SECTION HEADER #1
   .text name
   11A70 virtual size
    1000 virtual address
   12000 size of raw data
    1000 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
60000020 flags
         Code
         Execute Read

SECTION HEADER #2
  .rdata name
     1F6 virtual size
   13000 virtual address
    1000 size of raw data
   13000 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
40000040 flags
         Initialized Data
         Read Only

SECTION HEADER #3
   .data name
     560 virtual size
   14000 virtual address
    1000 size of raw data
   14000 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
C0000040 flags
         Initialized Data
         Read Write

SECTION HEADER #4
  .idata name
     58D virtual size
   15000 virtual address
    1000 size of raw data
   15000 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
C0000040 flags
         Initialized Data
         Read Write

SECTION HEADER #5
  .didat name
     7A2 virtual size
   16000 virtual address
    1000 size of raw data
   16000 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
C0000040 flags
         Initialized Data
         Read Write

SECTION HEADER #6
  .reloc name
     26D virtual size
   17000 virtual address
    1000 size of raw data
   17000 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
42000040 flags
         Initialized Data
         Discardable
         Read Only

   Summary
        1000 .data
        1000 .didat
        1000 .idata
        1000 .rdata
        1000 .reloc
       12000 .text

#pragma data_seg("sectionname")

#pragma data_seg("Shared")
LONG g_lInstanceCount = 0;
#pragma data_seg()

#pragma data_seg("Shared")
LONG g_lInstanceCount;
#pragma data_seg()

// Create Shared section & have compiler place initialized data in it.
#pragma data_seg("Shared")

// Initialized, in Shared section
int a = 0;

// Uninitialized, not in Shared section
int b;

// Have compiler stop placing initialized data in Shared section.
#pragma data_seg()

// Initialized, in Shared section
__declspec(allocate("Shared")) int c = 0;

// Uninitialized, in Shared section
__declspec(allocate("Shared")) int d;

// Initialized, not in Shared section
int e = 0;

// Uninitialized, not in Shared section
int f;        

/SECTION:name,attributes

/SECTION:Shared,RWS

#pragma comment(linker, "/SECTION:Shared,RWS")

// Tell the compiler to put this initialized variable in its own Shared
// section so it is shared by all instances of this application.
#pragma data_seg("Shared")
volatile LONG g_lApplicationInstances = 0;
#pragma data_seg()

// Tell the linker to make the Shared section
// readable, writable, and shared.
#pragma comment(linker, "/Section:Shared,RWS")

PostMessage(HWND_BROADCAST, g_aMsgAppInstCountUpdate, 0, 0);

/******************************************************************************
Module:  AppInst.cpp
Notices: Copyright (c) 2000 Jeffrey Richter
******************************************************************************/


#include "..\CmnHdr.h"     /* See Appendix A. */
#include <windowsx.h>
#include <tchar.h>
#include "Resource.h"


///////////////////////////////////////////////////////////////////////////////


// The system-wide unique window message
UINT g_uMsgAppInstCountUpdate = INVALID_ATOM;


///////////////////////////////////////////////////////////////////////////////


// Tell the compiler to put this initialized variable in its own Shared 
// section so it is shared by all instances of this application.
#pragma data_seg("Shared")
volatile LONG g_lApplicationInstances = 0;
#pragma data_seg()

// Tell the linker to make the Shared section readable, writable, and shared.
#pragma comment(linker, "/Section:Shared,RWS")


///////////////////////////////////////////////////////////////////////////////


BOOL Dlg_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam) {

   chSETDLGICONS(hwnd, IDI_APPINST);

   // Force the static control to be initialized correctly.
   PostMessage(HWND_BROADCAST, g_uMsgAppInstCountUpdate, 0, 0);
   return(TRUE);
}


///////////////////////////////////////////////////////////////////////////////


void Dlg_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) {

   switch (id) {
      case IDCANCEL:
         EndDialog(hwnd, id);
         break;
   }
}


///////////////////////////////////////////////////////////////////////////////


INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {

   if (uMsg == g_uMsgAppInstCountUpdate) {
      SetDlgItemInt(hwnd, IDC_COUNT, g_lApplicationInstances, FALSE);
   }

   switch (uMsg) {
      chHANDLE_DLGMSG(hwnd, WM_INITDIALOG, Dlg_OnInitDialog);
      chHANDLE_DLGMSG(hwnd, WM_COMMAND,    Dlg_OnCommand);
   }
   return(FALSE);
}


///////////////////////////////////////////////////////////////////////////////


int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) {

   // Get the numeric value of the systemwide window message used to notify 
   // all top-level windows when the module's usage count has changed.
   g_uMsgAppInstCountUpdate =
      RegisterWindowMessage(TEXT("MsgAppInstCountUpdate"));

   // There is another instance of this application running
   InterlockedExchangeAdd((PLONG) &g_lApplicationInstances, 1);

   DialogBox(hinstExe, MAKEINTRESOURCE(IDD_APPINST), NULL, Dlg_Proc);

   // This instance of the application is terminating
   InterlockedExchangeAdd((PLONG) &g_lApplicationInstances, -1);

   // Have all other instances update their display
   PostMessage(HWND_BROADCAST, g_uMsgAppInstCountUpdate, 0, 0);

   return(0);
}


//////////////////////////////// End of File //////////////////////////////////

//Microsoft Developer Studio generated resource script.
//
#include "Resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// English (U.S.) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
#ifdef _WIN32
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#endif //_WIN32

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE DISCARDABLE 
BEGIN
    "Resource.h\0"
END

2 TEXTINCLUDE DISCARDABLE 
BEGIN
    "#include ""afxres.h""\r\n"
    "\0"
END

3 TEXTINCLUDE DISCARDABLE 
BEGIN
    "\r\n"
    "\0"
END

#endif    // APSTUDIO_INVOKED


/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//

IDD_APPINST DIALOG DISCARDABLE  0, 0, 140, 21
STYLE WS_MINIMIZEBOX | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION "Application Instances"
FONT 8, "MS Sans Serif"
BEGIN
    LTEXT           "Number of instances running:",IDC_STATIC,12,4,93,8,
                    SS_NOPREFIX
    RTEXT           "#",IDC_COUNT,112,4,16,12,SS_NOPREFIX
END


