一段代码，演示Win32下超大文件读写

来源：互联网发布：华东师范大学数据库编辑：程序博客网时间：2024/06/06 01:49
一段代码,演示在win32下读写4G以上的超大文件
上限为unsigned __int64,4G的平方字节
// ****************************************************************************************************// 文件: fs32demo\\main.cpp// 作者: 虎胆游侠(blog.csdn.net/prsniper; cto@renshenguo.com)// 时间: 2015-12-30 06:02:11// 注释:// Win32下超大文件读写演示程序, Demonstration for large file operation in win32// ****************************************************************************************************#include <windows.h>#include <stdio.h>// FS是起初想做File Splitter, 将大文件分割, 虽然只有部分数据无意义, 但对于断点续传很关键#define FS_ARG_COUNT5// 用GUID作为共享内存名称避免重复#define FS_OPEN_NAME"Global\\LargeFileOpen{E4FCF358-8BF8-4b59-A046-CCF85620AC36}"#define FS_SAVE_NAME"Global\\LargeFileSave{E4FCF358-8BF8-4b59-A046-CCF85620AC36}"// 默认的文件参数(本机调试使用)#define FS_FILE_OPEN"F:\\Win2003Ent.rar"#define FS_FILE_SAVE"F:\\Win2003Ent.rar.bak"#define FS_FILE_SIZE8316302716#define FS_FILE_BYTE0x10000000// 256 MB (268435456)// 进程退出代码#define FS_ERROR_SUCCESS0#define FS_ERROR_OPEN_FILE1#define FS_ERROR_OPEN_MAPPING2#define FS_ERROR_MULTI_OPEN3#define FS_ERROR_SAVE_FILE4#define FS_ERROR_SAVE_MAPPING5#define FS_ERROR_MULTI_SAVE6#define FS_ERROR_VIEW_OPEN7#define FS_ERROR_VIEW_SAVE8#define FS_ERROR_CLOSE_FILE9// 类型定义typedef unsigned __int64QWORD;typedef struct tagLargeFile{HANDLE File;HANDLE Mapping;LPBYTE Buffer;union {struct {DWORD Bit32;DWORD Bit64;};QWORD Offset;QWORD Length;};} LARGEFILE, *PLARGEFILE;// 入口函数, 用法: fs32demo[.exe][ inputfile outputfile filesize cachesize]int main(int argc, char **argv){LARGEFILE lfOpen;LARGEFILE lfSave;char *szOpen;char *szSave;//QWORD nLength;// use lfSave.LengthDWORD dwSize;union {struct {DWORD dwSizeLow;DWORD dwSizeHigh;};QWORD nSize;// temp var};BOOL dwRet;if(argc == FS_ARG_COUNT){// 处理运行参数, 自动过滤引号: argv[0] == ...\\fs32demo.exeszOpen = argv[1];szSave = argv[2];lfSave.Length = _atoi64(argv[3]);// 文件大小dwSize = atoi(argv[4]);// 不应超过2GB, 且小于文件大小}else{szOpen = FS_FILE_OPEN;szSave = FS_FILE_SAVE;lfSave.Length = FS_FILE_SIZE;dwSize = FS_FILE_BYTE;}// 输出参数信息printf(" Input file: %s\r\n", szOpen);printf("Output file: %s\r\n", szSave);printf("  File size: 0x%I64X (%I64d bytes)\r\n", lfSave.Length, lfSave.Length);printf(" Cache size: 0x%08X (%d bytes)\r\n", dwSize, dwSize);printf("Press any key to fuck: \r\n");getchar();// 任意键继续lfOpen.File = CreateFile(szOpen,// file to fuck withGENERIC_READ,// 只读打开FILE_SHARE_READ,// 