merge changes from mpd-tree:

-use tree for tagTracker
-eliminate the master process

git-svn-id: https://svn.musicpd.org/mpd/trunk@4571 09075e82-0dd4-0310-85a5-a0d7c8717e4f

1 files changed, 712 insertions, 0 deletions

diff --git a/src/tree.c b/src/tree.c
new file mode 100644
index 000000000..9462d2a2c
--- /dev/null
+++ b/src/tree.c
@@ -0,0 +1,712 @@
+/* the Music Player Daemon (MPD)
+ * (c)2006 by Warren Dukes (warren.dukes@gmail.com)
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "tree.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef CHILDREN_PER_NODE
+#define CHILDREN_PER_NODE 25
+#endif
+
+#define DATA_PER_NODE (CHILDREN_PER_NODE-1)
+
+#if CHILDREN_PER_NODE > 7
+#define USE_BINARY_SEARCH 1
+#endif
+
+
+/************************* DATA STRUCTURES **********************************/
+
+struct _TreeNode
+{
+	TreeKeyData keyData[DATA_PER_NODE];
+	struct _TreeNode * parent;
+	short parentPos;
+	struct _TreeNode * children[CHILDREN_PER_NODE];
+	short count;
+};
+
+struct _Tree
+{
+	TreeCompareKeyFunction compareKey;
+	TreeFreeFunction freeKey;
+	TreeFreeFunction freeData;
+	TreeNode * rootNode;
+	int size;
+};
+
+/************************* STATIC METHODS ***********************************/
+
+static
+TreeNode *
+_MakeNode()
+{
+	TreeNode * ret = malloc(sizeof(TreeNode));
+	memset(ret, 0, sizeof(TreeNode));
+	return ret;
+}
+
+static
+void
+_ClearKeyData(TreeKeyData * keyData)
+{
+	memset(keyData, 0, sizeof(TreeKeyData));
+}
+
+static
+int
+_FindPosition(Tree * tree, TreeNode * node, void * key, int * pos)
+{
+#ifdef USE_BINARY_SEARCH
+	int low = 0;
+	int high = node->count;
+	int cmp = -1;
+
+	while (high > low)
+	{
+		int cur = (high + low) >> 1;
+		cmp = tree->compareKey(key, node->keyData[cur].key);
+		if (cmp > 0)
+		{
+			low = cur+1;
+		}
+		else if (cmp < 0)
+		{
+			high = cur;
+		}
+		else
+		{
+			low = cur;
+			break;
+		}
+	}
+
+	*pos = low;
+	return (cmp == 0);
+#else
+	int i = 0;
+	int cmp = -1;
+	for (; 
+	     i < node->count &&
+	     (cmp = tree->compareKey(key, node->keyData[i].key)) > 0;
+	     i++);
+	*pos = i;
+	return (cmp == 0);
+#endif
+}
+
+static
+int
+_Find(TreeIterator * iter, void * key)
+{
+	while (1)
+	{
+		if (_FindPosition(iter->tree, iter->node, key, &iter->which))
+		{
+			iter->which++;
+			return 1;
+		}
+
+		if (iter->node->children[iter->which])
+		{
+			iter->node = iter->node->children[iter->which];
+		}
+		else
+		{
+			return 0;
+		}
+	}
+}
+
+static void _SetIteratorToRoot(Tree * tree, TreeIterator * iter)
+{
+	iter->tree = tree;
+	iter->node = tree->rootNode;
+	iter->which = 0;
+}
+
+static
+TreeNode *
+_SplitNode(TreeNode * node)
+{
+	assert(node->count == DATA_PER_NODE);
+
+	TreeNode * newNode = _MakeNode();
+
+	int i = DATA_PER_NODE/2;
+	int j = 0;
+	for (; i < DATA_PER_NODE; i++, j++)
+	{
+		newNode->keyData[j] = node->keyData[i];
+		newNode->children[j+1] = node->children[i+1];
+		if (newNode->children[j+1])
+		{
+			newNode->children[j+1]->parent = newNode;
+			newNode->children[j+1]->parentPos = j+1;
+		}
+		_ClearKeyData(&(node->keyData[i]));
+		node->children[i+1] = NULL;
+	}
+	newNode->count = (DATA_PER_NODE-DATA_PER_NODE/2);
+	node->count -= (DATA_PER_NODE-DATA_PER_NODE/2);
+
+	return newNode;
+}
+
+static
+void
+_InsertNodeAndData(Tree * tree, 
+		   TreeNode * node,
+		   int pos,
+		   TreeNode * newNode,
+		   TreeKeyData keyData)
+{
+	assert(node->count < DATA_PER_NODE);
+
+	int j = node->count;
+	for (; j > pos; j--)
+	{
+		node->keyData[j] = node->keyData[j-1];
+		node->children[j+1] = node->children[j];
+		if (node->children[j+1])
+		{
+			node->children[j+1]->parentPos = j+1;
+		}
+	}
+
+	node->keyData[pos] = keyData;
+	node->count++;
+
