parse KiB and MiB to bytes

HumanReadableByteParser.java

package io.github.lumue.ydlwrapper;

import java.math.BigDecimal;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.function.Function;

/**
 *
 * Parse byte value from human readable format
 *
 * Created by lm on 09.03.16.
 */
public class HumanReadableByteParser implements Function<String,Long>{



	public static class ValueConverter  implements Function<BigDecimal,Long> {
		private final BigDecimal faktor;

		private ValueConverter(BigDecimal faktor) {
			this.faktor = Objects.requireNonNull(faktor,"faktor must not be null");
		}

		public Long apply(BigDecimal input){
			Objects.requireNonNull(input,"input must not be null");
			return input.multiply(faktor).longValue();
		}
	}

	private final static ValueConverter KIB_CONVERTER=new ValueConverter(new BigDecimal(1024));

	private final static ValueConverter MIB_CONVERTER=new ValueConverter(new BigDecimal(1024*1024));



	@Override
	public Long apply(String input) {
		Objects.requireNonNull(input,"input must not be null");
		if(input.endsWith("MiB"))
			return MIB_CONVERTER.apply(new BigDecimal(input.substring(0, input.length() - 3)));
		if(input.endsWith("KiB"))
			return KIB_CONVERTER.apply(new BigDecimal(input.substring(0, input.length() - 3)));
		throw new IllegalArgumentException("failure parsing "+input);
	}

}