
  return "{$path}/{$bin}";
}

/**
 * Implements hook_session_cache_set().
 */
function session_cache_file_session_cache_set($method, $bin, $data) {
  if ($method != SESSION_CACHE_FILE_STORAGE_FILE) {
    return;
  }
  $path = session_cache_file_directory($bin);
  $sid = session_cache_get_sid();
  if ($data == NULL) {
    if (!$path || !$sid || !@unlink("{$path}/{$sid}")) {
      drupal_set_message(t('Session cache file for empty session state could not be deleted.', array(
        '%bin' => "{$bin}/{$sid}",
      )), 'warning', FALSE);
    }
  }
  elseif (!$path || !$sid || @file_put_contents("{$path}/{$sid}", json_encode($data), FILE_EXISTS_REPLACE) === FALSE) {
    drupal_set_message(t('Session cache file for session state %bin could not be written.', array(
      '%bin' => "{$bin}/{$sid}",
    )), 'error', FALSE);
  }
}

/**
 * Implements hook_session_cache_get().
 */
function session_cache_file_session_cache_get($method, $bin) {
  if ($method != SESSION_CACHE_FILE_STORAGE_FILE) {
    return NULL;
  }
  $path = session_cache_file_directory($bin);
  $sid = session_cache_get_sid();
  $data = $path && $sid && file_exists("{$path}/{$sid}") ? json_decode(file_get_contents("{$path}/{$sid}"), TRUE) : NULL;
  return $data;
}

/**
 * Implements hook_cron().
 */
function session_cache_file_cron() {
  $session_cache_root = session_cache_file_directory();
  if (empty($session_cache_root)) {
    return;
  }
  if ($bin_dirs = scandir($session_cache_root)) {
    foreach ($bin_dirs as $bin_dir) {
      if (strpos($bin_dir, '.') !== 0) {
        if ($filenames = scandir("{$session_cache_root}/{$bin_dir}")) {
          foreach ($filenames as $filename) {
            if (strpos($filename, '.') !== 0) {
              $filespec = "{$session_cache_root}/{$bin_dir}/{$filename}";
              $last_modified = filemtime($filespec);
              if ($last_modified && time() - $last_modified > SESSION_CACHE_DEFAULT_EXPIRATION_DAYS * 24 * 60 * 60) {
                if (!@unlink($filespec)) {
                  drupal_set_message(t('Could not delete expired session cache file %file.', array(
                    '%file' => $filespec,
                  )), 'warning');
                }
              }
            }
          }
        }
      }
    }
  }
}

Functions

Name	Description
session_cache_file_cron	Implements hook_cron().
session_cache_file_directory	Returns the directory path to where session cache files are stored.
session_cache_file_form_session_cache_admin_config_alter	Implements hook_form_FORM_ID_alter().
session_cache_file_session_cache_get	Implements hook_session_cache_get().
session_cache_file_session_cache_set	Implements hook_session_cache_set().

Constants

Name	Description
SESSION_CACHE_FILE_STORAGE_FILE	@file session_cache_file.module