content/browser/loader/detachable_resource_handler.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_LOADER_DETACHABLE_RESOURCE_HANDLER_H_
   6 #define CONTENT_BROWSER_LOADER_DETACHABLE_RESOURCE_HANDLER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/time/time.h"
  13 #include "base/timer/timer.h"
  14 #include "content/browser/loader/resource_handler.h"
  15 #include "content/public/browser/resource_controller.h"
  16
  17 namespace net {
  18 class IOBuffer;
  19 class URLRequest;
  20 }  // namespace net
  21
  22 namespace content {
  23
  24 // A ResourceHandler which delegates all calls to the next handler, unless
  25 // detached. Once detached, it drives the request to completion itself. This is
  26 // used for requests which outlive the owning renderer, such as <link
  27 // rel=prefetch> and <a ping>. Requests do not start out detached so, e.g.,
  28 // prefetches appear in DevTools and get placed in the renderer's local
  29 // cache. If the request does not complete after a timeout on detach, it is
  30 // cancelled.
  31 //
  32 // Note that, once detached, the request continues without the original next
  33 // handler, so any policy decisions in that handler are skipped.
  34 class DetachableResourceHandler : public ResourceHandler,
  35                                   public ResourceController {
  36  public:
  37   DetachableResourceHandler(net::URLRequest* request,
  38                             base::TimeDelta cancel_delay,
  39                             scoped_ptr<ResourceHandler> next_handler);
  40   ~DetachableResourceHandler() override;
  41
  42   bool is_detached() const { return next_handler_ == NULL; }
  43   void Detach();
  44
  45   void set_cancel_delay(base::TimeDelta cancel_delay) {
  46     cancel_delay_ = cancel_delay;
  47   }
  48
  49   // ResourceHandler implementation:
  50   void SetController(ResourceController* controller) override;
  51   bool OnRequestRedirected(const net::RedirectInfo& redirect_info,
  52                            ResourceResponse* response,
  53                            bool* defer) override;
  54   bool OnResponseStarted(ResourceResponse* response, bool* defer) override;
  55   bool OnWillStart(const GURL& url, bool* defer) override;
  56   bool OnBeforeNetworkStart(const GURL& url, bool* defer) override;
  57   bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
  58                   int* buf_size,
  59                   int min_size) override;
  60   bool OnReadCompleted(int bytes_read, bool* defer) override;
  61   void OnResponseCompleted(const net::URLRequestStatus& status,
  62                            const std::string& security_info,
  63                            bool* defer) override;
  64   void OnDataDownloaded(int bytes_downloaded) override;
  65
  66   // ResourceController implementation:
  67   void Resume() override;
  68   void Cancel() override;
  69   void CancelAndIgnore() override;
  70   void CancelWithError(int error_code) override;
  71
  72  private:
  73   scoped_ptr<ResourceHandler> next_handler_;
  74   scoped_refptr<net::IOBuffer> read_buffer_;
  75
  76   scoped_ptr<base::OneShotTimer<DetachableResourceHandler> > detached_timer_;
  77   base::TimeDelta cancel_delay_;
  78
  79   bool is_deferred_;
  80   bool is_finished_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(DetachableResourceHandler);
  83 };
  84
  85 }  // namespace content
  86
  87 #endif  // CONTENT_BROWSER_LOADER_DETACHABLE_RESOURCE_HANDLER_H_