Imported code from old repository

CloudObjects/SDK/AccountGateway/DataLoader.php

@@ -0,0 +1,81 @@
+<?php
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+ 
+namespace CloudObjects\SDK\AccountGateway;
+
+use Doctrine\Common\Cache\Cache;
+use ML\JsonLD\JsonLD;
+use GuzzleHttp\Psr7\Request;
+
+class DataLoader {
+
+  const CACHE_TTL = 172800; // cache at most 48 hours
+
+  private $cache;
+  private $cachePrefix = 'accdata:';
+  private $mountPointName = '~';
+
+  public function getCache() {
+    return $this->cache;
+  }
+
+  public function setCache(Cache $cache) {
+    $this->cache = $cache;
+    return $this;
+  }
+
+  public function getCachePrefix() {
+    return $this->cachePrefix;
+  }
+
+  public function setCachePrefix($cachePrefix) {
+    $this->cachePrefix = $cachePrefix;
+    return $this;
+  }
+
+  public function getMountPointName() {
+    return $this->mountPointName;
+  }
+
+  public function setMountPointName($mountPointName) {
+    $this->mountPointName = $mountPointName;
+    return $this;
+  }
+
+  public function fetchAccountGraphDataDocument(AccountContext $accountContext) {
+    $dataRequest = new Request('GET', '/'.$this->mountPointName.'/',
+      ['Accept' => 'application/ld+json']);
+    
+    if (!$this->cache || !$accountContext->getRequest()
+        || !$accountContext->getRequest()->hasHeader('C-Data-Updated')) {
+      // No cache or no timestamp available, so always fetch from Account Gateway
+      $dataString = (string)$accountContext->getClient()->send($dataRequest)->getBody();
+    } else {
+      $key = $this->cachePrefix.$accountContext->getAAUID();
+      $remoteTimestamp = $accountContext->getRequest()->getHeaderLine('C-Data-Updated');
+      if ($this->cache->contains($key)) {
+        // Check timestamp
+        $cacheEntry = $this->cache->fetch($key);
+        $timestamp = substr($cacheEntry, 0, strpos($cacheEntry, '|'));
+        if ($timestamp==$remoteTimestamp) {
+          // Cache data is up to date, can be returned
+          $dataString = substr($cacheEntry, strpos($cacheEntry, '|')+1);
+        } else {
+          // Fetch from Account Gateway and update cache entry
+          $dataString = (string)$accountContext->getClient()->send($dataRequest)->getBody();
+          $this->cache->save($key, $remoteTimestamp.'|'.$dataString, self::CACHE_TTL);
+        }
+      } else {
+        // Fetch from Account Gateway and store in cache
+        $dataString = (string)$accountContext->getClient()->send($dataRequest)->getBody();
+        $this->cache->save($key, $remoteTimestamp.'|'.$dataString, self::CACHE_TTL);
+      }
+    }
+
+    return JsonLD::getDocument($dataString);
+  }
+
+}