136 lines
3.2 KiB
C++
136 lines
3.2 KiB
C++
/*****************************************************************************************************************
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FILE: LoadFile.cpp
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COPYRIGHT© 2001 Microsoft Corporation and Executive Software International, Inc.
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FUNCTION:
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This module reads the specified file from the disk and loads it into memory returning
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a handle to the memory
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INPUT + OUTPUT:
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IN cFileName - is a valid file name
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IN pdwFileSize - specifies how many bytes to read - if zero then the size of the memory
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is checked and this value is calculated
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IN dwSharing - is the DWORD to pass to CreateFile about file sharing
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IN dwCreate - is the DWORD to pass to CreateFile about file creation
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GLOBALS:
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None.
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RETURN:
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Valid handle to the memory which holds the specified file
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NULL if not succesful
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*/
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#include "stdafx.h"
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#include <windows.h>
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#include "ErrMacro.h"
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HANDLE
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LoadFile(
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IN PTCHAR cLoadFileName,
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IN PDWORD pdwFileSize,
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IN DWORD dwSharing,
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IN DWORD dwCreate
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)
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{
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HANDLE hFileHandle = INVALID_HANDLE_VALUE; // File handle
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DWORD dwFileSizeHi; // Hi word of file size
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DWORD dwFileSizeLo = 0xFFFFFFFF; // Lo word of file size and initialize
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DWORD dwReadTotal = 0; // Total bytes read during ReadFile
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HANDLE hMemory = NULL; // Memory handle
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LPVOID pMemory = NULL; // Memory pointer
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DWORD dwLastError = 0;
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BOOL bReturn = FALSE;
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__try{
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// Get the file handle.
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if((hFileHandle = CreateFile(cLoadFileName,
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0,
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dwSharing,
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NULL,
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dwCreate,
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FILE_ATTRIBUTE_NORMAL,
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NULL)) == INVALID_HANDLE_VALUE) {
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// No error handling here! The calling function may wish
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// to handle different situations in different ways. Save the error.
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dwLastError = GetLastError();
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__leave;
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}
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// Get the file size.
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if (*pdwFileSize != 0) {
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dwFileSizeLo = *pdwFileSize;
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}
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else{
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// File size not passed in so calculate it
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dwFileSizeLo = GetFileSize(hFileHandle,&dwFileSizeHi);
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if (dwFileSizeLo == 0xFFFFFFFF){
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EH_ASSERT(FALSE);
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__leave;
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}
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}
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// Set the file size to the actual size of the file for the calling function.
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*pdwFileSize = dwFileSizeLo;
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// Return a NULL pointer if the file size is 0.
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if(dwFileSizeLo == 0){
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__leave;
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}
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// Allocate memory for the file.
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hMemory = GlobalAlloc(GHND, dwFileSizeLo);
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if (!hMemory){
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EH_ASSERT(FALSE);
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__leave;
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}
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// Lock the memory and get pointer to the memory.
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pMemory = GlobalLock(hMemory);
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if (!pMemory){
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EH_ASSERT(FALSE);
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__leave;
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}
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// Read the file into memory.
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if (!ReadFile(hFileHandle, pMemory, dwFileSizeLo, &dwReadTotal,0)){
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__leave;
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}
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bReturn = TRUE; // all is ok
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}
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__finally {
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// Close the file handle.
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if(hFileHandle != INVALID_HANDLE_VALUE){
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CloseHandle(hFileHandle);
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}
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// Success so unlock the memory and return the memory handle.
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if(bReturn) {
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GlobalUnlock(hMemory);
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}
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else { // had an error
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// So cleanup and return NULL.
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if(hMemory){
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EH_ASSERT(GlobalUnlock(hMemory) == FALSE);
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EH_ASSERT(GlobalFree(hMemory) == NULL);
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hMemory = NULL;
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}
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// Recover the error if any since another API may have cleared it.
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if(dwLastError){
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SetLastError(dwLastError);
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}
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}
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}
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return hMemory;
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}
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