text: /*
      WDL - queue.h
      Copyright (C) 2005 and later, Cockos Incorporated
  
      This software is provided 'as-is', without any express or implied
      warranty.  In no event will the authors be held liable for any damages
      arising from the use of this software.
  
      Permission is granted to anyone to use this software for any purpose,
      including commercial applications, and to alter it and redistribute it
      freely, subject to the following restrictions:
  
      1. The origin of this software must not be misrepresented; you must not
         claim that you wrote the original software. If you use this software
         in a product, an acknowledgment in the product documentation would be
         appreciated but is not required.
      2. Altered source versions must be plainly marked as such, and must not be
         misrepresented as being the original software.
      3. This notice may not be removed or altered from any source distribution.
        
  */
  
  /*
  
    This file provides a simple class for a FIFO queue of bytes. It uses a simple buffer,
    so should not generally be used for large quantities of data (it can advance the queue 
    pointer, but Compact() needs to be called regularly to keep memory usage down, and when
    it is called, there's a memcpy() penalty for the remaining data. oh well, is what it is).
  
    You may also wish to look at fastqueue.h or circbuf.h if these limitations aren't acceptable.
  
  */
  
  #ifndef _WDL_QUEUE_H_
  #define _WDL_QUEUE_H_
  
  #include "heapbuf.h"
  
  
  class WDL_Queue 
  {
  public:
    WDL_Queue() : m_hb(4096 WDL_HEAPBUF_TRACEPARM("WDL_Queue")), m_pos(0) { }
    WDL_Queue(int hbgran) : m_hb(hbgran WDL_HEAPBUF_TRACEPARM("WDL_Queue")), m_pos(0) { }
    ~WDL_Queue() { }
  
    template <class T> void* AddT(T* buf)
    {
      return Add(buf, sizeof(T));
    }
  
    void *Add(const void *buf, int len)
    {
      int olen=m_hb.GetSize();
      if (m_pos >= olen) m_pos=olen=0; // if queue is empty then autoreset it
  
      void *obuf=m_hb.Resize(olen+len,false);
      if (m_hb.GetSize() != olen+len) return NULL;
  
      char* newbuf = (char*) obuf + olen;
      if (buf) memcpy(newbuf,buf,len);
      return newbuf; 
    }
  
    template <class T> T* GetT(T* val=0)
    {
      T* p = (T*) Get(sizeof(T));
      if (val && p) *val = *p;
      return p;
    }
    
    void* Get(int size)
    {
      void* p = Get();
      if (p) Advance(size);
      return p;
    }
      
    void *Get() const
    {
      void *buf=m_hb.Get();
      if (buf && m_pos >= 0 && m_pos < m_hb.GetSize()) return (char *)buf+m_pos;
      return NULL;
    }
    
    void* Rewind()
    {
      m_pos = 0;
      return m_hb.Get();
    }
  
    int GetSize() const
    {
      return m_hb.GetSize()-m_pos;
    }
    int Available() const { return GetSize(); }
  
    void Clear()
    {
      m_pos=0;
      m_hb.Resize(0,false);
    }
  
    void Advance(int bytecnt) 
    { 
      m_pos+=bytecnt; 
      if (m_pos<0)m_pos=0;
      else if (m_pos > m_hb.GetSize()) m_pos=m_hb.GetSize();
    }
  
    void Compact(bool allocdown=false, bool force=false)
    {
      int olen=m_hb.GetSize();
      if (m_pos > (force ? 0 : olen/2))
      {
        if (m_pos < olen)
        {
          void *a=m_hb.Get();
          if (a) memmove(a,(char*)a+m_pos,olen-m_pos);
          m_hb.Resize(olen-m_pos,allocdown);
        }
        else m_hb.Resize(0,allocdown);
        m_pos=0;
      }
    }
  
    void SetGranul(int granul) { m_hb.SetGranul(granul); }
  
  
  
  
    // endian-management stuff 
  
    static void WDL_Queue__bswap_buffer(void *buf, int len)
    {
    #ifdef __ppc__
      char *p=(char *)buf;
      char *ep=p+len;
      while ((len-=2) >= 0)
      {
        char tmp=*p; *p++=*--ep; *ep=tmp;
      }
    #endif
    }
  
