Add content/browser/loader/ for resource loading related classes.

This infrastructure is shared by both renderer and worker processes, so having
it live in renderer_host/ was not quite right.  This change also nicely reduces
the number of files in renderer_host/.

R=jam@chromium.org
Review URL: https://codereview.chromium.org/11414299

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171194 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 116 insertions, 0 deletions

diff --git a/content/browser/loader/resource_handler.h b/content/browser/loader/resource_handler.h
new file mode 100644
index 0000000..dceeefb
--- /dev/null
+++ b/content/browser/loader/resource_handler.h
@@ -0,0 +1,116 @@
+// Copyright (c) 2012 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.
+
+// This is the browser side of the resource dispatcher, it receives requests
+// from the RenderProcessHosts, and dispatches them to URLRequests. It then
+// fowards the messages from the URLRequests back to the correct process for
+// handling.
+//
+// See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
+
+#ifndef CONTENT_BROWSER_LOADER_RESOURCE_HANDLER_H_
+#define CONTENT_BROWSER_LOADER_RESOURCE_HANDLER_H_
+
+#include <string>
+
+#include "base/sequenced_task_runner_helpers.h"
+#include "base/threading/non_thread_safe.h"
+#include "content/common/content_export.h"
+#include "content/public/browser/browser_thread.h"
+
+class GURL;
+
+namespace net {
+class IOBuffer;
+class URLRequestStatus;
+}  // namespace net
+
+namespace content {
+class ResourceController;
+struct ResourceResponse;
+
+// The resource dispatcher host uses this interface to process network events
+// for an URLRequest instance.  A ResourceHandler's lifetime is bound to its
+// associated URLRequest.
+class CONTENT_EXPORT ResourceHandler
+    : public NON_EXPORTED_BASE(base::NonThreadSafe) {
+ public:
+  virtual ~ResourceHandler() {}
+
+  // Sets the controller for this handler.
+  virtual void SetController(ResourceController* controller);
+
+  // Called as upload progress is made.  The return value is ignored.
+  virtual bool OnUploadProgress(int request_id,
+                                uint64 position,
+                                uint64 size) = 0;
+
+  // The request was redirected to a new URL.  |*defer| has an initial value of
+  // false.  Set |*defer| to true to defer the redirect.  The redirect may be
+  // followed later on via ResourceDispatcherHost::FollowDeferredRedirect.  If
+  // the handler returns false, then the request is cancelled.
+  virtual bool OnRequestRedirected(int request_id, const GURL& url,
+                                   ResourceResponse* response,
+                                   bool* defer) = 0;
+
+  // Response headers and meta data are available.  If the handler returns
+  // false, then the request is cancelled.  Set |*defer| to true to defer
+  // processing of the response.  Call ResourceDispatcherHostImpl::
+  // ResumeDeferredRequest to continue processing the response.
+  virtual bool OnResponseStarted(int request_id,
+                                 ResourceResponse* response,
+                                 bool* defer) = 0;
+
+  // Called before the net::URLRequest for |request_id| (whose url is |url|) is
+  // to be started.  If the handler returns false, then the request is
+  // cancelled.  Otherwise if the return value is true, the ResourceHandler can
+  // delay the request from starting by setting |*defer = true|.  A deferred
+  // request will not have called net::URLRequest::Start(), and will not resume
+  // until someone calls ResourceDispatcherHost::StartDeferredRequest().
+  virtual bool OnWillStart(int request_id, const GURL& url, bool* defer) = 0;
+
+  // Data will be read for the response.  Upon success, this method places the
+  // size and address of the buffer where the data is to be written in its
+  // out-params.  This call will be followed by either OnReadCompleted or
+  // OnResponseCompleted, at which point the buffer may be recycled.
+  //
+  // If the handler returns false, then the request is cancelled.  Otherwise,
+  // once data is available, OnReadCompleted will be called.
+  virtual bool OnWillRead(int request_id,
+                          net::IOBuffer** buf,
+                          int* buf_size,
+                          int min_size) = 0;
+
+  // Data (*bytes_read bytes) was written into the buffer provided by
+  // OnWillRead.  A return value of false cancels the request, true continues
+  // reading data.  Set |*defer| to true to defer reading more response data.
+  // Call ResourceDispatcherHostImpl::ResumeDeferredRequest to continue reading
+  // response data.
+  virtual bool OnReadCompleted(int request_id, int bytes_read,
+                               bool* defer) = 0;
+
+  // The response is complete.  The final response status is given.  Returns
+  // false if the handler is deferring the call to a later time.  Otherwise,
+  // the request will be destroyed upon return.
+  virtual bool OnResponseCompleted(int request_id,
+                                   const net::URLRequestStatus& status,
+                                   const std::string& security_info) = 0;
+
+  // This notification is synthesized by the RedirectToFileResourceHandler
+  // to indicate progress of 'download_to_file' requests. OnReadCompleted
+  // calls are consumed by the RedirectToFileResourceHandler and replaced
+  // with OnDataDownloaded calls.
+  virtual void OnDataDownloaded(int request_id, int bytes_downloaded) {}
+
+ protected:
+  ResourceHandler() : controller_(NULL) {}
+  ResourceController* controller() { return controller_; }
+
+ private:
+  ResourceController* controller_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_RESOURCE_HANDLER_H_