diff options
author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
---|---|---|
committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /libjava/classpath/gnu/java/security/der/BitString.java | |
download | cbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.bz2 cbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.xz |
obtained gcc-4.6.4.tar.bz2 from upstream website;upstream
verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.
downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.
if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.
Diffstat (limited to 'libjava/classpath/gnu/java/security/der/BitString.java')
-rw-r--r-- | libjava/classpath/gnu/java/security/der/BitString.java | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/security/der/BitString.java b/libjava/classpath/gnu/java/security/der/BitString.java new file mode 100644 index 000000000..ac10be22e --- /dev/null +++ b/libjava/classpath/gnu/java/security/der/BitString.java @@ -0,0 +1,332 @@ +/* BitString.java -- Java representation of the BIT STRING type. + Copyright (C) 2003 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.java.security.der; + +import gnu.java.lang.CPStringBuilder; + +import java.math.BigInteger; +import java.util.Arrays; + +/** + * Immutable representation of a bit string, which is equivalent to a + * byte array except some number of the rightmost bits are ignored. For + * example, this could be the bit string: + * + * <pre> 00010101 11101101 11010xxx</pre> + * + * <p>Where the "xxx" represents three bits that should be ignored, and + * can have any value. + * + * @author Casey Marshall (csm@gnu.org) + */ +public class BitString implements Cloneable, Comparable +{ + + // Fields. + // ------------------------------------------------------------------------ + + /** The bits themselves. */ + private final byte[] bytes; + + /** + * The exportable byte array. This array has the ignored bits + * removed. + */ + private transient byte[] externBytes; + + /** The number of bits ignored at the end of the byte array. */ + private final int ignoredBits; + + /** This bit string as a boolean array. */ + private transient boolean[] boolVal; + + // Constructors. + // ------------------------------------------------------------------------ + + /** + * Create a new bit string, shifting the given byte array if needed. + * + * @param bytes The byte array holding the bit string. + * @param ignoredBits The number of bits to ignore. + * @param doShift Pass true in this parameter if the byte array has + * not yet been shifted left by <i>ignoredBits</i>. + * @throws IllegalArgumentException If <i>ignoredBits</i> is negative + * or greater than 7. + * @throws NullPointerException If <i>bytes</i> is null. + */ + public BitString(byte[] bytes, int ignoredBits, boolean doShift) + { + this(bytes, 0, bytes.length, ignoredBits, doShift); + } + + /** + * Create a new bit string, shifting the given byte array if needed. + * + * @param bytes The byte array holding the bit string. + * @param offset The offset where the meaningful bytes begin. + * @param length The number of meaningful bytes. + * @param ignoredBits The number of bits to ignore. + * @param doShift Pass true in this parameter if the byte array has + * not yet been shifted left by <i>ignoredBits</i>. + * @throws IllegalArgumentException If <i>ignoredBits</i> is negative + * or greater than 7. + * @throws NullPointerException If <i>bytes</i> is null. + */ + public BitString(byte[] bytes, int offset, int length, + int ignoredBits, boolean doShift) + { + if (ignoredBits < 0 || ignoredBits > 7) + throw new IllegalArgumentException(); + if (bytes == null) + throw new NullPointerException(); + if (doShift && ignoredBits > 0) + { + this.externBytes = new byte[length]; + System.arraycopy(bytes, offset, externBytes, 0, length); + this.bytes = new BigInteger(externBytes).shiftLeft(ignoredBits) + .toByteArray(); + } + else + { + this.bytes = new byte[length]; + System.arraycopy(bytes, offset, this.bytes, 0, length); + } + this.ignoredBits = ignoredBits; + } + + /** + * Create a new bit string. + * + * @param bytes The byte array holding the bit string. + * @param offset The offset where the meaningful bytes begin. + * @param length The number of meaningful bytes. + * @param ignoredBits The number of bits to ignore. + * @throws IllegalArgumentException If <i>ignoredBits</i> is negative + * or greater than 7. + * @throws NullPointerException If <i>bytes</i> is null. + */ + public BitString(byte[] bytes, int offset, int length, int ignoredBits) + { + this(bytes, offset, length, ignoredBits, false); + } + + /** + * Create a new bit string. + * + * @param bytes The byte array holding the bit string. + * @param ignoredBits The number of bits to ignore. + * @throws IllegalArgumentException If <i>ignoredBits</i> is negative + * or greater than 7. + * @throws NullPointerException If <i>bytes</i> is null. + */ + public BitString(byte[] bytes, int ignoredBits) + { + this(bytes, 0, bytes.length, ignoredBits, false); + } + + /** + * Create a new bit string. + * + * @param bytes The byte array holding the bit string. + * @param offset The offset where the meaningful bytes begin. + * @param length The number of meaningful bytes. + * @throws NullPointerException If <i>bytes</i> is null. + */ + public BitString(byte[] bytes, int offset, int length) + { + this(bytes, offset, length, 0, false); + } + + /** + * Create a new bit string. + * + * @param bytes The byte array holding the bit string. + * @throws NullPointerException If <i>bytes</i> is null. + */ + public BitString(byte[] bytes) + { + this(bytes, 0, bytes.length, 0, false); + } + + // Instance methods. + // ------------------------------------------------------------------------ + + /** + * Return this bit string as a byte array, with the ignored bits + * trimmed off. The byte array is cloned every time this method is + * called to prevent modification. + * + * @return The trimmed byte array. + */ + public byte[] toByteArray() + { + if (ignoredBits == 0) + return (byte[]) bytes.clone(); + if (externBytes == null) + externBytes = new BigInteger(bytes).shiftRight(ignoredBits).toByteArray(); + return (byte[]) externBytes.clone(); + } + + /** + * Returns this bit string as a byte array, with the ignored bits + * present. The byte array is cloned every time this method is + * called to prevent modification. + * + * @return The byte array. + */ + public byte[] getShiftedByteArray() + { + return (byte[]) bytes.clone(); + } + + /** + * Returns the number of ignored bits. + * + * @return The number of ignored bits. + */ + public int getIgnoredBits() + { + return ignoredBits; + } + + /** + * Returns the size, in bits, of this bit string. + * + * @return The size of this bit string. + */ + public int size() + { + return (bytes.length << 3) - ignoredBits; + } + + /** + * Return this bit string as a boolean array. The value returned is of + * size {@link #size()}, and each <code>true</code> value + * corresponding to each "1" in this bit string. The boolean array is + * cloned before it is returned. + * + * @return The boolean array. + */ + public boolean[] toBooleanArray() + { + if (boolVal == null) + { + boolVal = new boolean[size()]; + for (int i = 0, j = 7, k = 0; i < boolVal.length; i++) + { + boolVal[i] = (bytes[k] & 1 << j--) != 0; + if (j < 0) + { + j = 7; + k++; + } + } + } + return (boolean[]) boolVal.clone(); + } + + public Object clone() + { + try + { + return super.clone(); + } + catch (CloneNotSupportedException cce) + { + throw new InternalError(cce.getMessage()); + } + } + + public int compareTo(Object o) + { + BitString that = (BitString) o; + if (this.equals(that)) + return 0; + if (this.bytes.length != that.bytes.length) + return (this.bytes.length < that.bytes.length) ? -1 : 1; + if (this.ignoredBits != that.ignoredBits) + return (this.ignoredBits < that.ignoredBits) ? -1 : 1; + for (int i = 0; i < this.bytes.length; i++) + if (this.bytes[i] != that.bytes[i]) + return (this.bytes[i] < that.bytes[i]) ? -1 : 1; + return 0; // not reached. + } + + public int hashCode() + { + int result = 0; + for (int i = 0; i < bytes.length - 1; ++i) + result = result * 31 + bytes[i]; + if (bytes.length > 0) + { + int lastByte = bytes[bytes.length - 1] & ~ ((1 << ignoredBits) - 1); + result = result * 31 + lastByte; + } + return result; + } + + public boolean equals(Object o) + { + if (!(o instanceof BitString)) + return false; + BitString that = (BitString) o; + // True for cloned instances. + if (this.bytes == that.bytes && this.ignoredBits == that.ignoredBits) + return true; + if (this.ignoredBits == that.ignoredBits) + return Arrays.equals(this.bytes, that.bytes); + return false; + } + + public String toString() + { + CPStringBuilder sb = new CPStringBuilder(); + for (int i = 0, j = 7, k = 0; i < size(); i++) + { + sb.append((bytes[k] & 1 << j) != 0 ? "1" : "0"); + j--; + if (j < 0) + { + j = 7; + k++; + } + } + return sb.toString(); + } +} |