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Commit 954dcec2 authored by Warren Dukes's avatar Warren Dukes
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tree optimization: reduce the number of compares required for insertion and…

tree optimization: reduce the number of compares required for insertion and deletion by storing the position in the parent node of each child git-svn-id: https://svn.musicpd.org/mpd/trunk@4532 09075e82-0dd4-0310-85a5-a0d7c8717e4f
parent 682fe8ce
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Showing with 103 additions and 101 deletions
src/tree.c
View file @ 954dcec2
...@@ -28,7 +28,7 @@ ...@@ -28,7 +28,7 @@
#define DATA_PER_NODE (CHILDREN_PER_NODE-1) #define DATA_PER_NODE (CHILDREN_PER_NODE-1)
#if CHILDREN_PER_NODE > 11 #if CHILDREN_PER_NODE > 7
#define USE_BINARY_SEARCH 1 #define USE_BINARY_SEARCH 1
#endif #endif
...@@ -39,8 +39,9 @@ struct _TreeNode ...@@ -39,8 +39,9 @@ struct _TreeNode
{ {
void * data[DATA_PER_NODE]; void * data[DATA_PER_NODE];
struct _TreeNode * parent; struct _TreeNode * parent;
short parentPos;
struct _TreeNode * children[CHILDREN_PER_NODE]; struct _TreeNode * children[CHILDREN_PER_NODE];
int dataCount; short dataCount;
}; };
struct _Tree struct _Tree
...@@ -140,35 +141,19 @@ _SplitNode(TreeNode * node) ...@@ -140,35 +141,19 @@ _SplitNode(TreeNode * node)
TreeNode * newNode = _MakeNode(); TreeNode * newNode = _MakeNode();
#ifdef USE_MEM_FUNC
memcpy(&(newNode->data[0]),
&(node->data[DATA_PER_NODE/2]),
(DATA_PER_NODE-DATA_PER_NODE/2)*sizeof(void *));
memset(&(node->data[DATA_PER_NODE/2]),
0,
(DATA_PER_NODE-DATA_PER_NODE/2)*sizeof(void *));
memcpy(&(newNode->children[1]),
&(node->children[DATA_PER_NODE/2+1]),
(DATA_PER_NODE-DATA_PER_NODE/2)*sizeof(TreeNode *));
memset(&(node->children[DATA_PER_NODE/2+1]),
0,
(DATA_PER_NODE-DATA_PER_NODE/2)*sizeof(TreeNode *));
#endif
int i = DATA_PER_NODE/2; int i = DATA_PER_NODE/2;
int j = 0; int j = 0;
for (; i < DATA_PER_NODE; i++, j++) for (; i < DATA_PER_NODE; i++, j++)
{ {
#ifndef USE_MEM_FUNC
newNode->data[j] = node->data[i]; newNode->data[j] = node->data[i];
newNode->children[j+1] = node->children[i+1]; newNode->children[j+1] = node->children[i+1];
node->data[i] = NULL;
node->children[i+1] = NULL;
#endif
if (newNode->children[j+1]) if (newNode->children[j+1])
{ {
newNode->children[j+1]->parent = newNode; newNode->children[j+1]->parent = newNode;
newNode->children[j+1]->parentPos = j+1;
} }
node->data[i] = NULL;
node->children[i+1] = NULL;
} }
newNode->dataCount = (DATA_PER_NODE-DATA_PER_NODE/2); newNode->dataCount = (DATA_PER_NODE-DATA_PER_NODE/2);
node->dataCount -= (DATA_PER_NODE-DATA_PER_NODE/2); node->dataCount -= (DATA_PER_NODE-DATA_PER_NODE/2);
...@@ -179,43 +164,41 @@ _SplitNode(TreeNode * node) ...@@ -179,43 +164,41 @@ _SplitNode(TreeNode * node)
static static
void void
_InsertNodeAndData(Tree * tree, _InsertNodeAndData(Tree * tree,
TreeNode * node, TreeNode * node,
int pos,
TreeNode * newNode, TreeNode * newNode,
void * data) void * data)
{ {
assert(node->dataCount < DATA_PER_NODE); assert(node->dataCount < DATA_PER_NODE);
#ifdef TREE_DEBUG
assert(!newNode || tree->compareData(data, newNode->data[0]) < 0); assert(!newNode || tree->compareData(data, newNode->data[0]) < 0);
#endif
if (newNode)
{
newNode->parent = node;
}
int i = 0;
_FindPosition(tree, node, data, &i);
