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VoltDB client interface libraries
/* This file is part of VoltDB.
* Copyright (C) 2008-2017 VoltDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see .
*/
package org.voltcore.utils;
import java.util.Collection;
import java.util.NavigableSet;
import java.util.concurrent.atomic.AtomicReference;
import com.google_voltpatches.common.base.Preconditions;
import com.google_voltpatches.common.collect.ForwardingNavigableSet;
import com.google_voltpatches.common.collect.ImmutableSortedSet;
public class COWNavigableSet> extends ForwardingNavigableSet {
private final AtomicReference> m_set;
public COWNavigableSet() {
m_set = new AtomicReference>(ImmutableSortedSet.of());
}
public COWNavigableSet(Collection c) {
Preconditions.checkNotNull(c);
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
for (E e : c) {
builder.add(e);
}
m_set = new AtomicReference>(builder.build());
}
@Override
protected NavigableSet delegate() {
return m_set.get();
}
@Override
public E pollFirst() {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
E first = null;
if (snapshot.size() > 0) {
first = snapshot.first();
} else {
return null;
}
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
builder.addAll(snapshot.tailSet(first, false));
if (m_set.compareAndSet(snapshot, builder.build())) {
return first;
}
}
}
@Override
public E pollLast() {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
E last = null;
if (snapshot.size() > 0) {
last = snapshot.last();
} else {
return null;
}
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
builder.addAll(snapshot.headSet(last, false));
if (m_set.compareAndSet(snapshot, builder.build())) {
return last;
}
}
}
@Override
public boolean add(E e) {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
if (snapshot.contains(e)) return false;
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
builder.addAll(snapshot);
builder.add(e);
if (m_set.compareAndSet(snapshot, builder.build())) {
return true;
}
}
}
@Override
public boolean addAll(Collection c) {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
boolean hadValues = false;
for (E e : c) {
if (!snapshot.contains(e)) {
builder.add(e);
hadValues = true;
}
}
if (hadValues) {
builder.addAll(snapshot);
if (m_set.compareAndSet(snapshot, builder.build())) {
return true;
}
} else {
return false;
}
}
}
@Override
public void clear() {
m_set.set(ImmutableSortedSet.of());
}
@Override
public boolean remove(Object o) {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
if (!snapshot.contains(o)) return false;
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
for (E e : snapshot) {
if (e.equals(o)) continue;
builder.add(e);
}
if (m_set.compareAndSet(snapshot, builder.build())) {
return true;
}
}
}
@Override
public boolean removeAll(Collection c) {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
boolean hadValues = false;
for (E e : snapshot) {
if (c.contains(e)) {
hadValues = true;
continue;
}
builder.add(e);
}
if (hadValues) {
if (m_set.compareAndSet(snapshot, builder.build())) {
return true;
}
} else {
return false;
}
}
}
@Override
public boolean retainAll(Collection c) {
while (true) {
ImmutableSortedSet snapshot = m_set.get();
ImmutableSortedSet.Builder builder = ImmutableSortedSet.naturalOrder();
boolean removedValues = false;
for (E e : snapshot) {
if (c.contains(e)) {
builder.add(e);
continue;
}
removedValues = true;
}
if (removedValues) {
if (m_set.compareAndSet(snapshot, builder.build())) {
return true;
}
} else {
return false;
}
}
}
}