/////////////////////////////////////////////////////////////////////////////
//
// Icon
//

// Icon with lowest ID value placed first to ensure application icon
// remains consistent on all systems.
IDI_APPINST             ICON    DISCARDABLE     "AppInst.Ico"

/////////////////////////////////////////////////////////////////////////////
//
// DESIGNINFO
//

#ifdef APSTUDIO_INVOKED
GUIDELINES DESIGNINFO DISCARDABLE 
BEGIN
    IDD_APPINST, DIALOG
    BEGIN
        RIGHTMARGIN, 76
        BOTTOMMARGIN, 20
    END
END
#endif    // APSTUDIO_INVOKED

#endif    // English (U.S.) resources
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//


/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

HANDLE CreateFile(
   PCSTR pszFileName,
   DWORD dwDesiredAccess,
   DWORD dwShareMode,
   PSECURITY_ATTRIBUTES psa,
   DWORD dwCreationDisposition,
   DWORD dwFlagsAndAttributes,
   HANDLE hTemplateFile);

HANDLE CreateFileMapping(
   HANDLE hFile,
   PSECURITY_ATTRIBUTES psa,
   DWORD fdwProtect,
   DWORD dwMaximumSizeHigh,
   DWORD dwMaximumSizeLow,
   PCTSTR pszName);

int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE,
   PTSTR pszCmdLine, int nCmdShow)
{
   //Before executing the line below, C:\ does not have
   //a file called "MMFTest.Dat."
   HANDLE hfile = CreateFile("C:\\MMFTest.dat", 
      GENERIC_READ | GENERIC_WRITE,
      FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS,
      FILE_ATTRIBUTE_NORMAL, NULL);

   //Before executing the line below, the MMFTest.Dat
   //file does exist but has a file size of 0 bytes.
   HANDLE hfilemap = CreateFileMapping(hfile, NULL, PAGE_READWRITE,
      0, 100, NULL);

   //After executing the line above, the MMFTest.Dat
   //file has a size of 100 bytes.

   //Cleanup
   CloseHandle(hfilemap);
   CloseHandle(hfile);

   //When the process terminates, MMFTest.Dat remains
   //on the disk with a size of 100 bytes.
   return(0);
}

PVOID MapViewOfFile(
   HANDLE hFileMappingObject,
   DWORD dwDesiredAccess,
   DWORD dwFileOffsetHigh,
   DWORD dwFileOffsetLow,
   SIZE_T dwNumberOfBytesToMap);

// Open the file that we want to map.
HANDLE hFile = CreateFile(pszFileName, GENERIC_READ | GENERIC_WRITE, 0, NULL,
   OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

// Create a file-mapping object for the file.
HANDLE hFileMapping = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY,
   0, 0, NULL);

// Map a copy-on-write view of the file; the system will commit
// enough physical storage from the paging file to accommodate
// the entire file. All pages in the view will initially have
// PAGE_WRITECOPY access.

PBYTE pbFile = (PBYTE) MapViewOfFile(hFileMapping, FILE_MAP_COPY,
   0, 0, 0);

// Read a byte from the mapped view.
BYTE bSomeByte = pbFile[0];

// When reading, the system does not touch the committed pages in
// the paging file. The page keeps its PAGE_WRITECOPY attribute.

// Write a byte to the mapped view.
pbFile[0] = 0;

// When writing for the first time, the system grabs a committed
// page from the paging file, copies the original contents of the
// page at the accessed memory address, and maps the new page
// (the copy) into the process's address space. The new page has
// an attribute of PAGE_READWRITE.

// Write another byte to the mapped view.
pbFile[1] = 0;

// Because this byte is now in a PAGE_READWRITE page, the system
// simply writes the byte to the page (backed by the paging file).

// When finished using the file's mapped view, unmap it.
// UnmapViewOfFile is discussed in the next section.
UnmapViewOfFile(pbFile);

// The system decommits the physical storage from the paging file.
// Any writes to the pages are lost.

// Clean up after ourselves.
CloseHandle(hFileMapping);
CloseHandle(hFile);

BOOL UnmapViewOfFile(PVOID pvBaseAddress);

BOOL FlushViewOfFile(
   PVOID pvAddress,
   SIZE_T dwNumberOfBytesToFlush);

HANDLE hFile = CreateFile(...);
HANDLE hFileMapping = CreateFileMapping(hFile, ...);
PVOID pvFile = MapViewOfFile(hFileMapping, ...);

// Use the memory-mapped file.

UnmapViewOfFile(pvFile);
CloseHandle(hFileMapping);
CloseHandle(hFile);

HANDLE hFile = CreateFile(...);
HANDLE hFileMapping = CreateFileMapping(hFile, ...);
CloseHandle(hFile);
PVOID pvFile = MapViewOfFile(hFileMapping, ...);
CloseHandle(hFileMapping);

// Use the memory-mapped file.

UnmapViewOfFile(pvFile);

dwFileSize = GetFileSize(hFile, NULL);

PSTR pchANSI = (PSTR) pvFile;
pchANSI[dwFileSize / sizeof(CHAR)] = 0;

while(pchANSI != NULL) 
{
   //We have found an occurrence....
   *pchANSI++ = '\r';     //Change '\n' to '\r'.
   *pchANSI++ = '\n';     //Change '\r' to '\n'.
   pchANSI = strchr(pchANSI, '\n'); //Find the next occurrence.
}

SetFilePointer(hFile, dwFileSize, NULL, FILE_BEGIN);
SetEndOfFile(hFile);

/******************************************************************************
Module:  FileRev.cpp
Notices: Copyright (c) 2000 Jeffrey Richter
******************************************************************************/


#include "..\CmnHdr.h"     /* See Appendix A. */
#include <windowsx.h>
#include <tchar.h>
#include <commdlg.h>
#include <string.h>       // For _strrev
#include "Resource.h"


///////////////////////////////////////////////////////////////////////////////


#define FILENAME  TEXT("FILEREV.DAT")


