[fireball] 31280: - Add shared->Exclusive promotion support to value cache routines as well. - Implement CmpCompareNewValueDataAgainstKCBCache as an optimization during Set Value Key operations, so that if the value is already identical, it will not be written again.
Author: fireball Date: Sun Dec 16 18:41:48 2007 New Revision: 31280
URL: http://svn.reactos.org/svn/reactos?rev=31280&view=rev Log: - Add shared->Exclusive promotion support to value cache routines as well. - Implement CmpCompareNewValueDataAgainstKCBCache as an optimization during Set Value Key operations, so that if the value is already identical, it will not be written again.
Modified: trunk/reactos/ntoskrnl/config/cmapi.c trunk/reactos/ntoskrnl/config/cmvalche.c
Modified: trunk/reactos/ntoskrnl/config/cmapi.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/config/cmapi.c?rev... ============================================================================== --- trunk/reactos/ntoskrnl/config/cmapi.c (original) +++ trunk/reactos/ntoskrnl/config/cmapi.c Sun Dec 16 18:41:48 2007 @@ -296,7 +296,11 @@ }
/* Search for the value */ - SearchResult = SearchFail; + SearchResult = CmpCompareNewValueDataAgainstKCBCache(Kcb, + ValueName, + Type, + Data, + DataLength); if (SearchResult == SearchNeedExclusiveLock) { /* Try again with the exclusive lock */
Modified: trunk/reactos/ntoskrnl/config/cmvalche.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/config/cmvalche.c?... ============================================================================== --- trunk/reactos/ntoskrnl/config/cmvalche.c (original) +++ trunk/reactos/ntoskrnl/config/cmvalche.c Sun Dec 16 18:41:48 2007 @@ -55,12 +55,10 @@ *ValueListToRelease = HCELL_NIL; *IndexIsCached = FALSE;
- /* Get the hive */ + /* Get the hive and value ceche */ Hive = Kcb->KeyHive; + ChildList = &Kcb->ValueCache; KeyNode = (PCM_KEY_NODE)HvGetCell(Hive, Kcb->KeyCell); - - /* Get the child value cache */ - //ChildList = &Kcb->ValueCache; ChildList = (PCACHED_CHILD_LIST)&KeyNode->ValueList;
/* Check if the value is cached */ @@ -73,10 +71,20 @@ } else { + /* Make sure the KCB is locked exclusive */ + if (!(CmpIsKcbLockedExclusive(Kcb)) && + !(CmpTryToConvertKcbSharedToExclusive(Kcb))) + { + /* We need the exclusive lock */ + return SearchNeedExclusiveLock; + } + /* Select the value list as our cell, and get the actual list array */ CellToRelease = ChildList->ValueList; *CellData = (PCELL_DATA)HvGetCell(Hive, CellToRelease); if (!(*CellData)) return SearchFail; + + /* FIXME: Here we would cache the value */
/* Return the cell to be released */ *ValueListToRelease = CellToRelease; @@ -210,12 +218,10 @@ *CellToRelease = HCELL_NIL; *Value = NULL;
- /* Get the hive */ + /* Get the hive and child list */ Hive = Kcb->KeyHive; + ChildList = &Kcb->ValueCache; KeyNode = (PCM_KEY_NODE)HvGetCell(Hive, Kcb->KeyCell); - - /* Get the child value cache */ - //ChildList = &Kcb->ValueCache; ChildList = (PCACHED_CHILD_LIST)&KeyNode->ValueList;
/* Check if the child list has any entries */ @@ -226,7 +232,13 @@ &CellData, &IndexIsCached, &Cell); - if (SearchResult != SearchSuccess) return SearchResult; + if (SearchResult != SearchSuccess) + { + /* We either failed or need the exclusive lock */ + ASSERT((SearchResult == SearchFail) || !(CmpIsKcbLockedExclusive(Kcb))); + ASSERT(Cell == HCELL_NIL); + return SearchResult; + }
/* The index shouldn't be cached right now */ if (IndexIsCached) ASSERT_VALUE_CACHE(); @@ -251,7 +263,13 @@ IndexIsCached, ValueIsCached, CellToRelease); - if (SearchResult != SearchSuccess) return SearchResult; + if (SearchResult != SearchSuccess) + { + /* We either failed or need the exclusive lock */ + ASSERT((SearchResult == SearchFail) || !(CmpIsKcbLockedExclusive(Kcb))); + ASSERT(Cell == HCELL_NIL); + return SearchResult; + }
