/*

 * Copyright (c) 2011, 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.

 *

 * 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.

 */

/**

 * ZIP inflater/deflater performance.

 */

/*

 * Run this test on JDK 6 and on later

 * JDKs to compare results:

 *     java -server -Xms1024M -Xmx1024M -Ddebug=true FlaterCriticalArray

 *

 * The performance issues can be readily seen on JDK 6, and so this code is

 * written to compile on that platform: it does *not* use any JDK 7 - specific

 * features.

 */

import java.io.*;

import java.nio.*;

import java.util.*;

import java.util.zip.*;

public class FlaterCriticalArray {

    // If true, print information about performance

    private static final boolean debug = System.getProperty("debug") != null;

    private static void debug(String s) {

        if (debug) System.out.println(s);

    }

    private static void debug(String name, String inOut, long time, int length) {

        debug(name + ": Duration of " + inOut + "(in ms): " + time);

        debug(name + ": " + inOut + "d data length: " + length + " bytes");

    }

    private static byte[] grow(byte[] a, int capacity) {

        while (a.length < capacity) {

            byte[] a2 = new byte[a.length * 2];

            System.arraycopy(a, 0, a2, 0, a.length);

            a = a2;

        }

        return a;

    }

    private static byte[] trim(byte[] a, int length) {

        byte[] res = new byte[length];

        System.arraycopy(a, 0, res, 0, length);

        return res;

    }

    /*

     * Base class for individual test cases

     */

        protected String name;  // For information in debug messages

        protected byte data[];  // Data to be deflated and subsequently inflated

        protected int level;    // Compression level for deflater

        protected TestCase(String name, byte data[]) {

            this(name, data, -1);

        }

        protected TestCase(String name, byte data[], int level) {

            this.name = name;

            this.data = data;

            this.level = level;

        }

        public void runTest() throws Throwable {

            long time0, time1;

            byte deflated[], inflated[];

            debug("");

            time0 = System.currentTimeMillis();

            deflated = deflate(data, level);

            time1 = System.currentTimeMillis();

            inform("Deflate", time1 - time0, deflated.length);

            time0 = System.currentTimeMillis();

            inflated = inflate(deflated);

            time1 = System.currentTimeMillis();

            inform("Inflate", time1 - time0, inflated.length);

            check(Arrays.equals(data, inflated),

                  name + ": Inflated and deflated arrays do not match");

        }

        private void inform(String inOut, long duration, int length) {

            debug(name, inOut, duration, length);

        }

    }

    /*

     * Following are  the individual test cases

     */

    private static class StrideTest extends TestCase {

        static final int STRIDE = 1024;

        public StrideTest(byte data[], int level) {

            super("STRIDE", data, level);

        }

        protected byte[] deflate(byte in[], int level) throws Throwable {

            final int len = in.length;

            final Deflater deflater = new Deflater(level);

            final byte[] smallBuffer = new byte[32];

            byte[] flated = new byte[32];

            int count = 0;

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

                deflater.setInput(in, i, Math.min(STRIDE, len-i));

                while (!deflater.needsInput()) {

                    int n = deflater.deflate(smallBuffer);

                    flated = grow(flated, count + n);

                    System.arraycopy(smallBuffer, 0, flated, count, n);

                    count += n;

                }

            }

            deflater.finish();

            int n;

            do {

                n = deflater.deflate(smallBuffer);

                flated = grow(flated, count + n);

                System.arraycopy(smallBuffer, 0, flated, count, n);

                count += n;

            } while (n > 0);

            return trim(flated, count);

        }

        protected byte[] inflate(byte in[]) throws Throwable {

            final int len = in.length;

            final Inflater inflater = new Inflater();

            final byte[] smallBuffer = new byte[3200];

            byte[] flated = new byte[32];

            int count = 0;

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

                inflater.setInput(in, i, Math.min(STRIDE, len-i));

                while (!inflater.needsInput()) {

                    int n;

                    while ((n = inflater.inflate(smallBuffer)) > 0) {

                        flated = grow(flated, count + n);

                        System.arraycopy(smallBuffer, 0, flated, count, n);

                        count += n;

                    }

                }

            }

            return trim(flated, count);