+	node->children[pos+1] = newNode;
+	if (newNode)
+	{
+		newNode->parent = node;
+		newNode->parentPos = pos+1;
+	}
+}
+
+static
+TreeKeyData
+_AddDataToSplitNodes(Tree * tree,
+		     TreeNode * lessNode, 
+		     TreeNode * moreNode,
+		     int pos,
+		     TreeNode * newNode,
+		     TreeKeyData keyData)
+{
+	assert(moreNode->children[0] == NULL);
+
+	TreeKeyData retKeyData;
+
+	if (pos <= lessNode->count)
+	{
+		_InsertNodeAndData(tree, lessNode, pos, newNode, keyData);
+		lessNode->count--;
+		retKeyData = lessNode->keyData[lessNode->count];
+		_ClearKeyData(&(lessNode->keyData[lessNode->count]));
+		moreNode->children[0] = 
+			lessNode->children[lessNode->count+1];
+		if (moreNode->children[0])
+		{
+			moreNode->children[0]->parent = moreNode;
+			moreNode->children[0]->parentPos = 0;
+		}
+		lessNode->children[lessNode->count+1] = NULL;
+	}
+	else
+	{
+		pos -= lessNode->count;
+		retKeyData = moreNode->keyData[0];
+		assert(!moreNode->children[0]);
+
+		int j = 0;
+		for (; j < pos; j++)
+		{
+			moreNode->keyData[j] = moreNode->keyData[j+1];
+			moreNode->children[j] = moreNode->children[j+1];
+			if (moreNode->children[j])
+			{
+				moreNode->children[j]->parentPos = j;
+			}
+		}
+
+		moreNode->keyData[pos-1] = keyData;
+		moreNode->children[pos] = newNode;
+		if (newNode)
+		{
+			newNode->parent = moreNode;
+			newNode->parentPos = pos;
+		}
+	}
+
+	return retKeyData;
+}
+
+static
+void
+_InsertAt(TreeIterator * iter, TreeKeyData keyData)
+{
+	TreeNode * node = iter->node;
+	TreeNode * insertNode = NULL;
+	int pos = iter->which;
+	
+	while (node != NULL)
+	{
+		// see if there's any NULL data in the current node
+		if (node->count == DATA_PER_NODE)
+		{
+			// no open data slots, split this node!
+			TreeNode * newNode = _SplitNode(node);
+
+			// insert data in split nodes
+			keyData = _AddDataToSplitNodes(iter->tree,
+						       node, 
+						       newNode,
+						       pos,
+						       insertNode,
+						       keyData);
+
+			if (node->parent == NULL)
+			{
+				assert(node == iter->tree->rootNode);
+				iter->tree->rootNode = _MakeNode();
+				iter->tree->rootNode->children[0] = node;
+				node->parent = iter->tree->rootNode;
+				node->parentPos = 0;
+				iter->tree->rootNode->children[1] = newNode;
+				newNode->parent = iter->tree->rootNode;
+				newNode->parentPos = 1;
+				iter->tree->rootNode->keyData[0] = keyData;
+				iter->tree->rootNode->count = 1;
+				return;
+			}
+
+			pos = node->parentPos;
+			node = node->parent;
+			insertNode = newNode;
+		}
+		else
+		{
+			// insert the data and newNode
+			_InsertNodeAndData(iter->tree, 
+					   node,
+					   pos,
+					   insertNode,
+					   keyData);
+			return;
+		}
+	}
+}
+
+static
+void
+_MergeNodes(TreeNode * lessNode, TreeNode * moreNode)
+{
+	int i = 0;
+	int j = lessNode->count;
+
+	assert((lessNode->count + moreNode->count) <= DATA_PER_NODE);
+	assert(lessNode->children[j] == NULL);
+
+	for(; i < moreNode->count; i++,j++)
+	{
+		assert(!lessNode->children[j]);
+		lessNode->keyData[j] = moreNode->keyData[i];
+		lessNode->children[j] = moreNode->children[i];
+		if (lessNode->children[j])
+		{
+			lessNode->children[j]->parent = lessNode;
+			lessNode->children[j]->parentPos = j;
+		}
+	}
+	lessNode->children[j] = moreNode->children[i];
+	if (lessNode->children[j])
+	{
+		lessNode->children[j]->parent = lessNode;
+		lessNode->children[j]->parentPos = j;
+	}
+	lessNode->count += i;
+
+	free(moreNode);
+}
+
+void
+_DeleteAt(TreeIterator * iter)
+{
+	TreeNode * node = iter->node;
+	int pos = iter->which - 1;
+	TreeKeyData * keyData = &(node->keyData[pos]);
+	TreeKeyData keyDataToFree = *keyData;
+
+	{
+		// find the least greater than data to fill the whole!
