system.install

<?php
// $Id$

/**
 * Test and report Drupal installation requirements.
 *
 * @param $phase
 *   The current system installation phase.
 * @return
 *   An array of system requirements.
 */
function system_requirements($phase) {
  global $base_url;
  $requirements = array();
  // Ensure translations don't break at install time
  $t = get_t();

  // Report Drupal version
  if ($phase == 'runtime') {
    $requirements['drupal'] = array(
      'title' => $t('Drupal'),
      'value' => VERSION,
      'severity' => REQUIREMENT_INFO,
      'weight' => -10,
    );
  }

  // Web server information.
  $software = $_SERVER['SERVER_SOFTWARE'];
  $requirements['webserver'] = array(
    'title' => $t('Web server'),
    'value' => $software,
  );

  // Test PHP version
  $requirements['php'] = array(
    'title' => $t('PHP'),
    'value' => ($phase == 'runtime') ? l(phpversion(), 'admin/reports/status/php') : phpversion(),
  );
  if (version_compare(phpversion(), DRUPAL_MINIMUM_PHP) < 0) {
    $requirements['php']['description'] = $t('Your PHP installation is too old. Drupal requires at least PHP %version.', array('%version' => DRUPAL_MINIMUM_PHP));
    $requirements['php']['severity'] = REQUIREMENT_ERROR;
  }

  // Test PHP register_globals setting.
  $requirements['php_register_globals'] = array(
    'title' => $t('PHP register globals'),
  );
  $register_globals = trim(ini_get('register_globals'));
  // Unfortunately, ini_get() may return many different values, and we can't
  // be certain which values mean 'on', so we instead check for 'not off'
  // since we never want to tell the user that their site is secure
  // (register_globals off), when it is in fact on. We can only guarantee
  // register_globals is off if the value returned is 'off', '', or 0.
  if (!empty($register_globals) && strtolower($register_globals) != 'off') {
    $requirements['php_register_globals']['description'] = $t('<em>register_globals</em> is enabled. Drupal requires this configuration directive to be disabled. Your site may not be secure when <em>register_globals</em> is enabled. The PHP manual has instructions for <a href="http://php.net/configuration.changes">how to change configuration settings</a>.');
    $requirements['php_register_globals']['severity'] = REQUIREMENT_ERROR;
    $requirements['php_register_globals']['value'] = $t("Enabled ('@value')", array('@value' => $register_globals));
  }
  else {
    $requirements['php_register_globals']['value'] = $t('Disabled');
  }

  // Test PHP memory_limit
  $memory_limit = ini_get('memory_limit');
  $requirements['php_memory_limit'] = array(
    'title' => $t('PHP memory limit'),
    'value' => $memory_limit,
  );

  if ($memory_limit && parse_size($memory_limit) < parse_size(DRUPAL_MINIMUM_PHP_MEMORY_LIMIT)) {
    $description = '';
    if ($phase == 'install') {
      $description = $t('Consider increasing your PHP memory limit to %memory_minimum_limit to help prevent errors in the installation process.', array('%memory_minimum_limit' => DRUPAL_MINIMUM_PHP_MEMORY_LIMIT));
    }
    elseif ($phase == 'update') {
      $description = $t('Consider increasing your PHP memory limit to %memory_minimum_limit to help prevent errors in the update process.', array('%memory_minimum_limit' => DRUPAL_MINIMUM_PHP_MEMORY_LIMIT));
    }
    elseif ($phase == 'runtime') {
      $description = $t('Depending on your configuration, Drupal can run with a %memory_limit PHP memory limit. However, a %memory_minimum_limit PHP memory limit or above is recommended, especially if your site uses additional custom or contributed modules.', array('%memory_limit' => $memory_limit, '%memory_minimum_limit' => DRUPAL_MINIMUM_PHP_MEMORY_LIMIT));
    }

    if (!empty($description)) {
      if ($php_ini_path = get_cfg_var('cfg_file_path')) {
        $description .= ' ' . $t('Increase the memory limit by editing the memory_limit parameter in the file %configuration-file and then restart your web server (or contact your system administrator or hosting provider for assistance).', array('%configuration-file' => $php_ini_path));
      }
      else {
        $description .= ' ' . $t('Contact your system administrator or hosting provider for assistance with increasing your PHP memory limit.');
      }

