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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) 2017, 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
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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.Sequence;
import org.javimmutable.collections.common.EmptySequence;
import org.javimmutable.collections.common.MutableDelta;
import org.javimmutable.collections.cursors.SequenceCursor;
import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;
@Immutable
class MultiHashValueListNode
implements HashValueListNode,
Sequence>
{
private final MultiHashValueListNode next;
private final SingleHashValueListNode entry;
private MultiHashValueListNode(MultiHashValueListNode next,
SingleHashValueListNode entry)
{
this.next = next;
this.entry = entry;
}
static MultiHashValueListNode of(K key,
V value)
{
return new MultiHashValueListNode(null, SingleHashValueListNode.of(key, value));
}
static MultiHashValueListNode of(SingleHashValueListNode entry1,
SingleHashValueListNode entry2)
{
return new MultiHashValueListNode(new MultiHashValueListNode(null, entry1), entry2);
}
static MultiHashValueListNode of(SingleHashValueListNode entry1,
SingleHashValueListNode entry2,
SingleHashValueListNode entry3)
{
return new MultiHashValueListNode(new MultiHashValueListNode(new MultiHashValueListNode(null, entry1), entry2), entry3);
}
@Override
public Holder getValueForKey(K key)
{
SingleHashValueListNode answer = getEntryForKeyImpl(key);
if (answer != null) {
return answer;
} else {
return Holders.of();
}
}
@Override
public JImmutableMap.Entry getEntryForKey(K key)
{
return getEntryForKeyImpl(key);
}
@Override
public MultiHashValueListNode setValueForKey(K key,
V value,
MutableDelta sizeDelta)
{
SingleHashValueListNode entry = getEntryForKeyImpl(key);
if (entry == null) {
sizeDelta.add(1);
return new MultiHashValueListNode(this, SingleHashValueListNode.of(key, value));
} else if (entry.getValue() == value) {
return this;
} else {
return new MultiHashValueListNode(removeKeyFromList(key), SingleHashValueListNode.of(key, value));
}
}
@Override
public HashValueListNode deleteValueForKey(K key,
MutableDelta sizeDelta)
{
if (getEntryForKey(key) == null) {
return this;
}
MultiHashValueListNode newList = removeKeyFromList(key);
sizeDelta.subtract(1);
return (newList != null && newList.next == null) ? newList.entry : newList;
}
@Override
public boolean isEmpty()
{
return false;
}
@Override
public JImmutableMap.Entry getHead()
{
return entry;
}
@Nonnull
@Override
public Sequence> getTail()
{
if (next == null) {
return EmptySequence.of();
} else {
return next;
}
}
@Override
@Nonnull
public Cursor> cursor()
{
return SequenceCursor.of(this);
}
@Override
public boolean equals(Object o)
{
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
MultiHashValueListNode that = (MultiHashValueListNode)o;
if (entry != null ? !entry.equals(that.entry) : that.entry != null) {
return false;
}
//noinspection RedundantIfStatement
if (next != null ? !next.equals(that.next) : that.next != null) {
return false;
}
return true;
}
@Override
public int hashCode()
{
int result = next != null ? next.hashCode() : 0;
result = 31 * result + (entry != null ? entry.hashCode() : 0);
return result;
}
@Override
public String toString()
{
return "MultiValueLeafNode{" +
"next=" + next +
", entry=" + entry +
'}';
}
private MultiHashValueListNode removeKeyFromList(K key)
{
MultiHashValueListNode newList = null;
for (MultiHashValueListNode node = this; node != null; node = node.next) {
if (!node.keyEquals(key)) {
newList = new MultiHashValueListNode(newList, node.entry);
}
}
return newList;
}
private SingleHashValueListNode getEntryForKeyImpl(K key)
{
for (MultiHashValueListNode node = this; node != null; node = node.next) {
if (node.keyEquals(key)) {
return node.entry;
}
}
return null;
}
private boolean keyEquals(K key)
{
return key.equals(entry.getKey());
}
}