blob: 4f3b9a1c22ac903cd83e22dc905d049e9bff56f9 [file] [log] [blame]
/*
* Copyright 2018 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef LOGGING_RTC_EVENT_LOG_ENCODER_DELTA_ENCODING_H_
#define LOGGING_RTC_EVENT_LOG_ENCODER_DELTA_ENCODING_H_
#include <string>
#include <vector>
namespace webrtc {
// Encode |values| as a sequence of deltas following on |base| and return it.
// If all of the values were equal to the base, an empty string will be
// returned; this is a valid encoding of that edge case.
// |base| is not guaranteed to be written into |output|, and must therefore
// be provided separately to the decoder.
// This function never fails.
std::string EncodeDeltas(uint64_t base, const std::vector<uint64_t>& values);
// EncodeDeltas() and DecodeDeltas() are inverse operations;
// invoking DecodeDeltas() over the output of EncodeDeltas(), will return
// the input originally given to EncodeDeltas().
// |num_of_deltas| must be greater than zero. If input is not a valid encoding
// of |num_of_deltas| elements based on |base|, the function returns an empty
// vector, which signals an error.
std::vector<uint64_t> DecodeDeltas(const std::string& input,
uint64_t base,
size_t num_of_deltas);
} // namespace webrtc
#endif // LOGGING_RTC_EVENT_LOG_ENCODER_DELTA_ENCODING_H_