///////////////////////////////////////////////////////////////////////////////


BOOL FileReverse(PCTSTR pszPathname, PBOOL pfIsTextUnicode) {

   *pfIsTextUnicode = FALSE;  // Assume text is Unicode

   // Open the file for reading and writing.
   HANDLE hFile = CreateFile(pszPathname, GENERIC_WRITE | GENERIC_READ, 0, 
      NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

   if (hFile == INVALID_HANDLE_VALUE) {
      chMB("File could not be opened.");
      return(FALSE);
   }

   // Get the size of the file (I assume the whole file can be mapped).
   DWORD dwFileSize = GetFileSize(hFile, NULL);

   // Create the file-mapping object. The file-mapping object is 1 character 
   // bigger than the file size so that a zero character can be placed at the 
   // end of the file to terminate the string (file). Because I don't yet know
   // if the file contains ANSI or Unicode characters, I assume worst case
   // and add the size of a WCHAR instead of CHAR.
   HANDLE hFileMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 
      0, dwFileSize + sizeof(WCHAR), NULL);

   if (hFileMap == NULL) {
      chMB("File map could not be opened.");
      CloseHandle(hFile);
      return(FALSE);
   }

   // Get the address where the first byte of the file is mapped into memory.
   PVOID pvFile = MapViewOfFile(hFileMap, FILE_MAP_WRITE, 0, 0, 0);

   if (pvFile == NULL) {
      chMB("Could not map view of file.");
      CloseHandle(hFileMap);
      CloseHandle(hFile);
      return(FALSE);
   }

   // Does the buffer contain ANSI or Unicode?
   int iUnicodeTestFlags = -1;   // Try all tests
   *pfIsTextUnicode = IsTextUnicode(pvFile, dwFileSize, &iUnicodeTestFlags);

   if (!*pfIsTextUnicode) {
      // For all the file manipulations below, we explicitly use ANSI 
      // functions because we are processing an ANSI file.

      // Put a zero character at the very end of the file.
      PSTR pchANSI = (PSTR) pvFile;
      pchANSI[dwFileSize / sizeof(CHAR)] = 0;

      // Reverse the contents of the file.
      _strrev(pchANSI);

      // Convert all "\n\r" combinations back to "\r\n" to 
      // preserve the normal end-of-line sequence.
      pchANSI = strchr(pchANSI, '\n'); // Find first '\n'.

      while (pchANSI != NULL) {
         // We have found an occurrence....
         *pchANSI++ = '\r';   // Change '\n' to '\r'.
         *pchANSI++ = '\n';   // Change '\r' to '\n'.
         pchANSI = strchr(pchANSI, '\n'); // Find the next occurrence.
      }

   } else {
      // For all the file manipulations below, we explicitly use Unicode
      // functions because we are processing a Unicode file.

      // Put a zero character at the very end of the file.
      PWSTR pchUnicode = (PWSTR) pvFile;
      pchUnicode[dwFileSize / sizeof(WCHAR)] = 0;

      if ((iUnicodeTestFlags & IS_TEXT_UNICODE_SIGNATURE) != 0) {
         // If the first character is the Unicode BOM (byte-order-mark), 
         // 0xFEFF, keep this character at the beginning of the file.
         pchUnicode++;
      }

      // Reverse the contents of the file.
      _wcsrev(pchUnicode);

      // Convert all "\n\r" combinations back to "\r\n" to 
      // preserve the normal end-of-line sequence.
      pchUnicode = wcschr(pchUnicode, L'\n'); // Find first '\n'.

      while (pchUnicode != NULL) {
         // We have found an occurrence....
         *pchUnicode++ = L'\r';   // Change '\n' to '\r'.
         *pchUnicode++ = L'\n';   // Change '\r' to '\n'.
         pchUnicode = wcschr(pchUnicode, L'\n'); // Find the next occurrence.
      }
   }

   // Clean up everything before exiting.
   UnmapViewOfFile(pvFile);
   CloseHandle(hFileMap);

   // Remove trailing zero character added earlier.
   SetFilePointer(hFile, dwFileSize, NULL, FILE_BEGIN);
   SetEndOfFile(hFile);
   CloseHandle(hFile);

   return(TRUE);
}


///////////////////////////////////////////////////////////////////////////////


BOOL Dlg_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam) {

   chSETDLGICONS(hwnd, IDI_FILEREV);

   // Initialize the dialog box by disabling the Reverse button
   EnableWindow(GetDlgItem(hwnd, IDC_REVERSE), FALSE);
   return(TRUE);
}



///////////////////////////////////////////////////////////////////////////////


void Dlg_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) {
   
   TCHAR szPathname[MAX_PATH];

   switch (id) {
      case IDCANCEL:
         EndDialog(hwnd, id);
         break;

      case IDC_FILENAME:
         EnableWindow(GetDlgItem(hwnd, IDC_REVERSE), 
            Edit_GetTextLength(hwndCtl) > 0);
         break;

      case IDC_REVERSE:
         GetDlgItemText(hwnd, IDC_FILENAME, szPathname, chDIMOF(szPathname));

         // Make copy of input file so that we don't destroy it
         if (!CopyFile(szPathname, FILENAME, FALSE)) {
            chMB("New file could not be created.");
            break;
         }

         BOOL fIsTextUnicode;
         if (FileReverse(FILENAME, &fIsTextUnicode)) {
            SetDlgItemText(hwnd, IDC_TEXTTYPE, 
               fIsTextUnicode ? TEXT("Unicode") : TEXT("ANSI"));

            // Spawn Notepad to see the fruits of our labors.
            STARTUPINFO si = { sizeof(si) };
            PROCESS_INFORMATION pi;
            TCHAR sz[] = TEXT("Notepad ") FILENAME;
            if (CreateProcess(NULL, sz,
               NULL, NULL, FALSE, 0, NULL, NULL, &si, π)) {