+		if (node->children[pos+1])
+		{
+			TreeNode * child = node->children[++pos];
+			while (child->children[0])
+			{
+				pos = 0;
+				child = child->children[0];
+			}
+
+			*keyData = child->keyData[0];
+			keyData = &(child->keyData[0]);
+			node = child;
+		}
+		// or the greatest lesser than data to fill the whole!
+		else if (node->children[pos])
+		{
+			TreeNode * child = node->children[pos];
+			while (child->children[child->count])
+			{
+				pos = child->count;
+				child = child->children[child->count];
+			}
+
+			*keyData = child->keyData[child->count-1];
+			keyData = &(child->keyData[child->count-1]);
+			node = child;
+		}
+		else
+		{
+			pos = node->parentPos;
+		}
+	}
+
+	// move data nodes over, we're at a leaf node, so we can ignore
+	// children
+	int i = keyData - node->keyData;;
+	for (; i < node->count-1; i++)
+	{
+		node->keyData[i] = node->keyData[i+1];
+	}
+	_ClearKeyData(&(node->keyData[--node->count]));
+
+	// merge the nodes from the bottom up which have too few data
+	while (node->count < (DATA_PER_NODE/2))
+	{
+		// if we're not the root
+		if (node->parent)
+		{
+			TreeNode ** child = &(node->parent->children[pos]);
+			assert(node->parent->children[pos] == node);
+
+			// check siblings for extra data
+			if (pos < node->parent->count &&
+			    (*(child+1))->count > (DATA_PER_NODE/2))
+			{
+				child++;
+				node->keyData[node->count++] = 
+					node->parent->keyData[pos];
+				node->children[node->count] =
+					(*child)->children[0];
+				if (node->children[node->count])
+				{
+					node->children[node->count]->
+						parent = node;
+					node->children[node->count]->
+						parentPos = node->count;
+				}
+				node->parent->keyData[pos] =
+					(*child)->keyData[0];
+				int i = 0;
+				for(; i < (*child)->count-1; i++)
+				{
+					(*child)->keyData[i] = 
+						(*child)->keyData[i+1];
+					(*child)->children[i] =
+						(*child)->children[i+1];
+					if ((*child)->children[i])
+					{
+						(*child)->children[i]->
+							parentPos = i;
+					}
+				}
+				(*child)->children[i] = (*child)->children[i+1];
+				if ((*child)->children[i])
+				{
+					(*child)->children[i]->parentPos = i;
+				}
+				(*child)->children[i+1] =NULL;
+				_ClearKeyData(&((*child)->keyData[i]));
+				(*child)->count--;
+			}
+			else if (pos > 0 &&
+				 (*(child-1))->count>(DATA_PER_NODE/2))
+			{
+				child--;
+				int i = node->count++;
+				for(; i > 0; i--)
+				{
+					node->keyData[i] = node->keyData[i-1];
+					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];
+				if (node->children[1])
+				{
+					node->children[1]->parentPos = 1;
+				}
+				node->keyData[0] = node->parent->keyData[pos-1];
+				node->children[0] = 
+					(*child)->children[(*child)->count];
+				if (node->children[0])
+				{
+					node->children[0]->parent = node;
+					node->children[0]->parentPos = 0;
+				}
+				node->parent->keyData[pos-1] = 
+					(*child)->keyData[(*child)->count-1];
+				(*child)->children[(*child)->count--] =
+					NULL;
+				_ClearKeyData(
+					&((*child)->keyData[(*child)->count]));
+			}
+			// merge with one of our siblings
+			else
+			{
+				if (pos < node->parent->count)
+				{
+					child++;
+					assert(*child);
+
+					node->keyData[node->count++] =
+						node->parent->keyData[pos];
+
+					_MergeNodes(node, *child);
+				}
+				else
+				{
+					assert(pos > 0);
+					child--;
+					assert(*child);
+					pos--;
+
+					(*child)->keyData[(*child)->count++] = 
+						node->parent->keyData[pos];
+
+					_MergeNodes(*child, node);
