[fsp] First part of support for reading files.

chrome/browser/chromeos/file_system_provider/provided_file_system.cc

 // Copyright 2014 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 "chrome/browser/chromeos/file_system_provider/provided_file_system.h"
 
 #include "base/files/file.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/close_file.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/get_metadata.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/open_file.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/read_directory.h"
+#include "chrome/browser/chromeos/file_system_provider/operations/read_file.h"
 #include "chrome/browser/chromeos/file_system_provider/operations/unmount.h"
 #include "chrome/browser/chromeos/file_system_provider/request_manager.h"
 #include "chrome/common/extensions/api/file_system_provider.h"
 #include "extensions/browser/event_router.h"
 
 namespace chromeos {
 namespace file_system_provider {
-namespace {
-
-}  // namespace
 
 ProvidedFileSystem::ProvidedFileSystem(
     extensions::EventRouter* event_router,
     const ProvidedFileSystemInfo& file_system_info)
     : event_router_(event_router), file_system_info_(file_system_info) {
 }
 
 ProvidedFileSystem::~ProvidedFileSystem() {}
 
 void ProvidedFileSystem::RequestUnmount(
@@ skipping 21 matching lines @@
     const fileapi::AsyncFileUtil::ReadDirectoryCallback& callback) {
   if (!request_manager_.CreateRequest(scoped_ptr<
           RequestManager::HandlerInterface>(new operations::ReadDirectory(
           event_router_, file_system_info_, directory_path, callback)))) {
     callback.Run(base::File::FILE_ERROR_SECURITY,
                  fileapi::AsyncFileUtil::EntryList(),
                  false /* has_more */);
   }
 }
 
+void ProvidedFileSystem::ReadFile(int file_handle,
+                                  net::IOBuffer* buffer,
+                                  int64 offset,
+                                  int length,
+                                  const ReadChunkReceivedCallback& callback) {
+  if (!request_manager_.CreateRequest(
+          make_scoped_ptr<RequestManager::HandlerInterface>(
+              new operations::ReadFile(event_router_,
+                                       file_system_info_,
+                                       file_handle,
+                                       buffer,
+                                       offset,
+                                       length,
+                                       callback)))) {
+    callback.Run(0 /* chunk_length */,
+                 false /* has_more */,
+                 base::File::FILE_ERROR_SECURITY);
+  }
+}
+
 void ProvidedFileSystem::OpenFile(const base::FilePath& file_path,
                                   OpenFileMode mode,
                                   bool create,
                                   const OpenFileCallback& callback) {
   // Writing is not supported. Note, that this includes a situation, when a file
   // exists, but |create| is set to true.
   if (mode == OPEN_FILE_MODE_WRITE || create) {
     callback.Run(0 /* file_handle */, base::File::FILE_ERROR_SECURITY);
     return;
   }
@@ skipping 24 matching lines @@
 const ProvidedFileSystemInfo& ProvidedFileSystem::GetFileSystemInfo() const {
   return file_system_info_;
 }
 
 RequestManager* ProvidedFileSystem::GetRequestManager() {
   return &request_manager_;
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos