/*

 * Copyright (c) 2005, 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.

 */

/*

 * @test

 * @bug     4655503

 * @summary Test for array cloning and slicing methods.

 * @author  John Rose

 * @key randomness

 */

import java.util.*;

import java.lang.reflect.*;

public class CopyMethods {

    static int muzzle;  // if !=0, suppresses ("muzzles") messages

    static int maxLen = 40;  // maximum length of test arrays

    static int shortStepsNear = 4;  // interesting span near critical values

    static int downShift = 3;

    static int testCasesRun = 0;

    static long consing = 0;

    // very simple tests, mainly to test the framework itself

    static void simpleTests() {

        int[] a = (int[]) makeArray(3, int.class);

        if (muzzle == 0)

            System.out.println("int[] a = "+Arrays.toString(a));

        check(a.length == 3);

        check(a[0] == testValues[0]);

        check(a[1] == testValues[1]);

        check(a[2] == testValues[2]);

        checkArray(a, int.class, 3, 0, 3);

        // negative test of testing framework:

        for (int bad = -2; bad < a.length; bad++) {

            try {

                int[] aa = a.clone();

                if (bad < 0)  aa = new int[4];

                else          aa[bad] = 0;

                ++muzzle;

                // the following check should fail!

                if (bad == -2)

                    checkArray(new String[3], int.class, 0, 0, a.length);

                else

                    checkArray(aa, int.class, 0, 0, a.length);

                throw new Error("Should Not Reach Here");

            } catch (RuntimeException ee) {

                --muzzle;

                if (muzzle == 0)

                    System.out.println("Expected: "+ee);

            }

        }

        checkArray(Arrays.copyOf(a, 0), int.class, 0, 0, 3);

        checkArray(Arrays.copyOf(a, 1), int.class, 1, 0, 3);

        checkArray(Arrays.copyOf(a, 2), int.class, 2, 0, 3);

        checkArray(Arrays.copyOf(a, 3), int.class, 3, 0, 3);

        checkArray(Arrays.copyOf(a, 4), int.class, 4, 0, 3);

        // quick test of copyOfRange

        int[] ar = Arrays.copyOfRange(a, 1, 3);

        check(ar.length == 2);

        check(ar[0] == a[1]);

        check(ar[1] == a[2]);

        checkArray(ar, int.class, 2, 1, 2);

        ar = Arrays.copyOfRange(a, 2, 4);

        check(ar.length == 2);

        check(ar[0] == a[2]);

        check(ar[1] == 0);

        checkArray(ar, int.class, 2, 2, 1);

        ar = Arrays.copyOfRange(a, 3, 5);

        check(ar.length == 2);

        check(ar[0] == 0);

        check(ar[1] == 0);

        checkArray(ar, int.class, 2, 3, 0);

        byte[] ba = (byte[]) makeArray(3, byte.class);

        if (muzzle == 0)

            System.out.println("byte[] ba = "+Arrays.toString(ba));

        for (int j = 0; j <= ba.length+2; j++) {

            byte[] bb = Arrays.copyOf(ba, j);

            if (muzzle == 0)

                System.out.println("copyOf(ba,"+j+") = "+

                                   Arrays.toString(bb));

            checkArray(bb, byte.class, j, 0, ba.length);

            byte[] bbr = Arrays.copyOfRange(ba, 0, j);

            check(Arrays.equals(bb, bbr));

        }

        for (int i = 0; i <= a.length; i++) {

            for (int j = i; j <= a.length+2; j++) {

                byte[] br = Arrays.copyOfRange(ba, i, j);

                if (muzzle == 0)

                    System.out.println("copyOfRange(ba,"+i+","+j+") = "+

                                       Arrays.toString(br));

                checkArray(br, byte.class, j-i, i, ba.length-i);

            }

        }

        String[] sa = (String[]) makeArray(3, String.class);

        if (muzzle == 0)

            System.out.println("String[] sa = "+Arrays.toString(sa));

        check(sa[0].equals(Integer.toHexString(testValues[0])));

        check(sa[1].equals(Integer.toHexString(testValues[1])));

        check(sa[2].equals(Integer.toHexString(testValues[2])));

        checkArray(sa, String.class, sa.length, 0, sa.length);

