ch.sourcepond.io.checksum.impl.pools.DigesterPool Maven / Gradle / Ivy

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/*Copyright (C) 2017 Roland Hauser, 

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 ch.sourcepond.io.checksum.impl.pools;

import ch.sourcepond.io.checksum.api.Algorithm;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Pool of {@link MessageDigest} instances.
 */
public class DigesterPool extends BasePool {
    private final Algorithm algorithm;

    public DigesterPool(final Algorithm pAlgorithm) {
        algorithm = pAlgorithm;
    }

    public Algorithm getAlgorithm() {
        return algorithm;
    }

    @Override
    MessageDigest newPooledObject() {
        try {
            return MessageDigest.getInstance(algorithm.toString());
        } catch (final NoSuchAlgorithmException e) {
            // This can never happen because the algorithm specified by the Algorithm
            // enum is valid
            throw new IllegalStateException(e.getMessage(), e);
        }
    }

    @Override
    void pooledObjectReleased(final MessageDigest pPooledObject) {
        // In any case reset the digest
        pPooledObject.reset();
    }
}