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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) 2013, 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
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// 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 ThreeNode
extends TreeNode
{
private final TreeNode left;
private final TreeNode middle;
private final TreeNode right;
private final K leftMaxKey;
private final K middleMaxKey;
private final K rightMaxKey;
public ThreeNode(TreeNode left,
TreeNode middle,
TreeNode right,
K leftMaxKey,
K middleMaxKey,
K rightMaxKey)
{
this.left = left;
this.middle = middle;
this.right = right;
this.leftMaxKey = leftMaxKey;
this.middleMaxKey = middleMaxKey;
this.rightMaxKey = rightMaxKey;
}
@Override
public Holder find(Comparator comparator,
K key)
{
if (comparator.compare(key, leftMaxKey) <= 0) {
return left.find(comparator, key);
}
if (comparator.compare(key, middleMaxKey) <= 0) {
return middle.find(comparator, key);
} else {
return right.find(comparator, key);
}
}
@Override
public Holder> findEntry(Comparator comparator,
K key)
{
if (comparator.compare(key, leftMaxKey) <= 0) {
return left.findEntry(comparator, key);
}
if (comparator.compare(key, middleMaxKey) <= 0) {
return middle.findEntry(comparator, key);
} else {
return right.findEntry(comparator, key);
}
}
@Override
public K getMaxKey()
{
return rightMaxKey;
}
@Override
public UpdateResult update(Comparator comparator,
K key,
V value)
{
if (comparator.compare(key, leftMaxKey) <= 0) {
UpdateResult result = left.update(comparator, key, value);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return UpdateResult.createInPlace(new ThreeNode(result.newNode,
middle,
right,
result.newNode.getMaxKey(),
middleMaxKey,
rightMaxKey),
result.sizeDelta);
case SPLIT:
return UpdateResult.createSplit(result.createTwoNode(),
new TwoNode(middle,
right,
middleMaxKey,
rightMaxKey),
result.sizeDelta);
}
} else if (comparator.compare(key, middleMaxKey) <= 0) {
UpdateResult result = middle.update(comparator, key, value);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return UpdateResult.createInPlace(new ThreeNode(left,
result.newNode,
right,
leftMaxKey,
result.newNode.getMaxKey(),
rightMaxKey),
result.sizeDelta);
case SPLIT:
return UpdateResult.createSplit(new TwoNode(left,
result.newNode,
leftMaxKey,
result.newNode.getMaxKey()),
new TwoNode(result.extraNode,
right,
result.extraNode.getMaxKey(),
rightMaxKey),
result.sizeDelta);
}
} else {
UpdateResult result = right.update(comparator, key, value);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return UpdateResult.createInPlace(new ThreeNode(left,
middle,
result.newNode,
leftMaxKey,
middleMaxKey,
result.newNode.getMaxKey()),
result.sizeDelta);
case SPLIT:
return UpdateResult.createSplit(new TwoNode(left,
middle,
leftMaxKey,
middleMaxKey),
result.createTwoNode(),
result.sizeDelta);
}
}
throw new RuntimeException();
}
@Override
public void addEntriesTo(Collection> collection)
{
left.addEntriesTo(collection);
middle.addEntriesTo(collection);
right.addEntriesTo(collection);
}
@Override
public int verifyDepthsMatch()
{
final int leftDepth = left.verifyDepthsMatch();
final int middleDepth = middle.verifyDepthsMatch();
final int rightDepth = right.verifyDepthsMatch();
if (leftDepth != middleDepth || leftDepth != rightDepth) {
throw new RuntimeException(String.format("depth mismatch %d %d %d", leftDepth, middleDepth, rightDepth));
}
return leftDepth + 1;
}
@Override
public DeleteResult delete(Comparator comparator,
K key)
{
if (comparator.compare(key, leftMaxKey) <= 0) {
DeleteResult result = left.delete(comparator, key);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return DeleteResult.createInPlace(new ThreeNode(result.node,
middle,
right,
result.node.getMaxKey(),
middleMaxKey,
rightMaxKey));
case ELIMINATED:
return DeleteResult.createInPlace(new TwoNode(middle,
right,
middleMaxKey,
rightMaxKey));
case REMNANT:
DeleteMergeResult mergeResult = middle.leftDeleteMerge(comparator, result.node);
if (mergeResult.right == null) {
return DeleteResult.createInPlace(mergeResult.createLeftTwoNode(right, rightMaxKey));
} else {
return DeleteResult.createInPlace(mergeResult.createLeftThreeNode(right, rightMaxKey));
}
}
} else if (comparator.compare(key, middleMaxKey) <= 0) {
DeleteResult result = middle.delete(comparator, key);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return DeleteResult.createInPlace(new ThreeNode(left,
result.node,
right,
leftMaxKey,
result.node.getMaxKey(),
rightMaxKey));
case ELIMINATED:
return DeleteResult.createInPlace(new TwoNode(left,
right,
leftMaxKey,
rightMaxKey));
case REMNANT:
DeleteMergeResult mergeResult = right.leftDeleteMerge(comparator, result.node);
if (mergeResult.right == null) {
return DeleteResult.createInPlace(mergeResult.createRightTwoNode(left, leftMaxKey));
} else {
return DeleteResult.createInPlace(mergeResult.createRightThreeNode(left, leftMaxKey));
}
}
} else {
DeleteResult result = right.delete(comparator, key);
switch (result.type) {
case UNCHANGED:
return result;
case INPLACE:
return DeleteResult.createInPlace(new ThreeNode(left,
middle,
result.node,
leftMaxKey,
middleMaxKey,
result.node.getMaxKey()));
case ELIMINATED:
return DeleteResult.createInPlace(new TwoNode(left,
middle,
leftMaxKey,
middleMaxKey));
case REMNANT:
DeleteMergeResult mergeResult = middle.rightDeleteMerge(comparator, result.node);
if (mergeResult.right == null) {
return DeleteResult.createInPlace(mergeResult.createRightTwoNode(left, leftMaxKey));
} else {
return DeleteResult.createInPlace(mergeResult.createRightThreeNode(left, leftMaxKey));
}
}
}
throw new RuntimeException();
}
@Override
public DeleteMergeResult leftDeleteMerge(Comparator props,
TreeNode node)
{
return new DeleteMergeResult(new TwoNode(node,
left,
node.getMaxKey(),
leftMaxKey),
new TwoNode(middle,
right,
middleMaxKey,
rightMaxKey));
}
@Override
public DeleteMergeResult rightDeleteMerge(Comparator props,
TreeNode node)
{
return new DeleteMergeResult(new TwoNode(left,
middle,
leftMaxKey,
middleMaxKey),
new TwoNode(right,
node,
rightMaxKey,
node.getMaxKey()));
}
@Override
public String toString()
{
return String.format("(%s,%s,%s)", left, middle, right);
}
@Override
public Cursor> cursor()
{
return MultiCursor.of(LazyCursor.of(left), LazyCursor.of(middle), LazyCursor.of(right));
}
}