Server push cancellation: add a new class HttpCacheLookupManager which implements ServerPushDelegate

net/http/http_cache_lookup_manager.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_HTTP_CACHE_LOOKUP_MANAGER_H_
+#define NET_HTTP_CACHE_LOOKUP_MANAGER_H_
+
+#include "net/base/net_export.h"
+#include "net/http/http_cache.h"
+#include "net/http/http_cache_transaction.h"
+#include "net/spdy/server_push_delegate.h"
+
+namespace net {
+
+// An implementation of ServerPushDelegate that issues an HttpCache::Transaction
+// to lookup whether the response to the pushed URL is cached and cancel the
+// push in that case.
+class NET_EXPORT_PRIVATE HttpCacheLookupManager : public ServerPushDelegate {
+ public:
+  // |http_cache| MUST outlive the HttpCacheLookupManager.
+  HttpCacheLookupManager(HttpCache* http_cache,
+                         const NetLogWithSource& net_log);
+  ~HttpCacheLookupManager() override;
+
+  void OnPush(std::unique_ptr<ServerPushHelper> push_helper) override;
+
+  // Invoked when the HttpCache::Transaction for |url| finishes to cancel the
+  // server push if the response to the server push is found cached.
+  void OnLookupComplete(const GURL& url, int rv);
+
+ private:
+  // A class that takes the ownership of ServerPushHelper and issues and owns an

[Zhongyi Shi, 2016/11/18 20:34:19]

The comment has been updated in next PS
// // A class that takes the ownership of ServerPushHelper, issues and owns an

+  // HttpCache::Transaction which lookups the response in cache for the server
+  // push.
+  class LookupTransaction {
+   public:
+    LookupTransaction(std::unique_ptr<ServerPushHelper> push_helper);
+    ~LookupTransaction();
+
+    // Issues an HttpCache::Transaction to lookup whether the response is cached
+    // without header validation.
+    int StartLookup(HttpCache* cache,
+                    const CompletionCallback& callback,
+                    const NetLogWithSource& net_log);
+
+    void CancelPush();
+
+   private:
+    std::unique_ptr<ServerPushHelper> push_helper;
+    std::unique_ptr<HttpRequestInfo> request;
+    std::unique_ptr<HttpTransaction> transaction;
+  };
+
+  NetLogWithSource net_log_;
+  // HttpCache must outlive the HttpCacheLookupManager.
+  HttpCache* http_cache_;
+  std::map<GURL, std::unique_ptr<LookupTransaction>> lookup_transactions_;
+  base::WeakPtrFactory<HttpCacheLookupManager> weak_factory_;
+};
+
+}  // namespace net
+
+#endif  // NET_HTTP_CACHE_LOOKUP_MANAGER_H_