共享读取NULL,// &sa(默认不能继承)OPEN_EXISTING,// CREATE_ALWAYSFILE_ATTRIBUTE_NORMAL,NULL);if(lfOpen.File == INVALID_HANDLE_VALUE){return FS_ERROR_OPEN_FILE;}lfOpen.Mapping = CreateFileMapping(lfOpen.File,NULL,// &saPAGE_READONLY,// 只读共享内存0,// 高双字0,// 低双字, 自动使用文件大小FS_OPEN_NAME);if(lfOpen.Mapping == NULL){CloseHandle(lfOpen.File);// system holds the corresponding file open until the last view of the file is unmapped.//lfOpen.File = NULL;return FS_ERROR_OPEN_MAPPING;}if(GetLastError() == ERROR_ALREADY_EXISTS){// FS_ERROR_MULTI_OPEN, Proceed..}lfSave.File = CreateFile(szSave,// file to fuck withGENERIC_READ | GENERIC_WRITE,// 读写打开FILE_SHARE_READ,// 共享读取(不共享写入)NULL,// &sa(默认不能继承)CREATE_ALWAYS,// OPEN_EXISTINGFILE_ATTRIBUTE_NORMAL,NULL);if(lfSave.File == INVALID_HANDLE_VALUE){CloseHandle(lfOpen.Mapping);CloseHandle(lfOpen.File);return FS_ERROR_SAVE_FILE;}//lfSave.Offset = lfSave.Length;lfSave.Mapping = CreateFileMapping(lfSave.File,NULL,// &saPAGE_READWRITE,// 读写共享内存lfSave.Bit64,// 高双字lfSave.Bit32,// 低双字FS_SAVE_NAME);if(lfSave.Mapping == NULL){CloseHandle(lfSave.File);CloseHandle(lfOpen.Mapping);CloseHandle(lfOpen.File);return FS_ERROR_SAVE_MAPPING;}if(GetLastError() == ERROR_ALREADY_EXISTS){CloseHandle(lfSave.Mapping);CloseHandle(lfSave.File);CloseHandle(lfOpen.Mapping);CloseHandle(lfOpen.File);return FS_ERROR_MULTI_SAVE;}dwRet = FS_ERROR_SUCCESS;// 默认成功lfOpen.Offset = 0;while(lfOpen.Offset < lfSave.Length){nSize = lfSave.Length - lfOpen.Offset;if(nSize > dwSize){nSize = dwSize;}// 映射lfOpen.Buffer = (LPBYTE)MapViewOfFile(lfOpen.Mapping, FILE_MAP_READ, lfOpen.Bit64, lfOpen.Bit32, dwSizeLow);if(lfOpen.Buffer == NULL){dwRet = FS_ERROR_VIEW_OPEN;break;}lfSave.Buffer = (LPBYTE)MapViewOfFile(lfSave.Mapping, FILE_MAP_ALL_ACCESS, lfOpen.Bit64, lfOpen.Bit32, dwSizeLow);if(lfOpen.Buffer == NULL){UnmapViewOfFile(lfSave.Buffer);dwRet = FS_ERROR_VIEW_SAVE;break;}// memcpy & unmapprintf("Offset: 0x%I64X, Size: 0x%08X; (%d bytes from %I64d)\r\n", lfOpen.Offset, dwSizeLow, dwSizeLow, lfOpen.Offset);CopyMemory(lfSave.Buffer, lfOpen.Buffer, dwSizeLow);UnmapViewOfFile(lfSave.Buffer);UnmapViewOfFile(lfOpen.Buffer);// nextlfOpen.Offset += FS_FILE_BYTE;}CloseHandle(lfSave.Mapping);CloseHandle(lfSave.File);CloseHandle(lfOpen.Mapping);if(CloseHandle(lfOpen.File) == FALSE){return FS_ERROR_CLOSE_FILE;// ...}return dwRet;}
VC工程源码下载地址:
CSDN: http://download.csdn.net/detail/prsniper/9384068
百度云盘 http://pan.baidu.com/s/1qXkGPcS
1 0