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/*
* Copyright (c) 2021 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 NET_DCSCTP_RX_INTERLEAVED_REASSEMBLY_STREAMS_H_
#define NET_DCSCTP_RX_INTERLEAVED_REASSEMBLY_STREAMS_H_
#include <cstdint>
#include <map>
#include <string>
#include <utility>
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "net/dcsctp/common/sequence_numbers.h"
#include "net/dcsctp/packet/chunk/forward_tsn_common.h"
#include "net/dcsctp/packet/data.h"
#include "net/dcsctp/rx/reassembly_streams.h"
namespace dcsctp {
// Handles reassembly of incoming data when interleaved message sending is
// enabled on the association, i.e. when RFC8260 is in use.
class InterleavedReassemblyStreams : public ReassemblyStreams {
public:
InterleavedReassemblyStreams(absl::string_view log_prefix,
OnAssembledMessage on_assembled_message);
int Add(UnwrappedTSN tsn, Data data) override;
size_t HandleForwardTsn(
UnwrappedTSN new_cumulative_ack_tsn,
rtc::ArrayView<const AnyForwardTsnChunk::SkippedStream> skipped_streams)
override;
void ResetStreams(rtc::ArrayView<const StreamID> stream_ids) override;
HandoverReadinessStatus GetHandoverReadiness() const override;
void AddHandoverState(DcSctpSocketHandoverState& state) override;
void RestoreFromState(const DcSctpSocketHandoverState& state) override;
private:
struct FullStreamId {
const IsUnordered unordered;
const StreamID stream_id;
FullStreamId(IsUnordered unordered, StreamID stream_id)
: unordered(unordered), stream_id(stream_id) {}
friend bool operator<(FullStreamId a, FullStreamId b) {
return a.unordered < b.unordered ||
(!(a.unordered < b.unordered) && (a.stream_id < b.stream_id));
}
};
class Stream {
public:
Stream(FullStreamId stream_id,
InterleavedReassemblyStreams* parent,
MID next_mid = MID(0))
: stream_id_(stream_id),
parent_(*parent),
next_mid_(mid_unwrapper_.Unwrap(next_mid)) {}
int Add(UnwrappedTSN tsn, Data data);
size_t EraseTo(MID message_id);
void Reset() {
mid_unwrapper_.Reset();
next_mid_ = mid_unwrapper_.Unwrap(MID(0));
}
bool has_unassembled_chunks() const { return !chunks_by_mid_.empty(); }
void AddHandoverState(DcSctpSocketHandoverState& state) const;
private:
using ChunkMap = std::map<FSN, std::pair<UnwrappedTSN, Data>>;
// Try to assemble one message identified by `mid`.
// Returns the number of bytes assembled if a message was assembled.
size_t TryToAssembleMessage(UnwrappedMID mid);
size_t AssembleMessage(const ChunkMap& tsn_chunks);
// Try to assemble one or several messages in order from the stream.
// Returns the number of bytes assembled if one or more messages were
// assembled.
size_t TryToAssembleMessages();
const FullStreamId stream_id_;
InterleavedReassemblyStreams& parent_;
std::map<UnwrappedMID, ChunkMap> chunks_by_mid_;
UnwrappedMID::Unwrapper mid_unwrapper_;
UnwrappedMID next_mid_;
};
Stream& GetOrCreateStream(const FullStreamId& stream_id);
const std::string log_prefix_;
// Callback for when a message has been assembled.
const OnAssembledMessage on_assembled_message_;
// All unordered and ordered streams, managing not-yet-assembled data.
std::map<FullStreamId, Stream> streams_;
};
} // namespace dcsctp
#endif // NET_DCSCTP_RX_INTERLEAVED_REASSEMBLY_STREAMS_H_
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