/*

 * 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.

 *

 * 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.

 */

/* @test

 * @bug 4691425

 * @summary Test the read and write of GZIPInput/OutputStream, including

 *          concatenated .gz inputstream

 */

import java.io.*;

import java.util.*;

import java.util.zip.*;

public class GZIPInputStreamRead {

    public static void main(String[] args) throws Throwable {

        Random rnd = new Random();

        for (int i = 1; i < 100; i++) {

            int members = rnd.nextInt(10) + 1;

            ByteArrayOutputStream srcBAOS = new ByteArrayOutputStream();

            ByteArrayOutputStream dstBAOS = new ByteArrayOutputStream();

            for (int j = 0; j < members; j++) {

                byte[] src = new byte[rnd.nextInt(8192) + 1];

                rnd.nextBytes(src);

                srcBAOS.write(src);

                try (GZIPOutputStream gzos = new GZIPOutputStream(dstBAOS)) {

                    gzos.write(src);

                }

            }

            byte[] srcBytes = srcBAOS.toByteArray();

            byte[] dstBytes = dstBAOS.toByteArray();

            // try different size of buffer to read the

            // GZIPInputStream

            /* just for fun when running manually

            for (int j = 1; j < 10; j++) {

                test(srcBytes, dstBytes, j);

            }

            */

            for (int j = 0; j < 10; j++) {

                int readBufSZ = rnd.nextInt(2048) + 1;

                test(srcBytes,

                     dstBytes,

                     readBufSZ,

                     512);    // the defualt buffer size

                test(srcBytes,

                     dstBytes,

                     readBufSZ,

                     rnd.nextInt(4096) + 1);

            }

        }

    }

    private static void test(byte[] src, byte[] dst,

                             int readBufSize, int gzisBufSize)

        throws Throwable

    {

        try (ByteArrayInputStream bais = new ByteArrayInputStream(dst);

             GZIPInputStream gzis = new GZIPInputStream(bais, gzisBufSize))

        {

            byte[] result = new byte[src.length + 10];

            byte[] buf = new byte[readBufSize];

            int n = 0;

            int off = 0;

            while ((n = gzis.read(buf, 0, buf.length)) != -1) {

                System.arraycopy(buf, 0, result, off, n);

                off += n;

                // no range check, if overflow, let it fail

            }

            if (off != src.length || gzis.available() != 0 ||

                !Arrays.equals(src, Arrays.copyOf(result, off))) {

                throw new RuntimeException(

                    "GZIPInputStream reading failed! " +

                    ", src.len=" + src.length +

                    ", read=" + off);

            }

        }

    }

}