org.javimmutable.collections.tree.LeafNode Maven / Gradle / Ivy

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///###////////////////////////////////////////////////////////////////////////
//
// Burton Computer Corporation
// http://www.burton-computer.com
//
// Copyright (c) 2014, Burton Computer Corporation
// All rights reserved.
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//     Redistributions in binary form must reproduce the above copyright
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package org.javimmutable.collections.tree;

import org.javimmutable.collections.Cursor;
import org.javimmutable.collections.Holder;
import org.javimmutable.collections.Holders;
import org.javimmutable.collections.JImmutableMap;
import org.javimmutable.collections.cursors.SingleValueCursor;

import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;
import java.util.Collection;
import java.util.Comparator;

@Immutable
public class LeafNode
        extends TreeNode
        implements JImmutableMap.Entry,
                   Holder
{
    private final K nodeKey;
    private final V value;

    public LeafNode(K key,
                    V value)
    {
        this.nodeKey = key;
        this.value = value;
    }

    @Nonnull
    public K getKey()
    {
        return nodeKey;
    }

    public V getValue()
    {
        return value;
    }

    public boolean isEmpty()
    {
        return false;
    }

    public boolean isFilled()
    {
        return true;
    }

    public V getValueOrNull()
    {
        return value;
    }

    public V getValueOr(V defaultValue)
    {
        return value;
    }

    @Override
    public V getValueOr(Comparator props,
                        K searchKey,
                        V defaultValue)
    {
        return props.compare(searchKey, nodeKey) == 0 ? value : defaultValue;
    }

    @Override
    public Holder find(Comparator props,
                          K searchKey)
    {
        return props.compare(searchKey, nodeKey) == 0 ? this : Holders.of();
    }

    @Override
    public Holder> findEntry(Comparator props,
                                                       K searchKey)
    {
        return props.compare(searchKey, nodeKey) == 0 ? Holders.>of(this) : Holders.>of();
    }

    @Override
    K getMaxKey()
    {
        return nodeKey;
    }

    @Override
    UpdateResult assignImpl(Comparator props,
                                  K key,
                                  V value)
    {
        final int diff = props.compare(key, nodeKey);
        if (diff == 0) {
            if (this.value == value) { // value identity - useful for sets, booleans, etc
                return UpdateResult.createUnchanged();
            } else {
                return UpdateResult.createInPlace(new LeafNode(key, value), 0);
            }
        } else if (diff < 0) {
            return UpdateResult.createSplit(new LeafNode(key, value), this, 1);
        } else {
            return UpdateResult.createSplit(this, new LeafNode(key, value), 1);
        }
    }

    @Override
    public void addEntriesTo(Collection> collection)
    {
        collection.add(this);
    }

    @Override
    public int verifyDepthsMatch()
    {
        return 1;
    }

    @Override
    DeleteResult deleteImpl(Comparator props,
                                  K key)
    {
        if (props.compare(key, nodeKey) == 0) {
            return DeleteResult.createEliminated();
        } else {
            return DeleteResult.createUnchanged();
        }
    }

    @Override
    DeleteMergeResult leftDeleteMerge(TreeNode node)
    {
        return new DeleteMergeResult(new TwoNode(node,
                                                             this,
                                                             node.getMaxKey(),
                                                             nodeKey));
    }

    @Override
    DeleteMergeResult rightDeleteMerge(TreeNode node)
    {
        return new DeleteMergeResult(new TwoNode(this,
                                                             node,
                                                             nodeKey,
                                                             node.getMaxKey()));
    }

    @Override
    public String toString()
    {
        return String.format("%s => %s", nodeKey, value);
    }

    @Override
    @Nonnull
    public Cursor> cursor()
    {
        return SingleValueCursor.>of(this);
    }

    @SuppressWarnings("RedundantIfStatement")
    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        LeafNode leafNode = (LeafNode)o;

        if (nodeKey != null ? !nodeKey.equals(leafNode.nodeKey) : leafNode.nodeKey != null) {
            return false;
        }
        if (value != null ? !value.equals(leafNode.value) : leafNode.value != null) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode()
    {
        int result = nodeKey != null ? nodeKey.hashCode() : 0;
        result = 31 * result + (value != null ? value.hashCode() : 0);
        return result;
    }
}