113 lines
3.8 KiB
C++
113 lines
3.8 KiB
C++
/*
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* Net2Packet.h
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef FLOW_NET2PACKET_H
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#define FLOW_NET2PACKET_H
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#pragma once
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#include "flow/flow.h"
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#include "flow/Histogram.h"
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// PacketWriter and PacketBuffer are in serialize.h because they are needed by the SerializeSource<> template
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struct ReliablePacket : FastAllocated<ReliablePacket> {
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PacketBuffer* buffer;
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ReliablePacket* cont; // More bytes in the same packet
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ReliablePacket *prev,
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*next; // Linked list of reliable packets on the same connection (only for the first packet in the cont chain)
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int begin, end;
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ReliablePacket() {}
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void insertBefore(ReliablePacket* p);
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void remove(); // Deletes this and cont chain, unlinks prev and next
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};
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class UnsentPacketQueue : NonCopyable {
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public:
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UnsentPacketQueue()
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: unsent_first(0), unsent_last(0),
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sendQueueLatencyHistogram(Histogram::getHistogram(LiteralStringRef("UnsentPacketQueue"),
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LiteralStringRef("QueueWait"),
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Histogram::Unit::microseconds)) {}
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~UnsentPacketQueue() {
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discardAll();
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unsent_first = (PacketBuffer*)0xDEADBEEF;
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unsent_last = (PacketBuffer*)0xCAFEBABE;
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sendQueueLatencyHistogram = Reference<Histogram>(nullptr);
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}
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// Get a PacketBuffer to write new packets into
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PacketBuffer* getWriteBuffer(size_t sizeHint = 0) {
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if (!unsent_last) {
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ASSERT(!unsent_first);
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unsent_first = unsent_last = PacketBuffer::create(sizeHint);
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};
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return unsent_last;
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}
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// Call after potentially adding to the chain returned by getWriteBuffer()
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void setWriteBuffer(PacketBuffer* pb) { unsent_last = pb; }
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// Prepend the given range of packetBuffers to the beginning of the unsent queue
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void prependWriteBuffer(PacketBuffer* first, PacketBuffer* last) {
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last->next = unsent_first;
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unsent_first = first;
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if (!unsent_last)
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unsent_last = last;
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}
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// false if there is anything unsent
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bool empty() const { return !unsent_first || unsent_first->bytes_sent == unsent_first->bytes_written; }
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// Get the next PacketBuffer to send data from
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PacketBuffer* getUnsent() const { return unsent_first; }
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// Call after sending bytes from getUnsent()
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void sent(int bytes);
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// Discard all unsent buffers
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void discardAll();
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private:
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PacketBuffer *unsent_first, *unsent_last; // Both nullptr, or inclusive range of PacketBuffers that haven't been
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// sent. The last one may have space for more packets to be written.
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Reference<Histogram> sendQueueLatencyHistogram;
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};
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class ReliablePacketList : NonCopyable {
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public:
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ReliablePacketList() {
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reliable.buffer = 0;
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reliable.prev = reliable.next = &reliable;
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}
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bool empty() const { return reliable.next == &reliable; }
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void insert(ReliablePacket* rp) { rp->insertBefore(&reliable); }
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// Concatenate those reliable packets which have already been sent (are not in the unsent range)
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// into the given chain of packet buffers, and return the tail of that chain
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PacketBuffer* compact(PacketBuffer* into, PacketBuffer* stopAt);
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void discardAll(); // just for testing
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private:
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ReliablePacket reliable; // Head/tail of a circularly linked list of reliable packets to be resent after a close
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};
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#endif
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