1 /*
   2  * Permission is hereby granted, free of charge, to any person obtaining a copy of
   3  * this software and associated documentation files (the "Software"), to deal in
   4  * the Software without restriction, including without limitation the rights to
   5  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   6  * of the Software, and to permit persons to whom the Software is furnished to do
   7  * so, subject to the following conditions:
   8  *
   9  * The above copyright notice and this permission notice shall be included in all
  10  * copies or substantial portions of the Software.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  13  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  14  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  15  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  16  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  17  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  18  * SOFTWARE.
  19  */
  20 package jdk.nashorn.internal.runtime.regexp.joni;
  21 
  22 @SuppressWarnings("javadoc")
  23 public final class BitSet {
  24     static final int BITS_PER_BYTE = 8;
  25     public static final int SINGLE_BYTE_SIZE = (1 << BITS_PER_BYTE);
  26     private static final int BITS_IN_ROOM = 4 * BITS_PER_BYTE;
  27     static final int BITSET_SIZE = (SINGLE_BYTE_SIZE / BITS_IN_ROOM);
  28     static final int ROOM_SHIFT = log2(BITS_IN_ROOM);
  29 
  30     final int[] bits = new int[BITSET_SIZE];
  31 
  32     private static final int BITS_TO_STRING_WRAP = 4;
  33     @Override
  34     public String toString() {
  35         final StringBuilder buffer = new StringBuilder();
  36         buffer.append("BitSet");
  37         for (int i=0; i<SINGLE_BYTE_SIZE; i++) {
  38             if ((i % (SINGLE_BYTE_SIZE / BITS_TO_STRING_WRAP)) == 0) {
  39                 buffer.append("\n  ");
  40             }
  41             buffer.append(at(i) ? "1" : "0");
  42         }
  43         return buffer.toString();
  44     }
  45 
  46     public boolean at(final int pos) {
  47         return (bits[pos >>> ROOM_SHIFT] & bit(pos)) != 0;
  48     }
  49 
  50     public void set(final int pos) {
  51         bits[pos >>> ROOM_SHIFT] |= bit(pos);
  52     }
  53 
  54     public void clear(final int pos) {
  55         bits[pos >>> ROOM_SHIFT] &= ~bit(pos);
  56     }
  57 
  58     public void clear() {
  59         for (int i=0; i<BITSET_SIZE; i++) {
  60             bits[i]=0;
  61         }
  62     }
  63 
  64     public boolean isEmpty() {
  65         for (int i=0; i<BITSET_SIZE; i++) {
  66             if (bits[i] != 0) {
  67                 return false;
  68             }
  69         }
  70         return true;
  71     }
  72 
  73     public void setRange(final int from, final int to) {
  74         for (int i=from; i<=to && i < SINGLE_BYTE_SIZE; i++) {
  75             set(i);
  76         }
  77     }
  78 
  79     public void invert() {
  80         for (int i=0; i<BITSET_SIZE; i++) {
  81             bits[i] = ~bits[i];
  82         }
  83     }
  84 
  85     public void invertTo(final BitSet to) {
  86         for (int i=0; i<BITSET_SIZE; i++) {
  87             to.bits[i] = ~bits[i];
  88         }
  89     }
  90 
  91     public void and(final BitSet other) {
  92         for (int i=0; i<BITSET_SIZE; i++) {
  93             bits[i] &= other.bits[i];
  94         }
  95     }
  96 
  97     public void or(final BitSet other) {
  98         for (int i=0; i<BITSET_SIZE; i++) {
  99             bits[i] |= other.bits[i];
 100         }
 101     }
 102 
 103     public void copy(final BitSet other) {
 104         System.arraycopy(other.bits, 0, bits, 0, BITSET_SIZE);
 105     }
 106 
 107     public int numOn() {
 108         int num = 0;
 109         for (int i=0; i<SINGLE_BYTE_SIZE; i++) {
 110             if (at(i)) {
 111                 num++;
 112             }
 113         }
 114         return num;
 115     }
 116 
 117     static int bit(final int pos){
 118         return 1 << (pos % SINGLE_BYTE_SIZE);
 119     }
 120 
 121     private static int log2(final int np) {
 122         int log = 0;
 123         int n = np;
 124         while ((n >>>= 1) != 0) {
 125             log++;
 126         }
 127         return log;
 128     }
 129 
 130 }