BaseTools: Library hashing fix and optimization for --hash feature

[mirror_edk2.git] / FatPkg / EnhancedFatDxe / DirectoryCache.c

/** @file\r
  Functions for directory cache operation.\r
\r
Copyright (c) 2005, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
\r
**/\r
\r
#include "Fat.h"\r
\r
/**\r
\r
  Free the directory structure and release the memory.\r
\r
  @param  ODir                  - The directory to be freed.\r
\r
**/\r
STATIC\r
VOID\r
FatFreeODir (\r
  IN FAT_ODIR    *ODir\r
  )\r
{\r
  FAT_DIRENT  *DirEnt;\r
\r
  //\r
  // Release Directory Entry Nodes\r
  //\r
  while (!IsListEmpty (&ODir->ChildList)) {\r
    DirEnt = DIRENT_FROM_LINK (ODir->ChildList.ForwardLink);\r
    RemoveEntryList (&DirEnt->Link);\r
    //\r
    // Make sure the OFile has been closed\r
    //\r
    ASSERT (DirEnt->OFile == NULL);\r
    FatFreeDirEnt (DirEnt);\r
  }\r
\r
  FreePool (ODir);\r
}\r
\r
/**\r
\r
  Allocate the directory structure.\r
\r
  @param  OFile                   - The corresponding OFile.\r
\r
**/\r
STATIC\r
FAT_ODIR *\r
FatAllocateODir (\r
  IN FAT_OFILE   *OFile\r
  )\r
{\r
  FAT_ODIR  *ODir;\r
\r
  ODir = AllocateZeroPool (sizeof (FAT_ODIR));\r
  if (ODir != NULL) {\r
    //\r
    // Initialize the directory entry list\r
    //\r
    ODir->Signature = FAT_ODIR_SIGNATURE;\r
    InitializeListHead (&ODir->ChildList);\r
    ODir->CurrentCursor = &ODir->ChildList;\r
  }\r
\r
  return ODir;\r
}\r
\r
/**\r
\r
  Discard the directory structure when an OFile will be freed.\r
  Volume will cache this directory if the OFile does not represent a deleted file.\r
\r
  @param  OFile                 - The OFile whose directory structure is to be discarded.\r
\r
**/\r
VOID\r
FatDiscardODir (\r
  IN FAT_OFILE    *OFile\r
  )\r
{\r
  FAT_ODIR    *ODir;\r
  FAT_VOLUME  *Volume;\r
\r
  Volume  = OFile->Volume;\r
  ODir    = OFile->ODir;\r
  if (!OFile->DirEnt->Invalid) {\r
    //\r
    // If OFile does not represent a deleted file, then we will cache the directory\r
    // We use OFile's first cluster as the directory's tag\r
    //\r
    ODir->DirCacheTag = OFile->FileCluster;\r
    InsertHeadList (&Volume->DirCacheList, &ODir->DirCacheLink);\r
    if (Volume->DirCacheCount == FAT_MAX_DIR_CACHE_COUNT) {\r
      //\r
      // Replace the least recent used directory\r
      //\r
      ODir = ODIR_FROM_DIRCACHELINK (Volume->DirCacheList.BackLink);\r
      RemoveEntryList (&ODir->DirCacheLink);\r
    } else {\r
      //\r
      // No need to find a replace\r
      //\r
      Volume->DirCacheCount++;\r
      ODir = NULL;\r
    }\r
  }\r
  //\r
  // Release ODir Structure\r
  //\r
  if (ODir != NULL) {\r
    FatFreeODir (ODir);\r
  }\r
}\r
\r
/**\r
\r
\r
  Request the directory structure when an OFile is newly generated.\r
  If the directory structure is cached by volume, then just return this directory;\r
  Otherwise, allocate a new one for OFile.\r
\r
  @param  OFile                 - The OFile which requests directory structure.\r
\r
**/\r
VOID\r
FatRequestODir (\r
  IN FAT_OFILE    *OFile\r
  )\r
{\r
  UINTN           DirCacheTag;\r
  FAT_VOLUME      *Volume;\r
  FAT_ODIR        *ODir;\r
  FAT_ODIR        *CurrentODir;\r
  LIST_ENTRY      *CurrentODirLink;\r
\r
  Volume      = OFile->Volume;\r
  ODir        = NULL;\r
  DirCacheTag = OFile->FileCluster;\r
  for (CurrentODirLink  = Volume->DirCacheList.ForwardLink;\r
       CurrentODirLink != &Volume->DirCacheList;\r
       CurrentODirLink  = CurrentODirLink->ForwardLink\r
      ) {\r
    CurrentODir = ODIR_FROM_DIRCACHELINK (CurrentODirLink);\r
    if (CurrentODir->DirCacheTag == DirCacheTag) {\r
      RemoveEntryList (&CurrentODir->DirCacheLink);\r
      Volume->DirCacheCount--;\r
      ODir = CurrentODir;\r
      break;\r
    }\r
  }\r
\r
  if (ODir == NULL) {\r
    //\r
    // This directory is not cached, then allocate a new one\r
    //\r
    ODir = FatAllocateODir (OFile);\r
  }\r
\r
  OFile->ODir = ODir;\r
}\r
\r
/**\r
\r
  Clean up all the cached directory structures when the volume is going to be abandoned.\r
\r
  @param  Volume                - FAT file system volume.\r
\r
**/\r
VOID\r
FatCleanupODirCache (\r
  IN FAT_VOLUME         *Volume\r
  )\r
{\r
  FAT_ODIR  *ODir;\r
  while (Volume->DirCacheCount > 0) {\r
    ODir = ODIR_FROM_DIRCACHELINK (Volume->DirCacheList.BackLink);\r
    RemoveEntryList (&ODir->DirCacheLink);\r
    FatFreeODir (ODir);\r
    Volume->DirCacheCount--;\r
  }\r
}\r