               CloseHandle(pi.hThread);
               CloseHandle(pi.hProcess);
            }
         }
         break;

      case IDC_FILESELECT:
         OPENFILENAME ofn = { OPENFILENAME_SIZE_VERSION_400 };
         ofn.hwndOwner = hwnd;
         ofn.lpstrFile = szPathname;
         ofn.lpstrFile[0] = 0;
         ofn.nMaxFile = chDIMOF(szPathname);
         ofn.lpstrTitle = TEXT("Select file for reversing");
         ofn.Flags = OFN_EXPLORER | OFN_FILEMUSTEXIST;
         GetOpenFileName(&ofn);
         SetDlgItemText(hwnd, IDC_FILENAME, ofn.lpstrFile);
         SetFocus(GetDlgItem(hwnd, IDC_REVERSE));
         break;
   }
}


///////////////////////////////////////////////////////////////////////////////


INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
   
   switch (uMsg) {
      chHANDLE_DLGMSG(hwnd, WM_INITDIALOG,  Dlg_OnInitDialog);
      chHANDLE_DLGMSG(hwnd, WM_COMMAND,     Dlg_OnCommand);
   }
   return(FALSE);
}


///////////////////////////////////////////////////////////////////////////////


int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) {

   DialogBox(hinstExe, MAKEINTRESOURCE(IDD_FILEREV), NULL, Dlg_Proc);
   return(0);
}


//////////////////////////////// End of File //////////////////////////////////

//Microsoft Developer Studio generated resource script.
//
#include "Resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// English (U.S.) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
#ifdef _WIN32
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#endif //_WIN32

/////////////////////////////////////////////////////////////////////////////
//
// Icon
//

// Icon with lowest ID value placed first to ensure application icon
// remains consistent on all systems.
IDI_FILEREV             ICON    DISCARDABLE     "FileRev.Ico"

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE DISCARDABLE 
BEGIN
    "Resource.h\0"
END

2 TEXTINCLUDE DISCARDABLE 
BEGIN
    "#include ""afxres.h""\r\n"
    "\0"
END

3 TEXTINCLUDE DISCARDABLE 
BEGIN
    "\r\n"
    "\0"
END

#endif    // APSTUDIO_INVOKED


/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//

IDD_FILEREV DIALOG DISCARDABLE  15, 24, 216, 46
STYLE WS_MINIMIZEBOX | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION "File Reverse"
FONT 8, "MS Sans Serif"
BEGIN
    LTEXT           "&Pathname:",IDC_STATIC,4,4,35,8
    EDITTEXT        IDC_FILENAME,44,4,168,12,ES_AUTOHSCROLL
    PUSHBUTTON      "&Browse...",IDC_FILESELECT,4,16,36,12,WS_GROUP
    DEFPUSHBUTTON   "&Reverse file contents",IDC_REVERSE,4,32,80,12
    LTEXT           "Type of characters in file:",IDC_STATIC,88,34,80,8
    LTEXT           "(unknown)",IDC_TEXTTYPE,172,34,34,8
END


/////////////////////////////////////////////////////////////////////////////
//
// DESIGNINFO
//

#ifdef APSTUDIO_INVOKED
GUIDELINES DESIGNINFO DISCARDABLE 
BEGIN
    IDD_FILEREV, DIALOG
    BEGIN
        RIGHTMARGIN, 192
        BOTTOMMARGIN, 42
    END
END
#endif    // APSTUDIO_INVOKED

#endif    // English (U.S.) resources
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//


/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

__int64 Count0s(void)
{
   //Views must always start on a multiple
   //of the allocation granularity
   SYSTEM_INFO sinf;
   GetSystemInfo(&sinf);

   //Open the data file.
   HANDLE hFile = CreateFile("C:\\HugeFile.Big", GENERIC_READ,
      FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL);

   //Create the file-mapping object.
   HANDLE hFileMapping = CreateFileMapping(hFile, NULL, 
      PAGE_READONLY, 0, 0, NULL);

   DWORD dwFileSizeHigh;
   __int64 qwFileSize = GetFileSize(hFile, &dwFileSizeHigh);
   qwFileSize += (((__int64) dwFileSizeHigh) << 32);

   //We no longer need access to the file object's handle.
   CloseHandle(hFile);

   __int64 qwFileOffset = 0, qwNumOf0s = 0;

   while (qwFileSize > 0) 
   {
      // Determine the number of bytes to be mapped in this view
      DWORD dwBytesInBlock = sinf.dwAllocationGranularity;

      if(qwFileSize < sinf.dwAllocationGranularity)
         dwBytesInBlock =(DWORD) qwFileSize;

      PBYTE pbFile = (PBYTE) MapViewOfFile(hFileMapping, FILE_MAP_READ,
         (DWORD)(qwFileOffset >> 32),          // Starting byte
         (DWORD)(qwFileOffset & 0xFFFFFFFF),   // in file
         dwBytesInBlock);                      // # of bytes to map

      // Count the number of Js in this block.
      for(DWORD dwByte = 0; dwByte < dwBytesInBlock; dwByte++)
      {
         if(pbFile[dwByte] == 0)
         qwNumOf0s++;
      }

      // Unmap the view; we don't want multiple views
      // in our address space.
      UnmapViewOfFile(pbFile);

      // Skip to the next set of bytes in the file.
      qwFileOffset += dwBytesInBlock;
      qwFileSize -= dwBytesInBlock;
   }

   CloseHandle(hFileMapping);
   return(qwNumOf0s);
}

PVOID MapViewOfFileEx(
   HANDLE hFileMappingObject,
   DWORD dwDesiredAccess,
   DWORD dwFileOffsetHigh,
   DWORD dwFileOffsetLow,
   SIZE_T dwNumberOfBytesToMap,
   PVOID pvBaseAddress);

#include <Windows.h>

int WINAPI WinMain(HINSTANCE hinstExe, HINSTANCE,
   PTSTR pszCmdLine, int nCmdShow) 
{
   //Open an existing file-it must be bigger than 64 KB.
   HANDLE hFile = CreateFile(pszCmdLine, GENERIC_READ | GENERIC_WRITE,
      0, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

   //Create a file-mapping object backed by the data file.
   HANDLE hFileMapping = CreateFileMapping(hFile, NULL,
      PAGE_READWRITE, 0, 0, NULL);

