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//
// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#ifndef UPDATE_ENGINE_COMMON_FILE_FETCHER_H_
#define UPDATE_ENGINE_COMMON_FILE_FETCHER_H_
#include <memory>
#include <string>
#include <utility>
#include <base/logging.h>
#include <base/macros.h>
#include <brillo/streams/stream.h>
#include "update_engine/common/http_fetcher.h"
// This is a concrete implementation of HttpFetcher that reads files
// asynchronously.
namespace chromeos_update_engine {
class FileFetcher : public HttpFetcher {
public:
// Returns whether the passed url is supported.
static bool SupportedUrl(const std::string& url);
FileFetcher() : HttpFetcher(nullptr) {}
// Cleans up all internal state. Does not notify delegate.
~FileFetcher() override;
// HttpFetcher overrides.
void SetOffset(off_t offset) override { offset_ = offset; }
void SetLength(size_t length) override { data_length_ = length; }
void UnsetLength() override { SetLength(0); }
// Begins the transfer if it hasn't already begun.
void BeginTransfer(const std::string& url) override;
// If the transfer is in progress, aborts the transfer early. The transfer
// cannot be resumed.
void TerminateTransfer() override;
// Ignore all extra headers for files.
void SetHeader(const std::string& header_name,
const std::string& header_value) override {}
bool GetHeader(const std::string& header_name,
std::string* header_value) const override {
header_value->clear();
return false;
}
// Suspend the asynchronous file read.
void Pause() override;
// Resume the suspended file read.
void Unpause() override;
size_t GetBytesDownloaded() override {
return static_cast<size_t>(bytes_copied_);
}
// Ignore all the time limits for files.
void set_low_speed_limit(int low_speed_bps, int low_speed_sec) override {}
void set_connect_timeout(int connect_timeout_seconds) override {}
void set_max_retry_count(int max_retry_count) override {}
private:
// Cleans up the fetcher, resetting its status to a newly constructed one.
void CleanUp();
// Schedule a new asynchronous read if the stream is not paused and no other
// read is in process. This method can be called at any point.
void ScheduleRead();
// Called from the main loop when a single read from |stream_| succeeds or
// fails, calling OnReadDoneCallback() and OnReadErrorCallback() respectively.
void OnReadDoneCallback(size_t bytes_read);
void OnReadErrorCallback(const brillo::Error* error);
// Whether the transfer was started and didn't finish yet.
bool transfer_in_progress_{false};
// Whether the transfer is paused.
bool transfer_paused_{false};
// Whether there's an ongoing asynchronous read. When this value is true, the
// the |buffer_| is being used by the |stream_|.
bool ongoing_read_{false};
// Total number of bytes copied.
uint64_t bytes_copied_{0};
// The offset inside the file where the read should start.
uint64_t offset_{0};
// The length of the data or -1 if unknown (will read until EOF).
int64_t data_length_{-1};
brillo::StreamPtr stream_;
// The buffer used for reading from the stream.
brillo::Blob buffer_;
DISALLOW_COPY_AND_ASSIGN(FileFetcher);
};
} // namespace chromeos_update_engine
#endif // UPDATE_ENGINE_COMMON_FILE_FETCHER_H_