--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/security/util/BitArray.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,275 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.security.util;
+
+import java.io.ByteArrayOutputStream;
+import java.util.Arrays;
+
+/**
+ * A packed array of booleans.
+ *
+ * @author Joshua Bloch
+ * @author Douglas Hoover
+ */
+
+public class BitArray {
+
+ private byte[] repn;
+ private int length;
+
+ private static final int BITS_PER_UNIT = 8;
+
+ private static int subscript(int idx) {
+ return idx / BITS_PER_UNIT;
+ }
+
+ private static int position(int idx) { // bits big-endian in each unit
+ return 1 << (BITS_PER_UNIT - 1 - (idx % BITS_PER_UNIT));
+ }
+
+ /**
+ * Creates a BitArray of the specified size, initialized to zeros.
+ */
+ public BitArray(int length) throws IllegalArgumentException {
+ if (length < 0) {
+ throw new IllegalArgumentException("Negative length for BitArray");
+ }
+
+ this.length = length;
+
+ repn = new byte[(length + BITS_PER_UNIT - 1)/BITS_PER_UNIT];
+ }
+
+
+ /**
+ * Creates a BitArray of the specified size, initialized from the
+ * specified byte array. The most significant bit of a[0] gets
+ * index zero in the BitArray. The array a must be large enough
+ * to specify a value for every bit in the BitArray. In other words,
+ * 8*a.length <= length.
+ */
+ public BitArray(int length, byte[] a) throws IllegalArgumentException {
+
+ if (length < 0) {
+ throw new IllegalArgumentException("Negative length for BitArray");
+ }
+ if (a.length * BITS_PER_UNIT < length) {
+ throw new IllegalArgumentException("Byte array too short to represent " +
+ "bit array of given length");
+ }
+
+ this.length = length;
+
+ int repLength = ((length + BITS_PER_UNIT - 1)/BITS_PER_UNIT);
+ int unusedBits = repLength*BITS_PER_UNIT - length;
+ byte bitMask = (byte) (0xFF << unusedBits);
+
+ /*
+ normalize the representation:
+ 1. discard extra bytes
+ 2. zero out extra bits in the last byte
+ */
+ repn = new byte[repLength];
+ System.arraycopy(a, 0, repn, 0, repLength);
+ if (repLength > 0) {
+ repn[repLength - 1] &= bitMask;
+ }
+ }
+
+ /**
+ * Create a BitArray whose bits are those of the given array
+ * of Booleans.
+ */
+ public BitArray(boolean[] bits) {
+ length = bits.length;
+ repn = new byte[(length + 7)/8];
+
+ for (int i=0; i < length; i++) {
+ set(i, bits[i]);
+ }
+ }
+
+
+ /**
+ * Copy constructor (for cloning).
+ */
+ private BitArray(BitArray ba) {
+ length = ba.length;
+ repn = ba.repn.clone();
+ }
+
+ /**
+ * Returns the indexed bit in this BitArray.
+ */
+ public boolean get(int index) throws ArrayIndexOutOfBoundsException {
+ if (index < 0 || index >= length) {
+ throw new ArrayIndexOutOfBoundsException(Integer.toString(index));
+ }
+
+ return (repn[subscript(index)] & position(index)) != 0;
+ }
+
+ /**
+ * Sets the indexed bit in this BitArray.
+ */
+ public void set(int index, boolean value)
+ throws ArrayIndexOutOfBoundsException {
+ if (index < 0 || index >= length) {
+ throw new ArrayIndexOutOfBoundsException(Integer.toString(index));
+ }
+ int idx = subscript(index);
+ int bit = position(index);
+
+ if (value) {
+ repn[idx] |= bit;
+ } else {
+ repn[idx] &= ~bit;
+ }
+ }
+
+ /**
+ * Returns the length of this BitArray.
+ */
+ public int length() {
+ return length;
+ }
+
+ /**
+ * Returns a Byte array containing the contents of this BitArray.
