Fix various issues in RedirectToFileResourceHandler.

content/browser/loader/redirect_to_file_resource_handler.h

 // 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.
 
 #ifndef CONTENT_BROWSER_LOADER_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_
 #define CONTENT_BROWSER_LOADER_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_
 
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/compiler_specific.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"
 #include "content/browser/loader/layered_resource_handler.h"
+#include "content/browser/loader/temporary_file_stream.h"
+#include "content/common/content_export.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_status.h"
+#include "url/gurl.h"
 
 namespace net {
 class FileStream;
 class GrowableIOBuffer;
 }
 
 namespace webkit_blob {
 class ShareableFileReference;
 }
 
 namespace content {
-class ResourceDispatcherHostImpl;
 
-// Redirects network data to a file.  This is intended to be layered in front
-// of either the AsyncResourceHandler or the SyncResourceHandler.
-class RedirectToFileResourceHandler : public LayeredResourceHandler {
+// Redirects network data to a file.  This is intended to be layered in front of
+// either the AsyncResourceHandler or the SyncResourceHandler.  The downstream
+// resource handler does not see OnWillRead or OnReadCompleted calls. Instead,
+// the ResourceResponse contains the path to a temporary file and
+// OnDataDownloaded is called as the file downloads.
+//
+// The temporary is vended through a delegate interface.

[darin (slow to review), 2014/03/11 05:15:58]

nit: "The temporary [file]..."

[davidben, 2014/03/11 19:50:04]

Oh whoops, that comment's no longer accurate anyway. Removed it.

+class CONTENT_EXPORT RedirectToFileResourceHandler
+    : public LayeredResourceHandler {
  public:
-  RedirectToFileResourceHandler(
-      scoped_ptr<ResourceHandler> next_handler,
-      net::URLRequest* request,
-      ResourceDispatcherHostImpl* resource_dispatcher_host);
+  typedef base::Callback<void(const CreateTemporaryFileStreamCallback&)>
+      CreateTemporaryFileStreamFunction;
+
+  // Create a RedirectToFileResourceHandler for |request| which wraps
+  // |next_handler|.
+  RedirectToFileResourceHandler(scoped_ptr<ResourceHandler> next_handler,
+                                net::URLRequest* request);
   virtual ~RedirectToFileResourceHandler();
 
-  // ResourceHandler implementation:
+  // Replace the CreateTemporaryFileStream implementation with a mocked one for
+  // testing purposes. The function should create a net::FileStream and a
+  // ShareableFileReference and then asynchronously pass them to the
+  // CreateTemporaryFileStreamCallback.
+  void SetCreateTemporaryFileStreamFunctionForTesting(
+      const CreateTemporaryFileStreamFunction& create_temporary_file_stream);
+
+  // LayeredResourceHandler implementation:
   virtual bool OnResponseStarted(int request_id,
                                  ResourceResponse* response,
                                  bool* defer) OVERRIDE;
   virtual bool OnWillStart(int request_id,
                            const GURL& url,
                            bool* defer) OVERRIDE;
   virtual bool OnWillRead(int request_id,
                           scoped_refptr<net::IOBuffer>* buf,
                           int* buf_size,
                           int min_size) OVERRIDE;
   virtual bool OnReadCompleted(int request_id,
                                int bytes_read,
                                bool* defer) OVERRIDE;
   virtual void OnResponseCompleted(int request_id,
                                    const net::URLRequestStatus& status,
                                    const std::string& security_info,
                                    bool* defer) OVERRIDE;
 
  private:
-  void DidCreateTemporaryFile(base::File::Error error_code,
-                              base::PassPlatformFile file_handle,
-                              const base::FilePath& file_path);
+  void DidCreateTemporaryFile(
+      base::File::Error error_code,
+      scoped_ptr<net::FileStream> file_stream,
+      webkit_blob::ShareableFileReference* deletable_file);
+
+  // Called by RedirectToFileResourceHandler::Writer.
   void DidWriteToFile(int result);
+
   bool WriteMore();
   bool BufIsFull() const;
   void ResumeIfDeferred();
 
-  base::WeakPtrFactory<RedirectToFileResourceHandler> weak_factory_;
-
-  ResourceDispatcherHostImpl* host_;
+  CreateTemporaryFileStreamFunction create_temporary_file_stream_;
 
   // We allocate a single, fixed-size IO buffer (buf_) used to read from the
   // network (buf_write_pending_ is true while the system is copying data into
   // buf_), and then write this buffer out to disk (write_callback_pending_ is
   // true while writing to disk).  Reading from the network is suspended while
   // the buffer is full (BufIsFull returns true).  The write_cursor_ member
   // tracks the offset into buf_ that we are writing to disk.
 
   scoped_refptr<net::GrowableIOBuffer> buf_;
   bool buf_write_pending_;
   int write_cursor_;
 
-  scoped_ptr<net::FileStream> file_stream_;
-  bool write_callback_pending_;
+  // Helper writer object which maintains references to the net::FileStream and
+  // webkit_blob::ShareableFileReference. This is maintained separately so that,
+  // on Windows, the temporary file isn't deleted until after it is closed.
+  class Writer;
+  Writer* writer_;
 
   // |next_buffer_size_| is the size of the buffer to be allocated on the next
   // OnWillRead() call.  We exponentially grow the size of the buffer allocated
   // when our owner fills our buffers. On the first OnWillRead() call, we
   // allocate a buffer of 32k and double it in OnReadCompleted() if the buffer
   // was filled, up to a maximum size of 512k.
   int next_buffer_size_;
 
-  // We create a ShareableFileReference that's deletable for the temp
-  // file created as  a result of the download.
-  scoped_refptr<webkit_blob::ShareableFileReference> deletable_file_;
-
-  bool did_defer_ ;
+  bool did_defer_;
 
   bool completed_during_write_;
+  GURL will_start_url_;
   net::URLRequestStatus completed_status_;
   std::string completed_security_info_;
 
+  base::WeakPtrFactory<RedirectToFileResourceHandler> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(RedirectToFileResourceHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_