ps_client_zip.cpp

这个程序是利用Glib接口实现文件的压缩功能

// PS_client_zip.cpp: implementation of the CPSClientZip class.
//
//////////////////////////////////////////////////////////////////////

#include "PS_client_zip.h"
#include "PS_blowfish.h"

#ifndef WIN32
#include <unistd.h>
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CPSClientZip::CPSClientZip():m_nBufferSize(4096)
{
	m_mode = 0;
}

CPSClientZip::~CPSClientZip()
{

}

int CPSClientZip::PS_zip_init(int mode)
{
	m_mode = mode;
	return 1;
}

int CPSClientZip::PS_zip_str_commpress(const char *src, char *dest)
{
	if (src == NULL || dest == NULL)
	{
		return -3;
	}
	if (strlen(src) >= m_nBufferSize)
	{
		return -2;
	}

	int ret = str_deflate((Byte *)dest, m_nBufferSize, src);

	if (ret != 0)
		return -1;

	return 0;
}

int CPSClientZip::PS_zip_str_uncommpress(const char *src, char *dest)
{	
	if (src == NULL || dest == NULL)
	{
		return -3;
	}
	if (strlen(src) >= m_nBufferSize)
	{
		return -2;
	}

	int ret = str_inflate((Byte *)src, m_nBufferSize, (Byte *)dest, m_nBufferSize);
	if (ret != 0)
	{
		return -1;
	}

	return 0;
}

int CPSClientZip::PS_zip_file_compress(const char *filename, char *destfile, int mode)
{
	if (filename == NULL || destfile == NULL) //  传入指针为空
	{
		return -3;
	}
	if (strlen(filename) >= MAX_NAME_LEN || strlen(destfile) >= MAX_NAME_LEN) // 长度超出最大范围
	{
		return -2;
	}

	char outmode[20];

    strcpy(outmode, "wb6 ");

	if (strlen(destfile) == 0)
	{
		strcpy(destfile, filename);
		strcat(destfile, GZ_SUFFIX);
	}

	int ret = file_compress(filename, outmode, destfile);

	if (mode != 0)
	{ 
		unlink(filename);
	}

	return ret;	
}

int CPSClientZip::PS_zip_file_uncompress(const char *filename, char *destfile, int mode)
{
	if (filename == NULL || destfile == NULL) //  传入指针为空
	{
		return -3;
	}
	if (strlen(filename) >= MAX_NAME_LEN || strlen(destfile) >= MAX_NAME_LEN) // 长度超出最大范围
	{
		return -2;
	}

	if (strlen(destfile) == 0) // 字符串长度为0
	{		
		uInt len = (uInt)strlen(filename);
		
		strcpy(destfile, filename);

		if (len > SUFFIX_LEN && strcmp(filename+len-SUFFIX_LEN, GZ_SUFFIX) == 0) 
		{
			destfile[len-4] = '\0';
		}
	}

	int ret = file_uncompress(filename, destfile);

	if (mode != 0)
	{ 
		unlink(filename);
	}

	return ret;
}

int CPSClientZip::PS_zip_set_mode(int mode)
{
	m_mode = mode;

	return 1;	
}

int CPSClientZip::PS_zip_buf_to_file_compress(const char *buf, char *destfile, unsigned long size)
{
	char outmode[20];
	strcpy(outmode, "wb6 ");
	int err;
	const char *p = NULL;

	unsigned char *pbuf = NULL;
	unsigned long ulsize;
	if (m_mode == 1)
	{	
		CBlowFish blow;

		unsigned char psw[19] = {0};
		blow.GenKey(psw, 18);
		
		blow.Initialize(psw, 18);

		ulsize = blow.GetOutputLength(size);
		pbuf = new unsigned char[ulsize];
		blow.Encode((unsigned char *)buf, pbuf, size);
		p = (char *)pbuf;
	}
	else
	{
		ulsize = size;
		p = buf;
	}

	gzFile file;
	file = gzopen(destfile, outmode);
	if (file == NULL) 
	{
		fprintf(stderr, "gzopen error\n");
		return 0;
	}