        }

    }

    private static class NoStrideTest extends TestCase {

        public NoStrideTest(byte data[], int level) {

            super("NO STRIDE", data, level);

        }

        public byte[] deflate(byte in[], int level) throws Throwable {

            final Deflater flater = new Deflater(level);

            flater.setInput(in);

            flater.finish();

            final byte[] smallBuffer = new byte[32];

            byte[] flated = new byte[32];

            int count = 0;

            int n;

            while ((n = flater.deflate(smallBuffer)) > 0) {

                flated = grow(flated, count + n);

                System.arraycopy(smallBuffer, 0, flated, count, n);

                count += n;

            }

            return trim(flated, count);

        }

        public byte[] inflate(byte in[]) throws Throwable {

            final Inflater flater = new Inflater();

            flater.setInput(in);

            final byte[] smallBuffer = new byte[32];

            byte[] flated = new byte[32];

            int count = 0;

            int n;

            while ((n = flater.inflate(smallBuffer)) > 0) {

                flated = grow(flated, count + n);

                System.arraycopy(smallBuffer, 0, flated, count, n);

                count += n;

            }

            return trim(flated, count);

        }

    }

    /**

     * Check Deflater{In,Out}putStream by way of GZIP{In,Out}putStream

     */

    private static class GZIPTest extends TestCase {

        public GZIPTest(byte data[]) {

            super("GZIP", data);

        }

        public byte[] deflate(byte data[], int ignored) throws Throwable {

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            OutputStream gzos = new GZIPOutputStream(baos);

            gzos.write(data, 0, data.length);

            gzos.close();

            return baos.toByteArray();

        }

        public byte[] inflate(byte deflated[]) throws Throwable {

            InputStream bais = new ByteArrayInputStream(deflated);

            GZIPInputStream gzis = new GZIPInputStream(bais);

            byte[] inflated = new byte[data.length];

            int numRead = 0;

            int count = 0;

            while ((numRead = gzis.read(inflated, count, data.length - count)) > 0) {

                count += numRead;

            }

            check(count == data.length, name + ": Read " + count + "; expected " + data.length);

            return inflated;

        }

    }

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

        byte data[];

        int level = -1;

        if (args.length > 0) {

          level = Integer.parseInt(args[0]);

        }

        debug("Using level " + level);

        if (args.length > 1) {

            FileInputStream fis = new FileInputStream(args[1]);

            int len = fis.available();

            data = new byte[len];

            check(fis.read(data, 0, len) == len, "Did not read complete file");

            debug("Original data from " + args[1]);

            fis.close();

        } else {

            ByteBuffer bb = ByteBuffer.allocate(8);

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            for (int i = 0; i < 1024 * 64; i++) { // data length

                bb.putDouble(0, Math.random());

                baos.write(bb.array(), 0, 8);

            }

            data = baos.toByteArray();

            debug("Original data from random byte array");

        }

        debug("Original data length: " + data.length + " bytes");

        new StrideTest(data, level).runTest();

        new NoStrideTest(data, level).runTest();

        new GZIPTest(data).runTest();

    }

    //--------------------- Infrastructure ---------------------------

    static volatile int passed = 0, failed = 0;

    static void pass() {passed++;}

    static void pass(String msg) {System.out.println(msg); passed++;}

    static void fail() {failed++; Thread.dumpStack();}

    static void fail(String msg) {System.out.println(msg); fail();}

    static void unexpected(Throwable t) {failed++; t.printStackTrace();}

    static void unexpected(Throwable t, String msg) {

        System.out.println(msg); failed++; t.printStackTrace();}

    static boolean check(boolean cond) {if (cond) pass(); else fail(); return cond;}

    static boolean check(boolean cond, String msg) {if (cond) pass(); else fail(msg); return cond;}

    static void equal(Object x, Object y) {

        if (x == null ? y == null : x.equals(y)) pass();

        else fail(x + " not equal to " + y);}

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

        try {realMain(args);} catch (Throwable t) {unexpected(t);}

        System.out.println("\nPassed = " + passed + " failed = " + failed);

        if (failed > 0) throw new AssertionError("Some tests failed");}

}