fileapi: Add modification time check for FileSystemFileStreamReader

webkit/fileapi/file_system_file_stream_reader.cc

 // 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.
 
 #include "webkit/fileapi/file_system_file_stream_reader.h"
 
 #include "base/file_util_proxy.h"
 #include "base/platform_file.h"
 #include "base/single_thread_task_runner.h"
 #include "net/base/file_stream.h"
@@ skipping 32 matching lines @@
 void Int64CallbackAdapter(const net::Int64CompletionCallback& callback,
                           int value) {
   callback.Run(value);
 }
 
 }  // namespace
 
 FileSystemFileStreamReader::FileSystemFileStreamReader(
     FileSystemContext* file_system_context,
     const FileSystemURL& url,
-    int64 initial_offset)
+    int64 initial_offset,
+    const base::Time& expected_modification_time)
     : file_system_context_(file_system_context),
       url_(url),
       initial_offset_(initial_offset),
+      expected_modification_time_(expected_modification_time),
       has_pending_create_snapshot_(false),
       weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
 }
 
 FileSystemFileStreamReader::~FileSystemFileStreamReader() {
 }
 
 int FileSystemFileStreamReader::Read(
     net::IOBuffer* buf, int buf_len,
     const net::CompletionCallback& callback) {
@@ skipping 37 matching lines @@
     const base::Closure& callback,
     const net::CompletionCallback& error_callback,
     base::PlatformFileError file_error,
     const base::PlatformFileInfo& file_info,
     const FilePath& platform_path,
     const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
   DCHECK(has_pending_create_snapshot_);
   DCHECK(!local_file_reader_.get());
   has_pending_create_snapshot_ = false;
 
-  if (file_error != base::PLATFORM_FILE_OK) {
-    error_callback.Run(net::PlatformFileErrorToNetError(file_error));
+  int net_error = net::PlatformFileErrorToNetError(file_error);
+
+  if (!expected_modification_time_.is_null() &&
+      expected_modification_time_.ToTimeT() !=
+      file_info.last_modified.ToTimeT())
+    net_error = net::ERR_UPLOAD_FILE_CHANGED;
+
+  if (net_error != net::OK) {
+    error_callback.Run(net_error);
     return;
   }
 
   // Keep the reference (if it's non-null) so that the file won't go away.
   snapshot_ref_ = file_ref;
 
   local_file_reader_.reset(
       new LocalFileStreamReader(
           file_system_context_->task_runners()->file_task_runner(),
           platform_path, initial_offset_, base::Time()));

[kinuko, 2012/10/15 07:24:07]

I guess it might just work if you pass the expected_modification_time_ to the
LocalFileStreamReader here?

[hashimoto, 2012/10/15 08:05:04]

Sounds great, thanks!
Done.

 
   callback.Run();
 }
 
 }  // namespace fileapi