1 /* 2 * Copyright 2006-2010, Haiku, Inc. All Rights Reserved. 3 * Distributed under the terms of the MIT License. 4 * 5 * Authors: 6 * Axel Dörfler, axeld@pinc-software.de 7 */ 8 #ifndef BUFFER_QUEUE_H 9 #define BUFFER_QUEUE_H 10 11 12 #include "tcp.h" 13 14 #include <util/DoublyLinkedList.h> 15 16 17 typedef DoublyLinkedList<struct net_buffer, 18 DoublyLinkedListCLink<struct net_buffer> > SegmentList; 19 20 class BufferQueue { 21 public: 22 BufferQueue(size_t maxBytes); 23 ~BufferQueue(); 24 25 void SetMaxBytes(size_t maxBytes); 26 void SetInitialSequence(tcp_sequence sequence); 27 28 void Add(net_buffer* buffer); 29 void Add(net_buffer* buffer, tcp_sequence sequence); 30 status_t RemoveUntil(tcp_sequence sequence); 31 status_t Get(net_buffer* buffer, tcp_sequence sequence, 32 size_t bytes); 33 status_t Get(size_t bytes, bool remove, 34 net_buffer** _buffer); 35 36 size_t Available() const { return fContiguousBytes; } 37 size_t Available(tcp_sequence sequence) const; 38 39 inline size_t PushedData() const; 40 void SetPushPointer(); 41 42 size_t Used() const { return fNumBytes; } 43 inline size_t Free() const; 44 size_t Size() const { return fMaxBytes; } 45 46 bool IsContiguous() const 47 { return fNumBytes == fContiguousBytes; } 48 49 tcp_sequence FirstSequence() const { return fFirstSequence; } 50 tcp_sequence LastSequence() const { return fLastSequence; } 51 tcp_sequence NextSequence() const 52 { return fFirstSequence + fContiguousBytes; } 53 54 #if DEBUG_TCP_BUFFER_QUEUE 55 void Verify() const; 56 void Dump() const; 57 #endif 58 59 private: 60 SegmentList fList; 61 size_t fMaxBytes; 62 size_t fNumBytes; 63 size_t fContiguousBytes; 64 tcp_sequence fFirstSequence; 65 tcp_sequence fLastSequence; 66 tcp_sequence fPushPointer; 67 }; 68 69 70 size_t 71 BufferQueue::PushedData() const 72 { 73 // We must check if fPushPointer is not 0 here due to 74 // tcp_sequence's special handling of > 75 return fPushPointer != 0 && fPushPointer > fFirstSequence 76 ? (fPushPointer - fFirstSequence).Number() : 0; 77 } 78 79 80 size_t 81 BufferQueue::Free() const 82 { 83 // Max bytes is a soft limit, so it can be lower than the actual amount of 84 // data in the queue. TCP should never advertize a window outside the max 85 // buffer size, though. 86 if (fMaxBytes > fNumBytes) 87 return fMaxBytes - fNumBytes; 88 89 return 0; 90 } 91 92 #endif // BUFFER_QUEUE_H 93