| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.johnzon.core; |
| |
| import java.io.Serializable; |
| import java.util.concurrent.ConcurrentLinkedQueue; |
| |
| public enum BufferStrategy { |
| BY_INSTANCE { |
| @Override |
| public BufferProvider<char[]> newCharProvider(final int size) { |
| return new CharBufferByInstanceProvider(size); |
| } |
| |
| @Override |
| public BufferProvider<StringBuilder> newStringBuilderProvider(final int size) { |
| return new StringBuilderByInstanceProvider(size); |
| } |
| }, |
| THREAD_LOCAL { |
| @Override |
| public BufferProvider<char[]> newCharProvider(final int size) { |
| return new CharBufferThreadLocalProvider(size); |
| } |
| |
| @Override |
| public BufferProvider<StringBuilder> newStringBuilderProvider(final int size) { |
| return new StringBuilderThreadLocalProvider(size); |
| } |
| }, |
| QUEUE { |
| @Override |
| public BufferProvider<char[]> newCharProvider(final int size) { |
| return new CharBufferQueueProvider(size); |
| } |
| |
| @Override |
| public BufferProvider<StringBuilder> newStringBuilderProvider(final int size) { |
| return new StringBuilderQueueProvider(size); |
| } |
| }, |
| SINGLETON { |
| @Override |
| public BufferProvider<char[]> newCharProvider(final int size) { |
| return new CharBufferSingletonProvider(size); |
| } |
| |
| @Override |
| public BufferProvider<StringBuilder> newStringBuilderProvider(final int size) { |
| return new StringBuilderSingletonProvider(size); |
| } |
| }; |
| |
| public abstract BufferProvider<char[]> newCharProvider(int size); |
| public abstract BufferProvider<StringBuilder> newStringBuilderProvider(int size); |
| |
| public static interface BufferProvider<T> extends Serializable { |
| T newBuffer(); |
| |
| void release(T value); |
| } |
| |
| private static class CharBufferSingletonProvider extends SingletonProvider<char[]> { |
| public CharBufferSingletonProvider(final int size) { |
| super(size); |
| } |
| |
| @Override |
| protected char[] newInstance(int size) { |
| return new char[size]; |
| } |
| |
| @Override |
| public void release(final char[] value) { |
| // no-op |
| } |
| } |
| |
| private static class StringBuilderSingletonProvider extends SingletonProvider<StringBuilder> { |
| public StringBuilderSingletonProvider(final int size) { |
| super(size); |
| } |
| |
| @Override |
| protected StringBuilder newInstance(final int size) { |
| return new StringBuilder(size); |
| } |
| |
| @Override |
| public void release(final StringBuilder value) { |
| value.setLength(0); |
| } |
| } |
| |
| private static abstract class SingletonProvider<T> implements BufferProvider<T> { |
| protected final T buffer; |
| |
| public SingletonProvider(final int size) { |
| buffer = newInstance(size); |
| } |
| |
| protected abstract T newInstance(int size); |
| |
| @Override |
| public T newBuffer() { |
| return buffer; |
| } |
| |
| @Override |
| public void release(final T value) { |
| // no-op |
| } |
| } |
| |
| private static abstract class ThreadLocalProvider<T> implements BufferProvider<T> { |
| private final ThreadLocalBufferCache<T> cache; |
| |
| public ThreadLocalProvider(final int size) { |
| cache = new ThreadLocalBufferCache<T>(size) { |
| @Override |
| protected T newValue(int defaultSize) { |
| return newInstance(size); |
| } |
| }; |
| } |
| |
| protected abstract T newInstance(int size); |
| |
| @Override |
| public T newBuffer() { |
| return cache.getCache(); |
| } |
| |
| @Override |
| public void release(final T value) { |
| cache.release(value); |
| } |
| } |
| |
| private static class CharBufferThreadLocalProvider extends ThreadLocalProvider<char[]> { |
| public CharBufferThreadLocalProvider(int size) { |
| super(size); |
| } |
| |
| @Override |
| protected char[] newInstance(final int size) { |
| return new char[size]; |
| } |
| } |
| |
| private static class StringBuilderThreadLocalProvider extends ThreadLocalProvider<StringBuilder> { |
| public StringBuilderThreadLocalProvider(int size) { |
| super(size); |
| } |
| |
| @Override |
| protected StringBuilder newInstance(final int size) { |
| return new StringBuilder(size); |
| } |
| |
| @Override |
| public void release(final StringBuilder value) { |
| value.setLength(0); |
| super.release(value); |
| } |
| } |
| |
| private static class CharBufferByInstanceProvider implements BufferProvider<char[]> { |
| private final int size; |
| |
| public CharBufferByInstanceProvider(final int size) { |
| this.size = size; |
| } |
| |
| @Override |
| public char[] newBuffer() { |
| return new char[size]; |
| } |
| |
| @Override |
| public void release(final char[] value) { |
| // no-op |
| } |
| } |
| |
| private static class StringBuilderByInstanceProvider implements BufferProvider<StringBuilder> { |
| private final int size; |
| |
| public StringBuilderByInstanceProvider(final int size) { |
| this.size = size; |
| } |
| |
| @Override |
| public StringBuilder newBuffer() { |
| return new StringBuilder(size); |
| } |
| |
| @Override |
| public void release(final StringBuilder value) { |
| // no-op |
| } |
| } |
| |
| private static abstract class QueueProvider<T> implements BufferProvider<T> { |
| private final int size; |
| private final ConcurrentLinkedQueue<T> queue = new ConcurrentLinkedQueue<T>(); |
| |
| public QueueProvider(final int size) { |
| this.size = size; |
| } |
| |
| protected abstract T newInstance(int size); |
| |
| @Override |
| public T newBuffer() { |
| final T buffer = queue.poll(); |
| if (buffer == null) { |
| return newInstance(size); |
| } |
| return buffer; |
| } |
| |
| @Override |
| public void release(final T value) { |
| queue.offer(value); |
| } |
| } |
| |
| private static class CharBufferQueueProvider extends QueueProvider<char[]> { |
| public CharBufferQueueProvider(final int size) { |
| super(size); |
| } |
| |
| @Override |
| protected char[] newInstance(int size) { |
| return new char[size]; |
| } |
| } |
| |
| private static class StringBuilderQueueProvider extends QueueProvider<StringBuilder> { |
| public StringBuilderQueueProvider(final int size) { |
| super(size); |
| } |
| |
| @Override |
| protected StringBuilder newInstance(int size) { |
| return new StringBuilder(size); |
| } |
| |
| @Override |
| public void release(final StringBuilder value) { |
| value.setLength(0); |
| super.release(value); |
| } |
| } |
| } |