package it.unimi.dsi.bits;
/*
* DSI utilities
*
* Copyright (C) 2007-2009 Sebastiano Vigna
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
import java.io.Serializable;
/**
* @deprecated Use {@link TransformationStrategies#utf16()} and {@link TransformationStrategies#prefixFreeUtf16()}.
*/
@Deprecated
public class Utf16TransformationStrategy implements TransformationStrategy<CharSequence>, Serializable {
private static final long serialVersionUID = 1L;
/** Creates a prefix-free UTF16 transformation strategy. The
* strategy will map a string to its natural UTF16 bit sequence, and the resulting set of binary words will be made prefix free by adding
*
*/
public Utf16TransformationStrategy() {}
private static class Utf16CharSequenceBitVector extends AbstractBitVector implements Serializable {
private static final long serialVersionUID = 1L;
private transient CharSequence s;
private transient long length;
private transient long actualEnd;
public Utf16CharSequenceBitVector( final CharSequence s ) {
this.s = s;
actualEnd = s.length() * Character.SIZE;
length = actualEnd + Character.SIZE;
}
public boolean getBoolean( long index ) {
if ( index > length ) throw new IndexOutOfBoundsException();
if ( index >= actualEnd ) return false;
final int charIndex = (int)( index / Character.SIZE );
return ( s.charAt( charIndex ) & 0x8000 >>> index % Character.SIZE ) != 0;
}
public long getLong( final long from, final long to ) {
if ( from % Long.SIZE == 0 && to % Character.SIZE == 0 ) {
long l;
int pos = (int)( from / Character.SIZE );
if ( to == from + Long.SIZE ) l = ( ( to > actualEnd ? 0 : (long)s.charAt( pos + 3 ) ) << 48 | (long)s.charAt( pos + 2 ) << 32 | (long)s.charAt( pos + 1 ) << 16 | s.charAt( pos ) );
else {
l = 0;
final int residual = (int)( Math.min( actualEnd, to ) - from );
for( int i = residual / Character.SIZE; i-- != 0; )
l |= (long)s.charAt( pos + i ) << i * Character.SIZE;
}
l = ( l & 0x5555555555555555L ) << 1 | ( l >>> 1 ) & 0x5555555555555555L;
l = ( l & 0x3333333333333333L ) << 2 | ( l >>> 2 ) & 0x3333333333333333L;
l = ( l & 0x0f0f0f0f0f0f0f0fL ) << 4 | ( l >>> 4 ) & 0x0f0f0f0f0f0f0f0fL;
return ( l & 0x00ff00ff00ff00ffL ) << 8 | ( l >>> 8 ) & 0x00ff00ff00ff00ffL;
}
return super.getLong( from, to );
}
public long length() {
return length;
}
}
public BitVector toBitVector( final CharSequence s ) {
return new Utf16CharSequenceBitVector( s );
}
public long numBits() { return 0; }
public TransformationStrategy<CharSequence> copy() {
return new Utf16TransformationStrategy();
}
}