Subversion-Projekte lars-tiefland.php_share

<?php
/*
 * Copyright 2010-2012 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */


/*%******************************************************************************************%*/
// CLASS

/**
 * The <CFCredentials> class enables developers to easily switch between multiple sets of credentials.
 *
 * @version 2011.11.15
 * @license See the included NOTICE.md file for more information.
 * @copyright See the included NOTICE.md file for more information.
 * @link http://aws.amazon.com/php/ PHP Developer Center
 */
class CFCredentials
{
        /**
         * The key used to specify the default credential set
         */
        const DEFAULT_KEY = '@default';

        /**
         * The key used to identify inherited credentials
         */
        const INHERIT_KEY = '@inherit';

        /**
         * Stores the credentials
         */
        protected static $credentials = array();

        /**
         * Prevents this class from being constructed
         */
        final private function __construct() {}

        /**
         * Stores the credentials for re-use.
         *
         * @param array $credential_sets (Required) The named credential sets that should be made available to the application.
         * @return void
         */
        public static function set(array $credential_sets)
        {
                // Make sure a default credential set is specified or can be inferred
                if (count($credential_sets) === 1)
                {
                        $credential_sets[self::DEFAULT_KEY] = reset($credential_sets);
                }
                elseif (!isset($credential_sets[self::DEFAULT_KEY]))
                {
                        throw new CFCredentials_Exception('If more than one credential set is provided, a default credential set (identified by the key "' . self::DEFAULT_KEY . '") must be specified.');
                }

                // Resolve any @inherit tags
                foreach ($credential_sets as $credential_name => &$credential_set)
                {
                        if (is_array($credential_set))
                        {
                                foreach ($credential_set as $credential_key => &$credential_value)
                                {
                                        if ($credential_key === self::INHERIT_KEY)
                                        {
                                                if (!isset($credential_sets[$credential_value]))
                                                {
                                                        throw new CFCredentials_Exception('The credential set, "' . $credential_value . '", does not exist and cannot be inherited.');
                                                }

                                                $credential_set = array_merge($credential_sets[$credential_value], $credential_set);
                                                unset($credential_set[self::INHERIT_KEY]);
                                        }
                                }
                        }
                }

                // Normalize the value of the @default credential set
                $default = $credential_sets[self::DEFAULT_KEY];
                if (is_string($default))
                {
                        if (!isset($credential_sets[$default]))
                        {
                                throw new CFCredentials_Exception('The credential set, "' . $default . '", does not exist and cannot be used as the default credential set.');
                        }

                        $credential_sets[self::DEFAULT_KEY] = $credential_sets[$default];
                }

                // Store the credentials
                self::$credentials = $credential_sets;
        }

        /**
         * Retrieves the requested credentials from the internal credential store.
         *
         * @param string $credential_set (Optional) The name of the credential set to retrieve. The default value is set in DEFAULT_KEY.
         * @return stdClass A stdClass object where the properties represent the keys that were provided.
         */
        public static function get($credential_name = self::DEFAULT_KEY)
        {
                // Make sure the credential set exists
                if (!isset(self::$credentials[$credential_name]))
                {
                        throw new CFCredentials_Exception('The credential set, "' . $credential_name . '", does not exist and cannot be retrieved.');
                }

                // Return the credential set as an object
                return new CFCredential(self::$credentials[$credential_name]);
        }
}

class CFCredentials_Exception extends Exception {}