      $requirements['php_memory_limit']['description'] = $description . ' ' . $t('See the <a href="@url">Drupal requirements</a> for more information.', array('@url' => 'http://drupal.org/requirements'));
      $requirements['php_memory_limit']['severity'] = REQUIREMENT_WARNING;
    }
  }

  // Test DB version
  global $db_type;
  if (function_exists('db_status_report')) {
    $requirements += db_status_report($phase);
  }

  // Test settings.php file writability
  if ($phase == 'runtime') {
    $conf_dir = drupal_verify_install_file(conf_path(), FILE_NOT_WRITABLE, 'dir');
    $conf_file = drupal_verify_install_file(conf_path() . '/settings.php', FILE_EXIST|FILE_READABLE|FILE_NOT_WRITABLE);
    if (!$conf_dir || !$conf_file) {
      $requirements['settings.php'] = array(
        'value' => $t('Not protected'),
        'severity' => REQUIREMENT_ERROR,
        'description' => '',
      );
      if (!$conf_dir) {
        $requirements['settings.php']['description'] .= $t('The directory %file is not protected from modifications and poses a security risk. You must change the directory\'s permissions to be non-writable. ', array('%file' => conf_path()));
      }
      if (!$conf_file) {
        $requirements['settings.php']['description'] .= $t('The file %file is not protected from modifications and poses a security risk. You must change the file\'s permissions to be non-writable.', array('%file' => conf_path() . '/settings.php'));
      }
    }
    else {
      $requirements['settings.php'] = array(
        'value' => $t('Protected'),
      );
    }
    $requirements['settings.php']['title'] = $t('Configuration file');
  }

  // Report cron status.
  if ($phase == 'runtime') {
    // Cron warning threshold defaults to two days.
    $threshold_warning = variable_get('cron_threshold_warning', 172800);
    // Cron error threshold defaults to two weeks.
    $threshold_error = variable_get('cron_threshold_error', 1209600);
    // Cron configuration help text.
    $help = $t('For more information, see the online handbook entry for <a href="@cron-handbook">configuring cron jobs</a>.', array('@cron-handbook' => 'http://drupal.org/cron'));

    // Determine when cron last ran.
    $cron_last = variable_get('cron_last', NULL);
    if (!is_numeric($cron_last)) {
      $cron_last = variable_get('install_time', 0);
    }

    // Determine severity based on time since cron last ran.
    $severity = REQUIREMENT_OK;
    if (REQUEST_TIME - $cron_last > $threshold_error) {
      $severity = REQUIREMENT_ERROR;
    }
    elseif (REQUEST_TIME - $cron_last > $threshold_warning) {
      $severity = REQUIREMENT_WARNING;
    }

    // Set summary and description based on values determined above.
    $summary = $t('Last run !time ago', array('!time' => format_interval(REQUEST_TIME - $cron_last)));
    $description = '';
    if ($severity != REQUIREMENT_OK) {
      $description = $t('Cron has not run recently.') . ' ' . $help;
    }

    $description .= ' ' . $t('You can <a href="@cron">run cron manually</a>.', array('@cron' => url('admin/reports/status/run-cron')));
    $description .= '<br />' . $t('To run cron from outside the site, go to <a href="!cron">!cron</a>', array('!cron' => url($base_url . '/cron.php', array('external' => TRUE, 'query' => 'cron_key=' . variable_get('cron_key', 'drupal')))));

    $requirements['cron'] = array(
      'title' => $t('Cron maintenance tasks'),
      'severity' => $severity,
      'value' => $summary,
      'description' => $description
    );
  }

  // Test files directory
  $directory = file_directory_path();
  $requirements['file system'] = array(
    'title' => $t('File system'),
  );

  // For installer, create the directory if possible.
  if ($phase == 'install' && !is_dir($directory) && @mkdir($directory)) {
    @chmod($directory, 0775); // Necessary for non-webserver users.
  }

