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[RTL]

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Implemenet SwapSplayLinks, return 'NewElement' correctly when inserting.
Thanks to Alex Ionescu for helping out with this patch.

svn path=/trunk/; revision=53015
This commit is contained in:
Art Yerkes 2011-08-01 03:23:53 +00:00
parent f1f448e2ba
commit a90824eeae
2 changed files with 125 additions and 3 deletions
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4
reactos/lib/rtl/generictable.c
View file

@ -213,7 +213,7 @@ RtlInsertElementGenericTableFull(IN PRTL_GENERIC_TABLE Table,
Table->TableRoot = RtlSplay(NewNode);
/* Return status */
if (NewElement) *NewElement = (SearchResult == TableFoundNode);
if (NewElement) *NewElement = (SearchResult != TableFoundNode);
/* Return pointer to user data */
return &((PTABLE_ENTRY_HEADER)NewNode)->UserData;
@ -300,7 +300,7 @@ RtlDeleteElementGenericTable(IN PRTL_GENERIC_TABLE Table,
/* Get the splay links and table search result immediately */
Result = RtlpFindGenericTableNodeOrParent(Table, Buffer, &NodeOrParent);
if ((Result == TableEmptyTree) || (Result != TableFoundNode))
if (Result != TableFoundNode)
{
/* Nothing to delete */
return FALSE;

124
reactos/lib/rtl/splaytree.c
View file

@ -13,13 +13,134 @@
#define NDEBUG
#include <debug.h>
//#define VERIFY_SWAP_SPLAY_LINKS
/* FUNCTIONS ***************************************************************/
static
VOID
FixupChildLinks(PRTL_SPLAY_LINKS Links, BOOLEAN Root, BOOLEAN LeftChild)
{
if (RtlLeftChild(Links)) {
RtlInsertAsLeftChild(Links, RtlLeftChild(Links));
}
if (RtlRightChild(Links)) {
RtlInsertAsRightChild(Links, RtlRightChild(Links));
}
if (!Root) {
if (LeftChild) {
RtlInsertAsLeftChild(RtlParent(Links), Links);
} else {
RtlInsertAsRightChild(RtlParent(Links), Links);
}
}
}
/*
Given the tree:
D
B F
A C E G
Swap(Q,S):
Q S Q.P Q.L Q.R S.P S.L S.R
A C S.P S.L S.R Q.P Q.L Q.R
B A S S.L S.R Q.P Q Q.R
B C S S.L S.R Q.P Q.L Q
D A S.P S.L S.R S Q.L Q.R
D B S S.L S.R S Q Q.R
D F S S.L S.R S Q.L Q
When Q is the immediate parent of S,
Set Q's parent to S, and the proper child ptr of S to Q
When Q is the root,
Set S's parent to S
*/
static
VOID
SwapSplayLinks(PRTL_SPLAY_LINKS LinkA,
PRTL_SPLAY_LINKS LinkB)
{
DPRINT1("UNIMPLEMENTED!\n");
if (RtlParent(LinkA) == LinkB || RtlIsRoot(LinkB)) {
PRTL_SPLAY_LINKS Tmp = LinkA;
LinkA = LinkB;
LinkB = Tmp;
}
{
RTL_SPLAY_LINKS Ta = *LinkA, Tb = *LinkB;
BOOLEAN RootA = RtlIsRoot(LinkA),
LeftA = RtlIsLeftChild(LinkA),
LeftB = RtlIsLeftChild(LinkB);
*LinkB = Ta; *LinkA = Tb;
// A was parent of B is a special case: A->Parent is now B
if (RtlParent(&Tb) == LinkA) {
if (!RootA) {
if (LeftA) {
RtlInsertAsLeftChild(RtlParent(&Ta), LinkB);
} else {
RtlInsertAsRightChild(RtlParent(&Ta), LinkB);
}
}
if (LeftB) {
RtlInsertAsLeftChild(LinkB, LinkA);
} else {
RtlInsertAsRightChild(LinkB, LinkA);
}
}
FixupChildLinks(LinkA, FALSE, LeftB);
FixupChildLinks(LinkB, RootA, LeftA);
// A was root is a special case: B->Parent is now B
if (RootA)
RtlParent(LinkB) = LinkB;
#ifdef VERIFY_SWAP_SPLAY_LINKS
// Verify the distinct cases of node swap
if (RootA) {
if (RtlParent(&Tb) == LinkA) {
// LinkA = D, LinkB = B
// D B S S.L S.R S Q Q.R
ASSERT(RtlParent(LinkA) == LinkB);
ASSERT(RtlLeftChild(LinkA) == RtlLeftChild(&Tb));
ASSERT(RtlRightChild(LinkA) == RtlRightChild(&Tb));
ASSERT(RtlParent(LinkB) == LinkB);
ASSERT(RtlLeftChild(LinkB) == (LeftB ? LinkA : RtlLeftChild(&Ta)));
ASSERT(RtlRightChild(LinkB) == (LeftB ? RtlRightChild(&Ta) : LinkA));
} else {
// LinkA = D, LinkB = A
// D A S.P S.L S.R S Q.L Q.R
ASSERT(RtlParent(LinkA) == RtlParent(&Tb));
ASSERT(RtlLeftChild(LinkA) == RtlLeftChild(&Tb));
ASSERT(RtlRightChild(LinkA) == RtlRightChild(&Tb));
ASSERT(RtlParent(LinkB) == LinkB);
ASSERT(RtlLeftChild(LinkB) == RtlLeftChild(&Ta));
ASSERT(RtlRightChild(LinkB) == RtlRightChild(&Ta));
}
} else {
if (RtlParent(&Tb) == LinkA) {
// LinkA = B, LinkB = A
// B A S S.L S.R Q.P Q Q.R
ASSERT(RtlParent(LinkA) == LinkB);
ASSERT(RtlLeftChild(LinkA) == RtlLeftChild(&Tb));
ASSERT(RtlRightChild(LinkA) == RtlRightChild(&Tb));
ASSERT(RtlParent(LinkB) == RtlParent(&Ta));
ASSERT(RtlLeftChild(LinkB) == (LeftB ? LinkA : RtlLeftChild(&Ta)));
ASSERT(RtlRightChild(LinkB) == (LeftB ? RtlRightChild(&Ta) : LinkA));
} else {
// LinkA = A, LinkB = C
// A C S.P S.L S.R Q.P Q.L Q.R
ASSERT(!memcmp(LinkA, &Tb, sizeof(Tb)));
ASSERT(!memcmp(LinkB, &Ta, sizeof(Ta)));
}
}
#endif
}
}
/*
@ -513,6 +634,7 @@ RtlSplay(PRTL_SPLAY_LINKS Links)
}
/* Return the root entry */
ASSERT(RtlIsRoot(N));
return N;
}