reactos/reactos/drivers/fs/vfat/direntry.c

/* $Id: direntry.c,v 1.9 2002/10/01 19:27:17 chorns Exp $
 *
 *
 * FILE:             DirEntry.c
 * PURPOSE:          Routines to manipulate directory entries.
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * PROGRAMMER:       Jason Filby (jasonfilby@yahoo.com)
 *                   Rex Jolliff (rex@lvcablemodem.com)
 */

/*  -------------------------------------------------------  INCLUDES  */

#include <ddk/ntddk.h>
#include <wchar.h>
#include <limits.h>

#define NDEBUG
#include <debug.h>

#include "vfat.h"

#define  CACHEPAGESIZE(pDeviceExt) ((pDeviceExt)->FatInfo.BytesPerCluster > PAGE_SIZE ? \
		   (pDeviceExt)->FatInfo.BytesPerCluster : PAGE_SIZE)

#define  ENTRIES_PER_CACHEPAGE(pDeviceExt)  (ENTRIES_PER_SECTOR * \
		   (CACHEPAGESIZE(pDeviceExt) / ((pDeviceExt)->FatInfo.BytesPerSector)))


ULONG 
vfatDirEntryGetFirstCluster (PDEVICE_EXTENSION  pDeviceExt,
                             PFAT_DIR_ENTRY  pFatDirEntry)
{
  ULONG  cluster;

  if (pDeviceExt->FatInfo.FatType == FAT32)
  {
    cluster = pFatDirEntry->FirstCluster + 
      pFatDirEntry->FirstClusterHigh * 65536;
  }
  else
  {
    cluster = pFatDirEntry->FirstCluster;
  }

  return  cluster;
}

BOOL
vfatIsDirEntryDeleted (FATDirEntry * pFatDirEntry)
{
  return  pFatDirEntry->Filename [0] == 0xe5;
}

BOOL
vfatIsDirEntryEndMarker (FATDirEntry * pFatDirEntry)
{
  return  pFatDirEntry->Filename [0] == 0;
}

BOOL
vfatIsDirEntryLongName (FATDirEntry * pFatDirEntry)
{
  return  pFatDirEntry->Attrib == 0x0f;
}

BOOL
vfatIsDirEntryVolume (FATDirEntry * pFatDirEntry)
{
  return pFatDirEntry->Attrib == 0x28;
}

void
vfatGetDirEntryName (PFAT_DIR_ENTRY  dirEntry,  PWSTR  entryName)
{
  vfat8Dot3ToString (dirEntry->Filename, dirEntry->Ext, entryName);
}

NTSTATUS
vfatGetNextDirEntry (PDEVICE_EXTENSION  pDeviceExt,
                     PVFATFCB  pDirectoryFCB,
                     ULONG * pDirectoryIndex,
                     PWSTR pLongFileName,
                     PFAT_DIR_ENTRY pDirEntry)
{
  ULONG  indexInPage = *pDirectoryIndex % ENTRIES_PER_CACHEPAGE(pDeviceExt);
  ULONG  pageNumber = *pDirectoryIndex / ENTRIES_PER_CACHEPAGE(pDeviceExt);
  PVOID  currentPage = NULL;
  FATDirEntry * fatDirEntry;
  slot * longNameEntry;
  ULONG  cpos;
  LARGE_INTEGER FileOffset;
  PVOID Context;

  DPRINT ("vfatGetNextDirEntry (%x,%x,%d,%x,%x)\n",
          pDeviceExt,
          pDirectoryFCB,
          *pDirectoryIndex,
          pLongFileName,
          pDirEntry);

  *pLongFileName = 0;

  FileOffset.QuadPart = pageNumber * CACHEPAGESIZE(pDeviceExt);
  if (!CcMapData(pDirectoryFCB->FileObject, &FileOffset, 
         CACHEPAGESIZE(pDeviceExt), TRUE, &Context, &currentPage))
  {
    return STATUS_UNSUCCESSFUL;
  }

  while (TRUE)
  {
    fatDirEntry = (FATDirEntry *) currentPage;

    if (vfatIsDirEntryEndMarker (&fatDirEntry [indexInPage]))
    {
      DPRINT ("end of directory, returning no more entries\n");
      CcUnpinData(Context);
      return  STATUS_NO_MORE_ENTRIES;
    }
    else if (vfatIsDirEntryLongName (&fatDirEntry [indexInPage])
      && !vfatIsDirEntryDeleted (&fatDirEntry [indexInPage]))
    {
      DPRINT ("  long name entry found at %d\n", *pDirectoryIndex);
      longNameEntry = (slot *) currentPage;

      DPRINT ("  name chunk1:[%.*S] chunk2:[%.*S] chunk3:[%.*S]\n",
              5, longNameEntry [indexInPage].name0_4,
              6, longNameEntry [indexInPage].name5_10,
              2, longNameEntry [indexInPage].name11_12);

      vfat_initstr (pLongFileName, 256);
      vfat_wcsncpy (pLongFileName, longNameEntry [indexInPage].name0_4, 5);
      vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name5_10, 5, 6);
      vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name11_12, 11, 2);

      DPRINT ("  longName: [%S]\n", pLongFileName);

      cpos = 0;
      while ((longNameEntry [indexInPage].id != 0x41) &&
             (longNameEntry [indexInPage].id != 0x01) &&
             (longNameEntry [indexInPage].attr > 0))
      {
        (*pDirectoryIndex)++;
        indexInPage++;
        if (indexInPage == ENTRIES_PER_CACHEPAGE(pDeviceExt))
        {
          indexInPage = 0;
          pageNumber++;

          CcUnpinData(Context);
          FileOffset.QuadPart = pageNumber * CACHEPAGESIZE(pDeviceExt);
          if (!CcMapData(pDirectoryFCB->FileObject, &FileOffset, 
                 CACHEPAGESIZE(pDeviceExt), TRUE, &Context, &currentPage))
          {
            return  STATUS_UNSUCCESSFUL;
          }
          longNameEntry = (slot *) currentPage;
        }
        DPRINT ("  index %d\n", *pDirectoryIndex);

        DPRINT ("  name chunk1:[%.*S] chunk2:[%.*S] chunk3:[%.*S]\n",
                5, longNameEntry [indexInPage].name0_4,
                6, longNameEntry [indexInPage].name5_10,
                2, longNameEntry [indexInPage].name11_12);

        cpos++;
        vfat_movstr (pLongFileName, 13, 0, cpos * 13);
        vfat_wcsncpy (pLongFileName, longNameEntry [indexInPage].name0_4, 5);
        vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name5_10, 5, 6);
        vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name11_12, 11, 2);

        DPRINT ("  longName: [%S]\n", pLongFileName);

      }
      (*pDirectoryIndex)++;
      indexInPage++;
      if (indexInPage == ENTRIES_PER_CACHEPAGE(pDeviceExt))
      {
        indexInPage = 0;
        pageNumber++;

        CcUnpinData(Context);
        FileOffset.QuadPart = pageNumber * CACHEPAGESIZE(pDeviceExt);
        if (!CcMapData(pDirectoryFCB->FileObject, &FileOffset, 
               CACHEPAGESIZE(pDeviceExt), TRUE, &Context, &currentPage))
         {
          return STATUS_UNSUCCESSFUL;
        }
      }
    }
    else
    {
      memcpy (pDirEntry, &fatDirEntry [indexInPage], sizeof (FAT_DIR_ENTRY));
      (*pDirectoryIndex)++;
      break;
    }
  }
  CcUnpinData(Context);
  return STATUS_SUCCESS;
}