src/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/elapsed_timer.h"
  14 #include "base/timer/timer.h"
  15 #include "content/browser/loader/resource_handler.h"
  16 #include "content/public/browser/resource_controller.h"
  17 #include "net/url_request/url_request_status.h"
  18
  19 namespace net {
  20 class IOBuffer;
  21 class URLRequest;
  22 }  // namespace net
  23
  24 namespace content {
  25
  26 // A ResourceHandler which delegates all calls to the next handler, unless
  27 // detached. Once detached, it drives the request to completion itself. This is
  28 // used for requests which outlive the owning renderer, such as <link
  29 // rel=prefetch> and <a ping>. Requests do not start out detached so, e.g.,
  30 // prefetches appear in DevTools and get placed in the renderer's local
  31 // cache. If the request does not complete after a timeout on detach, it is
  32 // cancelled.
  33 //
  34 // Note that, once detached, the request continues without the original next
  35 // handler, so any policy decisions in that handler are skipped.
  36 class DetachableResourceHandler : public ResourceHandler,
  37                                   public ResourceController {
  38  public:
  39   DetachableResourceHandler(net::URLRequest* request,
  40                             base::TimeDelta cancel_delay,
  41                             scoped_ptr<ResourceHandler> next_handler);
  42   virtual ~DetachableResourceHandler();
  43
  44   bool is_detached() const { return next_handler_ == NULL; }
  45   void Detach();
  46
  47   void set_cancel_delay(base::TimeDelta cancel_delay) {
  48     cancel_delay_ = cancel_delay;
  49   }
  50
  51   // ResourceHandler implementation:
  52   virtual void SetController(ResourceController* controller) OVERRIDE;
  53   virtual bool OnUploadProgress(int request_id, uint64 position,
  54                                 uint64 size) OVERRIDE;
  55   virtual bool OnRequestRedirected(int request_id, const GURL& url,
  56                                    ResourceResponse* response,
  57                                    bool* defer) OVERRIDE;
  58   virtual bool OnResponseStarted(int request_id,
  59                                  ResourceResponse* response,
  60                                  bool* defer) OVERRIDE;
  61   virtual bool OnWillStart(int request_id, const GURL& url,
  62                            bool* defer) OVERRIDE;
  63   virtual bool OnBeforeNetworkStart(int request_id,
  64                                     const GURL& url,
  65                                     bool* defer) OVERRIDE;
  66   virtual bool OnWillRead(int request_id,
  67                           scoped_refptr<net::IOBuffer>* buf,
  68                           int* buf_size,
  69                           int min_size) OVERRIDE;
  70   virtual bool OnReadCompleted(int request_id, int bytes_read,
  71                                bool* defer) OVERRIDE;
  72   virtual void OnResponseCompleted(int request_id,
  73                                    const net::URLRequestStatus& status,
  74                                    const std::string& security_info,
  75                                    bool* defer) OVERRIDE;
  76   virtual void OnDataDownloaded(int request_id, int bytes_downloaded) OVERRIDE;
  77
  78   // ResourceController implementation:
  79   virtual void Resume() OVERRIDE;
  80   virtual void Cancel() OVERRIDE;
  81   virtual void CancelAndIgnore() OVERRIDE;
  82   virtual void CancelWithError(int error_code) OVERRIDE;
  83
  84  private:
  85   void TimedOut();
  86
  87   scoped_ptr<ResourceHandler> next_handler_;
  88   scoped_refptr<net::IOBuffer> read_buffer_;
  89
  90   scoped_ptr<base::OneShotTimer<DetachableResourceHandler> > detached_timer_;
  91   base::TimeDelta cancel_delay_;
  92
  93   bool is_deferred_;
  94   bool is_finished_;
  95   bool timed_out_;
  96
  97   bool response_started_;
  98   base::ElapsedTimer time_since_start_;
  99
 100   // The status recorded from OnResponseCompleted. Value is
 101   // net::URLRequestStatus::IO_PENDING if OnResponseCompleted is never received.
 102   net::URLRequestStatus::Status status_;
 103
 104   DISALLOW_COPY_AND_ASSIGN(DetachableResourceHandler);
 105 };
 106
 107 }  // namespace content
 108
 109 #endif  // CONTENT_BROWSER_LOADER_DETACHABLE_RESOURCE_HANDLER_H_