   //Map a view of the whole file into our address space.
   PBYTE pbFile = (PBYTE) MapViewOfFile(hFileMapping,
      FILE_MAP_WRITE, 0, 0, 0);

   //Map a view of the file (starting 64 KB in) into our address space
   PBYTE pbFile2 = (PBYTE) MapViewOfFile(hFileMapping,
      FILE_MAP_WRITE, 0, 65536, 0);

   if((pbFile + 65536) == pbFile2) 
   {
      // If the addresses overlap, there is one address
      // space region for both views: this must be Windows 98.
      MessageBox(NULL, "We are running under Windows 98", NULL, MB_OK);
   } 
   else 
   {
      // If the addresses do not overlap, each view has its own
      // address space region: this must be Windows 2000.
      MessageBox(NULL, "We are running under Windows 2000", NULL, MB_OK);
   }

   UnmapViewOfFile(pbFile2);
   UnmapViewOfFile(pbFile);
   CloseHandle(hFileMapping);
   CloseHandle(hFile);

   return(0);
}

HANDLE hFile = CreateFile(...);
HANDLE hMap = CreateFileMapping(hFile, ...);
if(hMap == NULL)
   return(GetLastError());

/******************************************************************************
Module:  MMFShare.cpp
Notices: Copyright (c) 2000 Jeffrey Richter
******************************************************************************/


#include "..\CmnHdr.h"     /* See Appendix A. */
#include <windowsx.h>
#include <tchar.h>
#include "Resource.h"


///////////////////////////////////////////////////////////////////////////////


BOOL Dlg_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam) {

   chSETDLGICONS(hwnd, IDI_MMFSHARE);

   // Initialize the edit control with some test data.
   Edit_SetText(GetDlgItem(hwnd, IDC_DATA), TEXT("Some test data"));

   // Disable the Close button because the file can't
   // be closed if it was never created or opened.
   Button_Enable(GetDlgItem(hwnd, IDC_CLOSEFILE), FALSE);
   return(TRUE);
}


///////////////////////////////////////////////////////////////////////////////


void Dlg_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) {
   
   // Handle of the open memory-mapped file
   static HANDLE s_hFileMap = NULL;

   switch (id) {
      case IDCANCEL:
         EndDialog(hwnd, id);
         break;

      case IDC_CREATEFILE:
         if (codeNotify != BN_CLICKED)
            break;

         // Create a paging file-backed MMF to contain the edit control text.
         // The MMF is 4 KB at most and is named MMFSharedData.
         s_hFileMap = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, 
            PAGE_READWRITE, 0, 4 * 1024, TEXT("MMFSharedData"));

         if (s_hFileMap != NULL) {

            if (GetLastError() == ERROR_ALREADY_EXISTS) {
               chMB("Mapping already exists - not created.");
               CloseHandle(s_hFileMap);

            } else {

               // File mapping created successfully.

               // Map a view of the file into the address space.
               PVOID pView = MapViewOfFile(s_hFileMap,
                  FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);

               if (pView != NULL) {
                  // Put edit text into the MMF.
                  Edit_GetText(GetDlgItem(hwnd, IDC_DATA), 
                     (PTSTR) pView, 4 * 1024);

                  // Protect the MMF storage by unmapping it.
                  UnmapViewOfFile(pView);

                  // The user can't create another file right now.
                  Button_Enable(hwndCtl, FALSE);

                  // The user closed the file.
                  Button_Enable(GetDlgItem(hwnd, IDC_CLOSEFILE), TRUE);

               } else {
                  chMB("Can't map view of file.");
               }
            }

         } else {
            chMB("Can't create file mapping.");
         }
         break;

      case IDC_CLOSEFILE:
         if (codeNotify != BN_CLICKED)
            break;

         if (CloseHandle(s_hFileMap)) {
            // User closed the file, fix up the buttons.
            Button_Enable(GetDlgItem(hwnd, IDC_CREATEFILE), TRUE);
            Button_Enable(hwndCtl, FALSE);
         }
         break;

      case IDC_OPENFILE:
         if (codeNotify != BN_CLICKED)
            break;

         // See if a memory-mapped file named MMFSharedData already exists.
         HANDLE hFileMapT = OpenFileMapping(FILE_MAP_READ | FILE_MAP_WRITE,
            FALSE, TEXT("MMFSharedData"));

         if (hFileMapT != NULL) {
            // The MMF does exist, map it into the process's address space.
            PVOID pView = MapViewOfFile(hFileMapT, 
               FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);

            if (pView != NULL) {

               // Put the contents of the MMF into the edit control.
               Edit_SetText(GetDlgItem(hwnd, IDC_DATA), (PTSTR) pView);
               UnmapViewOfFile(pView);
            } else {
               chMB("Can't map view.");
            }

            CloseHandle(hFileMapT);

         } else {
            chMB("Can't open mapping.");
         }
         break;
   }
}


///////////////////////////////////////////////////////////////////////////////


INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
   
   switch (uMsg) {
      chHANDLE_DLGMSG(hwnd, WM_INITDIALOG, Dlg_OnInitDialog);
      chHANDLE_DLGMSG(hwnd, WM_COMMAND,    Dlg_OnCommand);
   }
   return(FALSE);
}


///////////////////////////////////////////////////////////////////////////////


int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) {

   DialogBox(hinstExe, MAKEINTRESOURCE(IDD_MMFSHARE), NULL, Dlg_Proc);
   return(0);
}


//////////////////////////////// End of File //////////////////////////////////

//Microsoft Developer Studio generated resource script.
//
#include "Resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// English (U.S.) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
#ifdef _WIN32
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#endif //_WIN32

/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//

IDD_MMFSHARE DIALOG DISCARDABLE  38, 36, 186, 61
STYLE WS_MINIMIZEBOX | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION "Memory-Mapped File Sharing"
FONT 8, "MS Sans Serif"
BEGIN
    PUSHBUTTON      "&Create mapping of Data",IDC_CREATEFILE,4,4,84,14,
                    WS_GROUP
    PUSHBUTTON      "&Close mapping of Data",IDC_CLOSEFILE,96,4,84,14
    LTEXT           "&Data:",IDC_STATIC,4,26,18,8
    EDITTEXT        IDC_DATA,28,24,153,12
    PUSHBUTTON      "&Open mapping and get Data",IDC_OPENFILE,40,44,104,14,
                    WS_GROUP
END