        String[] sa4 = Arrays.copyOf(sa, sa.length+1);

        check(sa4[0] == sa[0]);

        check(sa4[1] == sa[1]);

        check(sa4[2] == sa[2]);

        check(sa4[sa.length] == null);

        checkArray(sa4, String.class, sa4.length, 0, sa.length);

        String[] sr4 = Arrays.copyOfRange(sa, 1, 5);

        check(sr4[0] == sa[1]);

        check(sr4[1] == sa[2]);

        check(sr4[2] == null);

        check(sr4[3] == null);

        checkArray(sr4, String.class, 4, 1, sa.length-1);

        if (muzzle == 0)

            System.out.println("simpleTests done");

    }

    // the framework:  a fixed series of test values

    static final int[] testValues;

    static {

        testValues = new int[1000];

        Random r = new Random();

        for (int i = 0; i < testValues.length; i++) {

            testValues[i] = r.nextInt();

        }

    }

    /** Return a canonical test value of a desired index and type.

     *  The original test values are random ints.  Derive other test

     *  values as follows:

     *  <pre>

     *  int tv = testValues[i]

     *  (C)tv                    C is byte, short, char, long, float, double

     *  (tv&1)!=0                C is boolean

     *  (Integer)tv              C is Object and tv%16 != 0

     *  null                     C is Object and tv%16 == 0

     *  Integer.toHexString(tv)  C is String and tv != 0

     *  null                     C is String and tv == 0

     *  </pre>

     *  are derived by ordinary Java coercions, except that boolean

     *  samples the LSB of the int value, and String is the hex numeral.

     *

     *  (Also, the 0th String is null, and the 0th Object mod 16 is null,

     *  regardless of the original int test value.)

     */

    static Object testValue(int i, Class<?> c) {

        int tv = testValues[i % testValues.length];

        if (i >= testValues.length)  tv ^= i;

        // Turn the canonical int to a float, boolean, String, whatever:

        return invoke(coercers.get(c), tv);

    }

    /** Build a test array of the given length,

     *  packed with a subsequence of the test values.

     *  The first element of the array is always testValue(0).

     */

    static Object makeArray(int len, Class<?> c) {

        Object a = Array.newInstance(c, len);

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

            Array.set(a, i, testValue(i, c));

        }

        return a;

    }

    /** Check that the given array has the required length.

     *  Check also that it is packed, up to firstNull, with

     *  a particular subsequence of the canonical test values.

     *  The subsequence must begin with a[0] == testValue(offset).

     *  At a[firstNull] and beyond, the array must contain null values.

     */

    static void checkArray(Object a, Class<?> c, int requiredLen, int offset, int firstNull) {

        check(c == a.getClass().getComponentType());

        Object nullValue = nullValues.get(c);

        // Note:  asserts in here are not part of the test program.

        // They verify the integrity of the test method itself.

        assert(nullValues.containsKey(c));

        int misses = 0;

        int firstMiss = -1;

        // Check required length first.

        int length = Array.getLength(a);

        if (length != requiredLen && requiredLen != -1) {

            if (muzzle == 0)

                System.out.println("*** a.length = "+length+" != "+requiredLen);

            ++misses;

        }

        for (int i = 0; i < length; i++) {

            Object tv = (i >= firstNull) ? nullValue : testValue(i+offset, c);

            Object ai = Array.get(a, i);

            if (!eq(ai, tv)) {

                if (muzzle == 0)

                    System.out.println("*** a["+i+"] = "+ai+" != "+tv);

                if (misses == 0)  firstMiss = i;

                if (++misses > 10)  break;

            }

        }

        if (misses != 0) {

            Method toString = toStrings.get(c);

            if (toString == null)  toString = toStrings.get(Object.class);

            throw new RuntimeException("checkArray failed at "+firstMiss

                                       +" "+c+"[]"

                                       +" : "+invoke(toString, a));

        }

    }

    // Typical comparison helper.  Why isn't this a method somewhere.

