D:/VL/BuildSystem/VL_DISTRO/Visualization_Library_SDK/src/vlCore/BufferedStream.hpp

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#ifndef BufferedStream_INCLUDE_ONCE
#define BufferedStream_INCLUDE_ONCE

#include <vlCore/String.hpp>
#include <vlCore/VirtualFile.hpp>
#include <string>
#include <vector>

namespace vl
{
//-----------------------------------------------------------------------------
// BufferedStream
//-----------------------------------------------------------------------------
  template<class Element_Type, int Chunk_Size>
  class BufferedStream: public Object
  {
  public:
    virtual const char* className() { return "vl::BufferedStream"; }

    BufferedStream()
    {
      mSize = 0;
      mPtr  = 0;
      mBuffer.resize(Chunk_Size);
    }

    void seek(long long pos)
    {
      mSize = 0;
      mPtr  = 0;
      if ( inputFile() )
        inputFile()->seekSet(pos);
    }

    bool readToken(Element_Type* token)
    {
      if ( mUngetBuffer.size() )
      {
        *token = mUngetBuffer.back();
        mUngetBuffer.pop_back();
        return true;
      }

      if (bufferEmpty())
        fillBuffer();
      if (bufferEmpty())
        return false;
      else
      {
        *token = mBuffer[mPtr];
        mPtr++;
        return true;
      }
    }

    bool bufferEmpty()
    {
      return mPtr == mSize;
    }

    int fillBuffer()
    {
      if ( inputFile() )
      {
        if ( !inputFile()->isOpen() )
          if(!inputFile()->open(OM_ReadOnly))
            return 0;

        mPtr = 0;
        mSize = (int)inputFile()->read(&mBuffer[0], Chunk_Size);
        return mSize;
      }
      else
      {
        return 0;
      }
    }

    void setInputFile(VirtualFile* file)
    {
      mInputFile = file;
    }

    VirtualFile* inputFile() const
    {
      return mInputFile.get();
    }

    void ungetToken(const Element_Type& token)
    {
      mUngetBuffer.push_back(token);
    }

  protected:
    ref<VirtualFile> mInputFile;
    std::vector<Element_Type> mUngetBuffer;
    std::vector<Element_Type> mBuffer;
    int mPtr;
    int mSize;
  };
}

#endif