FastByteArrayInputStream.java

package org.overture.codegen.runtime.copying;

import java.io.InputStream;

/**
 * ByteArrayInputStream implementation that does not synchronize methods.
 */
public class FastByteArrayInputStream extends InputStream
{
	/**
	 * Our byte buffer
	 */
	protected byte[] buf = null;

	/**
	 * Number of bytes that we can read from the buffer
	 */
	protected int count = 0;

	/**
	 * Number of bytes that have been read from the buffer
	 */
	protected int pos = 0;

	public FastByteArrayInputStream(byte[] buf, int count)
	{
		this.buf = buf;
		this.count = count;
	}

	public final int available()
	{
		return count - pos;
	}

	public final int read()
	{
		return pos < count ? buf[pos++] & 0xff : -1;
	}

	public final int read(byte[] b, int off, int len)
	{
		if (pos >= count)
		{
			return -1;
		}

		if (pos + len > count)
		{
			len = count - pos;
		}

		System.arraycopy(buf, pos, b, off, len);
		pos += len;
		return len;
	}

	public final long skip(long n)
	{
		if (pos + n > count)
		{
			n = count - pos;
		}
		if (n < 0)
		{
			return 0;
		}
		pos += n;
		return n;
	}

}