    static boolean eq(Object x, Object y) {

        return x == null? y == null: x.equals(y);

    }

    // Exception-ignoring invoke function.

    static Object invoke(Method m, Object... args) {

        Exception ex;

        try {

            return m.invoke(null, args);

        } catch (InvocationTargetException ee) {

            ex = ee;

        } catch (IllegalAccessException ee) {

            ex = ee;

        } catch (IllegalArgumentException ee) {

            ex = ee;

        }

        ArrayList<Object> call = new ArrayList<Object>();

        call.add(m); Collections.addAll(call, args);

        throw new RuntimeException(call+" : "+ex);

    }

    // version of assert() that runs unconditionally

    static void check(boolean z) {

        if (!z)  throw new RuntimeException("check failed");

    }

    /** Run about 10**5 distinct parameter combinations

     *  on copyOf and copyOfRange.  Use all primitive types,

     *  and String and Object.

     *  Try to all critical values, looking for fencepost errors.

     */

    static void fullTests(int maxLen, Class<?> c) {

        Method cloner      = cloners.get(c);

        assert(cloner != null) : c;

        Method cloneRanger = cloneRangers.get(c);

        // Note:  asserts in here are not part of the test program.

        // They verify the integrity of the test method itself.

        assert(cloneRanger != null) : c;

        for (int src = 0; src <= maxLen; src = inc(src, 0, maxLen)) {

            Object a = makeArray(src, c);

            for (int x : new ArrayList<Integer>()) {}

            for (int j = 0; j <= maxLen; j = inc(j, src, maxLen)) {

                // b = Arrays.copyOf(a, j);

                Object b = invoke(cloner, a, j);

                checkArray(b, c, j, 0, src);

                testCasesRun++;

                consing += j;

                int maxI = Math.min(src, j);

                for (int i = 0; i <= maxI; i = inc(i, src, maxI)) {

                    // r = Arrays.copyOfRange(a, i, j);

                    Object r = invoke(cloneRanger, a, i, j);

                    checkArray(r, c, j-i, i, src-i);

                    //System.out.println("case c="+c+" src="+src+" i="+i+" j="+j);

                    testCasesRun++;

                    consing += j-i;

                }

            }

        }

    }

    // Increment x by at least one.  Increment by a little more unless

    // it is near a critical value, either zero, crit1, or crit2.

    static int inc(int x, int crit1, int crit2) {

        int D = shortStepsNear;

        if (crit1 > crit2) { int t = crit1; crit1 = crit2; crit2 = t; }

        assert(crit1 <= crit2);

        assert(x <= crit2);  // next1 or next2 must be the limit value

        x += 1;

        if (x > D) {

            if (x < crit1-D) {

                x += (x << 1) >> downShift;  // giant step toward crit1-D

                if (x > crit1-D)  x = crit1-D;

            } else if (x >= crit1+D && x < crit2-D) {

                x += (x << 1) >> downShift;  // giant step toward crit2-D

                if (x > crit2-D)  x = crit2-D;

            }

        }

        return x;

    }

    public static void main(String[] av) {

        boolean verbose = (av.length != 0);

        muzzle = (verbose? 0: 1);

        if (muzzle == 0)

            System.out.println("test values: "+Arrays.toString(Arrays.copyOf(testValues, 5))+"...");

        simpleTests();

        muzzle = 0;  // turn on print statements (affects failures only)

        fullTests();

        if (verbose)

            System.out.println("ran "+testCasesRun+" tests, avg len="

                               +(float)consing/testCasesRun);

        // test much larger arrays, more sparsely

        maxLen = 500;

        shortStepsNear = 2;

        downShift = 0;

        testCasesRun = 0;

        consing = 0;

        fullTests();

        if (verbose)

            System.out.println("ran "+testCasesRun+" tests, avg len="

                               +(float)consing/testCasesRun);

    }

    static void fullTests() {

        for (Class<?> c : allTypes) {

            fullTests(maxLen, c);

        }

    }

    // We must run all the our tests on each of 8 distinct primitive types,

    // and two reference types (Object, String) for good measure.