/////////////////////////////////////////////////////////////////////////////
//
// Icon
//

// Icon with lowest ID value placed first to ensure application icon
// remains consistent on all systems.
IDI_MMFSHARE            ICON    DISCARDABLE     "MMFShare.Ico"

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE DISCARDABLE 
BEGIN
    "Resource.h\0"
END

2 TEXTINCLUDE DISCARDABLE 
BEGIN
    "#include ""afxres.h""\r\n"
    "\0"
END

3 TEXTINCLUDE DISCARDABLE 
BEGIN
    "\r\n"
    "\0"
END

#endif    // APSTUDIO_INVOKED

#endif    // English (U.S.) resources
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//


/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

CELLDATA CellData[200][256];

PVOID VirtualAlloc(
   PVOID pvAddress,
   SIZE_T dwSize,
   DWORD fdwAllocationType,
   DWORD fdwProtect);

/******************************************************************************
Module:  MMFSparse.cpp
Notices: Copyright (c) 2000 Jeffrey Richter
******************************************************************************/


#include "..\CmnHdr.h"     /* See Appendix A. */
#include <tchar.h>
#include <WindowsX.h>
#include <WinIoCtl.h>
#include "SparseStream.h"
#include "Resource.h"


//////////////////////////////////////////////////////////////////////////////


// This class makes it easy to work with memory-mapped sparse files
class CMMFSparse : public CSparseStream {
private:
   HANDLE m_hfilemap;      // File-mapping object
   PVOID  m_pvFile;        // Address to start of mapped file

public:
   // Creates a Sparse MMF and maps it in the process's address space.
   CMMFSparse(HANDLE hstream = NULL, SIZE_T dwStreamSizeMax = 0);

   // Closes a Sparse MMF
   virtual ~CMMFSparse() { ForceClose(); }

   // Creates a sparse MMF and maps it in the process's address space.
   BOOL Initialize(HANDLE hstream, SIZE_T dwStreamSizeMax);

   // MMF to BYTE cast operator returns address of first byte 
   // in the memory-mapped sparse file. 
   operator PBYTE() const { return((PBYTE) m_pvFile); }

   // Allows you to explicitly close the MMF without having
   // to wait for the destructor to be called.
   VOID ForceClose();
};


//////////////////////////////////////////////////////////////////////////////


CMMFSparse::CMMFSparse(HANDLE hstream, SIZE_T dwStreamSizeMax) {

   Initialize(hstream, dwStreamSizeMax);
}


//////////////////////////////////////////////////////////////////////////////


BOOL CMMFSparse::Initialize(HANDLE hstream, SIZE_T dwStreamSizeMax) {

   if (m_hfilemap != NULL) 
      ForceClose();

   // Initialize to NULL in case something goes wrong
   m_hfilemap = m_pvFile = NULL;

   BOOL fOk = TRUE;  // Assume success

   if (hstream != NULL) {
      if (dwStreamSizeMax == 0) {
         DebugBreak();  // Illegal stream size
      }

      CSparseStream::Initialize(hstream);
      fOk = MakeSparse();  // Make the stream sparse
      if (fOk) {
         // Create a file-mapping object
         m_hfilemap = ::CreateFileMapping(hstream, NULL, PAGE_READWRITE, 
            (DWORD) (dwStreamSizeMax >> 32I64), (DWORD) dwStreamSizeMax, NULL);

         if (m_hfilemap != NULL) {
            // Map the stream into the process's address space
            m_pvFile = ::MapViewOfFile(m_hfilemap, 
               FILE_MAP_WRITE | FILE_MAP_READ, 0, 0, 0);
         } else {
            // Failed to map the file, cleanup
            CSparseStream::Initialize(NULL);
            ForceClose();
            fOk = FALSE;
         }
      }
   }
   return(fOk);
}


//////////////////////////////////////////////////////////////////////////////


VOID CMMFSparse::ForceClose() {

   // Cleanup everything that was done sucessfully
   if (m_pvFile != NULL) { 
      ::UnmapViewOfFile(m_pvFile); 
      m_pvFile = NULL; 
   }
   if (m_hfilemap != NULL) { 
      ::CloseHandle(m_hfilemap);   
      m_hfilemap = NULL; 
   }
}


//////////////////////////////////////////////////////////////////////////////


#define STREAMSIZE      (1 * 1024 * 1024)    // 1 MB (1024 KB)
TCHAR szPathname[] = TEXT("C:\\MMFSparse.");
HANDLE g_hstream = INVALID_HANDLE_VALUE;
CMMFSparse g_mmf;


///////////////////////////////////////////////////////////////////////////////


BOOL Dlg_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam) {

   chSETDLGICONS(hwnd, IDI_MMFSPARSE);

   // Initialize the dialog box controls.
   EnableWindow(GetDlgItem(hwnd, IDC_OFFSET), FALSE);
   Edit_LimitText(GetDlgItem(hwnd, IDC_OFFSET), 4);
   SetDlgItemInt(hwnd, IDC_OFFSET, 1000, FALSE);

   EnableWindow(GetDlgItem(hwnd, IDC_BYTE), FALSE);
   Edit_LimitText(GetDlgItem(hwnd, IDC_BYTE), 3);
   SetDlgItemInt(hwnd, IDC_BYTE, 5, FALSE);

