/* * Copyright (c) 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_VAR_INT_H_ #define LOGGING_RTC_EVENT_LOG_ENCODER_VAR_INT_H_ #include <stddef.h> #include <stdint.h> #include <string> #include <utility> #include "absl/strings/string_view.h" #include "rtc_base/bitstream_reader.h" namespace webrtc { extern const size_t kMaxVarIntLengthBytes; // Encode a given uint64_t as a varint. From least to most significant, // each batch of seven bits are put into the lower bits of a byte, and the last // remaining bit in that byte (the highest one) marks whether additional bytes // follow (which happens if and only if there are other bits in `input` which // are non-zero). // Notes: If input == 0, one byte is used. If input is uint64_t::max, exactly // kMaxVarIntLengthBytes are used. std::string EncodeVarInt(uint64_t input); // Inverse of EncodeVarInt(). // Returns true and the remaining (unread) slice of the input if decoding // succeeds. Returns false otherwise and `output` is not modified. std::pair<bool, absl::string_view> DecodeVarInt(absl::string_view input, uint64_t* output); // Same as other version, but uses a BitstreamReader for input. // If decoding is successful returns the decoded varint. // If not successful, `input` reader is set into the failure state, return value // is unspecified. uint64_t DecodeVarInt(BitstreamReader& input); } // namespace webrtc #endif // LOGGING_RTC_EVENT_LOG_ENCODER_VAR_INT_H_