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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,
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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package org.javimmutable.collections.tree;
import org.javimmutable.collections.Cursor;
import org.javimmutable.collections.Cursorable;
import org.javimmutable.collections.Holder;
import org.javimmutable.collections.JImmutableMap;
import org.javimmutable.collections.common.MutableDelta;
import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;
import java.util.Collection;
import java.util.Comparator;
/**
* Abstract base class for 2-3 tree nodes. Provides public methods for searching and modifying
* the tree and package private methods used to implement the public methods.
*
* @param
* @param
*/
@Immutable
public abstract class TreeNode
implements Cursorable>
{
public static TreeNode of()
{
return EmptyNode.of();
}
/**
* Return the value matching key or defaultValue if no match is found. Searches this node
* and its appropriate children.
*
* @param comparator
* @param key
* @param defaultValue
* @return
*/
public abstract V getValueOr(Comparator comparator,
K key,
V defaultValue);
/**
* Return a (possibly empty) Holder containing the value matching key. Searches this node
* and its appropriate children.
*
* @param comparator
* @param key
* @return
*/
public abstract Holder find(Comparator comparator,
K key);
/**
* Return a (possibly empty) Holder containing the an Entry matching key. Searches this node
* and its appropriate children.
*
* @param comparator
* @param key
* @return
*/
public abstract Holder> findEntry(Comparator comparator,
K key);
/**
* Adds this node's value and all of its children's value to the collection.
*
* @param collection
*/
public abstract void addEntriesTo(Collection> collection);
/**
* Returns a Cursor visiting all entries in sorted order.
*
* @return
*/
@Nonnull
public abstract Cursor> cursor();
/**
* Assign the specified value to the specified key. Returns a node (possibly this same node)
* reflecting the assignment and updates sizeDelta with the change in size (if any).
*
* @param comparator
* @param key
* @param value
* @param sizeDelta
* @return
*/
public TreeNode assign(Comparator comparator,
K key,
V value,
MutableDelta sizeDelta)
{
UpdateResult result = assignImpl(comparator, key, value);
switch (result.type) {
case UNCHANGED:
return this;
case INPLACE:
sizeDelta.add(result.sizeDelta);
return result.newNode;
case SPLIT:
sizeDelta.add(result.sizeDelta);
return new TwoNode(result.newNode,
result.extraNode,
result.newNode.getMaxKey(),
result.extraNode.getMaxKey());
}
throw new RuntimeException();
}
/**
* Deletes the specified key. Returns a node (possibly this same node)
* reflecting the deletion and updates sizeDelta with the change in size (if any).
*
* @param comparator
* @param key
* @param sizeDelta
* @return
*/
public TreeNode delete(Comparator comparator,
K key,
MutableDelta sizeDelta)
{
DeleteResult result = deleteImpl(comparator, key);
switch (result.type) {
case UNCHANGED:
return this;
default:
sizeDelta.subtract(1);
return result.node;
}
}
/**
* Return true if this node contains no children or value.
*
* @return
*/
public boolean isEmpty()
{
return false;
}
abstract int verifyDepthsMatch();
abstract K getMaxKey();
abstract UpdateResult assignImpl(Comparator comparator,
K key,
V value);
abstract DeleteResult deleteImpl(Comparator comparator,
K key);
abstract DeleteMergeResult leftDeleteMerge(TreeNode node);
abstract DeleteMergeResult rightDeleteMerge(TreeNode node);
}