Proyectos de Subversion Moodle

<?php

namespace Aws\EndpointDiscovery;

use Aws\AbstractConfigurationProvider;

use Aws\CacheInterface;

use Aws\ConfigurationProviderInterface;

use Aws\EndpointDiscovery\Exception\ConfigurationException;

use GuzzleHttp\Promise;

use GuzzleHttp\Promise\PromiseInterface;

/**

 * A configuration provider is a function that returns a promise that is

 * fulfilled with a {@see \Aws\EndpointDiscovery\ConfigurationInterface}

 * or rejected with an {@see \Aws\EndpointDiscovery\Exception\ConfigurationException}.

 *

 * <code>

 * use Aws\EndpointDiscovery\ConfigurationProvider;

 * $provider = ConfigurationProvider::defaultProvider();

 * // Returns a ConfigurationInterface or throws.

 * $config = $provider()->wait();

 * </code>

 *

 * Configuration providers can be composed to create configuration using

 * conditional logic that can create different configurations in different

 * environments. You can compose multiple providers into a single provider using

 * {@see Aws\EndpointDiscovery\ConfigurationProvider::chain}. This function

 * accepts providers as variadic arguments and returns a new function that will

 * invoke each provider until a successful configuration is returned.

 *

 * <code>

 * // First try an INI file at this location.

 * $a = ConfigurationProvider::ini(null, '/path/to/file.ini');

 * // Then try an INI file at this location.

 * $b = ConfigurationProvider::ini(null, '/path/to/other-file.ini');

 * // Then try loading from environment variables.

 * $c = ConfigurationProvider::env();

 * // Combine the three providers together.

 * $composed = ConfigurationProvider::chain($a, $b, $c);

 * // Returns a promise that is fulfilled with a configuration or throws.

 * $promise = $composed();

 * // Wait on the configuration to resolve.

 * $config = $promise->wait();

 * </code>

 */

class ConfigurationProvider extends AbstractConfigurationProvider

    implements ConfigurationProviderInterface

{

    const DEFAULT_ENABLED = false;

    const DEFAULT_CACHE_LIMIT = 1000;

    const ENV_ENABLED = 'AWS_ENDPOINT_DISCOVERY_ENABLED';

    const ENV_ENABLED_ALT = 'AWS_ENABLE_ENDPOINT_DISCOVERY';

    const ENV_PROFILE = 'AWS_PROFILE';

    public static $cacheKey = 'aws_cached_endpoint_discovery_config';

    protected static $interfaceClass = ConfigurationInterface::class;

    protected static $exceptionClass = ConfigurationException::class;

    /**

     * Create a default config provider that first checks for environment

     * variables, then checks for a specified profile in the environment-defined

     * config file location (env variable is 'AWS_CONFIG_FILE', file location

     * defaults to ~/.aws/config), then checks for the "default" profile in the

     * environment-defined config file location, and failing those uses a default

     * fallback set of configuration options.

     *

     * This provider is automatically wrapped in a memoize function that caches

     * previously provided config options.

     *

     * @param array $config

     *

     * @return callable

     */

    public static function defaultProvider(array $config = [])

    {

        $configProviders = [self::env()];

        if (

            !isset($config['use_aws_shared_config_files'])

            || $config['use_aws_shared_config_files'] != false

        ) {

            $configProviders[] = self::ini();

        }

        $configProviders[] = self::fallback($config);

        $memo = self::memoize(

            call_user_func_array([ConfigurationProvider::class, 'chain'], $configProviders)

        );

        if (isset($config['endpoint_discovery'])

            && $config['endpoint_discovery'] instanceof CacheInterface

        ) {

            return self::cache($memo, $config['endpoint_discovery'], self::$cacheKey);

        }

        return $memo;

    }

    /**

     * Provider that creates config from environment variables.

