汇编内存映射文件

内存映射文件来读取大文件，用汇编速度会不会更快呢？

测试测试呗：

用到的API：



调用CreateFile打开您想要映射的文件。

调用CreateFileMapping，其中要求传入先前CreateFile前往的句柄，该函数生成一个建立在CreateFile函数创建的文件对象基础上的内存映射对象。

调用MapViewOfFile函数映射整个文件的一个区域或者整个文件到内存。该函数前往指向映射到内存的第一个字节的指针。

用该指针来读写文件。

调用UnmapViewOfFile来解除文件映射。

调用CloseHandle来关闭内存映射文件。注意必须传入内存映射文件的句柄。

调用CloseHandle来关闭文件。注意必须传入由CreateFile创建的文件的句柄。

code：

.386 
.model flat,stdcall 
WinMain proto WORD,WORD,WORD,WORD 
include \masm32\include\windows.inc 
include \masm32\include\user32.inc 
include \masm32\include\kernel32.inc 
include \masm32\include\comdlg32.inc 
includelib \masm32\lib\user32.lib 
includelib \masm32\lib\kernel32.lib 
includelib \masm32\lib\comdlg32.lib 
.const 
IDM_OPEN equ 1 
IDM_SAVE equ 2 
IDM_EXIT equ 3 
MAXSIZE equ 260 
.data 
ClassName db "Win32ASMFileMappingClass",0 
AppName db "Win32 ASM File Mapping Example",0 
MenuName db "FirstMenu",0 
ofn OPENFILENAME <> 
FilterString db "All Files",0,"*.*",0 
db "Text Files",0,"*.txt",0,0 
来源：www.va1314.com/bc
buffer db MAXSIZE dup(0) 
hMapFile HANDLE 0 ; Handle to the memory mapped file, must be 
;initialized with 0 because we also use it as 
;a flag in WM_DESTROY section too 
.data? 
hInstance HINSTANCE ? 
CommandLine LPSTR ? 
hFileRead HANDLE ? ; Handle to the source file 
hFileWrite HANDLE ? ; Handle to the output file 
hMenu HANDLE ? 
pMemory DWORD ? ; pointer to the data in the source file 
SizeWritten DWORD ? ; number of bytes actually written by WriteFile 
.code 
start: 
invoke GetModuleHandle, NULL 
mov hInstance,eax 
invoke GetCommandLine 
mov CommandLine,eax 
invoke WinMain, hInstance,NULL,CommandLine, SW_SHOWDEFAULT 
invoke ExitProcess,eax 
WinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLinePSTR,CmdShowWORD 
LOCAL wc:WNDCLASSEX 
LOCAL msg:MSG 
LOCAL hwnd:HWND 
mov wc.cbSize,SIZEOF WNDCLASSEX 
mov wc.style, CS_HREDRAW or CS_VREDRAW 
mov wc.lpfnWndProc, OFFSET WndProc 
mov wc.cbClsExtra,NULL 
mov wc.cbWndExtra,NULL 
push hInst 
pop wc.hInstance 
mov wc.hbrBackground,COLOR_WINDOW+1 
mov wc.lpszMenuName,OFFSET MenuName 
mov wc.lpszClassName,OFFSET ClassName 
invoke LoadIcon,NULL,IDI_APPLICATION 
mov wc.hIcon,eax 
mov wc.hIconSm,eax 
invoke LoadCursor,NULL,IDC_ARROW 
mov wc.hCursor,eax 
invoke RegisterClassEx, addr wc 
invoke CreateWindowEx,WS_EX_CLIENTEDGE,ADDR ClassName,\ 
ADDR AppName, WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,\ 
CW_USEDEFAULT,300,200,NULL,NULL,\ 
hInst,NULL 
mov hwnd,eax 
invoke ShowWindow, hwnd,SW_SHOWNORMAL 
invoke UpdateWindow, hwnd 
.WHILE TRUE 
invoke GetMessage, ADDR msg,NULL,0,0 
.BREAK .IF (!eax) 
invoke TranslateMessage, ADDR msg 
invoke DispatchMessage, ADDR msg 
.ENDW 
mov eax,msg.wParam 
ret 
WinMain endp 
WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParamPARAM 
.IF uMsg==WM_CREATE 
invoke GetMenu,hWnd ;Obtain the menu handle 
mov hMenu,eax 
mov ofn.lStructSize,SIZEOF ofn 
push hWnd 
pop ofn.hWndOwner 
push hInstance 
pop ofn.hInstance 
mov ofn.lpstrFilter, OFFSET FilterString 
mov ofn.lpstrFile, OFFSET buffer 
mov ofn.nMaxFile,MAXSIZE 
.ELSEIF uMsg==WM_DESTROY 
.if hMapFile!=0 
call CloseMapFile 
.endif 
invoke PostQuitMessage,NULL 
.ELSEIF uMsg==WM_COMMAND 
mov eax,wParam 
.if lParam==0 
.if ax==IDM_OPEN 
mov ofn.Flags, OFN_FILEMUSTEXIST or \ 
OFN_PATHMUSTEXIST or OFN_LONGNAMES or\ 
OFN_EXPLORER or OFN_HIDEREADONLY 
invoke GetOpenFileName, ADDR ofn 
.if eax==TRUE 
invoke CreateFile,ADDR buffer,\ 
GENERIC_READ ,\ 
0,\ 
NULL,OPEN_EXISTING,FILE_ATTRIBUTE_ARCHIVE,\ 
NULL 
mov hFileRead,eax 
invoke CreateFileMapping,hFileRead,NULL,PAGE_READONLY,0,0,NULL 
mov hMapFile,eax 
mov eax,OFFSET buffer 
movzx edx,ofn.nFileOffset 
add eax,edx 
invoke SetWindowText,hWnd,eax 
invoke EnableMenuItem,hMenu,IDM_OPEN,MF_GRAYED 
invoke EnableMenuItem,hMenu,IDM_SAVE,MF_ENABLED 
.endif 
.elseif ax==IDM_SAVE 
mov ofn.Flags,OFN_LONGNAMES or\ 
OFN_EXPLORER or OFN_HIDEREADONLY 
invoke GetSaveFileName, ADDR ofn 
.if eax==TRUE 
invoke CreateFile,ADDR buffer,\ 
GENERIC_READ or GENERIC_WRITE ,\ 
FILE_SHARE_READ or FILE_SHARE_WRITE,\ 
NULL,CREATE_NEW,FILE_ATTRIBUTE_ARCHIVE,\ 
NULL 
mov hFileWrite,eax 
invoke MapViewOfFile,hMapFile,FILE_MAP_READ,0,0,0 
mov pMemory,eax 
invoke GetFileSize,hFileRead,NULL 
invoke WriteFile,hFileWrite,pMemory,eax,ADDR SizeWritten,NULL 
invoke UnmapViewOfFile,pMemory 
call CloseMapFile 
invoke CloseHandle,hFileWrite 
invoke SetWindowText,hWnd,ADDR AppName 
invoke EnableMenuItem,hMenu,IDM_OPEN,MF_ENABLED 
invoke EnableMenuItem,hMenu,IDM_SAVE,MF_GRAYED 
.endif 
.else 
invoke DestroyWindow, hWnd 
.endif 
.endif 
.ELSE 
invoke DefWindowProc,hWnd,uMsg,wParam,lParam 
ret 
.ENDIF 
xor eax,eax 
ret 
WndProc endp 
CloseMapFile PROC 
invoke CloseHandle,hMapFile 
mov hMapFile,0 
invoke CloseHandle,hFileRead 
ret 
CloseMapFile endp