<?php
namespace Aws\Api;
use Aws\Exception\UnresolvedApiException;
/**
* API providers.
*
* An API provider is a function that accepts a type, service, and version and
* returns an array of API data on success or NULL if no API data can be created
* for the provided arguments.
*
* You can wrap your calls to an API provider with the
* {@see ApiProvider::resolve} method to ensure that API data is created. If the
* API data is not created, then the resolve() method will throw a
* {@see Aws\Exception\UnresolvedApiException}.
*
* use Aws\Api\ApiProvider;
* $provider = ApiProvider::defaultProvider();
* // Returns an array or NULL.
* $data = $provider('api', 's3', '2006-03-01');
* // Returns an array or throws.
* $data = ApiProvider::resolve($provider, 'api', 'elasticfood', '2020-01-01');
*
* You can compose multiple providers into a single provider using
* {@see Aws\or_chain}. This method accepts providers as arguments and
* returns a new function that will invoke each provider until a non-null value
* is returned.
*
* $a = ApiProvider::filesystem(sys_get_temp_dir() . '/aws-beta-models');
* $b = ApiProvider::manifest();
*
* $c = \Aws\or_chain($a, $b);
* $data = $c('api', 'betaservice', '2015-08-08'); // $a handles this.
* $data = $c('api', 's3', '2006-03-01'); // $b handles this.
* $data = $c('api', 'invalid', '2014-12-15'); // Neither handles this.
*/
class ApiProvider
{
/** @var array A map of public API type names to their file suffix. */
private static $typeMap = [
'api' => 'api-2',
'paginator' => 'paginators-1',
'waiter' => 'waiters-2',
'docs' => 'docs-2',
];
/** @var array API manifest */
private $manifest;
/** @var string The directory containing service models. */
private $modelsDir;
/**
* Resolves an API provider and ensures a non-null return value.
*
* @param callable $provider Provider function to invoke.
* @param string $type Type of data ('api', 'waiter', 'paginator').
* @param string $service Service name.
* @param string $version API version.
*
* @return array
* @throws UnresolvedApiException
*/
public static function resolve(callable $provider, $type, $service, $version)
{
// Execute the provider and return the result, if there is one.
$result = $provider($type, $service, $version);
if (is_array($result)) {
return $result;
}
// Throw an exception with a message depending on the inputs.
if (!isset(self::$typeMap[$type])) {
$msg = "The type must be one of: " . implode(', ', self::$typeMap);
} elseif ($service) {
$msg = "The {$service} service does not have version: {$version}.";
} else {
$msg = "You must specify a service name to retrieve its API data.";
}
throw new UnresolvedApiException($msg);
}
/**
* Default SDK API provider.
*
* This provider loads pre-built manifest data from the `data` directory.
*
* @return self
*/
public static function defaultProvider()
{
return new self(__DIR__ . '/../data', \Aws\manifest());
}
/**
* Loads API data after resolving the version to the latest, compatible,
* available version based on the provided manifest data.
*
* Manifest data is essentially an associative array of service names to
* associative arrays of API version aliases.
*
* [
* ...
* 'ec2' => [
* 'latest' => '2014-10-01',
* '2014-10-01' => '2014-10-01',
* '2014-09-01' => '2014-10-01',
* '2014-06-15' => '2014-10-01',
* ...
* ],
* 'ecs' => [...],
* 'elasticache' => [...],
* ...
* ]
*
* @param string $dir Directory containing service models.
* @param array $manifest The API version manifest data.
*
* @return self
*/
public static function manifest($dir, array $manifest)
{
return new self($dir, $manifest);
}
/**
* Loads API data from the specified directory.
*
* If "latest" is specified as the version, this provider must glob the
* directory to find which is the latest available version.
*
* @param string $dir Directory containing service models.
*
* @return self
* @throws \InvalidArgumentException if the provided `$dir` is invalid.
*/
public static function filesystem($dir)
{
return new self($dir);
}
/**
* Retrieves a list of valid versions for the specified service.
*
* @param string $service Service name
*
* @return array
*/
public function getVersions($service)
{
if (!isset($this->manifest)) {
$this->buildVersionsList($service);
}
if (!isset($this->manifest[$service]['versions'])) {
return [];
}
return array_values(array_unique($this->manifest[$service]['versions']));
}
/**
* Execute the the provider.
*
* @param string $type Type of data ('api', 'waiter', 'paginator').
* @param string $service Service name.
* @param string $version API version.
*
* @return array|null
*/
public function __invoke($type, $service, $version)
{
// Resolve the type or return null.
if (isset(self::$typeMap[$type])) {
$type = self::$typeMap[$type];
} else {
return null;
}
// Resolve the version or return null.
if (!isset($this->manifest)) {
$this->buildVersionsList($service);
}
if (!isset($this->manifest[$service]['versions'][$version])) {
return null;
}
$version = $this->manifest[$service]['versions'][$version];
$path = "{$this->modelsDir}/{$service}/{$version}/{$type}.json";
try {
return \Aws\load_compiled_json($path);
} catch (\InvalidArgumentException $e) {
return null;
}
}
/**
* @param string $modelsDir Directory containing service models.
* @param array $manifest The API version manifest data.
*/
private function __construct($modelsDir, array $manifest = null)
{
$this->manifest = $manifest;
$this->modelsDir = rtrim($modelsDir, '/');
if (!is_dir($this->modelsDir)) {
throw new \InvalidArgumentException(
"The specified models directory, {$modelsDir}, was not found."
);
}
}
/**
* Build the versions list for the specified service by globbing the dir.
*/
private function buildVersionsList($service)
{
$dir = "{$this->modelsDir}/{$service}/";
if (!is_dir($dir)) {
return;
}
// Get versions, remove . and .., and sort in descending order.
$results = array_diff(scandir($dir, SCANDIR_SORT_DESCENDING), ['..', '.']);
if (!$results) {
$this->manifest[$service] = ['versions' => []];
} else {
$this->manifest[$service] = [
'versions' => [
'latest' => $results[0]
]
];
$this->manifest[$service]['versions'] += array_combine($results, $results);
}
}
}
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