     *

     * @param $cacheLimit

     * @return callable

     */

    public static function env($cacheLimit = self::DEFAULT_CACHE_LIMIT)

    {

        return function () use ($cacheLimit) {

            // Use config from environment variables, if available

            $enabled = getenv(self::ENV_ENABLED);

            if ($enabled === false || $enabled === '') {

                $enabled = getenv(self::ENV_ENABLED_ALT);

            }

            if ($enabled !== false && $enabled !== '') {

                return Promise\Create::promiseFor(

                    new Configuration($enabled, $cacheLimit)

                );

            }

            return self::reject('Could not find environment variable config'

                . ' in ' . self::ENV_ENABLED);

        };

    }

    /**

     * Fallback config options when other sources are not set. Will check the

     * service model for any endpoint discovery required operations, and enable

     * endpoint discovery in that case. If no required operations found, will use

     * the class default values.

     *

     * @param array $config

     * @return callable

     */

    public static function fallback($config = [])

    {

        $enabled = self::DEFAULT_ENABLED;

        if (!empty($config['api_provider'])

            && !empty($config['service'])

            && !empty($config['version'])

        ) {

            $provider = $config['api_provider'];

            $apiData = $provider('api', $config['service'], $config['version']);

            if (!empty($apiData['operations'])) {

                foreach ($apiData['operations'] as $operation) {

                    if (!empty($operation['endpointdiscovery']['required'])) {

                        $enabled = true;

                    }

                }

            }

        }

        return function () use ($enabled) {

            return Promise\Create::promiseFor(

                new Configuration(

                    $enabled,

                    self::DEFAULT_CACHE_LIMIT

                )

            );

        };

    }

    /**

     * Config provider that creates config using a config file whose location

     * is specified by an environment variable 'AWS_CONFIG_FILE', defaulting to

     * ~/.aws/config if not specified

     *

     * @param string|null $profile  Profile to use. If not specified will use

     *                              the "default" profile.

     * @param string|null $filename If provided, uses a custom filename rather

     *                              than looking in the default directory.

     * @param int         $cacheLimit

     *

     * @return callable

     */

    public static function ini(

        $profile = null,

        $filename = null,

        $cacheLimit = self::DEFAULT_CACHE_LIMIT

    ) {

        $filename = $filename ?: (self::getDefaultConfigFilename());

        $profile = $profile ?: (getenv(self::ENV_PROFILE) ?: 'default');

        return function () use ($profile, $filename, $cacheLimit) {

            if (!@is_readable($filename)) {

                return self::reject("Cannot read configuration from $filename");

            }

            $data = \Aws\parse_ini_file($filename, true);

            if ($data === false) {

                return self::reject("Invalid config file: $filename");

            }

            if (!isset($data[$profile])) {

                return self::reject("'$profile' not found in config file");

            }

            if (!isset($data[$profile]['endpoint_discovery_enabled'])) {

                return self::reject("Required endpoint discovery config values

                    not present in INI profile '{$profile}' ({$filename})");

            }

            return Promise\Create::promiseFor(

                new Configuration(

                    $data[$profile]['endpoint_discovery_enabled'],

                    $cacheLimit

                )

            );

        };

    }

    /**

     * Unwraps a configuration object in whatever valid form it is in,

     * always returning a ConfigurationInterface object.

     *

     * @param  mixed $config

     * @return ConfigurationInterface

     * @throws \InvalidArgumentException

     */

    public static function unwrap($config)

    {

        if (is_callable($config)) {

            $config = $config();

        }

        if ($config instanceof PromiseInterface) {

            $config = $config->wait();

        }

        if ($config instanceof ConfigurationInterface) {

            return $config;

        } elseif (is_array($config) && isset($config['enabled'])) {

            if (isset($config['cache_limit'])) {

                return new Configuration(

                    $config['enabled'],

                    $config['cache_limit']

                );

            }

            return new Configuration(

                $config['enabled'],

                self::DEFAULT_CACHE_LIMIT

            );

        }

        throw new \InvalidArgumentException('Not a valid endpoint_discovery '

            . 'configuration argument.');

    }

}