同志们用什么方法来压缩文件?(我是说用代码,不是WINRAR,WINZIP之类的)

[cdws222]

我扫描了一个光驱的目录,生成的文件居然有5M多(Visual Studio的光盘)
我想压缩一下

[codecb]

#include <zlib.hpp>
void __fastcall TFrmMain::BtnCompressClick(TObject *Sender) // 压缩
{
TMemoryStream *pMemsrc=new TMemoryStream();
pMemsrc->LoadFromFile("E:\\Test.bdb"); //源流
pMemsrc->Seek(0,soFromEnd);
pMemsrc->Seek(0,soFromBeginning);
int count=pMemsrc->Size;

TMemoryStream *pDestMem=new TMemoryStream; //目的流
TCompressionStream *pCompress=new TCompressionStream(Zlib::clMax, pDestMem);
pMemsrc->SaveToStream(pCompress); // 压缩

delete pCompress; //析构，完成数据压缩的任务

pDestMem->Seek(0,soFromBeginning);
pDestMem ->SaveToFile("E:\\Compressed.dat");

delete pDestMem;
delete pMemsrc;}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender) // 解压
{
TMemoryStream *pMemsrc=new TMemoryStream;
pMemsrc->LoadFromFile("E:\\Compressed.dat");
pMemsrc->Seek(0,soFromBeginning);

TDecompressionStream *pCompress;
pCompress=new TDecompressionStream(pMemsrc);
pCompress->Seek(0,soFromBeginning);
TMemoryStream *pDestMem=new TMemoryStream;
pCompress->Seek(0,soFromBeginning);
try
{
while(1)
pCompress->Seek(1,soFromCurrent);
}
catch(...)
{
}
int count=pCompress->Position;
char * pbuf=(char*)malloc(count);
pCompress->Seek(0,soFromBeginning);
pCompress->ReadBuffer(pbuf,count);
pDestMem->WriteBuffer(pbuf,count);
pDestMem->Seek(0,soFromBeginning);
pDestMem->SaveToFile("E:\\test1.bdb");

delete pDestMem;
delete pCompress;
delete pMemsrc;
}

[codecb]

Zlib在Delphi中才有，但是也不是缺省安装的，你需要在Delphi5光盘中的\Info\Extras\Zlib中才能找到Zlib的东西。
1．先将D:\ Info\Extras\Zlib\(假设你的光驱盘符为D：)下的东西复制到你的硬盘上的某个目录。
2．将 \Info\Extras\Zlib\obj\*.obj与\Info\Extras\Zlib\*.pas复制到 ..\CBuilder5\Lib\Obj
3．新建一个工程，然后将zlib.pas添加到你的工程中（通过Project|Add to Project…），然后移除Form1，选择菜单Project|Complie Unit，编译zlib.pas此时此生成zlib.dcu、zlib.obj、zlib.hpp、zlibconst.dcu、zlibconst.obj、zlibconst.hpp六个文件
4．打开zlib.hpp在namespace Zlib前添加如下代码：
#pragma link "zlib.obj"
#pragma link "zlibconst.obj"
5．将zlib.hpp和zlibconst.hpp拷贝到…\CBuilder5\Include目录下
6．将zlib.obj和zlibconst.obj拷贝到…\Cbuilder5\Lib\Obh目录下
这样你就将zlib安装到了C++Builder中，你可以开始使用它

[cdws222]

哦,还有没有更好的?

