56 lines
1.7 KiB
C++
56 lines
1.7 KiB
C++
/*
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* Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "net/dcsctp/rx/reassembly_streams.h"
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#include <cstddef>
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#include <map>
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#include <utility>
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namespace dcsctp {
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ReassembledMessage AssembleMessage(std::map<UnwrappedTSN, Data>::iterator start,
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std::map<UnwrappedTSN, Data>::iterator end) {
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size_t count = std::distance(start, end);
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if (count == 1) {
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// Fast path - zero-copy
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Data& data = start->second;
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return ReassembledMessage{
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.tsns = {start->first},
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.message = DcSctpMessage(data.stream_id, data.ppid,
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std::move(start->second.payload)),
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};
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}
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// Slow path - will need to concatenate the payload.
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std::vector<UnwrappedTSN> tsns;
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std::vector<uint8_t> payload;
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size_t payload_size = std::accumulate(
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start, end, 0,
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[](size_t v, const auto& p) { return v + p.second.size(); });
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tsns.reserve(count);
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payload.reserve(payload_size);
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for (auto it = start; it != end; ++it) {
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Data& data = it->second;
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tsns.push_back(it->first);
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payload.insert(payload.end(), data.payload.begin(), data.payload.end());
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}
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return ReassembledMessage{
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.tsns = std::move(tsns),
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.message = DcSctpMessage(start->second.stream_id, start->second.ppid,
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std::move(payload)),
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};
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}
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} // namespace dcsctp
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