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/*
* Copyright 2010-2012 Luca Garulli (l.garulli--at--orientechnologies.com)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.orientechnologies.common.collection;
import java.util.Map;
@SuppressWarnings("unchecked")
public abstract class OMVRBTreeEntry implements Map.Entry, Comparable> {
protected OMVRBTree tree;
private int pageSplitItems;
public static final int BINARY_SEARCH_THRESHOLD = 10;
/**
* Constructor called on unmarshalling.
*
*/
protected OMVRBTreeEntry(final OMVRBTree iTree) {
tree = iTree;
}
public abstract void setLeft(OMVRBTreeEntry left);
public abstract OMVRBTreeEntry getLeft();
public abstract void setRight(OMVRBTreeEntry right);
public abstract OMVRBTreeEntry getRight();
public abstract OMVRBTreeEntry setParent(OMVRBTreeEntry parent);
public abstract OMVRBTreeEntry getParent();
protected abstract OMVRBTreeEntry getLeftInMemory();
protected abstract OMVRBTreeEntry getParentInMemory();
protected abstract OMVRBTreeEntry getRightInMemory();
protected abstract OMVRBTreeEntry getNextInMemory();
/**
* Returns the first Entry only by traversing the memory, or null if no such.
*/
public OMVRBTreeEntry getFirstInMemory() {
OMVRBTreeEntry node = this;
OMVRBTreeEntry prev = this;
while (node != null) {
prev = node;
node = node.getPreviousInMemory();
}
return prev;
}
/**
* Returns the previous of the current Entry only by traversing the memory, or null if no such.
*/
public OMVRBTreeEntry getPreviousInMemory() {
OMVRBTreeEntry t = this;
OMVRBTreeEntry p = null;
if (t.getLeftInMemory() != null) {
p = t.getLeftInMemory();
while (p.getRightInMemory() != null)
p = p.getRightInMemory();
} else {
p = t.getParentInMemory();
while (p != null && t == p.getLeftInMemory()) {
t = p;
p = p.getParentInMemory();
}
}
return p;
}
protected OMVRBTree getTree() {
return tree;
}
public int getDepth() {
int level = 0;
OMVRBTreeEntry entry = this;
while (entry.getParent() != null) {
level++;
entry = entry.getParent();
}
return level;
}
/**
* Returns the key.
*
* @return the key
*/
public K getKey() {
return getKey(tree.pageIndex);
}
public K getKey(final int iIndex) {
if (iIndex >= getSize())
throw new IndexOutOfBoundsException("Requested index " + iIndex + " when the range is 0-" + getSize());
tree.pageIndex = iIndex;
return getKeyAt(iIndex);
}
protected abstract K getKeyAt(final int iIndex);
/**
* Returns the value associated with the key.
*
* @return the value associated with the key
*/
public V getValue() {
if (tree.pageIndex == -1)
return getValueAt(0);
return getValueAt(tree.pageIndex);
}
public V getValue(final int iIndex) {
tree.pageIndex = iIndex;
return getValueAt(iIndex);
}
protected abstract V getValueAt(int iIndex);
public int getFreeSpace() {
return getPageSize() - getSize();
}
/**
* Execute a binary search between the keys of the node. The keys are always kept ordered. It update the pageIndex attribute with
* the most closer key found (useful for the next inserting).
