WDL/circbuf.h

   1 /*
   2     WDL - circbuf.h
   3     Copyright (C) 2005 Cockos Incorporated
   4
   5     This software is provided 'as-is', without any express or implied
   6     warranty.  In no event will the authors be held liable for any damages
   7     arising from the use of this software.
   8
   9     Permission is granted to anyone to use this software for any purpose,
  10     including commercial applications, and to alter it and redistribute it
  11     freely, subject to the following restrictions:
  12
  13     1. The origin of this software must not be misrepresented; you must not
  14        claim that you wrote the original software. If you use this software
  15        in a product, an acknowledgment in the product documentation would be
  16        appreciated but is not required.
  17     2. Altered source versions must be plainly marked as such, and must not be
  18        misrepresented as being the original software.
  19     3. This notice may not be removed or altered from any source distribution.
  20
  21 */
  22
  23 /*
  24
  25   This file provides a simple class for a circular FIFO queue of bytes.
  26
  27 */
  28
  29 #ifndef _WDL_CIRCBUF_H_
  30 #define _WDL_CIRCBUF_H_
  31
  32 #include "heapbuf.h"
  33
  34 class WDL_CircBuf
  35 {
  36 public:
  37   WDL_CircBuf() : m_hb(4096 WDL_HEAPBUF_TRACEPARM("WDL_CircBuf"))
  38   {
  39     m_inbuf = m_wrptr = 0;
  40   }
  41   ~WDL_CircBuf()
  42   {
  43   }
  44   void SetSize(int size)
  45   {
  46     m_inbuf = m_wrptr = 0;
  47     m_hb.Resize(size,true);
  48   }
  49   void Reset() { m_inbuf = m_wrptr = 0; }
  50   int Add(const void *buf, int l)
  51   {
  52     const int bf = m_hb.GetSize() - m_inbuf;
  53     if (l > bf) l = bf;
  54     if (l > 0)
  55     {
  56       const int wr1 = m_hb.GetSize()-m_wrptr;
  57       if (wr1 < l)
  58       {
  59         memmove((char*)m_hb.Get() + m_wrptr, buf, wr1);
  60         memmove(m_hb.Get(), (char*)buf + wr1, l-wr1);
  61         m_wrptr = l-wr1;
  62       }
  63       else
  64       {
  65         memmove((char*)m_hb.Get() + m_wrptr, buf, l);
  66         m_wrptr = wr1 == l ? 0 : m_wrptr+l;
  67       }
  68       m_inbuf += l;
  69     }
  70     return l;
  71   }
  72   int Peek(void *buf, int offs, int len) const
  73   {
  74     if (offs<0) return 0;
  75     const int ibo = m_inbuf-offs;
  76     if (len > ibo) len = ibo;
  77     if (len > 0)
  78     {
  79       int rp = m_wrptr - ibo;
  80       if (rp < 0) rp += m_hb.GetSize();
  81       const int wr1 = m_hb.GetSize() - rp;
  82       if (wr1 < len)
  83       {
  84         memmove(buf,(char*)m_hb.Get()+rp,wr1);
  85         memmove((char*)buf+wr1,m_hb.Get(),len-wr1);
  86       }
  87       else
  88       {
  89         memmove(buf,(char*)m_hb.Get()+rp,len);
  90       }
  91     }
  92     return len;
  93   }
  94   int Get(void *buf, int l)
  95   {
  96     const int amt = Peek(buf,0,l);
  97     m_inbuf -= amt;
  98     return amt;
  99   }
 100   int NbFree() const { return m_hb.GetSize() - m_inbuf; } // formerly Available()
 101   int NbInBuf() const { return m_inbuf; }
 102
 103 private:
 104   WDL_HeapBuf m_hb;
 105   int m_inbuf, m_wrptr;
 106 } WDL_FIXALIGN;
 107
 108
 109 template <class T>
 110 class WDL_TypedCircBuf
 111 {
 112 public:
 113
 114     WDL_TypedCircBuf() {}
 115     ~WDL_TypedCircBuf() {}
 116
 117     void SetSize(int size)
 118     {
 119         mBuf.SetSize(size * sizeof(T));
 120     }
 121
 122     void Reset()
 123     {
 124         mBuf.Reset();
 125     }
 126
 127     int Add(const T* buf, int l)
 128     {
 129         return mBuf.Add(buf, l * sizeof(T)) / sizeof(T);
 130     }
 131
 132     int Get(T* buf, int l)
 133     {
 134         return mBuf.Get(buf, l * sizeof(T)) / sizeof(T);
 135     }
 136
 137     int NbFree()  // formerly Available()
 138     {
 139         return mBuf.NbFree() / sizeof(T);
 140     }
 141      int NbInBuf()
 142      {
 143          return mBuf.NbInBuf() / sizeof(T);
 144      }
 145
 146 private:
 147     WDL_CircBuf mBuf;
 148 } WDL_FIXALIGN;
 149
 150 #endif