[sjd163]

codecb(阿星) ：
你好！看到你的贴子很精彩，能发zlib.hpp、zlibconst.hpp、zlib.obj、zlibconst.obj到 [e-mail] 吗？定以百分相酬。
sjd163 恭候

[codecb]

不好意思　我没有Delphi了！
你有Delphi的光盘就可以了呀！

[cdws222]

sjd163

你不能自已编译吗?我已编译而且试过了,不错!正在找更好的方法,如果没有就给codecb加分了

[cdws222]

我不用DLL或OCX类的东东,只用VCL或.PAS之类的,因为这些东东在发布时不需要带任何文件

[lj_csdn]

我这里还有一个内存压缩的（源码），我在通讯程序中用的

[lj_csdn]

用ADDZIP动态连接库
在工程中加入azip32.lib,在运行目录下拷贝一个azip32.dll

#include "azip.h"

int zip(char *name,char *files)
{ addZIP_ArchiveName(name);
addZIP_Overwrite(OVERWRITE_ALL);
addZIP_Include(files);
if (addZIP()>=0) return 1;
return 0;
}

[lj_csdn]

刚从刻录的备份光盘中找出:

是C代码,自定义了一个类TLZWCompress；
用法：
TLZWCompress lzw;
压缩后字节数=lzw.Compress(待压缩的数据,待压缩字节数，压缩后数据缓冲区);
解压字节数=lzw.Expand(解压数据，解压字节数，解压缓存);


#ifndef _TLZWCOMPRESS

#define _TLZWCOMPRESS

#define INIT_BITS 9
#define MAX_BITS 14
#define HASHING_SHIFT (MAX_BITS-8)

#define TABLE_SIZE 18041

#define CLEAR_TABLE 256
#define TERMINATOR 257
#define FIRST_CODE 258
#define CHECK_TIME 100

#define MAXVAL(n) ((1<<(n))-1)

class TLZWCompress {
private:
short code_value[TABLE_SIZE];
unsigned short prefix_code[TABLE_SIZE];
unsigned char append_character[TABLE_SIZE];
unsigned char decode_stack[4000];

short num_bits;
unsigned long bytes_in,bytes_out;
short max_code;
unsigned long checkpoint;

long ReadCount;
short output_bit_count;
unsigned long output_bit_buffer;
short input_bit_count;
unsigned long input_bit_buffer;

unsigned short find_match(short hash_prefix, unsigned short hash_character);
long output_code(unsigned char *OutBuffer,long count,unsigned short code);
unsigned short input_code(unsigned char *InBuffer,long len);
unsigned char *decode_string(unsigned char *buffer, unsigned short code);

public:
long Compress(unsigned char *InBuffer,long len,unsigned char *OutBuffer);
long Expand(unsigned char *InBuffer,long len,unsigned char *OutBuffer);
};

unsigned short TLZWCompress::find_match(short hash_prefix, unsigned short hash_character)
{ short index, offset;
index = (hash_character << HASHING_SHIFT ) ^ hash_prefix;
if (index == 0 ) offset=1; else offset = TABLE_SIZE - index;
while (code_value[index]!=-1)
{ if ((prefix_code[index]==hash_prefix)&&(append_character[index]==hash_character)) return (index);
index-=offset;
if (index<0) index+=TABLE_SIZE;
}
return (index);
}

long TLZWCompress::output_code(unsigned char *OutBuffer,long count,unsigned short code)
{ output_bit_buffer|=(unsigned long)code<<(32-num_bits-output_bit_count);
output_bit_count+=num_bits;
while (output_bit_count>=8)
{ OutBuffer[count]=output_bit_buffer>>24;
count++;
output_bit_buffer<<=8;
output_bit_count-=8;
bytes_out++;
}
return count;
}