    // older API of static functions (that endedu p warning a bit anyway)
  #define WDL_Queue__AddToLE(q, v) (q)->AddToLE(v)
  #define WDL_Queue__AddDataToLE(q,d,ds,us) (q)->AddDataToLE(d,ds,us)
  #define WDL_Queue__GetTFromLE(q,v) (q)->GetTFromLE(v)
  #define WDL_Queue__GetDataFromLE(q,ds,us) (q)->GetDataFromLE(ds,us)
  
    template<class T> void AddToLE(T *val)
    {
      WDL_Queue__bswap_buffer(AddT(val),sizeof(T));
    }
    void AddDataToLE(void *data, int datasize, int unitsize)
    {
      #ifdef __ppc__
      char *dout = (char *)Add(data,datasize);
      while (datasize >= unitsize)
      {
        WDL_Queue__bswap_buffer(dout,unitsize);
        dout+=unitsize;
        datasize-=unitsize;
      }
      #else
      Add(data,datasize);
      #endif
    }
  
  
    // NOTE: these thrash the contents of the queue if on LE systems. So for example if you are going to rewind it later or use it elsewhere, 
    // then get ready to get unhappy.
    template<class T> T *GetTFromLE(T* val=0)
    {
      T *p = GetT(val);
      if (p) {
        WDL_Queue__bswap_buffer(p,sizeof(T));
        if (val) *val = *p;
      }
      return p;
    }
  
    void *GetDataFromLE(int datasize, int unitsize)
    {
      void *data=Get(datasize);
      #ifdef __ppc__
      char *dout=(char *)data;
      if (dout) while (datasize >= unitsize)
      {
        WDL_Queue__bswap_buffer(dout,unitsize);
        dout+=unitsize;
        datasize-=unitsize;
      }
      #endif
      return data;
    }
  
  
  private:
    WDL_HeapBuf m_hb;
    int m_pos;
    int __pad; // keep 8 byte aligned
  };
  
  template <class T> class WDL_TypedQueue
  {
  public:
    WDL_TypedQueue() : m_hb(4096 WDL_HEAPBUF_TRACEPARM("WDL_TypedQueue")), m_pos(0) { }
    ~WDL_TypedQueue() { }
  
    T *Add(const T *buf, int len)
    {
      int olen=m_hb.GetSize();
      if (m_pos >= olen) olen=m_pos=0;
      len *= sizeof(T);
      void *obuf=m_hb.Resize(olen+len,false);
      if (!obuf||m_hb.GetSize()!=olen+len) return 0;
      if (buf) memcpy((char*)obuf+olen,buf,len);
      return (T*) ((char*)obuf+olen);
    }
  
    T *Get() const
    {
      void *buf=m_hb.Get();
      if (buf && m_pos >= 0 && m_pos < m_hb.GetSize()) return (T*)((char *)buf+m_pos);
      return NULL;
    }
  
    int GetSize() const
    {
      return (m_hb.GetSize()-m_pos)/sizeof(T);
    }
    int Available() const { return GetSize(); }
  
    void Clear()
    {
      m_pos=0;
      m_hb.Resize(0,false);
    }
  
    void Advance(int cnt) 
    { 
      m_pos+=cnt*sizeof(T); 
      if (m_pos<0)m_pos=0;
      else if (m_pos > m_hb.GetSize()) m_pos=m_hb.GetSize();
    }
  
    void Compact(bool allocdown=false, bool force=false)
    {
      int olen=m_hb.GetSize();
      if (m_pos > (force ? 0 : olen/2))
      {
        if (m_pos < olen)
        {
          void *a=m_hb.Get();
          if (a) memmove(a,(char*)a+m_pos,olen-m_pos);
          m_hb.Resize(olen-m_pos,allocdown);
        }
        else m_hb.Resize(0,allocdown);
        m_pos=0;
      }
    }
  
    void SetGranul(int granul) { m_hb.SetGranul(granul); }
  
  private:
    WDL_HeapBuf m_hb;
    int m_pos;
    int __pad; // keep 8 byte aligned
  };
  
  #endif
  