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 #ifndef DEBUG_BUFFER_QUEUE 17 # define DEBUG_BUFFER_QUEUE 1 18 #endif 19 20 21 typedef DoublyLinkedList<struct net_buffer, 22 DoublyLinkedListCLink<struct net_buffer> > SegmentList; 23 24 class BufferQueue { 25 public: 26 BufferQueue(size_t maxBytes); 27 ~BufferQueue(); 28 29 void SetMaxBytes(size_t maxBytes); 30 void SetInitialSequence(tcp_sequence sequence); 31 32 void Add(net_buffer* buffer); 33 void Add(net_buffer* buffer, tcp_sequence sequence); 34 status_t RemoveUntil(tcp_sequence sequence); 35 status_t Get(net_buffer* buffer, tcp_sequence sequence, 36 size_t bytes); 37 status_t Get(size_t bytes, bool remove, 38 net_buffer** _buffer); 39 40 size_t Available() const { return fContiguousBytes; } 41 size_t Available(tcp_sequence sequence) const; 42 43 inline size_t PushedData() const; 44 void SetPushPointer(); 45 46 size_t Used() const { return fNumBytes; } 47 inline size_t Free() const; 48 size_t Size() const { return fMaxBytes; } 49 50 bool IsContiguous() const 51 { return fNumBytes == fContiguousBytes; } 52 53 tcp_sequence FirstSequence() const { return fFirstSequence; } 54 tcp_sequence LastSequence() const { return fLastSequence; } 55 tcp_sequence NextSequence() const 56 { return fFirstSequence + fContiguousBytes; } 57 58 #if DEBUG_BUFFER_QUEUE 59 void Verify() const; 60 void Dump() const; 61 #endif 62 63 private: 64 SegmentList fList; 65 size_t fMaxBytes; 66 size_t fNumBytes; 67 size_t fContiguousBytes; 68 tcp_sequence fFirstSequence; 69 tcp_sequence fLastSequence; 70 tcp_sequence fPushPointer; 71 }; 72 73 74 size_t 75 BufferQueue::PushedData() const 76 { 77 // We must check if fPushPointer is not 0 here due to 78 // tcp_sequence's special handling of > 79 return fPushPointer != 0 && fPushPointer > fFirstSequence 80 ? (fPushPointer - fFirstSequence).Number() : 0; 81 } 82 83 84 size_t 85 BufferQueue::Free() const 86 { 87 // Max bytes is a soft limit, so it can be lower than the actual amount of 88 // data in the queue. TCP should never advertize a window outside the max 89 // buffer size, though. 90 if (fMaxBytes > fNumBytes) 91 return fMaxBytes - fNumBytes; 92 93 return 0; 94 } 95 96 #endif // BUFFER_QUEUE_H 97