   EnableWindow(GetDlgItem(hwnd, IDC_WRITEBYTE), FALSE);
   EnableWindow(GetDlgItem(hwnd, IDC_READBYTE),  FALSE);
   EnableWindow(GetDlgItem(hwnd, IDC_FREEALLOCATEDREGIONS), FALSE);

   return(TRUE);
}


///////////////////////////////////////////////////////////////////////////////


void Dlg_ShowAllocatedRanges(HWND hwnd) {

   // Fill in the Allocated Ranges edit control
   DWORD dwNumEntries;
   FILE_ALLOCATED_RANGE_BUFFER* pfarb = 
      g_mmf.QueryAllocatedRanges(&dwNumEntries);

   if (dwNumEntries == 0) {
      SetDlgItemText(hwnd, IDC_FILESTATUS, 
         TEXT("No allocated ranges in the file"));
   } else {
      TCHAR sz[4096] = { 0 };
      for (DWORD dwEntry = 0; dwEntry < dwNumEntries; dwEntry++) {
         wsprintf(_tcschr(sz, 0), TEXT("Offset: %7.7u, Length: %7.7u\r\n"), 
            pfarb[dwEntry].FileOffset.LowPart, pfarb[dwEntry].Length.LowPart);
      }
      SetDlgItemText(hwnd, IDC_FILESTATUS, sz);
   }
   g_mmf.FreeAllocatedRanges(pfarb);
}


///////////////////////////////////////////////////////////////////////////////


void Dlg_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) {
   
   switch (id) {
      case IDCANCEL:
         if (g_hstream != INVALID_HANDLE_VALUE) 
            CloseHandle(g_hstream);
         EndDialog(hwnd, id);
         break;

      case IDC_CREATEMMF:
         // Create the file
         g_hstream = CreateFile(szPathname, GENERIC_READ | GENERIC_WRITE, 
            0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
         if (g_hstream == INVALID_HANDLE_VALUE) {
            chFAIL("Failed to create file.");
         }

         // Create a 1MB (1024 KB) MMF using the file
         if (!g_mmf.Initialize(g_hstream, STREAMSIZE)) {
            chFAIL("Failed to initialize Sparse MMF.");
         }
         Dlg_ShowAllocatedRanges(hwnd);

         // Enable/disable the other controls.
         EnableWindow(GetDlgItem(hwnd, IDC_CREATEMMF), FALSE);
         EnableWindow(GetDlgItem(hwnd, IDC_OFFSET),    TRUE);
         EnableWindow(GetDlgItem(hwnd, IDC_BYTE),      TRUE);
         EnableWindow(GetDlgItem(hwnd, IDC_WRITEBYTE), TRUE);
         EnableWindow(GetDlgItem(hwnd, IDC_READBYTE),  TRUE);
         EnableWindow(GetDlgItem(hwnd, IDC_FREEALLOCATEDREGIONS), TRUE);

         // Force the Offset edit control to have the focus.
         SetFocus(GetDlgItem(hwnd, IDC_OFFSET));
         break;

      case IDC_WRITEBYTE:
         {
         BOOL fTranslated;
         DWORD dwOffset = GetDlgItemInt(hwnd, IDC_OFFSET, &fTranslated, FALSE);
         if (fTranslated) {
            g_mmf[dwOffset * 1024] = (BYTE) 
               GetDlgItemInt(hwnd, IDC_BYTE, NULL, FALSE);
            Dlg_ShowAllocatedRanges(hwnd);
         }
         }
         break;

      case IDC_READBYTE:
         {
         BOOL fTranslated;
         DWORD dwOffset = GetDlgItemInt(hwnd, IDC_OFFSET, &fTranslated, FALSE);
         if (fTranslated) {
            SetDlgItemInt(hwnd, IDC_BYTE, g_mmf[dwOffset * 1024], FALSE);
            Dlg_ShowAllocatedRanges(hwnd);
         }
         }
         break;

      case IDC_FREEALLOCATEDREGIONS:
         // Normally the destructor causes the file-mapping to close.
         // But, in this case, we wish to force it so that we can reset 
         // a portion of the file back to all zeroes.
         g_mmf.ForceClose();

         // We call ForceClose above because attempting to zero a portion of 
         // the file while it is mapped, causes DeviceIoControl to fail with 
         // error ERROR_USER_MAPPED_FILE ("The requested operation cannot 
         // be performed on a file with a user-mapped section open.")
         g_mmf.DecommitPortionOfStream(0, STREAMSIZE);
         g_mmf.Initialize(g_hstream, STREAMSIZE);
         Dlg_ShowAllocatedRanges(hwnd);
         break;
   }
}


///////////////////////////////////////////////////////////////////////////////


INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {

   switch (uMsg) {
      chHANDLE_DLGMSG(hwnd, WM_INITDIALOG, Dlg_OnInitDialog);
      chHANDLE_DLGMSG(hwnd, WM_COMMAND,    Dlg_OnCommand);
   }
   return(FALSE);
}


///////////////////////////////////////////////////////////////////////////////


int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) {

   chWindows2000Required();

   DialogBox(hinstExe, MAKEINTRESOURCE(IDD_MMFSPARSE), NULL, Dlg_Proc);
   return(0);
}


//////////////////////////////// End of File //////////////////////////////////

//Microsoft Developer Studio generated resource script.
//
#include "Resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// English (U.S.) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
#ifdef _WIN32
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#endif //_WIN32

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE DISCARDABLE 
BEGIN
    "Resource.h\0"
END

2 TEXTINCLUDE DISCARDABLE 
BEGIN
    "#include ""afxres.h""\r\n"
    "\0"
END

3 TEXTINCLUDE DISCARDABLE 
BEGIN
    "\r\n"
    "\0"
END

#endif    // APSTUDIO_INVOKED


/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//

IDD_MMFSPARSE DIALOG DISCARDABLE  15, 24, 172, 197
STYLE DS_CENTER | WS_MINIMIZEBOX | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION "MMF Sparse"
FONT 8, "MS Sans Serif"
BEGIN
    DEFPUSHBUTTON   "&Create a 1MB (1024 KB) Sparse MMF",IDC_CREATEMMF,4,4,
                    164,14,WS_GROUP
    LTEXT           "&Offset (0 - 1023KB):",IDC_STATIC,4,24,63,8
    EDITTEXT        IDC_OFFSET,72,22,44,12
    PUSHBUTTON      "&Read byte",IDC_READBYTE,122,20,46,14
    LTEXT           "&Byte (0-255):",IDC_STATIC,4,36,41,8
    EDITTEXT        IDC_BYTE,72,36,44,12,ES_UPPERCASE | ES_NUMBER
    PUSHBUTTON      "&Write byte",IDC_WRITEBYTE,122,36,46,14
    PUSHBUTTON      "&Free all allocated regions",IDC_FREEALLOCATEDREGIONS,
                    76,52,92,14
    LTEXT           "&Allocated Ranges:",IDC_STATIC,4,68,59,8
    EDITTEXT        IDC_FILESTATUS,4,80,164,116,ES_MULTILINE | 
                    ES_AUTOVSCROLL | ES_AUTOHSCROLL | ES_READONLY | 
                    WS_VSCROLL
END


