org.jclouds.collect.InputSupplierMap.java Source code

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Here is the source code for org.jclouds.collect.InputSupplierMap.java

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/*
 * 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.jclouds.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import java.io.IOException;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import com.google.common.base.Function;
import com.google.common.base.Throwables;
import com.google.common.io.InputSupplier;

/**
 * 
 * 
 * @author Adrian Cole
 * 
 */
public class InputSupplierMap<K, V> extends AbstractMap<K, V> {
    private final Map<K, InputSupplier<V>> toMap;
    private final Function<V, InputSupplier<V>> putFunction;

    public InputSupplierMap(Map<K, InputSupplier<V>> toMap, Function<V, InputSupplier<V>> putFunction) {
        this.toMap = checkNotNull(toMap);
        this.putFunction = checkNotNull(putFunction);
    }

    @Override
    public int size() {
        return toMap.size();
    }

    @Override
    public V put(K key, V value) {
        V old = get(key);
        toMap.put(key, value != null ? putFunction.apply(value) : null);
        return old;
    }

    @Override
    public boolean containsKey(Object key) {
        return toMap.containsKey(key);
    }

    @Override
    public V get(Object key) {
        InputSupplier<V> value = toMap.get(key);
        try {
            return value != null ? value.getInput() : null;
        } catch (IOException e) {
            throw Throwables.propagate(e);
        }
    }

    @Override
    public V remove(Object key) {
        try {
            return toMap.containsKey(key) ? toMap.remove(key).getInput() : null;
        } catch (IOException e) {
            throw Throwables.propagate(e);
        }
    }

    @Override
    public void clear() {
        toMap.clear();
    }

    @Override
    public Set<Entry<K, V>> entrySet() {
        return new EntrySet();
    }

    private class EntrySet extends AbstractSet<Entry<K, V>> {
        @Override
        public int size() {
            return InputSupplierMap.this.size();
        }

        @Override
        public Iterator<Entry<K, V>> iterator() {
            final Iterator<java.util.Map.Entry<K, InputSupplier<V>>> mapIterator = toMap.entrySet().iterator();

            return new Iterator<Entry<K, V>>() {
                public boolean hasNext() {
                    return mapIterator.hasNext();
                }

                public Entry<K, V> next() {
                    final java.util.Map.Entry<K, InputSupplier<V>> entry = mapIterator.next();
                    return new AbstractMapEntry<K, V>() {
                        @Override
                        public K getKey() {
                            return entry.getKey();
                        }

                        @Override
                        public V getValue() {
                            try {
                                return entry.getValue().getInput();
                            } catch (IOException e) {
                                throw Throwables.propagate(e);
                            }
                        }
                    };
                }

                public void remove() {
                    mapIterator.remove();
                }
            };
        }

        @Override
        public void clear() {
            toMap.clear();
        }

        @Override
        public boolean contains(Object o) {
            if (!(o instanceof Entry)) {
                return false;
            }
            Entry<?, ?> entry = (Entry<?, ?>) o;
            Object entryKey = entry.getKey();
            Object entryValue = entry.getValue();
            V mapValue = InputSupplierMap.this.get(entryKey);
            if (mapValue != null) {
                return mapValue.equals(entryValue);
            }
            return entryValue == null && containsKey(entryKey);
        }

        @Override
        public boolean remove(Object o) {
            if (contains(o)) {
                Entry<?, ?> entry = (Entry<?, ?>) o;
                Object key = entry.getKey();
                toMap.remove(key);
                return true;
            }
            return false;
        }
    }
}