zlib解压（在未知解压后大小情况）

#include <stdio.h>
#include <Windows.h>
#include <stdlib.h>
#include "zlib/zlib.h"

/*
作者：zhujian198
邮件：zhujian198@gmail.com
描叙：zlib解压
主要是为了做内存泄漏测试检测而写，顺便做个笔记
*/

int  inflate_UnCompress(char * source,int len,char **dest,DWORD * dwDest)
{
    int                nResult = 0;
    z_stream           zstrm = {0};
    BYTE               out[0x8000] = {0};
    DWORD              dwHave = 0;
    int                totalsize   =   0; 
    zstrm.zalloc     = Z_NULL;
    zstrm.zfree      = Z_NULL;
    zstrm.opaque     = Z_NULL;
    zstrm.avail_in   = 0;
    zstrm.next_in    = Z_NULL;

    nResult = inflateInit(&zstrm);
    if (nResult != Z_OK)
        goto Exit0;
    zstrm.avail_in    = len;
    zstrm.next_in     = (Bytef *)source;
    do 
    {
        zstrm.avail_out = 0x8000;
        zstrm.next_out  = out;
        nResult = inflate(&zstrm,Z_NO_FLUSH);
        if (nResult == Z_STREAM_ERROR)
        {
            inflateEnd(&zstrm);
            goto Exit0;
        }
        switch(nResult)
        {
        case Z_NEED_DICT:
            nResult = Z_DATA_ERROR;
        case Z_DATA_ERROR:
        case Z_MEM_ERROR:
           inflateEnd(&zstrm);
           goto Exit0;
        }
        dwHave = 0x8000 - zstrm.avail_out;
        totalsize += dwHave;
        *dest   =   (char *)realloc(*dest,totalsize);
        if (*dest == NULL)
        {
            break;
        }
        memcpy(*dest + totalsize - dwHave,out,dwHave);
    } while (zstrm.avail_out   ==   0);
    (void)inflateEnd(&zstrm); 
Exit0:
    if (nResult   ==   Z_STREAM_END)
    {
        *dwDest = totalsize; 
    }
    else
    {
        *dwDest = 0;
    }

    return   (nResult   ==   Z_STREAM_END   ?   Z_OK   :   Z_DATA_ERROR); 
}
void main()
{
    char * Buffer = NULL;
    HANDLE hFile  = INVALID_HANDLE_VALUE;
    DWORD  dwFileSize = 0;
    BYTE   *byInBuffer = NULL;
    DWORD  dwNumBytes = 0;
    DWORD  dwOutSize = 0;
    int    nRes = 0;
    HANDLE houtFile = INVALID_HANDLE_VALUE;
    hFile = CreateFile("123.bin",
               GENERIC_READ,
               FILE_SHARE_READ,
               NULL,
               OPEN_EXISTING,
               FILE_ATTRIBUTE_NORMAL,
               NULL);
    if (INVALID_HANDLE_VALUE == hFile)
    {
        printf("打开文件失败\n");
        goto Exit0;
    }
    dwFileSize = GetFileSize(hFile,NULL);
    if (dwFileSize == 0)
    {
        printf("文件大小为零\n");
        goto Exit0;
    }
    byInBuffer = new BYTE[dwFileSize];
    memset(byInBuffer,0,dwFileSize);
    if (byInBuffer == NULL)
    {
        printf("内存申请失败\n");
        goto Exit0;
    }
    ReadFile(hFile,byInBuffer,dwFileSize,&dwNumBytes,NULL);
    if (dwNumBytes != dwFileSize)
    {
        printf("读取文件失败\n");
        goto Exit0;
    }

    nRes = inflate_UnCompress((char *)byInBuffer,dwFileSize,&Buffer,&dwOutSize);
    if (nRes != Z_OK)
        goto Exit0;
    if (dwOutSize == 0)
        goto Exit0;
    houtFile = CreateFile("out.exe",
           GENERIC_WRITE,
           FILE_SHARE_WRITE,
           NULL,
           CREATE_ALWAYS,
           NULL,
           NULL);
    if (INVALID_HANDLE_VALUE == houtFile)
    {
        printf("创建文件失败!\n");
        goto Exit0;
    }
    WriteFile(houtFile,Buffer,dwOutSize,&dwNumBytes,NULL);
    if (dwOutSize != dwNumBytes)
    {
        printf("写入文件失败\n");
        goto Exit0;
    }
Exit0:

    if (byInBuffer)
    {
        delete[] byInBuffer;
        byInBuffer = NULL;
    }
    if (hFile != INVALID_HANDLE_VALUE)
    {
        CloseHandle(hFile);
        hFile = INVALID_HANDLE_VALUE;
    }
    if (houtFile != INVALID_HANDLE_VALUE)
    {
        CloseHandle(houtFile);
        houtFile = INVALID_HANDLE_VALUE;
    }
    if (Buffer)
    {
        free(Buffer);
        Buffer = NULL;
    }
}