mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-25 16:37:42 +01:00
d7c710f9e3
Signed-off-by: SergeySlice <sergey.slice@gmail.com>
235 lines
4.5 KiB
C
235 lines
4.5 KiB
C
/*++
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Copyright (c) 2005, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the Software
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License Agreement which accompanies this distribution.
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Module Name:
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DirectoryCache.c
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Abstract:
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Functions for directory cache operation
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Revision History
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--*/
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#include "Fat.h"
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STATIC
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VOID
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FatFreeODir (
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IN FAT_ODIR *ODir
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)
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/*++
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Routine Description:
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Free the directory structure and release the memory.
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Arguments:
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ODir - The directory to be freed.
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Returns:
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None.
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--*/
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{
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FAT_DIRENT *DirEnt;
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//
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// Release Directory Entry Nodes
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//
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while (!IsListEmpty (&ODir->ChildList)) {
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DirEnt = DIRENT_FROM_LINK (ODir->ChildList.ForwardLink);
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RemoveEntryList (&DirEnt->Link);
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//
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// Make sure the OFile has been closed
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//
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ASSERT (DirEnt->OFile == NULL);
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FatFreeDirEnt (DirEnt);
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}
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FreePool(ODir);
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}
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STATIC
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FAT_ODIR *
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FatAllocateODir (
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IN FAT_OFILE *OFile
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)
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/*++
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Routine Description:
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Allocate the directory structure.
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Arguments:
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OFile - The corresponding OFile.
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Returns:
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None.
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--*/
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{
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FAT_ODIR *ODir;
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ODir = AllocateZeroPool(sizeof (FAT_ODIR));
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if (ODir != NULL) {
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//
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// Initialize the directory entry list
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//
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ODir->Signature = FAT_ODIR_SIGNATURE;
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InitializeListHead (&ODir->ChildList);
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ODir->CurrentCursor = &ODir->ChildList;
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}
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return ODir;
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}
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VOID
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FatDiscardODir (
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IN FAT_OFILE *OFile
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)
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/*++
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Routine Description:
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Discard the directory structure when an OFile will be freed.
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Volume will cache this directory if the OFile does not represent a deleted file.
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Arguments:
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OFile - The OFile whose directory structure is to be discarded.
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Returns:
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None.
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--*/
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{
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FAT_ODIR *ODir;
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FAT_VOLUME *Volume;
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Volume = OFile->Volume;
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ODir = OFile->ODir;
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if (!OFile->DirEnt->Invalid) {
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//
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// If OFile does not represent a deleted file, then we will cache the directory
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// We use OFile's first cluster as the directory's tag
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//
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ODir->DirCacheTag = OFile->FileCluster;
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InsertHeadList (&Volume->DirCacheList, &ODir->DirCacheLink);
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if (Volume->DirCacheCount == FAT_MAX_DIR_CACHE_COUNT) {
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//
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// Replace the least recent used directory
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//
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ODir = ODIR_FROM_DIRCACHELINK (Volume->DirCacheList.BackLink);
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RemoveEntryList (&ODir->DirCacheLink);
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} else {
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//
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// No need to find a replace
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//
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Volume->DirCacheCount++;
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ODir = NULL;
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}
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}
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//
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// Release ODir Structure
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//
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if (ODir != NULL) {
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FatFreeODir (ODir);
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}
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}
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VOID
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FatRequestODir (
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IN FAT_OFILE *OFile
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)
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/*++
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Routine Description:
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Request the directory structure when an OFile is newly generated.
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If the directory structure is cached by volume, then just return this directory;
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Otherwise, allocate a new one for OFile.
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Arguments:
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OFile - The OFile which requests directory structure.
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Returns:
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None.
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--*/
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{
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UINTN DirCacheTag;
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FAT_VOLUME *Volume;
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FAT_ODIR *ODir;
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FAT_ODIR *CurrentODir;
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LIST_ENTRY *CurrentODirLink;
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Volume = OFile->Volume;
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ODir = NULL;
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DirCacheTag = OFile->FileCluster;
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for (CurrentODirLink = Volume->DirCacheList.ForwardLink;
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CurrentODirLink != &Volume->DirCacheList;
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CurrentODirLink = CurrentODirLink->ForwardLink
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) {
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CurrentODir = ODIR_FROM_DIRCACHELINK (CurrentODirLink);
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if (CurrentODir->DirCacheTag == DirCacheTag) {
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RemoveEntryList (&CurrentODir->DirCacheLink);
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Volume->DirCacheCount--;
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ODir = CurrentODir;
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break;
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}
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}
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if (ODir == NULL) {
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//
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// This directory is not cached, then allocate a new one
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//
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ODir = FatAllocateODir (OFile);
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}
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OFile->ODir = ODir;
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}
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VOID
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FatCleanupODirCache (
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IN FAT_VOLUME *Volume
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)
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/*++
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Routine Description:
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Clean up all the cached directory structures when the volume is going to be abandoned.
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Arguments:
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Volume - FAT file system volume.
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Returns:
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None.
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--*/
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{
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FAT_ODIR *ODir;
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while (Volume->DirCacheCount > 0) {
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ODir = ODIR_FROM_DIRCACHELINK (Volume->DirCacheList.BackLink);
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RemoveEntryList (&ODir->DirCacheLink);
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FatFreeODir (ODir);
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Volume->DirCacheCount--;
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}
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}
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