  $is_writable = is_writable($directory);
  $is_directory = is_dir($directory);
  if (!$is_writable || !$is_directory) {
    $description = '';
    $requirements['file system']['value'] = $t('Not writable');
    if (!$is_directory) {
      $error = $t('The directory %directory does not exist.', array('%directory' => $directory));
    }
    else {
      $error = $t('The directory %directory is not writable.', array('%directory' => $directory));
    }
    // The files directory requirement check is done only during install and runtime.
    if ($phase == 'runtime') {
      $description = $error . ' ' . $t('You may need to set the correct directory at the <a href="@admin-file-system">file system settings page</a> or change the current directory\'s permissions so that it is writable.', array('@admin-file-system' => url('admin/settings/file-system')));
    }
    elseif ($phase == 'install') {
      // For the installer UI, we need different wording. 'value' will
      // be treated as version, so provide none there.
      $description = $error . ' ' . $t('An automated attempt to create this directory failed, possibly due to a permissions problem. To proceed with the installation, either create the directory and modify its permissions manually, or ensure that the installer has the permissions to create it automatically. For more information, please see INSTALL.txt or the <a href="@handbook_url">online handbook</a>.', array('@handbook_url' => 'http://drupal.org/server-permissions'));
      $requirements['file system']['value'] = '';
    }
    if (!empty($description)) {
      $requirements['file system']['description'] = $description;
      $requirements['file system']['severity'] = REQUIREMENT_ERROR;
    }
  }
  else {
    if (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PUBLIC) {
      $requirements['file system']['value'] = $t('Writable (<em>public</em> download method)');
    }
    else {
      $requirements['file system']['value'] = $t('Writable (<em>private</em> download method)');
    }
  }

  // See if updates are available in update.php.
  if ($phase == 'runtime') {
    $requirements['update'] = array(
      'title' => $t('Database updates'),
      'severity' => REQUIREMENT_OK,
      'value' => $t('Up to date'),
    );

    // Check installed modules.
    foreach (module_list() as $module) {
      $updates = drupal_get_schema_versions($module);
      if ($updates !== FALSE) {
        $default = drupal_get_installed_schema_version($module);
        if (max($updates) > $default) {
          $requirements['update']['severity'] = REQUIREMENT_ERROR;
          $requirements['update']['value'] = $t('Out of date');
          $requirements['update']['description'] = $t('Some modules have database schema updates to install. You should run the <a href="@update">database update script</a> immediately.', array('@update' => base_path() . 'update.php'));
          break;
        }
      }
    }
  }

  // Verify the update.php access setting
  if ($phase == 'runtime') {
    if (!empty($GLOBALS['update_free_access'])) {
      $requirements['update access'] = array(
        'value' => $t('Not protected'),
        'severity' => REQUIREMENT_ERROR,
        'description' => $t('The update.php script is accessible to everyone without authentication check, which is a security risk. You must change the $update_free_access value in your settings.php back to FALSE.'),
      );
    }
    else {
      $requirements['update access'] = array(
        'value' => $t('Protected'),
      );
    }
    $requirements['update access']['title'] = $t('Access to update.php');
  }

  // Test Unicode library
  include_once DRUPAL_ROOT . '/includes/unicode.inc';
  $requirements = array_merge($requirements, unicode_requirements());

  // Check for update status module.
  if ($phase == 'runtime') {
    if (!module_exists('update')) {
      $requirements['update status'] = array(
        'value' => $t('Not enabled'),
        'severity' => REQUIREMENT_WARNING,
        'description' => $t('Update notifications are not enabled. It is <strong>highly recommended</strong> that you enable the update status module from the <a href="@module">module administration page</a> in order to stay up-to-date on new releases. For more information please read the <a href="@update">Update status handbook page</a>.', array('@update' => 'http://drupal.org/handbook/modules/update', '@module' => url('admin/build/modules'))),
      );
    }
    else {
      $requirements['update status'] = array(
        'value' => $t('Enabled'),
      );
      if (variable_get('drupal_http_request_fails', FALSE)) {
        $requirements['http requests'] = array(
          'title' => $t('HTTP request status'),
          'value' => $t('Fails'),
          'severity' => REQUIREMENT_ERROR,
          'description' => $t('Your system or network configuration does not allow Drupal to access web pages, resulting in reduced functionality. This could be due to your webserver configuration or PHP settings, and should be resolved in order to download information about available updates, fetch aggregator feeds, sign in via OpenID, or use other network-dependent services.'),
        );
      }
    }
    $requirements['update status']['title'] = $t('Update notifications');
  }

  return $requirements;
}

/**
 * Implementation of hook_install().
 */
function system_install() {
  if (db_driver() == 'pgsql') {
    // We create some custom types and functions using global names instead of
    // prefixing them like we do with table names. If this function is ever
    // called again (for example, by the test framework when creating prefixed
    // test databases), the global names will already exist. We therefore avoid
    // trying to create them again in that case.

