LZ77压缩算法(C语言版)

测试压缩一个425K的文件需要9.4秒，压缩后的文件为177K。


/*********************************************************************
*
*   Project description:
*       Lz77 compression/decompression algorithm.
*
*********************************************************************/


#include <windows.h>
#include <conio.h>
#include <stdio.h>
#include <assert.h>

#define OFFSET_CODING_LENGTH    (10)
#define MAX_WND_SIZE            1024
//#define MAX_WND_SIZE          (1<<OFFSET_CODING_LENGTH)
#define OFFSET_MASK_CODE        (MAX_WND_SIZE-1)

const ULONG     m=3;


UCHAR   __buffer1__[0x200000];
UCHAR   __buffer2__[0x200000];


////////////////////////////////////////////////////////////////////////////////

void
Write1ToBitStream(
   PUCHAR  pBuffer,
   ULONG   ulBitOffset
   )
{
   ULONG   ulByteBoundary;
   ULONG   ulOffsetInByte;

   ulByteBoundary = ulBitOffset>>3 ;
   ulOffsetInByte = ulBitOffset&7;

   *(pBuffer+ulByteBoundary) |= (1<<ulOffsetInByte);
}

void
Write0ToBitStream(
   PUCHAR  pBuffer,
   ULONG   ulBitOffset
   )
{
   ULONG   ulByteBoundary;
   ULONG   ulOffsetInByte;

   ulByteBoundary = ulBitOffset>>3 ;
   ulOffsetInByte = ulBitOffset&7;

   *(pBuffer+ulByteBoundary) &= (~(1<<ulOffsetInByte));
}