#ifdef USE_MEM_FUNC
memmove(&(node->data[i+1]),
&(node->data[i]),
(node->dataCount-i)*sizeof(void *));
memmove(&(node->children[i+2]),
&(node->children[i+1]),
(node->dataCount-i)*sizeof(TreeNode *));
#else
int j = node->dataCount; int j = node->dataCount;
for (; j > i; j--) for (; j > pos; j--)
{ {
node->data[j] = node->data[j-1]; node->data[j] = node->data[j-1];
node->children[j+1] = node->children[j]; node->children[j+1] = node->children[j];
if (node->children[j+1])
{
node->children[j+1]->parentPos = j+1;
}
} }
#endif
assert(!node->children[i] || #ifdef TREE_DEBUG
tree->compareData(data, node->children[i]->data[0]) > 0); assert(!node->children[pos] ||
tree->compareData(data, node->children[pos]->data[0]) > 0);
#endif
node->data[i] = data; node->data[pos] = data;
node->children[i+1] = newNode;
node->dataCount++; node->dataCount++;
node->children[pos+1] = newNode;
if (newNode)
{
newNode->parent = node;
newNode->parentPos = pos+1;
}
} }
static static
...@@ -223,18 +206,21 @@ void * ...@@ -223,18 +206,21 @@ void *
_AddDataToSplitNodes(Tree * tree, _AddDataToSplitNodes(Tree * tree,
TreeNode * lessNode, TreeNode * lessNode,
TreeNode * moreNode, TreeNode * moreNode,
int pos,
TreeNode * newNode, TreeNode * newNode,
void * data) void * data)
{ {
#ifdef TREE_DEBUG
assert(newNode == NULL || assert(newNode == NULL ||
tree->compareData(data, newNode->data[0]) < 0); tree->compareData(data, newNode->data[0]) < 0);
#endif
assert(moreNode->children[0] == NULL); assert(moreNode->children[0] == NULL);
void * retData; void * retData;
if (tree->compareData(data, moreNode->data[0]) < 0) if (pos <= lessNode->dataCount)
{ {
_InsertNodeAndData(tree, lessNode, newNode, data); _InsertNodeAndData(tree, lessNode, pos, newNode, data);
lessNode->dataCount--; lessNode->dataCount--;
retData = lessNode->data[lessNode->dataCount]; retData = lessNode->data[lessNode->dataCount];
lessNode->data[lessNode->dataCount] = NULL; lessNode->data[lessNode->dataCount] = NULL;
...@@ -243,51 +229,39 @@ _AddDataToSplitNodes(Tree * tree, ...@@ -243,51 +229,39 @@ _AddDataToSplitNodes(Tree * tree,
if (moreNode->children[0]) if (moreNode->children[0])
{ {
moreNode->children[0]->parent = moreNode; moreNode->children[0]->parent = moreNode;
moreNode->children[0]->parentPos = 0;
} }
lessNode->children[lessNode->dataCount+1] = NULL; lessNode->children[lessNode->dataCount+1] = NULL;
} }
else else
{ {
if (newNode) pos -= lessNode->dataCount;
{ retData = moreNode->data[0];
newNode->parent = moreNode; assert(!moreNode->children[0]);
} assert(!moreNode->data[moreNode->dataCount]);
int i = 0;
_FindPosition(tree, moreNode, data, &i);
if (i == 0)
{
moreNode->children[0] = newNode;
return data;
}
else
{
retData = moreNode->data[0];
}
#ifdef USE_MEM_FUNC
memmove(&(moreNode->data[0]),
&(moreNode->data[1]),
i*sizeof(void *));
memmove(&(moreNode->children[0]),
&(moreNode->children[1]),
i*sizeof(TreeNode *));
#else
int j = 0; int j = 0;
for (; j < i; j++) for (; j < pos; j++)
{ {
moreNode->data[j] = moreNode->data[j+1]; moreNode->data[j] = moreNode->data[j+1];
moreNode->children[j] = moreNode->children[j+1]; moreNode->children[j] = moreNode->children[j+1];
if (moreNode->children[j])
{
moreNode->children[j]->parentPos = j;
}
} }
#endif
assert(!moreNode->children[i-1] || assert(!moreNode->children[pos-1] ||
tree->compareData(data, tree->compareData(data,
