org.bouncycastle.tsp.ers.ERSCachingData Maven / Gradle / Ivy
package org.bouncycastle.tsp.ers;
import java.util.HashMap;
import java.util.Map;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.operator.DigestCalculator;
/**
* An ERSData object that caches hash calculations.
*/
public abstract class ERSCachingData
implements ERSData
{
private Map preCalcs = new HashMap();
/**
* Generates a hash for the whole DataGroup.
*
* @param digestCalculator the {@link DigestCalculator} to use for computing the hash
* @return a hash that is representative of the whole DataGroup
*/
public byte[] getHash(DigestCalculator digestCalculator)
{
AlgorithmIdentifier digAlgID = digestCalculator.getAlgorithmIdentifier();
if (preCalcs.containsKey(digAlgID))
{
return (byte[])preCalcs.get(digAlgID);
}
byte[] hash = calculateHash(digestCalculator);
preCalcs.put(digAlgID, hash);
return hash;
}
protected abstract byte[] calculateHash(DigestCalculator digestCalculator);
}