lcache.install

<?php

/**
 * Implements hook_requirements().
 */
function lcache_requirements($phase) {
  // @TODO: Version check for APCu.
  // @TODO: Check for a sane apcu_sma_info() configuration here.
}

/**
 * Implements hook_schema().
 */
function lcache_schema() {
  $schema['lcache_events'] = array(
    'description' => 'Stores a stream of cache changes for coherency management.',
    'fields' => array(
      'event_id' => array(
        'description' => 'Primary Key: Event ID.',
        'type' => 'serial',
        'not null' => TRUE,
        'unsigned' => TRUE,
      ),
      'pool' => array(
        'description' => 'PHP process pool that wrote the change.',
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'binary' => TRUE,
        'default' => '',
      ),
      'address' => array(
        'description' => 'Cache entry address (bin and key).',
        'type' => 'varchar_ascii',
        'length' => 512,
        'not null' => FALSE,
        'binary' => TRUE,
        'default' => NULL,
      ),
      'value' => array(
        'description' => 'Cache entry value.',
        'type' => 'blob',
        'not null' => FALSE,
        'binary' => TRUE,
        'size' => 'big',
      ),
      'expiration' => array(
        'description' => 'A Unix timestamp indicating when the cache entry should expire, or NULL for never.',
        'type' => 'int',
        'not null' => FALSE,
        'default' => NULL,
      ),
      'created' => array(
        'description' => 'A Unix timestamp indicating when the cache entry was created.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
    ),
    'indexes' => array(
      'expiration' => array('expiration'),
      'lookup_miss' => array('address', 'event_id'),
    ),
    'primary key' => array('event_id'),
  );
  $schema['lcache_tags'] = array(
    'description' => 'Stores mappings from tags to cache items.',
    'fields' => array(
      'tag' => array(
        'description' => 'Cache tag.',
        'type' => 'varchar',
        'length' => 128,
        'not null' => FALSE,
        'binary' => TRUE,
        'default' => NULL,
      ),
      'event_id' => array(
        'description' => 'The event_id associated with the cache entry.',
        'type' => 'int',
        'not null' => TRUE,
        'unsigned' => TRUE,
        'default' => 0,
      ),
    ),
    'indexes' => array(
      'rewritten_entry' => array('event_id'),
    ),
    'primary key' => array('tag', 'event_id'),
    'foreign keys' => array(
      'lcache_events_event_id' => array(
        'table' => 'lcache_events',
        'columns' => array('event_id' => 'event_id'),
      ),
    ),
  );

  return $schema;
}

/**
 * Implements hook_install().
 */
function lcache_install() {
  db_query('
    ALTER TABLE {lcache_tags}
    ADD CONSTRAINT {lcache_tags_event_id}
    FOREIGN KEY (event_id) REFERENCES {lcache_events} (event_id)
    ON DELETE CASCADE
  ');
}

/**
 * Implements hook_uninstall().
 */
function lcache_uninstall() {
  db_query('
    ALTER TABLE {lcache_tags}
    DROP FOREIGN KEY {lcache_tags_event_id}
  ');
}