    // Create unsigned types.
    if (!db_result(db_query("SELECT COUNT(*) FROM pg_constraint WHERE conname = 'int_unsigned_check'"))) {
      db_query("CREATE DOMAIN int_unsigned integer CHECK (VALUE >= 0)");
    }
    if (!db_result(db_query("SELECT COUNT(*) FROM pg_constraint WHERE conname = 'smallint_unsigned_check'"))) {
      db_query("CREATE DOMAIN smallint_unsigned smallint CHECK (VALUE >= 0)");
    }
    if (!db_result(db_query("SELECT COUNT(*) FROM pg_constraint WHERE conname = 'bigint_unsigned_check'"))) {
      db_query("CREATE DOMAIN bigint_unsigned bigint CHECK (VALUE >= 0)");
    }

    // Create functions.
    db_query('CREATE OR REPLACE FUNCTION "greatest"(numeric, numeric) RETURNS numeric AS
      \'SELECT CASE WHEN (($1 > $2) OR ($2 IS NULL)) THEN $1 ELSE $2 END;\'
      LANGUAGE \'sql\''
    );
    db_query('CREATE OR REPLACE FUNCTION "greatest"(numeric, numeric, numeric) RETURNS numeric AS
      \'SELECT greatest($1, greatest($2, $3));\'
      LANGUAGE \'sql\''
    );
    if (!db_result(db_query("SELECT COUNT(*) FROM pg_proc WHERE proname = 'rand'"))) {
      db_query('CREATE OR REPLACE FUNCTION "rand"() RETURNS float AS
        \'SELECT random();\'
        LANGUAGE \'sql\''
      );
    }

    if (!db_result(db_query("SELECT COUNT(*) FROM pg_proc WHERE proname = 'concat'"))) {
      db_query('CREATE OR REPLACE FUNCTION "concat"(text, text) RETURNS text AS
        \'SELECT $1 || $2;\'
        LANGUAGE \'sql\''
      );
    }
    db_query('CREATE OR REPLACE FUNCTION "if"(boolean, text, text) RETURNS text AS
      \'SELECT CASE WHEN $1 THEN $2 ELSE $3 END;\'
      LANGUAGE \'sql\''
    );
    db_query('CREATE OR REPLACE FUNCTION "if"(boolean, integer, integer) RETURNS integer AS
      \'SELECT CASE WHEN $1 THEN $2 ELSE $3 END;\'
      LANGUAGE \'sql\''
    );
  }

  // Create tables.
  $modules = array('system', 'filter', 'block', 'user', 'node', 'comment', 'taxonomy');
  foreach ($modules as $module) {
    drupal_install_schema($module);
  }

  // Load system theme data appropriately.
  system_theme_data();

  // Inserting uid 0 here confuses MySQL -- the next user might be created as
  // uid 2 which is not what we want. So we insert the first user here, the
  // anonymous user. uid is 1 here for now, but very soon it will be changed
  // to 0.
  db_query("INSERT INTO {users} (name, mail) VALUES('%s', '%s')", '', '');
  // We need some placeholders here as name and mail are uniques and data is
  // presumed to be a serialized array. Install will change uid 1 immediately
  // anyways. So we insert the superuser here, the uid is 2 here for now, but
  // very soon it will be changed to 1.
  db_query("INSERT INTO {users} (name, mail, created, status, data) VALUES('%s', '%s', %d, %d, '%s')", 'placeholder-for-uid-1', 'placeholder-for-uid-1', REQUEST_TIME, 1, serialize(array()));
  // This sets the above two users uid 0 (anonymous). We avoid an explicit 0
  // otherwise MySQL might insert the next auto_increment value.
  db_query("UPDATE {users} SET uid = uid - uid WHERE name = '%s'", '');
  // This sets uid 1 (superuser). We skip uid 2 but that's not a big problem.
  db_query("UPDATE {users} SET uid = 1 WHERE name = '%s'", 'placeholder-for-uid-1');

