first commit -> move some files from one-api

vendor/aws_sdk/Aws/Identity/S3/S3ExpressIdentity.php

@@ -0,0 +1,6 @@
+<?php
+namespace Aws\Identity\S3;
+
+use Aws\Credentials\Credentials;
+
+class S3ExpressIdentity extends Credentials {}

vendor/aws_sdk/Aws/Identity/S3/S3ExpressIdentityProvider.php

@@ -0,0 +1,54 @@
+<?php
+namespace Aws\Identity\S3;
+
+use Aws;
+use Aws\LruArrayCache;
+use GuzzleHttp\Promise;
+
+class S3ExpressIdentityProvider
+{
+
+    private $cache;
+    private $region;
+    private $config;
+    private $s3Client;
+    public function __construct($clientRegion, array $config = [])
+    {
+        $this->cache = new LruArrayCache(100);
+        $this->region = $clientRegion;
+        $this->config = $config;
+    }
+
+    public function __invoke($command)
+    {
+        $s3Client = $this->getS3Client();
+        $bucket = $command['Bucket'];
+        if ($identity = $this->cache->get($bucket)) {
+            if (!$identity->isExpired()) {
+                return Promise\Create::promiseFor($identity);
+            }
+        }
+        $response = $s3Client->createSession(['Bucket' => $bucket]);
+        $identity = new Aws\Identity\S3\S3ExpressIdentity(
+            $response['Credentials']['AccessKeyId'],
+            $response['Credentials']['SecretAccessKey'],
+            $response['Credentials']['SessionToken'],
+            $response['Credentials']['Expiration']->getTimestamp()
+        );
+        $this->cache->set($bucket, $identity);
+        return Promise\Create::promiseFor($identity);
+    }
+
+    private function getS3Client()
+    {
+        if (is_null($this->s3Client)) {
+            $this->s3Client = isset($this->config['client'])
+                ? $this->config['client'] // internal use only
+                : new Aws\S3\S3Client([
+                    'region' => $this->region,
+                    'disable_express_session_auth' => true
+                ]);
+        }
+        return $this->s3Client;
+    }
+}