org.javimmutable.collections.hash.SingleHashValueListNode Maven / Gradle / Ivy

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//
// Burton Computer Corporation
// http://www.burton-computer.com
//
// Copyright (c) 2017, 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.hash;

import org.javimmutable.collections.Cursor;
import org.javimmutable.collections.Holder;
import org.javimmutable.collections.Holders;
import org.javimmutable.collections.JImmutableMap;
import org.javimmutable.collections.SplitableIterator;
import org.javimmutable.collections.common.MutableDelta;
import org.javimmutable.collections.cursors.SingleValueCursor;
import org.javimmutable.collections.iterators.SingleValueIterator;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;

@Immutable
class SingleHashValueListNode
    implements HashValueListNode,
               JImmutableMap.Entry,
               Holder
{
    private final K key;
    private final V value;

    private SingleHashValueListNode(K key,
                                    V value)
    {
        this.key = key;
        this.value = value;
    }

    static  SingleHashValueListNode of(K key,
                                                   V value)
    {
        return new SingleHashValueListNode(key, value);
    }

    @Override
    public Holder getValueForKey(K key)
    {
        return this.key.equals(key) ? this : Holders.of();
    }

    @Override
    public JImmutableMap.Entry getEntryForKey(K key)
    {
        return this.key.equals(key) ? this : null;
    }

    @Override
    public HashValueListNode setValueForKey(K key,
                                                  V value,
                                                  MutableDelta sizeDelta)
    {
        if (key.equals(this.key)) {
            return (this.value == value) ? this : new SingleHashValueListNode(key, value);
        } else {
            sizeDelta.add(1);
            return MultiHashValueListNode.of(this, new SingleHashValueListNode(key, value));
        }
    }

    @Override
    public HashValueListNode deleteValueForKey(K key,
                                                     MutableDelta sizeDelta)
    {
        if (this.key.equals(key)) {
            sizeDelta.subtract(1);
            return null;
        } else {
            return this;
        }
    }

    @Nonnull
    @Override
    public K getKey()
    {
        return key;
    }

    @Override
    public V getValue()
    {
        return value;
    }

    @Override
    public boolean isEmpty()
    {
        return false;
    }

    @Override
    public boolean isFilled()
    {
        return true;
    }

    @Override
    public V getValueOrNull()
    {
        return value;
    }

    @Override
    public V getValueOr(@Nullable V defaultValue)
    {
        return value;
    }

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

    @Nonnull
    @Override
    public SplitableIterator> iterator()
    {
        return SingleValueIterator.of(this);
    }

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

        SingleHashValueListNode that = (SingleHashValueListNode)o;

        if (key != null ? !key.equals(that.key) : that.key != null) {
            return false;
        }
        //noinspection RedundantIfStatement
        if (value != null ? !value.equals(that.value) : that.value != null) {
            return false;
        }

        return true;
    }

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

    @Override
    public String toString()
    {
        return "SingleValueLeafNode{" +
               "key=" + key +
               ", value=" + value +
               '}';
    }
}