	while (ulsize > BUFLEN)
	{
		if (gzwrite(file, p, BUFLEN) != (int)BUFLEN) 
		{
			error(gzerror(file, &err));
		    gzclose(file);
			return 0;
		}
		p += BUFLEN;
		ulsize -= BUFLEN;
	}

	if (ulsize > 0 && ulsize <= BUFLEN)
	{	
		if (gzwrite(file, p, ulsize) != (int)ulsize) 
		{
			error(gzerror(file, &err));
		    gzclose(file);
			return 0;
		}
	}

    gzclose(file);

	if (m_mode == 1)
	{
		delete []pbuf;
	}

	return 1;
}

int CPSClientZip::PS_zip_file_to_buf_uncompress(char *filename, char *buf, unsigned long size)
{
    local char buffer[BUFLEN];

    uLong len;
    int err;
	char *p = NULL;

	unsigned char *pbuf = NULL;
	unsigned long ulsize;

	if (m_mode == 1)
	{	
		ulsize =  CBlowFish::GetOutputLength(size);
		pbuf = new unsigned char[ulsize];
		p = (char *)pbuf;
	}
	else
	{
		ulsize = size;
		p = buf;
	}

	gzFile file;
    file = gzopen(filename, "rb");

	if (file == NULL) 
	{
        fprintf(stderr, "gzopen error\n");
		delete []pbuf;
        return 0;
    }

	unsigned long destsize(0);

	while (ulsize > 0)
	{
        len = gzread(file, buffer, BUFLEN);
        if (len < 0) 
		{
			error (gzerror(file, &err));
			break;
		}
		if (len == 0)
			break;
		if (ulsize > len)  // 剩余缓冲区比len大
		{
			memcpy(p, buffer, len);

			p += len;
			destsize += len;
		}
		else   // 剩余缓冲区比len小，则写入size否则缓冲区溢出
		{
			memcpy(p, buffer, len);
			
			destsize += ulsize;
			break;
		}
		ulsize -= len;
    }

    gzclose(file);

	if (m_mode == 1)
	{	
		if (0 != destsize % 8)
		{
			delete []pbuf;
			return 0;
		}

		CBlowFish blow;

		unsigned char psw[19] = {0};
		blow.GenKey(psw, 18);
		
		blow.Initialize(psw, 18);

		unsigned char *ptmp = new unsigned char[destsize];

		blow.Decode((unsigned char *)pbuf, ptmp, destsize);

		memcpy(buf, ptmp, destsize);

		delete []pbuf;

		delete []ptmp;
	}

	return 1;
}

char *prog;

/* ===========================================================================
 * Display error message and exit
 */
void error(const char *msg)
{
    fprintf(stderr, "%s: %s\n", prog, msg);
    exit(1);
}

/* ===========================================================================
 * Compress input to output then close both files.
 */
void CPSClientZip::gz_compress(FILE *in, gzFile out)
{
    local char buf[BUFLEN];
    int len;
    int err;

#ifdef USE_MMAP
    /* Try first compressing with mmap. If mmap fails (minigzip used in a
     * pipe), use the normal fread loop.
     */
    if (gz_compress_mmap(in, out) == Z_OK) return;
#endif
    for (;;) {
        len = (int)fread(buf, 1, sizeof(buf), in);
        if (ferror(in)) {
            perror("fread");
            exit(1);
        }
        if (len == 0) break;

        if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));
    }
    fclose(in);
    if (gzclose(out) != Z_OK) error("failed gzclose");
}

#ifdef USE_MMAP /* MMAP version, Miguel Albrecht <[e-mail]> */

/* Try compressing the input file at once using mmap. Return Z_OK if
 * if success, Z_ERRNO otherwise.
 */
int gz_compress_mmap(in, out)
    FILE   *in;
    gzFile out;
{
    int len;
    int err;
    int ifd = fileno(in);
    caddr_t buf;    /* mmap'ed buffer for the entire input file */
    off_t buf_len;  /* length of the input file */
    struct stat sb;

    /* Determine the size of the file, needed for mmap: */
    if (fstat(ifd, &sb) < 0) return Z_ERRNO;
    buf_len = sb.st_size;
    if (buf_len <= 0) return Z_ERRNO;

    /* Now do the actual mmap: */
    buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
    if (buf == (caddr_t)(-1)) return Z_ERRNO;