/////////////////////////////////////////////////////////////////////////////
//
// Icon
//

// Icon with lowest ID value placed first to ensure application icon
// remains consistent on all systems.
IDI_MMFSPARSE           ICON    DISCARDABLE     "MMFSparse.Ico"
#endif    // English (U.S.) resources
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//


/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

/******************************************************************************
Module:  SparseStream.h
Notices: Copyright (c) 2000 Jeffrey Richter
******************************************************************************/


#include "..\CmnHdr.h"     /* See Appendix A. */
#include <WinIoCtl.h>


///////////////////////////////////////////////////////////////////////////////


#pragma once


///////////////////////////////////////////////////////////////////////////////


class CSparseStream {
public:
   static BOOL DoesFileSystemSupportSparseStreams(PCTSTR pszVolume);
   static BOOL DoesFileContainAnySparseStreams(PCTSTR pszPathname);

public:
   CSparseStream(HANDLE hstream = INVALID_HANDLE_VALUE) { 
      Initialize(hstream); 
   }

   virtual ~CSparseStream() { }

   void Initialize(HANDLE hstream = INVALID_HANDLE_VALUE) { 
      m_hstream = hstream; 
   }

public:
   operator HANDLE() const { return(m_hstream); }

public:
   BOOL IsStreamSparse() const;
   BOOL MakeSparse();
   BOOL DecommitPortionOfStream(
      __int64 qwFileOffsetStart, __int64 qwFileOffsetEnd);

   FILE_ALLOCATED_RANGE_BUFFER* QueryAllocatedRanges(PDWORD pdwNumEntries);
   BOOL FreeAllocatedRanges(FILE_ALLOCATED_RANGE_BUFFER* pfarb);

private:
   HANDLE m_hstream;

private:
   static BOOL AreFlagsSet(DWORD fdwFlagBits, DWORD fFlagsToCheck) {
      return((fdwFlagBits & fFlagsToCheck) == fFlagsToCheck);
   }
};


///////////////////////////////////////////////////////////////////////////////


inline BOOL CSparseStream::DoesFileSystemSupportSparseStreams(
   PCTSTR pszVolume) {

   DWORD dwFileSystemFlags = 0;
   BOOL fOk = GetVolumeInformation(pszVolume, NULL, 0, NULL, NULL, 
      &dwFileSystemFlags, NULL, 0);
   fOk = fOk && AreFlagsSet(dwFileSystemFlags, FILE_SUPPORTS_SPARSE_FILES);
   return(fOk);
}


///////////////////////////////////////////////////////////////////////////////


inline BOOL CSparseStream::IsStreamSparse() const {

   BY_HANDLE_FILE_INFORMATION bhfi;
   GetFileInformationByHandle(m_hstream, &bhfi);
   return(AreFlagsSet(bhfi.dwFileAttributes, FILE_ATTRIBUTE_SPARSE_FILE));
}


///////////////////////////////////////////////////////////////////////////////


inline BOOL CSparseStream::MakeSparse() {

   DWORD dw;
   return(DeviceIoControl(m_hstream, FSCTL_SET_SPARSE, 
      NULL, 0, NULL, 0, &dw, NULL));
}


///////////////////////////////////////////////////////////////////////////////


inline BOOL CSparseStream::DecommitPortionOfStream(
   __int64 qwOffsetStart, __int64 qwOffsetEnd) {

   // NOTE: This function does not work if this file is memory-mapped.
   DWORD dw;
   FILE_ZERO_DATA_INFORMATION fzdi;
   fzdi.FileOffset.QuadPart = qwOffsetStart;
   fzdi.BeyondFinalZero.QuadPart = qwOffsetEnd + 1;
   return(DeviceIoControl(m_hstream, FSCTL_SET_ZERO_DATA, (PVOID) &fzdi, 
      sizeof(fzdi), NULL, 0, &dw, NULL));
}


///////////////////////////////////////////////////////////////////////////////


inline BOOL CSparseStream::DoesFileContainAnySparseStreams(
   PCTSTR pszPathname) {

   DWORD dw = GetFileAttributes(pszPathname);
   return((dw == 0xfffffff) 
      ? FALSE : AreFlagsSet(dw, FILE_ATTRIBUTE_SPARSE_FILE));
}


///////////////////////////////////////////////////////////////////////////////


inline FILE_ALLOCATED_RANGE_BUFFER* CSparseStream::QueryAllocatedRanges(
   PDWORD pdwNumEntries) {

   FILE_ALLOCATED_RANGE_BUFFER farb;
   farb.FileOffset.QuadPart = 0;
   farb.Length.LowPart = 
      GetFileSize(m_hstream, (PDWORD) &farb.Length.HighPart);

   // There is no way to determine the correct memory block size prior to 
   // attempting to collect this data, so I just picked 100 * sizeof(*pfarb)
   DWORD cb = 100 * sizeof(farb);
   FILE_ALLOCATED_RANGE_BUFFER* pfarb = (FILE_ALLOCATED_RANGE_BUFFER*) 
      HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, cb);

   DeviceIoControl(m_hstream, FSCTL_QUERY_ALLOCATED_RANGES,
      &farb, sizeof(farb), pfarb, cb, &cb, NULL);
   *pdwNumEntries = cb / sizeof(*pfarb);
   return(pfarb);
}


///////////////////////////////////////////////////////////////////////////////


inline BOOL CSparseStream::FreeAllocatedRanges(
   FILE_ALLOCATED_RANGE_BUFFER* pfarb) {

   // Free the queue entry's allocated memory
   return(HeapFree(GetProcessHeap(), 0, pfarb));
}


///////////////////////////////// End Of File /////////////////////////////////

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