| // 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/operations/read_file.h" |
| |
| #include <limits> |
| #include <string> |
| |
| #include "chrome/common/extensions/api/file_system_provider.h" |
| #include "chrome/common/extensions/api/file_system_provider_internal.h" |
| |
| namespace chromeos { |
| namespace file_system_provider { |
| namespace operations { |
| namespace { |
| |
| // Convert |value| into |output|. If parsing fails, then returns a negative |
| // value. Otherwise returns number of bytes written to the buffer. |
| int CopyRequestValueToBuffer(scoped_ptr<RequestValue> value, |
| net::IOBuffer* buffer, |
| int buffer_offset, |
| int buffer_length) { |
| using extensions::api::file_system_provider_internal:: |
| ReadFileRequestedSuccess::Params; |
| |
| const Params* params = value->read_file_success_params(); |
| if (!params) |
| return -1; |
| |
| const size_t chunk_size = params->data.length(); |
| |
| // Check for overflows. |
| if (chunk_size > static_cast<size_t>(buffer_length) - buffer_offset) |
| return -1; |
| |
| memcpy(buffer->data() + buffer_offset, params->data.c_str(), chunk_size); |
| |
| return chunk_size; |
| } |
| |
| } // namespace |
| |
| ReadFile::ReadFile( |
| extensions::EventRouter* event_router, |
| const ProvidedFileSystemInfo& file_system_info, |
| int file_handle, |
| net::IOBuffer* buffer, |
| int64 offset, |
| int length, |
| const ProvidedFileSystemInterface::ReadChunkReceivedCallback& callback) |
| : Operation(event_router, file_system_info), |
| file_handle_(file_handle), |
| buffer_(buffer), |
| offset_(offset), |
| length_(length), |
| current_offset_(0), |
| callback_(callback) { |
| } |
| |
| ReadFile::~ReadFile() { |
| } |
| |
| bool ReadFile::Execute(int request_id) { |
| scoped_ptr<base::ListValue> values(new base::ListValue); |
| values->AppendInteger(file_handle_); |
| values->AppendDouble(offset_); |
| values->AppendInteger(length_); |
| return SendEvent( |
| request_id, |
| extensions::api::file_system_provider::OnReadFileRequested::kEventName, |
| values.Pass()); |
| } |
| |
| void ReadFile::OnSuccess(int /* request_id */, |
| scoped_ptr<RequestValue> result, |
| bool has_next) { |
| const int copy_result = CopyRequestValueToBuffer( |
| result.Pass(), buffer_, current_offset_, length_); |
| DCHECK_LE(0, copy_result); |
| DCHECK(!has_next || copy_result > 0); |
| if (copy_result > 0) |
| current_offset_ += copy_result; |
| callback_.Run(copy_result, has_next, base::File::FILE_OK); |
| } |
| |
| void ReadFile::OnError(int /* request_id */, base::File::Error error) { |
| callback_.Run(0 /* chunk_length */, false /* has_next */, error); |
| } |
| |
| } // namespace operations |
| } // namespace file_system_provider |
| } // namespace chromeos |