Headless: make URLRequestDispatcher aware of navigations

headless/public/util/deterministic_dispatcher.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 HEADLESS_PUBLIC_UTIL_DETERMINISTIC_DISPATCHER_H_
 #define HEADLESS_PUBLIC_UTIL_DETERMINISTIC_DISPATCHER_H_
 
 #include <deque>
 #include <map>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "headless/public/util/url_request_dispatcher.h"
 #include "net/base/net_errors.h"
 
 namespace headless {
 
 class ManagedDispatchURLRequestJob;
 
 // The purpose of this class is to queue up calls to OnHeadersComplete and
 // OnStartError and dispatch them in order of URLRequestJob creation. This
 // helps make renders deterministic at the cost of slower page loads.

[Sami, 2017/02/09 12:03:26]

Could you also add a brief description here how navigations and resource
requests interact?

[alex clarke (OOO till 29th), 2017/02/09 12:44:44]

Done.

 class DeterministicDispatcher : public URLRequestDispatcher {
  public:
   explicit DeterministicDispatcher(
       scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner);
 
   ~DeterministicDispatcher() override;
 
   // UrlRequestDispatcher implementation:
   void JobCreated(ManagedDispatchURLRequestJob* job) override;
   void JobKilled(ManagedDispatchURLRequestJob* job) override;
   void JobFailed(ManagedDispatchURLRequestJob* job, net::Error error) override;
   void DataReady(ManagedDispatchURLRequestJob* job) override;
   void JobDeleted(ManagedDispatchURLRequestJob* job) override;
+  void NavigationRequested(
+      std::unique_ptr<NavigationRequest> navigation_request) override;
 
  private:
+  void MaybeDispatchNavigationJobLocked();
   void MaybeDispatchJobLocked();
   void MaybeDispatchJobOnIOThreadTask();
+  void NavigationDoneTask();
 
   scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner_;
 
   // Protects all members below.
   base::Lock lock_;
 
-  std::deque<ManagedDispatchURLRequestJob*> pending_requests_;
+  // TODO(alexclarke): Use std::varient when c++17 is allowed in chromium.

[altimin, 2017/02/09 12:01:52]

nit: std::variant?

[alex clarke (OOO till 29th), 2017/02/09 12:44:43]

Done.

+  struct Request {
+    Request();
+    explicit Request(ManagedDispatchURLRequestJob* url_request);
+    explicit Request(std::unique_ptr<NavigationRequest> navigation_request);
+    ~Request();
+
+    Request& operator=(Request&& other);
+
+    ManagedDispatchURLRequestJob* url_request;  // NOT OWNED
+    std::unique_ptr<NavigationRequest> navigation_request;
+  };
+
+  std::deque<Request> pending_requests_;
 
   using StatusMap = std::map<ManagedDispatchURLRequestJob*, net::Error>;
   StatusMap ready_status_map_;
 
   // Whether or not a MaybeDispatchJobOnIoThreadTask has been posted on the
   // |io_thread_task_runner_|
   bool dispatch_pending_;
+  bool navigation_in_progress_;
 
   base::WeakPtrFactory<DeterministicDispatcher> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeterministicDispatcher);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_UTIL_DETERMINISTIC_DISPATCHER_H_