+					node = *child;
+				}
+
+				int i = pos;
+				for(; i < node->parent->count-1; i++)
+				{
+					node->parent->keyData[i] =
+						node->parent->keyData[i+1];
+					node->parent->children[i+1] =
+						node->parent->children[i+2];
+					if (node->parent->children[i+1])
+					{
+						node->parent->children[i+1]->
+							parentPos = i+1;
+					}
+				}
+				_ClearKeyData(&(node->parent->keyData[i]));
+				node->parent->children[i+1] = NULL;
+				node->parent->count--;
+
+				node = node->parent;
+				pos = node->parentPos;
+			}
+		}
+		// this is a root node
+		else 
+		{
+			if (node->count == 0)
+			{
+				if (node->children[0])
+				{
+					node->children[0]->parent = NULL;
+					node->children[0]->parentPos = 0;
+				}
+
+				iter->tree->rootNode = node->children[0];
+
+				free(node);
+			}
+
+			break;
+		}
+	}
+
+	if (iter->tree->freeKey)
+	{
+		iter->tree->freeData(keyDataToFree.key);
+	}
+	if (iter->tree->freeData)
+	{
+		iter->tree->freeData(keyDataToFree.data);
+	}
+}
+
+/************************* PUBLIC METHODS ***********************************/
+
+Tree *
+MakeTree(TreeCompareKeyFunction compareKey,
+	 TreeFreeFunction freeKey,
+	 TreeFreeFunction freeData)
+{
+	Tree * ret = malloc(sizeof(Tree));
+	ret->compareKey = compareKey;
+	ret->freeKey = freeKey;
+	ret->freeData = freeData;
+	ret->rootNode = _MakeNode();
+	ret->size = 0;
+	return ret;
+}
+
+void
+FreeTree(Tree * tree)
+{
+	assert(tree->rootNode == NULL);
+	free(tree);
+}
+
+int
+GetTreeSize(Tree * tree)
+{
+	return tree->size;
+}
+
+void SetTreeIteratorToBegin(Tree * tree, TreeIterator * iter)
+{
+	_SetIteratorToRoot(tree, iter);
+	IncrementTreeIterator(iter);
+}
+
+int IsTreeIteratorAtEnd(const TreeIterator * iter)
+{
+	return (iter->node == NULL);
+}
+
+void IncrementTreeIterator(TreeIterator * iter)
+{
+	while(iter->node)
+	{
+		if (iter->node->children[iter->which])
+		{
+			iter->node = iter->node->children[iter->which];
+			iter->which = 0;
+		}
+		else
+		{
+			iter->which++;
+		}
+
+		while (iter->node && iter->which > iter->node->count)
+		{
+			TreeNode * childNode = iter->node;
+			iter->node = childNode->parent;
+			if (iter->node)
+			{
+				for (iter->which = 0;
+				     childNode != 
+				     iter->node->children[iter->which];
+				     iter->which++)
+				{
+					assert(iter->which <= 
+					       iter->node->count);
+				}
+				iter->which++;
+			}
+		}
+
+		if (iter->node &&
+		    iter->which > 0 && iter->which <= iter->node->count)
+		{
+			return;
+		}
+	}
+}
+
+TreeKeyData
+GetTreeKeyData(TreeIterator * iter)
+{
+	assert(iter->node && 
+	       iter->which > 0 && 
+	       iter->which <= iter->node->count);
+	return iter->node->keyData[iter->which-1];
+}
+
+int
+InsertInTree(Tree * tree, void * key, void * data)
+{
+	TreeKeyData keyData = {key, data};
+	TreeIterator iter;
+	_SetIteratorToRoot(tree, &iter);
+
+	if (_Find(&iter, key))
+	{
+		return 0;
+	}
+
+	_InsertAt(&iter, keyData);
+	tree->size++;
+
+	return 1;
+}
+
+int
+RemoveFromTreeByKey(Tree * tree, void * key)
+{
+	TreeIterator iter;
+	_SetIteratorToRoot(tree, &iter);
+
+	if (_Find(&iter, key))
+	{
+		_DeleteAt(&iter);
+		tree->size--;
+		return 1;
+	}
+
+	return 0;
+}
+
+void
+RemoveFromTreeByIterator(Tree * tree, TreeIterator * iter)
+{
+	_DeleteAt(iter);
+	tree->size--;
+}
+
+int
+FindInTree(Tree * tree, void * key, TreeIterator * iter)
+{
+	TreeIterator i;
+	
+	if (iter == NULL)
+	{
+		iter = &i;
+	}
+
+	_SetIteratorToRoot(tree, iter);
+	if (_Find(iter, key))
+	{
+		return 1;
+	}
+
+	return 0;
+}