+++ /dev/null
-/*
- * FreeLoader
- * Copyright (C) 1998-2003 Brian Palmer <brianp@sginet.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#include <freeldr.h>
-#include <debug.h>
-
-DBG_DEFAULT_CHANNEL(CACHE);
-
-// Returns a pointer to a CACHE_BLOCK structure
-// Adds the block to the cache manager block list
-// in cache memory if it isn't already there
-PCACHE_BLOCK CacheInternalGetBlockPointer(PCACHE_DRIVE CacheDrive, ULONG BlockNumber)
-{
- PCACHE_BLOCK CacheBlock = NULL;
-
- TRACE("CacheInternalGetBlockPointer() BlockNumber = %d\n", BlockNumber);
-
- CacheBlock = CacheInternalFindBlock(CacheDrive, BlockNumber);
-
- if (CacheBlock != NULL)
- {
- TRACE("Cache hit! BlockNumber: %d CacheBlock->BlockNumber: %d\n", BlockNumber, CacheBlock->BlockNumber);
-
- return CacheBlock;
- }
-
- TRACE("Cache miss! BlockNumber: %d\n", BlockNumber);
-
- CacheBlock = CacheInternalAddBlockToCache(CacheDrive, BlockNumber);
-
- // Optimize the block list so it has a LRU structure
- CacheInternalOptimizeBlockList(CacheDrive, CacheBlock);
-
- return CacheBlock;
-}
-
-PCACHE_BLOCK CacheInternalFindBlock(PCACHE_DRIVE CacheDrive, ULONG BlockNumber)
-{
- PCACHE_BLOCK CacheBlock = NULL;
-
- TRACE("CacheInternalFindBlock() BlockNumber = %d\n", BlockNumber);
-
- //
- // Make sure the block list has entries before I start searching it.
- //
- if (!IsListEmpty(&CacheDrive->CacheBlockHead))
- {
- //
- // Search the list and find the BIOS drive number
- //
- CacheBlock = CONTAINING_RECORD(CacheDrive->CacheBlockHead.Flink, CACHE_BLOCK, ListEntry);
-
- while (&CacheBlock->ListEntry != &CacheDrive->CacheBlockHead)
- {
- //
- // We found the block, so return it
- //
- if (CacheBlock->BlockNumber == BlockNumber)
- {
- //
- // Increment the blocks access count
- //
- CacheBlock->AccessCount++;
-
- return CacheBlock;
- }
-
- CacheBlock = CONTAINING_RECORD(CacheBlock->ListEntry.Flink, CACHE_BLOCK, ListEntry);
- }
- }
-
- return NULL;
-}
-
-PCACHE_BLOCK CacheInternalAddBlockToCache(PCACHE_DRIVE CacheDrive, ULONG BlockNumber)
-{
- PCACHE_BLOCK CacheBlock = NULL;
-
- TRACE("CacheInternalAddBlockToCache() BlockNumber = %d\n", BlockNumber);
-
- // Check the size of the cache so we don't exceed our limits
- CacheInternalCheckCacheSizeLimits(CacheDrive);
-
- // We will need to add the block to the
- // drive's list of cached blocks. So allocate
- // the block memory.
- CacheBlock = FrLdrTempAlloc(sizeof(CACHE_BLOCK), TAG_CACHE_BLOCK);
- if (CacheBlock == NULL)
- {
- return NULL;
- }
-
- // Now initialize the structure and
- // allocate room for the block data
- RtlZeroMemory(CacheBlock, sizeof(CACHE_BLOCK));
- CacheBlock->BlockNumber = BlockNumber;
- CacheBlock->BlockData = FrLdrTempAlloc(CacheDrive->BlockSize * CacheDrive->BytesPerSector,
- TAG_CACHE_DATA);
- if (CacheBlock->BlockData ==NULL)
- {
- FrLdrTempFree(CacheBlock, TAG_CACHE_BLOCK);
- return NULL;
- }
-
- // Now try to read in the block
- if (!MachDiskReadLogicalSectors(CacheDrive->DriveNumber, (BlockNumber * CacheDrive->BlockSize), CacheDrive->BlockSize, DiskReadBuffer))
- {
- FrLdrTempFree(CacheBlock->BlockData, TAG_CACHE_DATA);
- FrLdrTempFree(CacheBlock, TAG_CACHE_BLOCK);
- return NULL;
- }
- RtlCopyMemory(CacheBlock->BlockData, DiskReadBuffer, CacheDrive->BlockSize * CacheDrive->BytesPerSector);
-
- // Add it to our list of blocks managed by the cache
- InsertTailList(&CacheDrive->CacheBlockHead, &CacheBlock->ListEntry);
-
- // Update the cache data
