FastOutputStream.java

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2000-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: FastOutputStream.java,v 12.2 2005/08/01 20:25:22 mark Exp $
 */

package com.sleepycat.util;

import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

public class FastOutputStream extends OutputStream {

    public static final int DEFAULT_INIT_SIZE = 100;

    public static final int DEFAULT_BUMP_SIZE = 0;

    private int len;
    private int bumpLen;
    private byte[] buf;

    public FastOutputStream() {

        initBuffer(DEFAULT_INIT_SIZE, DEFAULT_BUMP_SIZE);
    }

    public FastOutputStream(int initialSize) {

        initBuffer(initialSize, DEFAULT_BUMP_SIZE);
    }

    public FastOutputStream(int initialSize, int bumpSize) {

        initBuffer(initialSize, bumpSize);
    }

    public FastOutputStream(byte[] buffer) {

        buf = buffer;
        bumpLen = DEFAULT_BUMP_SIZE;
    }

    public FastOutputStream(byte[] buffer, int bumpSize) {

        buf = buffer;
        bumpLen = bumpSize;
    }

    private void initBuffer(int bufferSize, int bumpLen) {
        buf = new byte[bufferSize];
        this.bumpLen = bumpLen;
    }

    // --- begin ByteArrayOutputStream compatible methods ---

    public int size() {

        return len;
    }

    public void reset() {

        len = 0;
    }

    public void write(int b) throws IOException {

        writeFast(b);
    }

    public void write(byte[] fromBuf) throws IOException {

        writeFast(fromBuf);
    }

    public void write(byte[] fromBuf, int offset, int length)
        throws IOException {

        writeFast(fromBuf, offset, length);
    }

    public void writeTo(OutputStream out) throws IOException {

        out.write(buf, 0, len);
    }

    public String toString() {

        return new String(buf, 0, len);
    }

    public String toString(String encoding)
        throws UnsupportedEncodingException {

        return new String(buf, 0, len, encoding);
    }

    public byte[] toByteArray() {

        byte[] toBuf = new byte[len];

        System.arraycopy(buf, 0, toBuf, 0, len);

        return toBuf;
    }

    // --- end ByteArrayOutputStream compatible methods ---

    public final void writeFast(int b) {

        if (len + 1 > buf.length)
            bump(1);

        buf[len++] = (byte) b;
    }

    public final void writeFast(byte[] fromBuf) {

        int needed = len + fromBuf.length - buf.length;
        if (needed > 0)
            bump(needed);

        System.arraycopy(fromBuf, 0, buf, len, fromBuf.length);
        len += fromBuf.length;
    }

    public final void writeFast(byte[] fromBuf, int offset, int length) {

        int needed = len + length - buf.length;
        if (needed > 0)
            bump(needed);

        System.arraycopy(fromBuf, offset, buf, len, length);
        len += length;
    }

    public byte[] getBufferBytes() {

        return buf;
    }

    public int getBufferOffset() {

        return 0;
    }

    public int getBufferLength() {

        return len;
    }

    public void makeSpace(int sizeNeeded) {

        int needed = len + sizeNeeded - buf.length;
        if (needed > 0)
            bump(needed);
    }

    public void addSize(int sizeAdded) {

        len += sizeAdded;
    }

    private void bump(int needed) {

        /* Double the buffer if the bumpLen is zero. */
        int bump = (bumpLen > 0) ? bumpLen : buf.length;

        byte[] toBuf = new byte[buf.length + needed + bump];

        System.arraycopy(buf, 0, toBuf, 0, len);

        buf = toBuf;
    }
}

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