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Library providing immutable/persistent collection classes for
Java. While collections are immutable they provide methods for
adding and removing values by creating new modified copies of
themselves. Each copy shares almost all of its structure with
other copies to minimize memory consumption.
///###////////////////////////////////////////////////////////////////////////
//
// Burton Computer Corporation
// http://www.burton-computer.com
//
// Copyright (c) 2014, Burton Computer Corporation
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in
// the documentation and/or other materials provided with the
// distribution.
//
// Neither the name of the Burton Computer Corporation nor the names
// of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package org.javimmutable.collections.tree;
import org.javimmutable.collections.Cursor;
import org.javimmutable.collections.Holder;
import org.javimmutable.collections.JImmutableMap;
import org.javimmutable.collections.cursors.LazyCursor;
import org.javimmutable.collections.cursors.MultiCursor;
import java.util.Collection;
import java.util.Comparator;
public class TwoNode
extends TreeNode
{
private final TreeNode left;
private final TreeNode right;
private final K leftMaxKey;
private final K rightMaxKey;
public TwoNode(TreeNode left,
TreeNode right,
K leftMaxKey,
K rightMaxKey)
{
this.left = left;
this.right = right;
this.leftMaxKey = leftMaxKey;
this.rightMaxKey = rightMaxKey;
}
@Override
public V getValueOr(Comparator props,
K key,
V defaultValue)
{
if (props.compare(key, leftMaxKey) <= 0) {
return left.getValueOr(props, key, defaultValue);
} else {
return right.getValueOr(props, key, defaultValue);
}
}
@Override
public Holder find(Comparator props,
K key)
{
if (props.compare(key, leftMaxKey) <= 0) {
return left.find(props, key);
} else {
return right.find(props, key);
}
}
@Override
public Holder> findEntry(Comparator props,
K key)
{
if (props.compare(key, leftMaxKey) <= 0) {
return left.findEntry(props, key);
} else {
return right.findEntry(props, key);
}
}
@Override
K getMaxKey()
{
return rightMaxKey;
}
@Override
UpdateResult assignImpl(Comparator props,
K key,
V value)
{
if (props.compare(key, leftMaxKey) <= 0) {
UpdateResult result = left.assignImpl(props, key, value);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return UpdateResult.createInPlace(result.createLeftTwoNode(right, rightMaxKey), result.sizeDelta);
case SPLIT:
return UpdateResult.createInPlace(result.createLeftThreeNode(right, rightMaxKey), result.sizeDelta);
}
} else {
UpdateResult result = right.assignImpl(props, key, value);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return UpdateResult.createInPlace(result.createRightTwoNode(left, leftMaxKey), result.sizeDelta);
case SPLIT:
return UpdateResult.createInPlace(result.createRightThreeNode(left, leftMaxKey), result.sizeDelta);
}
}
throw new RuntimeException();
}
@Override
public void addEntriesTo(Collection> collection)
{
left.addEntriesTo(collection);
right.addEntriesTo(collection);
}
@Override
public int verifyDepthsMatch()
{
final int leftDepth = left.verifyDepthsMatch();
final int rightDepth = right.verifyDepthsMatch();
if (leftDepth != rightDepth) {
throw new RuntimeException(String.format("depth mismatch %d %d", leftDepth, rightDepth));
}
return leftDepth + 1;
}
@Override
DeleteResult deleteImpl(Comparator props,
K key)
{
if (props.compare(key, leftMaxKey) <= 0) {
DeleteResult result = left.deleteImpl(props, key);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return DeleteResult.createInPlace(new TwoNode(result.node,
right,
result.node.getMaxKey(),
rightMaxKey));
case ELIMINATED:
return DeleteResult.createRemnant(right);
case REMNANT:
DeleteMergeResult mergeResult = right.leftDeleteMerge(props, result.node);
if (mergeResult.right == null) {
return DeleteResult.createRemnant(mergeResult.left);
} else {
return DeleteResult.createInPlace(mergeResult.createTwoNode());
}
}
} else {
DeleteResult result = right.deleteImpl(props, key);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return DeleteResult.createInPlace(new TwoNode(left,
result.node,
leftMaxKey,
result.node.getMaxKey()));
case ELIMINATED:
return DeleteResult.createRemnant(left);
case REMNANT:
DeleteMergeResult mergeResult = left.rightDeleteMerge(props, result.node);
if (mergeResult.right == null) {
return DeleteResult.createRemnant(mergeResult.left);
} else {
return DeleteResult.createInPlace(mergeResult.createTwoNode());
}
}
}
throw new RuntimeException();
}
@Override
DeleteMergeResult leftDeleteMerge(Comparator props,
TreeNode node)
{
return new DeleteMergeResult(new ThreeNode(node,
left,
right,
node.getMaxKey(),
leftMaxKey,
rightMaxKey));
}
@Override
DeleteMergeResult rightDeleteMerge(Comparator props,
TreeNode node)
{
return new DeleteMergeResult(new ThreeNode(left,
right,
node,
leftMaxKey,
rightMaxKey,
node.getMaxKey()));
}
public TreeNode getLeft()
{
return left;
}
public TreeNode getRight()
{
return right;
}
public K getLeftMaxKey()
{
return leftMaxKey;
}
public K getRightMaxKey()
{
return rightMaxKey;
}
@Override
public String toString()
{
return String.format("(%s,%s)", left, right);
}
@Override
public Cursor> cursor()
{
return MultiCursor.of(LazyCursor.of(left), LazyCursor.of(right));
}
@SuppressWarnings("RedundantIfStatement")
@Override
public boolean equals(Object o)
{
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
TwoNode twoNode = (TwoNode)o;
if (left != null ? !left.equals(twoNode.left) : twoNode.left != null) {
return false;
}
if (leftMaxKey != null ? !leftMaxKey.equals(twoNode.leftMaxKey) : twoNode.leftMaxKey != null) {
return false;
}
if (right != null ? !right.equals(twoNode.right) : twoNode.right != null) {
return false;
}
if (rightMaxKey != null ? !rightMaxKey.equals(twoNode.rightMaxKey) : twoNode.rightMaxKey != null) {
return false;
}
return true;
}
@Override
public int hashCode()
{
int result = left != null ? left.hashCode() : 0;
result = 31 * result + (right != null ? right.hashCode() : 0);
result = 31 * result + (leftMaxKey != null ? leftMaxKey.hashCode() : 0);
result = 31 * result + (rightMaxKey != null ? rightMaxKey.hashCode() : 0);
return result;
}
}