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Groovy example source code file (AbstractConcurrentMap.java)

This example Groovy source code file (AbstractConcurrentMap.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Groovy tags/keywords

abstractconcurrentmap, abstractconcurrentmapbase, entry, entry, object, object, segment, segment, v, v

The Groovy AbstractConcurrentMap.java source code

/*
 * Copyright 2003-2010 the original author or authors.
 *
 * Licensed 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.codehaus.groovy.util;

public abstract class AbstractConcurrentMap<K, V> extends AbstractConcurrentMapBase {

    public AbstractConcurrentMap(Object segmentInfo) {
        super(segmentInfo);
    }

    public Segment segmentFor (int hash) {
        return (Segment) super.segmentFor(hash);
    }

    public V get(K key) {
        int hash = hash(key);
        return (V) segmentFor(hash).get(key, hash);
    }

    public Entry<K,V> getOrPut(K key, V value) {
        int hash = hash(key);
        return segmentFor(hash).getOrPut(key, hash, value);
    }

    public void put(K key, V value) {
        int hash = hash(key);
        segmentFor(hash).put(key, hash, value);
    }

    public void remove(K key) {
        int hash = hash(key);
        segmentFor(hash).remove(key, hash);
    }

    public abstract static class Segment<K,V> extends AbstractConcurrentMapBase.Segment {

        protected Segment(int initialCapacity) {
            super(initialCapacity);
        }

        public final V get(K key, int hash) {
            Object[] tab = table;
            Object o = tab[hash & (tab.length - 1)];
            if (o != null) {
                if (o instanceof Entry) {
                    Entry<K,V> e = (Entry) o;
                    if (e.isEqual(key, hash)) {
                        return e.getValue();
                    }
                }
                else {
                    Object arr [] = (Object[]) o;
                    for (int i = 0; i < arr.length; i++) {
                        Entry<K,V> e = (Entry) arr[i];
                        if (e != null && e.isEqual(key, hash)) {
                            return e.getValue();
                        }
                    }
                }
            }
            return null;
        }

        public final Entry<K,V> getOrPut(K key, int hash, V value) {
            Object[] tab = table;
            Object o = tab[hash & (tab.length - 1)];
            if (o != null) {
                if (o instanceof Entry) {
                    Entry<K,V> e = (Entry) o;
                    if (e.isEqual(key, hash)) {
                        return e;
                    }
                }
                else {
                    Object arr [] = (Object[]) o;
                    for (int i = 0; i < arr.length; i++) {
                        Entry<K,V> e = (Entry) arr[i];
                        if (e != null && e.isEqual(key, hash)) {
                            return e;
                        }
                    }
                }
            }
            return put(key, hash, value);
        }

        public final Entry put(K key, int hash, V value) {
            lock();
            try {
                int c = count;
                if (c++ > threshold) {
                    rehash();
                }

                Object[] tab = table;
                int index = hash & (tab.length - 1);
                Object o = tab[index];
                if (o != null) {
                    if (o instanceof Entry) {
                        Entry e = (Entry) o;
                        if (e.isEqual(key, hash)) {
                            e.setValue(value);
                            return e;
                        }
                        else {
                            Object arr [] = new Object [2];
                            final Entry ee = createEntry(key, hash, value);
                            arr [0] = ee;
                            arr [1] = e;
                            tab[index] = arr;
                            count = c;
                            return ee;
                        }
                    }
                    else {
                        Object arr [] = (Object[]) o;
                        for (int i = 0; i < arr.length; i++) {
                            Entry e = (Entry) arr[i];
                            if (e != null && e.isEqual(key, hash)) {
                                e.setValue(value);
                                return e;
                            }
                        }

                        final Entry ee = createEntry(key, hash, value);
                        for (int i = 0; i < arr.length; i++) {
                            Entry e = (Entry) arr[i];
                            if (e == null) {
                                arr [i] = ee;
                                count = c;
                                return ee;
                            }
                        }

                        Object newArr [] = new Object[arr.length+1];
                        newArr [0] = ee;
                        System.arraycopy(arr, 0, newArr, 1, arr.length);
                        tab [index] = newArr;
                        count = c;
                        return ee;
                    }
                }

                Entry e = createEntry(key, hash, value);
                tab[index] = e;
                count = c; // write-volatile
                return e;
            } finally {
                unlock();
            }
        }

        public void remove(K key, int hash) {
            lock();
            try {
                int c = count-1;
                final Object[] tab = table;
                final int index = hash & (tab.length - 1);
                Object o = tab[index];

                if (o != null) {
                    if (o instanceof Entry) {
                        if (((Entry<K,V>)o).isEqual(key, hash)) {
                          tab[index] = null;
                          count = c;
                        }
                    }
                    else {
                        Object arr [] = (Object[]) o;
                        for (int i = 0; i < arr.length; i++) {
                            Entry<K,V> e = (Entry) arr[i];
                            if (e != null && e.isEqual(key, hash)) {
                                arr [i] = null;
                                count = c;
                                break;
                            }
                        }
                    }
                }
            }
            finally {
                unlock();
            }
        }

        protected abstract Entry<K,V> createEntry(K key, int hash, V value);
    }

    public interface Entry<K, V> extends AbstractConcurrentMapBase.Entry{
        boolean isEqual(K key, int hash);
    }
}

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