webkit/child/resource_loader_bridge.h

   1 // Copyright (c) 2012 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 // The intent of this file is to provide a type-neutral abstraction between
   6 // Chrome and WebKit for resource loading. This pure-virtual interface is
   7 // implemented by the embedder.
   8 //
   9 // One of these objects will be created by WebKit for each request. WebKit
  10 // will own the pointer to the bridge, and will delete it when the request is
  11 // no longer needed.
  12 //
  13 // In turn, the bridge's owner on the WebKit end will implement the
  14 // RequestPeer interface, which we will use to communicate notifications
  15 // back.
  16
  17 #ifndef WEBKIT_CHILD_RESOURCE_LOADER_BRIDGE_H_
  18 #define WEBKIT_CHILD_RESOURCE_LOADER_BRIDGE_H_
  19
  20 #include "base/macros.h"
  21 #include "net/base/request_priority.h"
  22 #include "webkit/child/webkit_child_export.h"
  23
  24 // TODO(pilgrim) remove this once resource loader is moved to content
  25 // http://crbug.com/338338
  26 namespace content {
  27 class RequestPeer;
  28 class ResourceRequestBody;
  29 struct SyncLoadResponse;
  30 }
  31
  32 namespace webkit_glue {
  33
  34 class ResourceLoaderBridge {
  35  public:
  36   // use WebKitPlatformSupportImpl::CreateResourceLoader() for construction, but
  37   // anybody can delete at any time, INCLUDING during processing of callbacks.
  38   WEBKIT_CHILD_EXPORT virtual ~ResourceLoaderBridge();
  39
  40   // Call this method before calling Start() to set the request body.
  41   // May only be used with HTTP(S) POST requests.
  42   virtual void SetRequestBody(content::ResourceRequestBody* request_body) = 0;
  43
  44   // Call this method to initiate the request.  If this method succeeds, then
  45   // the peer's methods will be called asynchronously to report various events.
  46   virtual bool Start(content::RequestPeer* peer) = 0;
  47
  48   // Call this method to cancel a request that is in progress.  This method
  49   // causes the request to immediately transition into the 'done' state. The
  50   // OnCompletedRequest method will be called asynchronously; this assumes
  51   // the peer is still valid.
  52   virtual void Cancel() = 0;
  53
  54   // Call this method to suspend or resume a load that is in progress.  This
  55   // method may only be called after a successful call to the Start method.
  56   virtual void SetDefersLoading(bool value) = 0;
  57
  58   // Call this method when the priority of the requested resource changes after
  59   // Start() has been called.  This method may only be called after a successful
  60   // call to the Start method.
  61   virtual void DidChangePriority(net::RequestPriority new_priority,
  62                                  int intra_priority_value) = 0;
  63
  64   // Call this method to load the resource synchronously (i.e., in one shot).
  65   // This is an alternative to the Start method.  Be warned that this method
  66   // will block the calling thread until the resource is fully downloaded or an
  67   // error occurs.  It could block the calling thread for a long time, so only
  68   // use this if you really need it!  There is also no way for the caller to
  69   // interrupt this method.  Errors are reported via the status field of the
  70   // response parameter.
  71   virtual void SyncLoad(content::SyncLoadResponse* response) = 0;
  72
  73  protected:
  74   // Construction must go through
  75   // WebKitPlatformSupportImpl::CreateResourceLoader()
  76   // For HTTP(S) POST requests, the AppendDataToUpload and AppendFileToUpload
  77   // methods may be called to construct the body of the request.
  78   WEBKIT_CHILD_EXPORT ResourceLoaderBridge();
  79
  80  private:
  81   DISALLOW_COPY_AND_ASSIGN(ResourceLoaderBridge);
  82 };
  83
  84 }  // namespace webkit_glue
  85
  86 #endif  // WEBKIT_CHILD_RESOURCE_LOADER_BRIDGE_H_