moreNode->children[i]->data[0]) > 0); moreNode->children[pos-1]->data[0]) > 0);
moreNode->data[i-1] = data; moreNode->data[pos-1] = data;
moreNode->children[i] = newNode; moreNode->children[pos] = newNode;
if (newNode)
{
newNode->parent = moreNode;
newNode->parentPos = pos;
}
} }
return retData; return retData;
...@@ -299,9 +273,15 @@ _InsertAt(TreeIterator * iter, void * data) ...@@ -299,9 +273,15 @@ _InsertAt(TreeIterator * iter, void * data)
{ {
TreeNode * node = iter->node; TreeNode * node = iter->node;
TreeNode * insertNode = NULL; TreeNode * insertNode = NULL;
int pos = iter->which;
while (node != NULL) while (node != NULL)
{ {
#ifdef TREE_DEBUG
assert((pos == node->dataCount ||
iter->tree->compareData(data, node->data[pos]) < 0));
#endif
// see if there's any NULL data in the current node // see if there's any NULL data in the current node
if (node->dataCount == DATA_PER_NODE) if (node->dataCount == DATA_PER_NODE)
{ {
...@@ -311,35 +291,39 @@ _InsertAt(TreeIterator * iter, void * data) ...@@ -311,35 +291,39 @@ _InsertAt(TreeIterator * iter, void * data)
// insert data in split nodes // insert data in split nodes
data = _AddDataToSplitNodes(iter->tree, data = _AddDataToSplitNodes(iter->tree,
node, node,
newNode, newNode,
pos,
insertNode, insertNode,
data); data);
insertNode = newNode;
if (node->parent == NULL) if (node->parent == NULL)
{ {
assert(node == iter->tree->rootNode); assert(node == iter->tree->rootNode);
iter->tree->rootNode = _MakeNode(); iter->tree->rootNode = _MakeNode();
iter->tree->rootNode->children[0] = node;
node->parent = iter->tree->rootNode; node->parent = iter->tree->rootNode;
node->parentPos = 0;
iter->tree->rootNode->children[1] = newNode;
newNode->parent = iter->tree->rootNode; newNode->parent = iter->tree->rootNode;
newNode->parentPos = 1;
iter->tree->rootNode->data[0] = data; iter->tree->rootNode->data[0] = data;
iter->tree->rootNode->children[0] = node;
iter->tree->rootNode->children[1] = newNode;
iter->tree->rootNode->dataCount = 1; iter->tree->rootNode->dataCount = 1;
return; return;
} }
pos = node->parentPos;
node = node->parent; node = node->parent;
insertNode = newNode;
} }
else else
{ {
// insert the data and newNode // insert the data and newNode
_InsertNodeAndData( iter->tree, _InsertNodeAndData(iter->tree,
node, node,
insertNode, pos,
data ); insertNode,
node = NULL; data);
return;
} }
} }
} }
...@@ -363,12 +347,14 @@ _MergeNodes(TreeNode * lessNode, TreeNode * moreNode) ...@@ -363,12 +347,14 @@ _MergeNodes(TreeNode * lessNode, TreeNode * moreNode)
if (lessNode->children[j]) if (lessNode->children[j])
{ {
lessNode->children[j]->parent = lessNode; lessNode->children[j]->parent = lessNode;
lessNode->children[j]->parentPos = j;
} }
} }
lessNode->children[j] = moreNode->children[i]; lessNode->children[j] = moreNode->children[i];
if (lessNode->children[j]) if (lessNode->children[j])
{ {
lessNode->children[j]->parent = lessNode; lessNode->children[j]->parent = lessNode;
lessNode->children[j]->parentPos = j;
} }
lessNode->dataCount += i; lessNode->dataCount += i;
...@@ -412,14 +398,9 @@ _DeleteAt(TreeIterator * iter) ...@@ -412,14 +398,9 @@ _DeleteAt(TreeIterator * iter)
data = &(child->data[child->dataCount-1]); data = &(child->data[child->dataCount-1]);
node = child; node = child;
} }
else if (node->parent) else
{ {
// if there are no children, we need to set _pos_ pos = node->parentPos;
