95 lines
2.1 KiB
C++
95 lines
2.1 KiB
C++
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#include "packet_buffer.hpp"
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#include "basic_header.hpp"
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namespace vanetza
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{
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namespace geonet
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{
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namespace packet_buffer
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{
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Expiry::Expiry(Clock::time_point now, Clock::duration lifetime) :
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m_buffered_since(now), m_expires_at(now)
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{
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m_expires_at += lifetime;
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}
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bool Expiry::is_expired(Clock::time_point now) const
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{
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return (m_expires_at < now);
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}
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} // namespace packet_buffer
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PacketBuffer::PacketBuffer(std::size_t capacity) :
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m_capacity(capacity), m_stored(0)
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{
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}
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bool PacketBuffer::push(data_ptr data, Clock::time_point now)
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{
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assert(data);
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bool pushed = false;
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drop_expired(now);
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if (drop(data->length())) {
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m_stored += data->length();
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m_nodes.push_back(std::make_tuple(
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expiry_type(now, data->reduce_lifetime(Clock::duration::zero())),
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std::move(data)
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));
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pushed = true;
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}
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return pushed;
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}
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void PacketBuffer::flush(Clock::time_point now)
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{
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decltype(m_nodes) nodes;
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std::swap(m_nodes, nodes);
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m_stored = 0;
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for (auto& node : nodes) {
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const auto& expiry = std::get<0>(node);
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if (!expiry.is_expired(now)) {
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auto& data = std::get<1>(node);
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const auto queuing_time = now - expiry.buffered_since();
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data->reduce_lifetime(queuing_time);
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data->flush();
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}
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}
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}
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bool PacketBuffer::drop_head()
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{
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bool dropped = !m_nodes.empty();
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if (dropped) {
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m_stored -= std::get<1>(m_nodes.front())->length();
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m_nodes.pop_front();
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}
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return dropped;
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}
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void PacketBuffer::drop_expired(Clock::time_point now)
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{
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std::list<decltype(m_nodes)::iterator> expired;
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for (auto it = m_nodes.begin(), end = m_nodes.end(); it != end;) {
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if (std::get<0>(*it).is_expired(now)) {
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m_stored -= std::get<1>(*it)->length();
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it = m_nodes.erase(it);
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} else {
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++it;
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}
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}
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}
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bool PacketBuffer::drop(std::size_t bytes)
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{
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while (free() < bytes && drop_head()) {}
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return free() >= bytes;
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}
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} // namespace geonet
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} // namespace vanetza
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