  // Built-in roles.
  db_query("INSERT INTO {role} (name) VALUES ('%s')", 'anonymous user');
  db_query("INSERT INTO {role} (name) VALUES ('%s')", 'authenticated user');

  // Anonymous role permissions.
  db_query("INSERT INTO {role_permission} (rid, permission) VALUES (%d, '%s')", 1, 'access content');

  // Authenticated role permissions.
  db_query("INSERT INTO {role_permission} (rid, permission) VALUES (%d, '%s')", 2, 'access comments');
  db_query("INSERT INTO {role_permission} (rid, permission) VALUES (%d, '%s')", 2, 'access content');
  db_query("INSERT INTO {role_permission} (rid, permission) VALUES (%d, '%s')", 2, 'post comments');
  db_query("INSERT INTO {role_permission} (rid, permission) VALUES (%d, '%s')", 2, 'post comments without approval');

  db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", 'theme_default', 's:7:"garland";');
  db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 1, 'theme', 'garland');
  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'user', 'login', 'garland', 1, 0, 'left', '', -1);
  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'user', 'navigation', 'garland', 1, 0, 'left', '', -1);
  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'system', 'powered-by', 'garland', 1, 10, 'footer', '', -1);

  db_query("INSERT INTO {node_access} (nid, gid, realm, grant_view, grant_update, grant_delete) VALUES (%d, %d, '%s', %d, %d, %d)", 0, 0, 'all', 1, 0, 0);

  // Add input formats.
  db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Filtered HTML', ',1,2,', 1);
  db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Full HTML', '', 1);

  // Enable filters for each input format.

  // Filtered HTML:
  // URL filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 2, 0);
  // HTML filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 0, 1);
  // Line break filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 1, 2);
  // HTML corrector filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 1, 'filter', 3, 10);

  // Full HTML:
  // URL filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 2, 'filter', 2, 0);
  // Line break filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 2, 'filter', 1, 1);
  // HTML corrector filter.
  db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", 2, 'filter', 3, 10);

  db_query("INSERT INTO {variable} (name, value) VALUES ('%s','%s')", 'filter_html_1', 'i:1;');

  db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", 'node_options_forum', 'a:1:{i:0;s:6:"status";}');

  $cron_key = serialize(md5(mt_rand()));

  db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", 'cron_key', $cron_key);
}

/**
 * Implementation of hook_schema().
 */
function system_schema() {
  // NOTE: {variable} needs to be created before all other tables, as
  // some database drivers, e.g. Oracle and DB2, will require variable_get()
  // and variable_set() for overcoming some database specific limitations.
  $schema['variable'] = array(
    'description' => 'Named variable/value pairs created by Drupal core or any other module or theme. All variables are cached in memory at the start of every Drupal request so developers should not be careless about what is stored here.',
    'fields' => array(
      'name' => array(
        'description' => 'The name of the variable.',
        'type' => 'varchar',
        'length' => 128,
        'not null' => TRUE,
        'default' => '',
      ),
      'value' => array(
        'description' => 'The value of the variable.',
        'type' => 'text',
        'not null' => TRUE,
        'size' => 'big',
      ),
    ),
    'primary key' => array('name'),
  );

  $schema['actions'] = array(
    'description' => 'Stores action information.',
    'fields' => array(
      'aid' => array(
        'description' => 'Primary Key: Unique actions ID.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '0',
      ),
      'type' => array(
        'description' => 'The object that that action acts on (node, user, comment, system or custom types.)',
        'type' => 'varchar',
        'length' => 32,
        'not null' => TRUE,
        'default' => '',
      ),
      'callback' => array(
        'description' => 'The callback function that executes when the action runs.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'parameters' => array(
        'description' => 'Parameters to be passed to the callback function.',
        'type' => 'text',
        'not null' => TRUE,
        'size' => 'big',
      ),
      'description' => array(
        'description' => 'Description of the action.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '0',
      ),
    ),
    'primary key' => array('aid'),
  );

