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   virtual ~DetachableResourceHandler();
  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   virtual void SetController(ResourceController* controller) OVERRIDE;
  51   virtual bool OnUploadProgress(uint64 position, uint64 size) OVERRIDE;
  52   virtual bool OnRequestRedirected(const net::RedirectInfo& redirect_info,
  53                                    ResourceResponse* response,
  54                                    bool* defer) OVERRIDE;
  55   virtual bool OnResponseStarted(ResourceResponse* response,
  56                                  bool* defer) OVERRIDE;
  57   virtual bool OnWillStart(const GURL& url, bool* defer) OVERRIDE;
  58   virtual bool OnBeforeNetworkStart(const GURL& url, bool* defer) OVERRIDE;
  59   virtual bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
  60                           int* buf_size,
  61                           int min_size) OVERRIDE;
  62   virtual bool OnReadCompleted(int bytes_read, bool* defer) OVERRIDE;
  63   virtual void OnResponseCompleted(const net::URLRequestStatus& status,
  64                                    const std::string& security_info,
  65                                    bool* defer) OVERRIDE;
  66   virtual void OnDataDownloaded(int bytes_downloaded) OVERRIDE;
  67
  68   // ResourceController implementation:
  69   virtual void Resume() OVERRIDE;
  70   virtual void Cancel() OVERRIDE;
  71   virtual void CancelAndIgnore() OVERRIDE;
  72   virtual void CancelWithError(int error_code) OVERRIDE;
  73
  74  private:
  75   scoped_ptr<ResourceHandler> next_handler_;
  76   scoped_refptr<net::IOBuffer> read_buffer_;
  77
  78   scoped_ptr<base::OneShotTimer<DetachableResourceHandler> > detached_timer_;
  79   base::TimeDelta cancel_delay_;
  80
  81   bool is_deferred_;
  82   bool is_finished_;
  83
  84   DISALLOW_COPY_AND_ASSIGN(DetachableResourceHandler);
  85 };
  86
  87 }  // namespace content
  88
  89 #endif  // CONTENT_BROWSER_LOADER_DETACHABLE_RESOURCE_HANDLER_H_