package jnpf.fileStorage.dms;

import jnpf.exception.DataException;

import java.io.ByteArrayOutputStream;
import java.util.Arrays;
import java.util.Objects;

final class DmsBoundedByteArrayOutputStream extends ByteArrayOutputStream {
    private final long maximumBytes;
    private final String limitMessage;

    DmsBoundedByteArrayOutputStream(long maximumBytes, String limitMessage) {
        super(8192);
        if (maximumBytes < 0) {
            throw new IllegalArgumentException("maximumBytes must not be negative");
        }
        this.maximumBytes = maximumBytes;
        this.limitMessage = limitMessage;
    }

    @Override
    public synchronized void write(int value) {
        ensureCapacityFor(1);
        super.write(value);
    }

    @Override
    public synchronized void write(byte[] data, int offset, int length) {
        Objects.checkFromIndexSize(offset, length, data.length);
        ensureCapacityFor(length);
        super.write(data, offset, length);
    }

    private void ensureCapacityFor(int additionalBytes) {
        if ((long) count + additionalBytes > maximumBytes) {
            throw new DataException(limitMessage);
        }
    }

    synchronized byte[] toByteArrayAndRelease() {
        byte[] result = count == buf.length ? buf : Arrays.copyOf(buf, count);
        buf = new byte[0];
        count = 0;
        return result;
    }
}