  $schema['actions_aid'] = array(
    'description' => 'Stores action IDs for non-default actions.',
    'fields' => array(
      'aid' => array(
        'description' => 'Primary Key: Unique actions ID.',
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
      ),
    ),
    'primary key' => array('aid'),
  );

  $schema['batch'] = array(
    'description' => 'Stores details about batches (processes that run in multiple HTTP requests).',
    'fields' => array(
      'bid' => array(
        'description' => 'Primary Key: Unique batch ID.',
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
      ),
      'token' => array(
        'description' => "A string token generated against the current user's session id and the batch id, used to ensure that only the user who submitted the batch can effectively access it.",
        'type' => 'varchar',
        'length' => 64,
        'not null' => TRUE,
      ),
      'timestamp' => array(
        'description' => 'A Unix timestamp indicating when this batch was submitted for processing. Stale batches are purged at cron time.',
        'type' => 'int',
        'not null' => TRUE,
      ),
      'batch' => array(
        'description' => 'A serialized array containing the processing data for the batch.',
        'type' => 'text',
        'not null' => FALSE,
        'size' => 'big',
      ),
    ),
    'primary key' => array('bid'),
    'indexes' => array(
      'token' => array('token'),
    ),
  );

  $schema['blocked_ips'] = array(
    'description' => 'Stores blocked IP addresses.',
    'fields' => array(
       'iid' => array(
        'description' => 'Primary Key: unique ID for IP addresses.',
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
      ),
      'ip' => array(
        'description' => 'IP address',
        'type' => 'varchar',
        'length' => 32,
        'not null' => TRUE,
        'default' => '',
      ),
    ),
    'indexes' => array(
      'blocked_ip' => array('ip'),
    ),
    'primary key' => array('iid'),
  );

  $schema['cache'] = array(
    'description' => 'Generic cache table for caching things not separated out into their own tables. Contributed modules may also use this to store cached items.',
    'fields' => array(
      'cid' => array(
        'description' => 'Primary Key: Unique cache ID.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'data' => array(
        'description' => 'A collection of data to cache.',
        'type' => 'blob',
        'not null' => FALSE,
        'size' => 'big',
      ),
      'expire' => array(
        'description' => 'A Unix timestamp indicating when the cache entry should expire, or 0 for never.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
      'created' => array(
        'description' => 'A Unix timestamp indicating when the cache entry was created.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
      'headers' => array(
        'description' => 'Any custom HTTP headers to be added to cached data.',
        'type' => 'text',
        'not null' => FALSE,
      ),
      'serialized' => array(
        'description' => 'A flag to indicate whether content is serialized (1) or not (0).',
        'type' => 'int',
        'size' => 'small',
        'not null' => TRUE,
        'default' => 0,
      ),
    ),
    'indexes' => array(
      'expire' => array('expire'),
    ),
    'primary key' => array('cid'),
  );

  $schema['cache_form'] = $schema['cache'];
  $schema['cache_form']['description'] = 'Cache table for the form system to store recently built forms and their storage data, to be used in subsequent page requests.';
  $schema['cache_page'] = $schema['cache'];
  $schema['cache_page']['description'] = 'Cache table used to store compressed pages for anonymous users, if page caching is enabled.';
  $schema['cache_menu'] = $schema['cache'];
  $schema['cache_menu']['description'] = 'Cache table for the menu system to store router information as well as generated link trees for various menu/page/user combinations.';
  $schema['cache_registry'] = $schema['cache'];
  $schema['cache_registry']['description'] = 'Cache table for the code registry system to remember what code files need to be loaded on any given page.';

