Author: tkreuzer
Date: Mon Oct 3 23:35:27 2011
New Revision: 53983
URL: http://svn.reactos.org/svn/reactos?rev=53983&view=rev
Log:
[FREELDR]
Implement directory buffer caching for FAT
Modified:
trunk/reactos/boot/freeldr/freeldr/fs/fat.c
Modified: trunk/reactos/boot/freeldr/freeldr/fs/fat.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/fs/fat.c?rev=53983&r1=53982&r2=53983&view=diff
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/fs/fat.c [iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/freeldr/fs/fat.c [iso-8859-1] Mon Oct 3
23:35:27 2011
@@ -370,9 +370,21 @@
}
}
+typedef struct _DIRECTORY_BUFFER
+{
+ LIST_ENTRY Link;
+ PVOID Volume;
+ ULONG DirectoryStartCluster;
+ ULONG DirectorySize;
+ UCHAR Data[];
+} DIRECTORY_BUFFER, *PDIRECTORY_BUFFER;
+
+LIST_ENTRY DirectoryBufferListHead = {&DirectoryBufferListHead,
&DirectoryBufferListHead};
+
PVOID FatBufferDirectory(PFAT_VOLUME_INFO Volume, ULONG DirectoryStartCluster,
ULONG *DirectorySize, BOOLEAN RootDirectory)
{
- PVOID DirectoryBuffer;
+ PDIRECTORY_BUFFER DirectoryBuffer;
+ PLIST_ENTRY Entry;
TRACE("FatBufferDirectory() DirectoryStartCluster = %d RootDirectory =
%s\n", DirectoryStartCluster, (RootDirectory ? "TRUE" : "FALSE"));
@@ -386,6 +398,23 @@
RootDirectory = FALSE;
}
+ /* Search the list for a match */
+ for (Entry = DirectoryBufferListHead.Flink;
+ Entry != &DirectoryBufferListHead;
+ Entry = Entry->Flink)
+ {
+ DirectoryBuffer = CONTAINING_RECORD(Entry, DIRECTORY_BUFFER,
Link);
+
+ /* Check if it matches */
+ if ((DirectoryBuffer->Volume == Volume) &&
+ (DirectoryBuffer->DirectoryStartCluster ==
DirectoryStartCluster))
+ {
+ TRACE("Found cached buffer\n");
+ *DirectorySize = DirectoryBuffer->DirectorySize;
+ return DirectoryBuffer->Data;
+ }
+ }
+
//
// Calculate the size of the directory
//
@@ -402,7 +431,7 @@
// Attempt to allocate memory for directory buffer
//
TRACE("Trying to allocate (DirectorySize) %d bytes.\n", *DirectorySize);
- DirectoryBuffer = MmHeapAlloc(*DirectorySize);
+ DirectoryBuffer = MmHeapAlloc(*DirectorySize +
sizeof(DIRECTORY_BUFFER));
if (DirectoryBuffer == NULL)
{
@@ -414,7 +443,7 @@
//
if (RootDirectory)
{
- if (!FatReadVolumeSectors(Volume, Volume->RootDirSectorStart,
Volume->RootDirSectors, DirectoryBuffer))
+ if (!FatReadVolumeSectors(Volume, Volume->RootDirSectorStart,
Volume->RootDirSectors, DirectoryBuffer->Data))
{
MmHeapFree(DirectoryBuffer);
return NULL;
@@ -422,14 +451,20 @@
}
else
{
- if (!FatReadClusterChain(Volume, DirectoryStartCluster,
0xFFFFFFFF, DirectoryBuffer))
+ if (!FatReadClusterChain(Volume, DirectoryStartCluster,
0xFFFFFFFF, DirectoryBuffer->Data))
{
MmHeapFree(DirectoryBuffer);
return NULL;
}
}
- return DirectoryBuffer;
+ /* Enqueue it in the list */
+ DirectoryBuffer->Volume = Volume;
+ DirectoryBuffer->DirectoryStartCluster = DirectoryStartCluster;
+ DirectoryBuffer->DirectorySize = *DirectorySize;
+ InsertTailList(&DirectoryBufferListHead, &DirectoryBuffer->Link);
+
+ return DirectoryBuffer->Data;
}
BOOLEAN FatSearchDirectoryBufferForFile(PFAT_VOLUME_INFO Volume, PVOID
DirectoryBuffer, ULONG DirectorySize, PCHAR FileName, PFAT_FILE_INFO
FatFileInfoPointer)
@@ -774,7 +809,6 @@
{
if (!FatXSearchDirectoryBufferForFile(Volume,
DirectoryBuffer, DirectorySize, PathPart, &FatFileInfo))
{
- MmHeapFree(DirectoryBuffer);
return ENOENT;
}
}
@@ -782,12 +816,9 @@
{
if (!FatSearchDirectoryBufferForFile(Volume,
DirectoryBuffer, DirectorySize, PathPart, &FatFileInfo))
{
- MmHeapFree(DirectoryBuffer);
return ENOENT;
}
}
-
- MmHeapFree(DirectoryBuffer);
//
// If we have another sub-directory to go then
