mirror of
https://github.com/kidfromjupiter/nearby.git
synced 2026-09-15 07:06:11 -04:00
46 lines
1.5 KiB
C++
46 lines
1.5 KiB
C++
// Copyright 2023 Google LLC
|
|
//
|
|
// 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
|
|
//
|
|
// https://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 THIRD_PARTY_NEARBY_INTERNAL_WEAVE_PACKET_SEQUENCE_NUMBER_GENERATOR_H_
|
|
#define THIRD_PARTY_NEARBY_INTERNAL_WEAVE_PACKET_SEQUENCE_NUMBER_GENERATOR_H_
|
|
|
|
#include "absl/base/thread_annotations.h"
|
|
#include "internal/platform/mutex.h"
|
|
|
|
namespace nearby {
|
|
namespace weave {
|
|
|
|
// Keeps a counter of the next Weave packet to set the new Weave packet sequence
|
|
// number in a connection. This counter automatically rolls over once it hits 7,
|
|
// since 3 bits are allocated in the packet to the counter, making its max value
|
|
// 0b111, or 7.
|
|
class PacketSequenceNumberGenerator {
|
|
public:
|
|
// Returns the next counter in the sequence, incrementing the counter
|
|
// internally.
|
|
int Next();
|
|
|
|
// Resets the counter to 0.
|
|
void Reset();
|
|
|
|
private:
|
|
Mutex mutex_;
|
|
int packet_counter_ ABSL_GUARDED_BY(mutex_) = 0;
|
|
};
|
|
|
|
} // namespace weave
|
|
} // namespace nearby
|
|
|
|
#endif // THIRD_PARTY_NEARBY_INTERNAL_WEAVE_PACKET_SEQUENCE_NUMBER_GENERATOR_H_
|