/*
 * Copyright 2016 the original author or authors.
 *
 * 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 org.gradle.api.internal.file;

import org.gradle.internal.serialize.Encoder;
import org.gradle.internal.serialize.kryo.KryoBackedEncoder;

import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.CRC32;
import java.util.zip.Checksum;

public class BufferedStreamingHasher {
    private final KryoBackedEncoder encoder;
    private final Checksum checksum;

    public BufferedStreamingHasher() {
        this.checksum = new CRC32();
        this.encoder = new KryoBackedEncoder(new OutputStream() {
            @Override
            public void write(int b) throws IOException {
                checksum.update(b);
            }

            @Override
            public void write(byte[] b, int off, int len) throws IOException {
                checksum.update(b, off, len);
            }
        });
    }

    public int checksum() {
        encoder.flush();
        return (int) checksum.getValue();
    }

    public Encoder getEncoder() {
        return encoder;
    }
}