// to the correct node of the parent
_FindPosition(iter->tree,
node->parent,
node->data[0],
&pos);
} }
} }
...@@ -454,6 +435,8 @@ _DeleteAt(TreeIterator * iter) ...@@ -454,6 +435,8 @@ _DeleteAt(TreeIterator * iter)
{ {
node->children[node->dataCount]-> node->children[node->dataCount]->
parent = node; parent = node;
node->children[node->dataCount]->
parentPos = node->dataCount;
} }
node->parent->data[pos] = node->parent->data[pos] =
(*child)->data[0]; (*child)->data[0];
...@@ -463,8 +446,17 @@ _DeleteAt(TreeIterator * iter) ...@@ -463,8 +446,17 @@ _DeleteAt(TreeIterator * iter)
(*child)->data[i] = (*child)->data[i+1]; (*child)->data[i] = (*child)->data[i+1];
(*child)->children[i] = (*child)->children[i] =
(*child)->children[i+1]; (*child)->children[i+1];
if ((*child)->children[i])
{
(*child)->children[i]->
parentPos = i;
}
} }
(*child)->children[i] = (*child)->children[i+1]; (*child)->children[i] = (*child)->children[i+1];
if ((*child)->children[i])
{
(*child)->children[i]->parentPos = i;
}
(*child)->children[i+1] =NULL; (*child)->children[i+1] =NULL;
(*child)->data[i] = NULL; (*child)->data[i] = NULL;
(*child)->dataCount--; (*child)->dataCount--;
...@@ -478,14 +470,24 @@ _DeleteAt(TreeIterator * iter) ...@@ -478,14 +470,24 @@ _DeleteAt(TreeIterator * iter)
{ {
node->data[i] = node->data[i-1]; node->data[i] = node->data[i-1];
node->children[i+1] = node->children[i]; node->children[i+1] = node->children[i];
if (node->children[i+1])
{
node->children[i+1]->parentPos =
i+1;
}
} }
node->children[1] = node->children[0]; node->children[1] = node->children[0];
if (node->children[1])
{
node->children[1]->parentPos = 1;
}
node->data[0] = node->parent->data[pos-1]; node->data[0] = node->parent->data[pos-1];
node->children[0] = node->children[0] =
(*child)->children[(*child)->dataCount]; (*child)->children[(*child)->dataCount];
if (node->children[0]) if (node->children[0])
{ {
node->children[0]->parent = node; node->children[0]->parent = node;
node->children[0]->parentPos = 0;
} }
node->parent->data[pos-1] = node->parent->data[pos-1] =
(*child)->data[(*child)->dataCount-1]; (*child)->data[(*child)->dataCount-1];
...@@ -527,19 +529,18 @@ _DeleteAt(TreeIterator * iter) ...@@ -527,19 +529,18 @@ _DeleteAt(TreeIterator * iter)
node->parent->data[i+1]; node->parent->data[i+1];
node->parent->children[i+1] = node->parent->children[i+1] =
node->parent->children[i+2]; node->parent->children[i+2];
if (node->parent->children[i+1])
{
node->parent->children[i+1]->
parentPos = i+1;
}
} }
node->parent->data[i] = NULL; node->parent->data[i] = NULL;
node->parent->children[i+1] = NULL; node->parent->children[i+1] = NULL;
node->parent->dataCount--; node->parent->dataCount--;
if (node->parent->parent)
{
_FindPosition(iter->tree,
node->parent->parent,
node->data[0],
&pos);
}
node = node->parent; node = node->parent;
pos = node->parentPos;
} }
} }
// this is a root node // this is a root node
...@@ -550,6 +551,7 @@ _DeleteAt(TreeIterator * iter) ...@@ -550,6 +551,7 @@ _DeleteAt(TreeIterator * iter)
if (node->children[0]) if (node->children[0])
{ {
node->children[0]->parent = NULL; node->children[0]->parent = NULL;
node->children[0]->parentPos = 0;
} }
iter->tree->rootNode = node->children[0]; iter->tree->rootNode = node->children[0];
......
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