    /* Compress the whole file at once: */
    len = gzwrite(out, (char *)buf, (unsigned)buf_len);

    if (len != (int)buf_len) error(gzerror(out, &err));

    munmap(buf, buf_len);
    fclose(in);
    if (gzclose(out) != Z_OK) error("failed gzclose");
    return Z_OK;
}
#endif /* USE_MMAP */

/* ===========================================================================
 * Uncompress input to output then close both files.
 */
void CPSClientZip::gz_uncompress(gzFile in, FILE   *out)
{
    local char buf[BUFLEN];
    int len;
    int err;

    for (;;) {
        len = gzread(in, buf, sizeof(buf));
        if (len < 0) error (gzerror(in, &err));
        if (len == 0) break;

        if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
            error("failed fwrite");
        }
    }
    if (fclose(out)) error("failed fclose");

    if (gzclose(in) != Z_OK) error("failed gzclose");
}

/* ===========================================================================
 * Compress the given file: create a corresponding .rsp file
 */
int CPSClientZip::file_compress(const char  *file, char  *mode, char *destfile)
{
    FILE  *in;
    gzFile out;

    in = fopen(file, "rb");
    if (in == NULL) {
        perror(file);
		return -1;
        exit(1);
    }
    out = gzopen(destfile, mode);
    if (out == NULL) {
        fprintf(stderr, "%s: can't gzopen %s\n", prog, destfile);
		return -1;
        exit(1);
    }
    gz_compress(in, out);

	return 0;
}

/* ===========================================================================
 * Uncompress the given file
 */
int CPSClientZip::file_uncompress(const char *file, char *destfile)
{
    FILE  *out;
    gzFile in;
    uInt len = (uInt)strlen(file);

    in = gzopen(file, "rb");
    if (in == NULL) {
        fprintf(stderr, "%s: can't gzopen %s\n", prog, file);
		return -1;
    }
    out = fopen(destfile, "wb");
    if (out == NULL) {
        perror(destfile);
		return -1;
    }

    gz_uncompress(in, out);

	return 0;
}

/* ===========================================================================
 * Test deflate() with small buffers
 */
int str_deflate(Byte *compr, uLong comprLen, const char *src)
{
    z_stream c_stream; /* compression stream */
    int err;
    uLong len = (uLong)strlen(src)+1;

    c_stream.zalloc = (alloc_func)0;
    c_stream.zfree = (free_func)0;
    c_stream.opaque = (voidpf)0;

    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
    CHECK_ERR(err, "deflateInit");

    c_stream.next_in  = (Bytef*)src;
    c_stream.next_out = compr;

    while (c_stream.total_in != len && c_stream.total_out < comprLen) {
        c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
        err = deflate(&c_stream, Z_NO_FLUSH);
        CHECK_ERR(err, "deflate");
    }
    /* Finish the stream, still forcing small buffers: */
    for (;;) {
        c_stream.avail_out = 1;
        err = deflate(&c_stream, Z_FINISH);
        if (err == Z_STREAM_END) break;
        CHECK_ERR(err, "deflate");
    }

    err = deflateEnd(&c_stream);
    CHECK_ERR(err, "deflateEnd");
	return err;
}

/* ===========================================================================
 * Test inflate() with small buffers
 */
int str_inflate(Byte *compr, uLong comprLen, Byte *uncompr, uLong uncomprLen)
{
    int err;
    z_stream d_stream; /* decompression stream */

    strcpy((char*)uncompr, "garbage");

    d_stream.zalloc = (alloc_func)0;
    d_stream.zfree = (free_func)0;
    d_stream.opaque = (voidpf)0;

    d_stream.next_in  = compr;
    d_stream.avail_in = 0;
    d_stream.next_out = uncompr;

    err = inflateInit(&d_stream);
    CHECK_ERR(err, "inflateInit");

    while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) {
        d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
        err = inflate(&d_stream, Z_NO_FLUSH);
        if (err == Z_STREAM_END) break;
        CHECK_ERR(err, "inflate");
    }

    err = inflateEnd(&d_stream);
    CHECK_ERR(err, "inflateEnd");

	return err;
}