uk.ac.ed.inf.ace.utils.SparseMatrix.java Source code

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Here is the source code for uk.ac.ed.inf.ace.utils.SparseMatrix.java

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/*
 * Copyright 2012 Daniel Renshaw <d.renshaw@sms.ed.ac.uk>.
 *
 * 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 uk.ac.ed.inf.ace.utils;

import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author "Daniel Renshaw" <d.renshaw@sms.ed.ac.uk>
 */
public class SparseMatrix<K, V> extends HashMap<List<K>, V> {

    private final int dimensions;

    public SparseMatrix(int dimensions) {
        Preconditions.checkArgument(dimensions > 1);
        this.dimensions = dimensions;
    }

    public V put(K key1, K key2, V value) {
        return put(ImmutableList.<K>builder().add(key1).add(key2).build(), value);
    }

    public V put(K key1, K key2, K key3, V value) {
        return put(ImmutableList.<K>builder().add(key1).add(key2).add(key3).build(), value);
    }

    public V get(K key1, K key2) {
        return get(ImmutableList.<K>builder().add(key1).add(key2).build());
    }

    public V get(K key1, K key2, K key3) {
        return get(ImmutableList.<K>builder().add(key1).add(key2).add(key3).build());
    }

    @Override
    public V put(List<K> keys, V value) {
        Preconditions.checkState(keys.size() == dimensions, "Dimensions mismatch");
        return super.put(keys, value);
    }

    private final Predicate<List<K>> CORRECT_SIZE = new Predicate<List<K>>() {
        @Override
        public boolean apply(List<K> keys) {
            return keys.size() == dimensions;
        }
    };

    @Override
    public void putAll(Map<? extends List<K>, ? extends V> m) {
        Preconditions.checkState(Iterables.all(m.keySet(), CORRECT_SIZE), "Dimensions mismatch");
        super.putAll(m);
    }
}