1 /*****************************************************************
2 |
3 |   Neptune - Ring Buffer
4 |
5 | Copyright (c) 2002-2008, Axiomatic Systems, LLC.
6 | All rights reserved.
7 |
8 | Redistribution and use in source and binary forms, with or without
9 | modification, are permitted provided that the following conditions are met:
10 |     * Redistributions of source code must retain the above copyright
11 |       notice, this list of conditions and the following disclaimer.
12 |     * Redistributions in binary form must reproduce the above copyright
13 |       notice, this list of conditions and the following disclaimer in the
14 |       documentation and/or other materials provided with the distribution.
15 |     * Neither the name of Axiomatic Systems nor the
16 |       names of its contributors may be used to endorse or promote products
17 |       derived from this software without specific prior written permission.
18 |
19 | THIS SOFTWARE IS PROVIDED BY AXIOMATIC SYSTEMS ''AS IS'' AND ANY
20 | EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 | DISCLAIMED. IN NO EVENT SHALL AXIOMATIC SYSTEMS BE LIABLE FOR ANY
23 | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26 | ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 |
30  ****************************************************************/
31 
32 #ifndef _NPT_RING_BUFFER_H_
33 #define _NPT_RING_BUFFER_H_
34 
35 /*----------------------------------------------------------------------
36 |   includes
37 +---------------------------------------------------------------------*/
38 #include "NptTypes.h"
39 #include "NptReferences.h"
40 
41 /*----------------------------------------------------------------------
42 |   NPT_RingBuffer
43 +---------------------------------------------------------------------*/
44 class NPT_RingBuffer
45 {
46  public:
47     // methods
48                   NPT_RingBuffer(NPT_Size size);
49                   NPT_RingBuffer(void* buffer, NPT_Size size);
50     virtual      ~NPT_RingBuffer();
51     NPT_Size      GetSpace() const;
52     NPT_Size      GetContiguousSpace() const;
53     NPT_Result    Write(const void* buffer, NPT_Size byte_count);
54     NPT_Size      GetAvailable() const;
55     NPT_Size      GetContiguousAvailable() const;
56     NPT_Result    Read(void* buffer, NPT_Size byte_count);
57     unsigned char ReadByte();
58     unsigned char PeekByte(NPT_Position offset);
59     NPT_Result    MoveIn(NPT_Position offset);
60     NPT_Result    MoveOut(NPT_Position offset);
61     NPT_Result    Flush();
62     NPT_Result    Close();
IsClosed()63     bool          IsClosed() { return m_Closed; }
64 
65     // accessors
GetWritePointer()66     unsigned char* GetWritePointer()  { return m_In; }
GetReadPointer()67     unsigned char* GetReadPointer()   { return m_Out;}
68 
69  private:
70     // members
71     struct {
72         unsigned char* start;
73         unsigned char* end;
74     }              m_Data;
75     unsigned char* m_In;
76     unsigned char* m_Out;
77     bool           m_BufferIsLocal;
78     bool           m_Closed;
79 };
80 
81 typedef NPT_Reference<NPT_RingBuffer> NPT_RingBufferReference;
82 
83 #endif // _NPT_RING_BUFFER_H_
84