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BEGIN LICENSE BLOCK ***** Version: CPL 1.0/GPL 2.0/LGPL 2.1 The contents of this file are subject to the Common Public License Version 1.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.eclipse.org/legal/cpl-v10.html Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. Alternatively, the contents of this file may be used under the terms of either of the GNU General Public License Version 2 or later (the "GPL"), or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), in which case the provisions of the GPL or the LGPL are applicable instead of those above. If you wish to allow use of your version of this file only under the terms of either the GPL or the LGPL, and not to allow others to use your version of this file under the terms of the CPL, indicate your decision by deleting the provisions above and replace them with the notice and other provisions required by the GPL or the LGPL. If you do not delete the provisions above, a recipient may use your version of this file under the terms of any one of the CPL, the GPL or the LGPL. END LICENSE BLOCK ***
 
 package org.jruby.util;
 
 
 public class Random {
     public static int N = 624;
     private static int M = 397;
     private static int MATRIX_A = 0x9908b0df; /* constant vector a */
     private static int UMASK = 0x80000000; /* most significant w-r bits */
     private static int LMASK = 0x7fffffff; /* least significant r bits */
 
     private static int MIXBITS(int uint v) {
         return (u & ) | (v & );
     }
 
     private static int TWIST(int uint v) {
         return (MIXBITS(uv) >>> 1) ^ (((v & 1) != 0) ?  : 0);
     }
 
     private final int[] state = new int[];
     private int left = 1;
 
     public Random(int s) {
         initGenrand(s);
     }
 
     public Random(int[] initKey) {
         initByArray(initKey);
     }
 
     public Random(Random orig) {
         System.arraycopy(orig.state, 0, this., 0, this..length);
         this. = orig.left;
     }
 
     public Random(int[] stateint left) {
         if (state.length != this..length) {
             throw new IllegalStateException("wrong state length: " + state.length);
         }
         System.arraycopy(state, 0, this., 0, this..length);
         this. = left;
     }
 
     @Override
     public boolean equals(Object obj) {
         if (this == obj) {
             return true;
         } else if (!(obj instanceof Random)) {
             return false;
         }
         Random rhs = (Randomobj;
         return ( == rhs.left) && Arrays.equals(rhs.state);
     }
 
     @Override
     public int hashCode() {
         // Using 17 as the initializer, 37 as the multiplier.
         return (629 + ) * 37 + .hashCode();
     }
     
     private void initGenrand(int s) {
         [0] = s;
         for (int j = 1; j < j++) {
             [j] = (1812433253 * ([j - 1] ^ ([j - 1] >>> 30)) + j);
         }
          = 1;
     }
 
     private void initByArray(int[] initKey) {
         initGenrand(19650218);
         int len = initKey.length;
         int i = 1;
         int j = 0;
        int k =  > len ?  : len;
        for (; k > 0; k--) {
            [i] = ([i] ^ (([i - 1] ^ ([i - 1] >>> 30)) * 1664525)) + initKey[j]
                    + j;
            i++;
            j++;
            if (i >= ) {
                [0] = [ - 1];
                i = 1;
            }
            if (j >= len) {
                j = 0;
            }
        }
        for (k =  - 1; k > 0; k--) {
            [i] = ([i] ^ (([i - 1] ^ ([i - 1] >>> 30)) * 1566083941)) - i;
            i++;
            if (i >= ) {
                [0] = [ - 1];
                i = 1;
            }
        }
        [0] = 0x80000000;
    }
    private void nextState() {
        int p = 0;
         = ;
        for (int j =  -  + 1; --j > 0; p++) {
            [p] = [p + ] ^ TWIST([p + 0], [p + 1]);
        }
        for (int j = ; --j > 0; p++) {
            [p] = [p +  - ] ^ TWIST([p + 0], [p + 1]);
        }
        [p] = [p +  - ] ^ TWIST([p + 0], [0]);
    }
    public int genrandInt32() {
        int y;
        synchronized (this) {
            if (-- <= 0)
                nextState();
            y = [ - ];
        }
        /* Tempering */
        y ^= (y >>> 11);
        y ^= (y << 7) & 0x9d2c5680L;
        y ^= (y << 15) & 0xefc60000L;
        y ^= (y >>> 18);
        return y;
    }
    public double genrandReal() {
        int a = genrandInt32() >>> 5;
        int b = genrandInt32() >>> 6;
        return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
    }
    public double genrandReal2() {
        int a = genrandInt32();
        int b = genrandInt32();
        return intPairToRealInclusive(ab);
    }
    private static final BigInteger INTPAIR_CONST = BigInteger.valueOf((1L << 53) + 1);
    private static final double LDEXP_CONST = Math.pow(2.0, -53);
    // c: ldexp((a<< 32)|b) * ((1<<53)+1) >> 64, -53)
    // TODO: not enough prec...
    private double intPairToRealInclusive(int aint b) {
        BigInteger c = BigInteger.valueOf(a & 0xffffffffL);
        BigInteger d = BigInteger.valueOf(b & 0xffffffffL);
        return c.shiftLeft(32).or(d).multiply().shiftRight(64).doubleValue()
                * ;
    }
    public int[] getState() {
        return ;
    }
    public int getLeft() {
        return ;
    }
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