*
* @param iKey
* Key to find
* @return The value found if any, otherwise null
*/
protected V search(final K iKey) {
tree.pageItemFound = false;
int size = getSize();
if (size == 0)
return null;
// CHECK THE LOWER LIMIT
if (tree.comparator != null)
tree.pageItemComparator = tree.comparator.compare(iKey, getKeyAt(0));
else
tree.pageItemComparator = ((Comparable) iKey).compareTo(getKeyAt(0));
if (tree.pageItemComparator == 0) {
// FOUND: SET THE INDEX AND RETURN THE NODE
tree.pageItemFound = true;
tree.pageIndex = 0;
return getValueAt(tree.pageIndex);
} else if (tree.pageItemComparator < 0) {
// KEY OUT OF FIRST ITEM: AVOID SEARCH AND RETURN THE FIRST POSITION
tree.pageIndex = 0;
return null;
} else {
// CHECK THE UPPER LIMIT
if (tree.comparator != null)
tree.pageItemComparator = tree.comparator.compare((K) iKey, getKeyAt(size - 1));
else
tree.pageItemComparator = ((Comparable) iKey).compareTo(getKeyAt(size - 1));
if (tree.pageItemComparator > 0) {
// KEY OUT OF LAST ITEM: AVOID SEARCH AND RETURN THE LAST POSITION
tree.pageIndex = size;
return null;
}
}
if (size < BINARY_SEARCH_THRESHOLD)
return linearSearch(iKey);
else
return binarySearch(iKey);
}
/**
* Linear search inside the node
*
* @param iKey
* Key to search
* @return Value if found, otherwise null and the tree.pageIndex updated with the closest-after-first position valid for further
* inserts.
*/
private V linearSearch(final K iKey) {
V value = null;
int i = 0;
tree.pageItemComparator = -1;
for (int s = getSize(); i < s; ++i) {
if (tree.comparator != null)
tree.pageItemComparator = tree.comparator.compare(getKeyAt(i), iKey);
else
tree.pageItemComparator = ((Comparable) getKeyAt(i)).compareTo(iKey);
if (tree.pageItemComparator == 0) {
// FOUND: SET THE INDEX AND RETURN THE NODE
tree.pageItemFound = true;
value = getValueAt(i);
break;
} else if (tree.pageItemComparator > 0)
break;
}
tree.pageIndex = i;
return value;
}
/**
* Binary search inside the node
*
* @param iKey
* Key to search
* @return Value if found, otherwise null and the tree.pageIndex updated with the closest-after-first position valid for further
* inserts.
*/
private V binarySearch(final K iKey) {
int low = 0;
int high = getSize() - 1;
int mid = 0;
while (low <= high) {
mid = (low + high) >>> 1;
Object midVal = getKeyAt(mid);
if (tree.comparator != null)
tree.pageItemComparator = tree.comparator.compare((K) midVal, iKey);
else
tree.pageItemComparator = ((Comparable) midVal).compareTo(iKey);
if (tree.pageItemComparator == 0) {
// FOUND: SET THE INDEX AND RETURN THE NODE
tree.pageItemFound = true;
tree.pageIndex = mid;
return getValueAt(tree.pageIndex);
}
if (low == high)
break;
if (tree.pageItemComparator < 0)
low = mid + 1;
else
high = mid;
}
tree.pageIndex = mid;
return null;
}
protected abstract void insert(final int iPosition, final K key, final V value);
protected abstract void remove();
protected abstract void setColor(boolean iColor);
public abstract boolean getColor();
public abstract int getSize();
public K getLastKey() {
return getKey(getSize() - 1);
}
public K getFirstKey() {
return getKey(0);
}
protected abstract void copyFrom(final OMVRBTreeEntry iSource);
public int getPageSplitItems() {
return pageSplitItems;
}
protected void init() {
pageSplitItems = (int) (getPageSize() * tree.pageLoadFactor);
}
public abstract int getPageSize();
/**
* Compares two nodes by their first keys.
*/
public int compareTo(final OMVRBTreeEntry o) {
if (o == null)
return 1;
if (o == this)
return 0;
if (getSize() == 0)
return -1;
if (o.getSize() == 0)
return 1;
if (tree.comparator != null)
return tree.comparator.compare(getFirstKey(), o.getFirstKey());
return ((Comparable) getFirstKey()).compareTo(o.getFirstKey());
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
int idx = tree.pageIndex;
if (idx > -1 && idx < getSize())
return getKeyAt(idx) + "=" + getValueAt(idx);
return null;
}
}
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