Initial

gif/ISTREAM.CPP

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+#include <gif/istream.hpp>
+
+IStream::IStream(void)
+: mFileDescriptor(-1), mCurrentWord(0), mCurrentChar(0), mhGlobalBuffer(0),
+	mlpBuffer(0), mBufferIndex(0), mlpBufferPointer(0)
+{
+}
+
+IStream::IStream(const char *pathFileName)
+: mFileDescriptor(-1), mCurrentWord(0), mCurrentChar(0), mhGlobalBuffer(0),
+	mlpBuffer(0), mBufferIndex(0), mlpBufferPointer(0)
+{
+  open(pathFileName);
+}
+
+IStream::~IStream()
+{
+  close();
+}
+
+BOOL IStream::open(const char *pathFileName)
+{
+  close();
+	if(-1==(mFileDescriptor=::open(pathFileName,O_RDONLY|O_BINARY,0,SH_DENYWR)))return FALSE;
+	mhGlobalBuffer=::GlobalAlloc(GMEM_FIXED,MaxInputBuffer);
+	if(!mhGlobalBuffer){close();return FALSE;}
+	mlpBuffer=(UCHAR FAR *)::GlobalLock(mhGlobalBuffer);
+	mlpBufferPointer=0;
+	mBufferIndex=0;
+	mCurrentChar=0;
+	mCurrentWord=0;
+	return TRUE;
+}
+
+void IStream::close(void)
+{
+	if(-1!=mFileDescriptor)::close(mFileDescriptor);
+	mFileDescriptor=-1;
+	if(mhGlobalBuffer)
+	{
+		::GlobalUnlock(mhGlobalBuffer);
+		::GlobalFree(mhGlobalBuffer);
+		mhGlobalBuffer=0;
+  }
+}
+
+WORD IStream::getChar(void)
+{
+	if(-1==mFileDescriptor)return FALSE;
+	if(!mBufferIndex)
+	{
+		mBufferIndex=::read(mFileDescriptor,(VPTR)mlpBuffer,MaxInputBuffer);
+		if(!mBufferIndex)return FALSE;
+		mlpBufferPointer=mlpBuffer;
+	}
+	mCurrentChar=*(mlpBufferPointer);
+	mlpBufferPointer++;
+	mBufferIndex--;
+	return TRUE;
+}
+
+WORD IStream::getWord(void)
+{
+	if(-1==mFileDescriptor)return FALSE;
+	mCurrentWord=0;
+	if(!getChar())return FALSE;
+	mCurrentWord=mCurrentChar;
+	if(!getChar())return FALSE;
+	mCurrentWord|=((short)mCurrentChar)<<8;
+	return TRUE;
+}