<?php

namespace Parse;

/**
 * ParseStorageInterface - Specifies an interface for implementing persistence.
 *
 * @author Fosco Marotto <fjm@fb.com>
 */
interface ParseStorageInterface
{
    /**
     * Sets a key-value pair in storage.
     *
     * @param string $key   The key to set
     * @param mixed  $value The value to set
     *
     * @return null
     */
    public function set($key, $value);

    /**
     * Remove a key from storage.
     *
     * @param string $key The key to remove.
     *
     * @return null
     */
    public function remove($key);

    /**
     * Gets the value for a key from storage.
     *
     * @param string $key The key to get the value for
     *
     * @return mixed
     */
    public function get($key);

    /**
     * Clear all the values in storage.
     *
     * @return null
     */
    public function clear();

    /**
     * Save the data, if necessary.    This would be a no-op when using the
     * $_SESSION implementation, but could be used for saving to file or
     * database as an action instead of on every set.
     *
     * @return null
     */
    public function save();

    /**
     * Get all keys in storage.
     *
     * @return array
     */
    public function getKeys();

    /**
     * Get all key-value pairs from storage.
     *
     * @return array
     */
    public function getAll();
}