long TLZWCompress::Compress(unsigned char *InBuffer,long len,unsigned char *OutBuffer)
{ unsigned short next_code=FIRST_CODE;
unsigned short character;
unsigned short string_code;
unsigned short index;
short i,ratio_new,ratio_old=100;
long OutCount=0L;
bytes_in=bytes_out=0;
checkpoint=CHECK_TIME;
output_bit_count=0;
output_bit_buffer=0L;
num_bits=INIT_BITS;
max_code=MAXVAL(num_bits);
ReadCount=0;
for (i=0;i<TABLE_SIZE;i++) code_value[i]=-1;
string_code=InBuffer[ReadCount];
ReadCount++;
while (ReadCount<len)
{ character=InBuffer[ReadCount];
ReadCount++;
++bytes_in;
index=find_match(string_code,character);
if (code_value[index] != -1) string_code=code_value[index];
else
{ if (next_code <= max_code )
{ code_value[index]=next_code++;
prefix_code[index]=string_code;
append_character[index]=character;
}
OutCount=output_code(OutBuffer,OutCount,string_code);
string_code=character;
if (next_code > max_code)
{ if ( num_bits < MAX_BITS) max_code = MAXVAL(++num_bits);
else
{ if (bytes_in > checkpoint)
{ if (num_bits == MAX_BITS )
{ ratio_new = bytes_out*100/bytes_in;
if (ratio_new > ratio_old)
{ OutCount=output_code(OutBuffer,OutCount,CLEAR_TABLE);
num_bits=INIT_BITS;
next_code=FIRST_CODE;
max_code = MAXVAL(num_bits);
bytes_in = bytes_out = 0;
ratio_old=100;
for (i=0;i<TABLE_SIZE;i++) code_value[i]=-1;
}
else ratio_old = ratio_new;
}
checkpoint = bytes_in + CHECK_TIME;
}
}
}
}
}
OutCount=output_code(OutBuffer,OutCount,string_code);
if (next_code == max_code) ++num_bits;
OutCount=output_code(OutBuffer,OutCount,TERMINATOR);
OutCount=output_code(OutBuffer,OutCount,0);
OutCount=output_code(OutBuffer,OutCount,0);
OutCount=output_code(OutBuffer,OutCount,0);
return OutCount;
}

unsigned short TLZWCompress::input_code(unsigned char *InBuffer,long len)
{ unsigned short return_value;
while (input_bit_count <= 24 )
{ if (ReadCount>=len) return TERMINATOR;
return_value=InBuffer[ReadCount++];
input_bit_buffer |= (unsigned long) return_value << (24 - input_bit_count);
input_bit_count += 8;
}
return_value=input_bit_buffer >> (32-num_bits);
input_bit_buffer <<= num_bits;
input_bit_count -= num_bits;
return (return_value);
}

unsigned char *TLZWCompress::decode_string(unsigned char *buffer, unsigned short code)
{ short i=0;
while (code>255)
{ *buffer++ = append_character[code];
code=prefix_code[code];
if (i++ >= 4000 ) return NULL;
}
*buffer=code;
return (buffer);
}

long TLZWCompress::Expand(unsigned char *InBuffer,long len,unsigned char *OutBuffer)
{ unsigned short next_code=FIRST_CODE;
unsigned short new_code;
unsigned short old_code;
short character,clear_flag=1;
unsigned char *string;
long OutCount=0L;
ReadCount=0;
input_bit_count=0;
input_bit_buffer=0L;
num_bits=INIT_BITS;
max_code=MAXVAL(num_bits);
while (1)
{ new_code=input_code(InBuffer,len);
if (new_code==TERMINATOR) break;
if (clear_flag)
{ clear_flag=0;
old_code=new_code;
character=old_code;
OutBuffer[OutCount++]=old_code;
continue;
}
if (new_code == CLEAR_TABLE)
{ clear_flag=1;
num_bits=INIT_BITS;
next_code=FIRST_CODE;
max_code = MAXVAL(num_bits);
continue;
}
if (new_code >= next_code)
{ *decode_stack=character;
string=decode_string(decode_stack+1,old_code);
}
else string=decode_string(decode_stack,new_code);
if (string==NULL) return 0L;
character = *string;
while (string >= decode_stack) OutBuffer[OutCount++]=*string--;
if (next_code <= max_code)
{ prefix_code[next_code]=old_code;
append_character[next_code++]=character;
if (next_code == max_code && num_bits < MAX_BITS) max_code = MAXVAL(++num_bits);
}
old_code=new_code;
}
return OutCount;
}

#endif

[peter2108]

to lj_csdn(大笨蛋) :给我一份（内存压缩），谢谢！
[e-mail]