  $schema['files'] = array(
    'description' => 'Stores information for uploaded files.',
    'fields' => array(
      'fid' => array(
        'description' => 'File ID.',
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
      ),
      'uid' => array(
        'description' => 'The {users}.uid of the user who is associated with the file.',
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'default' => 0,
      ),
      'filename' => array(
        'description' => 'Name of the file with no path components. This may differ from the basename of the filepath if the file is renamed to avoid overwriting an existing file.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'filepath' => array(
        'description' => 'Path of the file relative to Drupal root.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'filemime' => array(
        'description' => "The file's MIME type.",
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'filesize' => array(
        'description' => 'The size of the file in bytes.',
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'default' => 0,
      ),
      'status' => array(
        'description' => 'A bitmapped field indicating the status of the file the least sigifigant bit indicates temporary (1) or permanent (0). Temporary files older than DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed during a cron run.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
      'timestamp' => array(
        'description' => 'UNIX timestamp for when the file was added.',
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'default' => 0,
      ),
    ),
    'indexes' => array(
      'uid' => array('uid'),
      'status' => array('status'),
      'timestamp' => array('timestamp'),
    ),
    'primary key' => array('fid'),
  );

  $schema['flood'] = array(
    'description' => 'Flood controls the threshold of events, such as the number of contact attempts.',
    'fields' => array(
      'fid' => array(
        'description' => 'Unique flood event ID.',
        'type' => 'serial',
        'not null' => TRUE,
      ),
      'event' => array(
        'description' => 'Name of event (e.g. contact).',
        'type' => 'varchar',
        'length' => 64,
        'not null' => TRUE,
        'default' => '',
      ),
      'hostname' => array(
        'description' => 'Hostname of the visitor.',
        'type' => 'varchar',
        'length' => 128,
        'not null' => TRUE,
        'default' => '',
      ),
      'timestamp' => array(
        'description' => 'Timestamp of the event.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
    ),
    'primary key' => array('fid'),
    'indexes' => array(
      'allow' => array('event', 'hostname', 'timestamp'),
    ),
  );

  $schema['history'] = array(
    'description' => 'A record of which {users} have read which {node}s.',
    'fields' => array(
      'uid' => array(
        'description' => 'The {users}.uid that read the {node} nid.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
      'nid' => array(
        'description' => 'The {node}.nid that was read.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
      'timestamp' => array(
        'description' => 'The Unix timestamp at which the read occurred.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
    ),
    'primary key' => array('uid', 'nid'),
    'indexes' => array(
      'nid' => array('nid'),
    ),
  );
  $schema['menu_router'] = array(
    'description' => 'Maps paths to various callbacks (access, page and title)',
    'fields' => array(
      'path' => array(
        'description' => 'Primary Key: the Drupal path this entry describes',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'load_functions' => array(
        'description' => 'A serialized array of function names (like node_load) to be called to load an object corresponding to a part of the current path.',
        'type' => 'text',
        'not null' => TRUE,
      ),
      'to_arg_functions' => array(
        'description' => 'A serialized array of function names (like user_uid_optional_to_arg) to be called to replace a part of the router path with another string.',
        'type' => 'text',
        'not null' => TRUE,
      ),
      'access_callback' => array(
        'description' => 'The callback which determines the access to this router path. Defaults to user_access.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'access_arguments' => array(
        'description' => 'A serialized array of arguments for the access callback.',
        'type' => 'text',
        'not null' => FALSE,
      ),
      'page_callback' => array(
        'description' => 'The name of the function that renders the page.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'page_arguments' => array(
        'description' => 'A serialized array of arguments for the page callback.',
        'type' => 'text',
        'not null' => FALSE,
      ),
      'fit' => array(
        'description' => 'A numeric representation of how specific the path is.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
      'number_parts' => array(
        'description' => 'Number of parts in this router path.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
        'size' => 'small',
      ),
      'tab_parent' => array(
        'description' => 'Only for local tasks (tabs) - the router path of the parent page (which may also be a local task).',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'tab_root' => array(
        'description' => 'Router path of the closest non-tab parent page. For pages that are not local tasks, this will be the same as the path.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'title' => array(
        'description' => 'The title for the current page, or the title for the tab if this is a local task.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'title_callback' => array(
        'description' => 'A function which will alter the title. Defaults to t()',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'title_arguments' => array(
        'description' => 'A serialized array of arguments for the title callback. If empty, the title will be used as the sole argument for the title callback.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
      ),
      'type' => array(
        'description' => 'Numeric representation of the type of the menu item, like MENU_LOCAL_TASK.',