/*

 * Copyright (c) 1996, 2009, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.util.zip;

import java.io.FilterOutputStream;

import java.io.OutputStream;

import java.io.InputStream;

import java.io.IOException;

/**

 * This class implements an output stream filter for compressing data in

 * the "deflate" compression format. It is also used as the basis for other

 * types of compression filters, such as GZIPOutputStream.

 *

 * @see         Deflater

 * @author      David Connelly

 */

public

class DeflaterOutputStream extends FilterOutputStream {

    /**

     * Compressor for this stream.

     */

    protected Deflater def;

    /**

     * Output buffer for writing compressed data.

     */

    protected byte[] buf;

    /**

     * Indicates that the stream has been closed.

     */

    private boolean closed = false;

    private final boolean syncFlush;

    /**

     * Creates a new output stream with the specified compressor,

     * buffer size and flush mode.

     * @param out the output stream

     * @param def the compressor ("deflater")

     * @param size the output buffer size

     * @param syncFlush

     *        if {@code true} the {@link #flush()} method of this

     *        instance flushes the compressor with flush mode

     *        {@link Deflater#SYNC_FLUSH} before flushing the output

     *        stream, otherwise only flushes the output stream

     *

     * @throws IllegalArgumentException if size is <= 0

     *

     * @since 1.7

     */

    public DeflaterOutputStream(OutputStream out,

                                Deflater def,

                                int size,

                                boolean syncFlush) {

        super(out);

        if (out == null || def == null) {

            throw new NullPointerException();

        } else if (size <= 0) {

            throw new IllegalArgumentException("buffer size <= 0");

        }

        this.def = def;

        this.buf = new byte[size];

        this.syncFlush = syncFlush;

    }

    /**

     * Creates a new output stream with the specified compressor and

     * buffer size.

     *

     * <p>The new output stream instance is created as if by invoking

     * the 4-argument constructor DeflaterOutputStream(out, def, size, false).

     *

     * @param out the output stream

     * @param def the compressor ("deflater")

     * @param size the output buffer size

     * @exception IllegalArgumentException if size is <= 0

     */

    public DeflaterOutputStream(OutputStream out, Deflater def, int size) {

        this(out, def, size, false);

    }

    /**

     * Creates a new output stream with the specified compressor, flush

     * mode and a default buffer size.

     *

     * @param out the output stream

     * @param def the compressor ("deflater")

     * @param syncFlush

     *        if {@code true} the {@link #flush()} method of this

     *        instance flushes the compressor with flush mode

     *        {@link Deflater#SYNC_FLUSH} before flushing the output

     *        stream, otherwise only flushes the output stream

     *

     * @since 1.7

     */

    public DeflaterOutputStream(OutputStream out,

                                Deflater def,

                                boolean syncFlush) {

        this(out, def, 512, syncFlush);

    }

    /**

     * Creates a new output stream with the specified compressor and

     * a default buffer size.

     *

     * <p>The new output stream instance is created as if by invoking

     * the 3-argument constructor DeflaterOutputStream(out, def, false).

     *

     * @param out the output stream

     * @param def the compressor ("deflater")

     */

    public DeflaterOutputStream(OutputStream out, Deflater def) {

        this(out, def, 512, false);

    }

    boolean usesDefaultDeflater = false;

    /**

     * Creates a new output stream with a default compressor, a default

     * buffer size and the specified flush mode.

     *

     * @param out the output stream

     * @param syncFlush

     *        if {@code true} the {@link #flush()} method of this

     *        instance flushes the compressor with flush mode

     *        {@link Deflater#SYNC_FLUSH} before flushing the output

     *        stream, otherwise only flushes the output stream

     *

     * @since 1.7

     */

    public DeflaterOutputStream(OutputStream out, boolean syncFlush) {

        this(out, new Deflater(), 512, syncFlush);

        usesDefaultDeflater = true;

    }

    /**

     * Creates a new output stream with a default compressor and buffer size.

     *

     * <p>The new output stream instance is created as if by invoking

     * the 2-argument constructor DeflaterOutputStream(out, false).

     *

     * @param out the output stream

     */

    public DeflaterOutputStream(OutputStream out) {

        this(out, false);

        usesDefaultDeflater = true;

    }

    /**

     * Writes a byte to the compressed output stream. This method will

     * block until the byte can be written.

     * @param b the byte to be written

     * @exception IOException if an I/O error has occurred

     */

    public void write(int b) throws IOException {

        byte[] buf = new byte[1];

        buf[0] = (byte)(b & 0xff);

        write(buf, 0, 1);

    }

    /**

     * Writes an array of bytes to the compressed output stream. This

     * method will block until all the bytes are written.

     * @param b the data to be written

     * @param off the start offset of the data

     * @param len the length of the data

     * @exception IOException if an I/O error has occurred

     */

    public void write(byte[] b, int off, int len) throws IOException {

        if (def.finished()) {

            throw new IOException("write beyond end of stream");

        }

        if ((off | len | (off + len) | (b.length - (off + len))) < 0) {

            throw new IndexOutOfBoundsException();

        } else if (len == 0) {

            return;

        }

        if (!def.finished()) {

            // Deflate no more than stride bytes at a time.  This avoids

            // excess copying in deflateBytes (see Deflater.c)

            int stride = buf.length;

            for (int i = 0; i < len; i+= stride) {

                def.setInput(b, off + i, Math.min(stride, len - i));

                while (!def.needsInput()) {

                    deflate();

                }

            }

        }

    }

    /**

     * Finishes writing compressed data to the output stream without closing

     * the underlying stream. Use this method when applying multiple filters

     * in succession to the same output stream.

     * @exception IOException if an I/O error has occurred

     */

    public void finish() throws IOException {

        if (!def.finished()) {

            def.finish();

            while (!def.finished()) {

                deflate();

            }

        }

    }

    /**

     * Writes remaining compressed data to the output stream and closes the

     * underlying stream.

     * @exception IOException if an I/O error has occurred

     */

    public void close() throws IOException {

        if (!closed) {

            finish();

            if (usesDefaultDeflater)

                def.end();

            out.close();

            closed = true;

        }

    }

    /**

     * Writes next block of compressed data to the output stream.

     * @throws IOException if an I/O error has occurred

     */

    protected void deflate() throws IOException {

        int len = def.deflate(buf, 0, buf.length);

        if (len > 0) {

            out.write(buf, 0, len);

        }

    }

    /**

     * Flushes the compressed output stream.

     *

     * If {@link #DeflaterOutputStream(OutputStream, Deflater, int, boolean)

     * syncFlush} is {@code true} when this compressed output stream is

     * constructed, this method first flushes the underlying {@code compressor}

     * with the flush mode {@link Deflater#SYNC_FLUSH} to force

     * all pending data to be flushed out to the output stream and then

     * flushes the output stream. Otherwise this method only flushes the

     * output stream without flushing the {@code compressor}.

     *

     * @throws IOException if an I/O error has occurred

     *

     * @since 1.7

     */

    public void flush() throws IOException {

        if (syncFlush && !def.finished()) {

            int len = 0;

            while ((len = def.deflate(buf, 0, buf.length, Deflater.SYNC_FLUSH)) > 0)

            {

                out.write(buf, 0, len);

                if (len < buf.length)

                    break;

            }

        }

        out.flush();

    }

}