    // This would be a pain to write out by hand, statically typed.

    // So, use reflection.  Following are the tables of methods we use.

    // (The initial simple tests exercise enough of the static typing

    // features of the API to ensure that they compile as advertised.)

    static Object  coerceToObject(int x) { return (x & 0xF) == 0? null: new Integer(x); }

    static String  coerceToString(int x) { return (x == 0)? null: Integer.toHexString(x); }

    static Integer coerceToInteger(int x) { return (x == 0)? null: x; }

    static byte    coerceToByte(int x) { return (byte)x; }

    static short   coerceToShort(int x) { return (short)x; }

    static int     coerceToInt(int x) { return x; }

    static long    coerceToLong(int x) { return x; }

    static char    coerceToChar(int x) { return (char)x; }

    static float   coerceToFloat(int x) { return x; }

    static double  coerceToDouble(int x) { return x; }

    static boolean coerceToBoolean(int x) { return (x&1) != 0; }

    static Integer[] copyOfIntegerArray(Object[] a, int len) {

        // This guy exercises the API based on a type-token.

        // Note the static typing.

        return Arrays.copyOf(a, len, Integer[].class);

    }

    static Integer[] copyOfIntegerArrayRange(Object[] a, int m, int n) {

        // This guy exercises the API based on a type-token.

        // Note the static typing.

        return Arrays.copyOfRange(a, m, n, Integer[].class);

    }

    static final List<Class<?>> allTypes

        = Arrays.asList(new Class<?>[]

                        {   Object.class, String.class, Integer.class,

                            byte.class, short.class, int.class, long.class,

                            char.class, float.class, double.class,

                            boolean.class

                        });

    static final HashMap<Class<?>,Method> coercers;

    static final HashMap<Class<?>,Method> cloners;

    static final HashMap<Class<?>,Method> cloneRangers;

    static final HashMap<Class<?>,Method> toStrings;

    static final HashMap<Class<?>,Object> nullValues;

    static {

        coercers = new HashMap<Class<?>,Method>();

        Method[] testMethods = CopyMethods.class.getDeclaredMethods();

        Method cia = null, ciar = null;

        for (int i = 0; i < testMethods.length; i++) {

            Method m = testMethods[i];

            if (!Modifier.isStatic(m.getModifiers()))  continue;

            Class<?> rt = m.getReturnType();

            if (m.getName().startsWith("coerceTo") && allTypes.contains(rt))

                coercers.put(m.getReturnType(), m);

            if (m.getName().equals("copyOfIntegerArray"))

                cia = m;

            if (m.getName().equals("copyOfIntegerArrayRange"))

                ciar = m;

        }

        Method[] arrayMethods = Arrays.class.getDeclaredMethods();

        cloners      = new HashMap<Class<?>,Method>();

        cloneRangers = new HashMap<Class<?>,Method>();

        toStrings    = new HashMap<Class<?>,Method>();

        for (int i = 0; i < arrayMethods.length; i++) {

            Method m = arrayMethods[i];

            if (!Modifier.isStatic(m.getModifiers()))  continue;

            Class<?> rt = m.getReturnType();

            if (m.getName().equals("copyOf")

                && m.getParameterTypes().length == 2)

                cloners.put(rt.getComponentType(), m);

            if (m.getName().equals("copyOfRange")

                && m.getParameterTypes().length == 3)

                cloneRangers.put(rt.getComponentType(), m);

            if (m.getName().equals("toString")) {

                Class<?> pt = m.getParameterTypes()[0];

                toStrings.put(pt.getComponentType(), m);

            }

        }

        cloners.put(String.class, cloners.get(Object.class));

        cloneRangers.put(String.class, cloneRangers.get(Object.class));

        assert(cia != null);

        cloners.put(Integer.class, cia);

        assert(ciar != null);

        cloneRangers.put(Integer.class, ciar);

        nullValues = new HashMap<Class<?>,Object>();

        for (Class<?> c : allTypes) {

            nullValues.put(c, invoke(coercers.get(c), 0));

        }

    }

}