+ * The bit stored at index zero in this BitArray will be copied
+ * into the most significant bit of the zeroth element of the
+ * returned byte array. The last byte of the returned byte array
+ * will be contain zeros in any bits that do not have corresponding
+ * bits in the BitArray. (This matters only if the BitArray's size
+ * is not a multiple of 8.)
+ */
+ public byte[] toByteArray() {
+ return repn.clone();
+ }
+
+ public boolean equals(Object obj) {
+ if (obj == this) return true;
+ if (obj == null || !(obj instanceof BitArray)) return false;
+
+ BitArray ba = (BitArray) obj;
+
+ if (ba.length != length) return false;
+
+ for (int i = 0; i < repn.length; i += 1) {
+ if (repn[i] != ba.repn[i]) return false;
+ }
+ return true;
+ }
+
+ /**
+ * Return a boolean array with the same bit values a this BitArray.
+ */
+ public boolean[] toBooleanArray() {
+ boolean[] bits = new boolean[length];
+
+ for (int i=0; i < length; i++) {
+ bits[i] = get(i);
+ }
+ return bits;
+ }
+
+ /**
+ * Returns a hash code value for this bit array.
+ *
+ * @return a hash code value for this bit array.
+ */
+ public int hashCode() {
+ int hashCode = 0;
+
+ for (int i = 0; i < repn.length; i++)
+ hashCode = 31*hashCode + repn[i];
+
+ return hashCode ^ length;
+ }
+
+
+ public Object clone() {
+ return new BitArray(this);
+ }
+
+
+ private static final byte[][] NYBBLE = {
+ { (byte)'0',(byte)'0',(byte)'0',(byte)'0'},
+ { (byte)'0',(byte)'0',(byte)'0',(byte)'1'},
+ { (byte)'0',(byte)'0',(byte)'1',(byte)'0'},
+ { (byte)'0',(byte)'0',(byte)'1',(byte)'1'},
+ { (byte)'0',(byte)'1',(byte)'0',(byte)'0'},
+ { (byte)'0',(byte)'1',(byte)'0',(byte)'1'},
+ { (byte)'0',(byte)'1',(byte)'1',(byte)'0'},
+ { (byte)'0',(byte)'1',(byte)'1',(byte)'1'},
+ { (byte)'1',(byte)'0',(byte)'0',(byte)'0'},
+ { (byte)'1',(byte)'0',(byte)'0',(byte)'1'},
+ { (byte)'1',(byte)'0',(byte)'1',(byte)'0'},
+ { (byte)'1',(byte)'0',(byte)'1',(byte)'1'},
+ { (byte)'1',(byte)'1',(byte)'0',(byte)'0'},
+ { (byte)'1',(byte)'1',(byte)'0',(byte)'1'},
+ { (byte)'1',(byte)'1',(byte)'1',(byte)'0'},
+ { (byte)'1',(byte)'1',(byte)'1',(byte)'1'}
+ };
+
+ private static final int BYTES_PER_LINE = 8;
+
+ /**
+ * Returns a string representation of this BitArray.
+ */
+ public String toString() {
+ ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+ for (int i = 0; i < repn.length - 1; i++) {
+ out.write(NYBBLE[(repn[i] >> 4) & 0x0F], 0, 4);
+ out.write(NYBBLE[repn[i] & 0x0F], 0, 4);
+
+ if (i % BYTES_PER_LINE == BYTES_PER_LINE - 1) {
+ out.write('\n');
+ } else {
+ out.write(' ');
+ }
+ }
+
+ // in last byte of repn, use only the valid bits
+ for (int i = BITS_PER_UNIT * (repn.length - 1); i < length; i++) {
+ out.write(get(i) ? '1' : '0');
+ }
+
+ return new String(out.toByteArray());
+
+ }
+
+ public BitArray truncate() {
+ for (int i=length-1; i>=0; i--) {
+ if (get(i)) {
+ return new BitArray(i+1, Arrays.copyOf(repn, (i + BITS_PER_UNIT)/BITS_PER_UNIT));
+ }
+ }
+ return new BitArray(1);
+ }
+
+}