- CacheBlockCount++;
- CacheSizeCurrent = CacheBlockCount * (CacheDrive->BlockSize * CacheDrive->BytesPerSector);
-
- CacheInternalDumpBlockList(CacheDrive);
-
- return CacheBlock;
-}
-
-BOOLEAN CacheInternalFreeBlock(PCACHE_DRIVE CacheDrive)
-{
- PCACHE_BLOCK CacheBlockToFree;
-
- TRACE("CacheInternalFreeBlock()\n");
-
- // Get a pointer to the last item in the block list
- // that isn't forced to be in the cache and remove
- // it from the list
- CacheBlockToFree = CONTAINING_RECORD(CacheDrive->CacheBlockHead.Blink, CACHE_BLOCK, ListEntry);
- while (&CacheBlockToFree->ListEntry != &CacheDrive->CacheBlockHead && CacheBlockToFree->LockedInCache)
- {
- CacheBlockToFree = CONTAINING_RECORD(CacheBlockToFree->ListEntry.Blink, CACHE_BLOCK, ListEntry);
- }
-
- // No blocks left in cache that can be freed
- // so just return
- if (IsListEmpty(&CacheDrive->CacheBlockHead))
- {
- return FALSE;
- }
-
- RemoveEntryList(&CacheBlockToFree->ListEntry);
-
- // Free the block memory and the block structure
- FrLdrTempFree(CacheBlockToFree->BlockData, TAG_CACHE_DATA);
- FrLdrTempFree(CacheBlockToFree, TAG_CACHE_BLOCK);
-
- // Update the cache data
- CacheBlockCount--;
- CacheSizeCurrent = CacheBlockCount * (CacheDrive->BlockSize * CacheDrive->BytesPerSector);
-
- return TRUE;
-}
-
-VOID CacheInternalCheckCacheSizeLimits(PCACHE_DRIVE CacheDrive)
-{
- SIZE_T NewCacheSize;
-
- TRACE("CacheInternalCheckCacheSizeLimits()\n");
-
- // Calculate the size of the cache if we added a block
- NewCacheSize = (CacheBlockCount + 1) * (CacheDrive->BlockSize * CacheDrive->BytesPerSector);
-
- // Check the new size against the cache size limit
- if (NewCacheSize > CacheSizeLimit)
- {
- CacheInternalFreeBlock(CacheDrive);
- CacheInternalDumpBlockList(CacheDrive);
- }
-}
-
-VOID CacheInternalDumpBlockList(PCACHE_DRIVE CacheDrive)
-{
- PCACHE_BLOCK CacheBlock;
-
- TRACE("Dumping block list for BIOS drive 0x%x.\n", CacheDrive->DriveNumber);
- TRACE("BytesPerSector: %d.\n", CacheDrive->BytesPerSector);
- TRACE("BlockSize: %d.\n", CacheDrive->BlockSize);
- TRACE("CacheSizeLimit: %d.\n", CacheSizeLimit);
- TRACE("CacheSizeCurrent: %d.\n", CacheSizeCurrent);
- TRACE("CacheBlockCount: %d.\n", CacheBlockCount);
-
- CacheBlock = CONTAINING_RECORD(CacheDrive->CacheBlockHead.Flink, CACHE_BLOCK, ListEntry);
- while (&CacheBlock->ListEntry != &CacheDrive->CacheBlockHead)
- {
- TRACE("Cache Block: CacheBlock: 0x%x\n", CacheBlock);
- TRACE("Cache Block: Block Number: %d\n", CacheBlock->BlockNumber);
- TRACE("Cache Block: Access Count: %d\n", CacheBlock->AccessCount);
- TRACE("Cache Block: Block Data: 0x%x\n", CacheBlock->BlockData);
- TRACE("Cache Block: Locked In Cache: %d\n", CacheBlock->LockedInCache);
-
- if (CacheBlock->BlockData == NULL)
- {
- BugCheck("CacheBlock->BlockData == NULL\n");
- }
-
- CacheBlock = CONTAINING_RECORD(CacheBlock->ListEntry.Flink, CACHE_BLOCK, ListEntry);
- }
-}
-
-VOID CacheInternalOptimizeBlockList(PCACHE_DRIVE CacheDrive, PCACHE_BLOCK CacheBlock)
-{
-
- TRACE("CacheInternalOptimizeBlockList()\n");
-
- // Don't do this if this block is already at the head of the list
- if (&CacheBlock->ListEntry != CacheDrive->CacheBlockHead.Flink)
- {
- // Remove this item from the block list
- RemoveEntryList(&CacheBlock->ListEntry);
-
- // Re-insert it at the head of the list
- InsertHeadList(&CacheDrive->CacheBlockHead, &CacheBlock->ListEntry);
- }
-}
projects / reactos.git / blobdiff