/* Check if the both the index and the value are cached */ if ((IndexIsCached) && (*ValueIsCached)) @@ -647,3 +665,143 @@ /* Return the search result as well */ return Result; } + +VALUE_SEARCH_RETURN_TYPE +NTAPI +CmpCompareNewValueDataAgainstKCBCache(IN PCM_KEY_CONTROL_BLOCK Kcb, + IN PUNICODE_STRING ValueName, + IN ULONG Type, + IN PVOID Data, + IN ULONG DataSize) +{ + VALUE_SEARCH_RETURN_TYPE SearchResult; + PCM_KEY_NODE KeyNode; + PCM_CACHED_VALUE *CachedValue; + ULONG Index; + PCM_KEY_VALUE Value; + BOOLEAN ValueCached, BufferAllocated = FALSE; + PVOID Buffer; + HCELL_INDEX ValueCellToRelease = HCELL_NIL, CellToRelease = HCELL_NIL; + BOOLEAN IsSmall; + ULONG CompareResult; + PAGED_CODE(); + + /* Check if this is a symlink */ + if (Kcb->Flags & KEY_SYM_LINK) + { + /* We need the exclusive lock */ + if (!(CmpIsKcbLockedExclusive(Kcb)) && + !(CmpTryToConvertKcbSharedToExclusive(Kcb))) + { + /* We need the exclusive lock */ + return SearchNeedExclusiveLock; + } + + /* Otherwise, get the key node */ + KeyNode = (PCM_KEY_NODE)HvGetCell(Kcb->KeyHive, Kcb->KeyCell); + if (!KeyNode) return SearchFail; + + /* Cleanup the KCB cache */ + CmpCleanUpKcbValueCache(Kcb); + + /* Sanity checks */ + ASSERT(!(CMP_IS_CELL_CACHED(Kcb->ValueCache.ValueList))); + ASSERT(!(Kcb->ExtFlags & CM_KCB_SYM_LINK_FOUND)); + + /* Set the value cache */ + Kcb->ValueCache.Count = KeyNode->ValueList.Count; + Kcb->ValueCache.ValueList = KeyNode->ValueList.List; + + /* Release the cell */ + HvReleaseCell(Kcb->KeyHive, Kcb->KeyCell); + } + + /* Do the search */ + SearchResult = CmpFindValueByNameFromCache(Kcb, + ValueName, + &CachedValue, + &Index, + &Value, + &ValueCached, + &ValueCellToRelease); + if (SearchResult == SearchNeedExclusiveLock) + { + /* We need the exclusive lock */ + ASSERT(!CmpIsKcbLockedExclusive(Kcb)); + ASSERT(ValueCellToRelease == HCELL_NIL); + ASSERT(Value == NULL); + goto Quickie; + } + else if (SearchResult == SearchSuccess) + { + /* Sanity check */ + ASSERT(Value); + + /* First of all, check if the key size and type matches */ + if ((Type == Value->Type) && + (DataSize == (Value->DataLength & ~CM_KEY_VALUE_SPECIAL_SIZE))) + { + /* Check if this is a small key */ + IsSmall = (DataSize <= CM_KEY_VALUE_SMALL) ? TRUE: FALSE; + if (IsSmall) + { + /* Compare against the data directly */ + Buffer = &Value->Data; + } + else + { + /* Do a search */ + SearchResult = CmpGetValueDataFromCache(Kcb, + CachedValue, + (PCELL_DATA)Value, + ValueCached, + &Buffer, + &BufferAllocated, + &CellToRelease); + if (SearchResult != SearchSuccess) + { + /* Sanity checks */ + ASSERT(Buffer == NULL); + ASSERT(BufferAllocated == FALSE); + goto Quickie; + } + } + + /* Now check the data size */ + if (DataSize) + { + /* Do the compare */ + CompareResult = RtlCompareMemory(Buffer, + Data, + DataSize & + ~CM_KEY_VALUE_SPECIAL_SIZE); + } + else + { + /* It's equal */ + CompareResult = 0; + } + + /* Now check if the compare wasn't equal */ + if (CompareResult != DataSize) SearchResult = SearchFail; + } + else + { + /* The length or type isn't equal */ + SearchResult = SearchFail; + } + } + +Quickie: + /* Release the value cell */ + if (ValueCellToRelease) HvReleaseCell(Kcb->KeyHive, ValueCellToRelease); + + /* Free the buffer */ + if (BufferAllocated) ExFreePool(Buffer); + + /* Free the cell */ + if (CellToRelease) HvReleaseCell(Kcb->KeyHive, CellToRelease); + + /* Return the search result */ + return SearchResult; +}
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