/*
* JBoss DNA (http://www.jboss.org/dna)
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
* See the AUTHORS.txt file in the distribution for a full listing of
* individual contributors.
*
* JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
* is licensed to you 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.
*
* JBoss DNA 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.dna.graph.property;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigDecimal;
import java.net.URI;
import java.util.Calendar;
import java.util.Comparator;
import java.util.Date;
import java.util.UUID;
import net.jcip.annotations.Immutable;
import org.jboss.dna.common.util.SecureHash;
import org.jboss.dna.graph.GraphI18n;
import org.jboss.dna.graph.property.basic.StringValueFactory;
/**
* A set of {@link Comparator} objects for the different kinds of property values.
*
* @see PropertyType#getComparator()
*/
@Immutable
public class ValueComparators {
/**
* A comparator of string values.
*/
public static final Comparator<String> STRING_COMPARATOR = new Comparator<String>() {
public int compare( String o1,
String o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of long values.
*/
public static final Comparator<Long> LONG_COMPARATOR = new Comparator<Long>() {
public int compare( Long o1,
Long o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of double values.
*/
public static final Comparator<Double> DOUBLE_COMPARATOR = new Comparator<Double>() {
public int compare( Double o1,
Double o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of decimal values.
*/
public static final Comparator<BigDecimal> DECIMAL_COMPARATOR = new Comparator<BigDecimal>() {
public int compare( BigDecimal o1,
BigDecimal o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of binary values. Although {@link Binary} is {@link Comparable}, this comparator does not rely upon any
* particular Binary implementation. Thus, Binary implementations can use this for their {@link Comparable#compareTo(Object)}
* implementation.
*/
public static final Comparator<Binary> BINARY_COMPARATOR = new Comparator<Binary>() {
public int compare( Binary o1,
Binary o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
try {
o1.acquire();
try {
o2.acquire();
final long len1 = o1.getSize();
final long len2 = o2.getSize();
if (len1 < len2) return -1;
if (len1 > len2) return 1;
// Compare using the hashes, if available
byte[] hash1 = o1.getHash();
byte[] hash2 = o2.getHash();
if (hash1.length != 0 || hash2.length != 0) {
assert hash1.length == hash2.length;
for (int i = 0; i != hash1.length; ++i) {
int diff = hash1[i] - hash2[i];
if (diff != 0) return diff;
}
return 0;
// If the hashes match, then we should assume that the values match.
// That's the whole point of using a secure hash.
}
// One or both of the hashes could not be generated, so we have to go compare
// the whole values. This is unfortunate, but should happen very rarely (if ever)
// as long as the BinaryValue.getHash() is always implemented
// Otherwise they are the same length ...
InputStream stream1 = null;
InputStream stream2 = null;
try {
stream1 = o1.getStream();
stream2 = o2.getStream();
byte[] buffer1 = new byte[1024];
byte[] buffer2 = new byte[1024];
while (true) {
int numRead1 = stream1.read(buffer1);
if (numRead1 < 0) break;
int numRead2 = stream2.read(buffer2);
if (numRead1 != numRead2) {
throw new IoException(GraphI18n.errorReadingPropertyValueBytes.text());
}
for (int i = 0; i != numRead1; ++i) {
int diff = buffer1[i] - buffer2[i];
if (diff != 0) return diff;
}
}
return 0;
} catch (IOException e) {
throw new IoException(GraphI18n.errorReadingPropertyValueBytes.text());
} finally {
if (stream1 != null) {
try {
stream1.close();
} catch (IOException e) {
// do nothing
}
}
if (stream2 != null) {
try {
stream2.close();
} catch (IOException e) {
// do nothing
}
}
}
} finally {
o2.release();
}
} finally {
o1.release();
}
}
};
/**
* A comparator of boolean values.
*/
public static final Comparator<Boolean> BOOLEAN_COMPARATOR = new Comparator<Boolean>() {
public int compare( Boolean o1,
Boolean o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of date-time instances.
*/
public static final Comparator<DateTime> DATE_TIME_COMPARATOR = new Comparator<DateTime>() {
public int compare( DateTime o1,
DateTime o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of date values.
*/
public static final Comparator<Date> DATE_COMPARATOR = new Comparator<Date>() {
public int compare( Date o1,
Date o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of calendar values.
*/
public static final Comparator<Calendar> CALENDAR_COMPARATOR = new Comparator<Calendar>() {
public int compare( Calendar o1,
Calendar o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of name values.
*/
public static final Comparator<Name> NAME_COMPARATOR = new Comparator<Name>() {
public int compare( Name o1,
Name o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of path values.
*/
public static final Comparator<Path> PATH_COMPARATOR = new Comparator<Path>() {
public int compare( Path o1,
Path o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of URI values.
*/
public static final Comparator<URI> URI_COMPARATOR = new Comparator<URI>() {
public int compare( URI o1,
URI o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of UUID values.
*/
public static final Comparator<UUID> UUID_COMPARATOR = new Comparator<UUID>() {
public int compare( UUID o1,
UUID o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of reference values.
*/
public static final Comparator<Reference> REFERENCE_COMPARATOR = new Comparator<Reference>() {
public int compare( Reference o1,
Reference o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
return o1.compareTo(o2);
}
};
/**
* A comparator of other values.
*/
public static final Comparator<Object> OBJECT_COMPARATOR = new Comparator<Object>() {
@SuppressWarnings( "unchecked" )
public int compare( Object o1,
Object o2 ) {
if (o1 == o2) return 0;
if (o1 == null) return -1;
if (o2 == null) return 1;
PropertyType type1 = PropertyType.discoverType(o1);
PropertyType type2 = PropertyType.discoverType(o2);
// Canonicalize the values ...
o1 = type1.getCanonicalValue(o1);
o2 = type2.getCanonicalValue(o2);
if (type1 != PropertyType.OBJECT && type2 != PropertyType.OBJECT) {
if (type1 == type2) return ((Comparator<Object>)type1.getComparator()).compare(o1, o2);
// The types are different but the classes are the same ...
if (type1.getValueClass().isAssignableFrom(type2.getValueClass())) {
return ((Comparator<Object>)type1.getComparator()).compare(o1, o2);
}
if (type2.getValueClass().isAssignableFrom(type1.getValueClass())) {
return ((Comparator<Object>)type2.getComparator()).compare(o1, o2);
}
}
// The types are different. See if one is a BINARY value (because we can use the secure
// hashes to efficiently do the comparison) ...
ValueFactory<String> stringFactory = getStringValueFactory();
String value1 = null;
String value2 = null;
if (type1 == PropertyType.BINARY || type2 == PropertyType.BINARY) {
try {
byte[] hash1 = null;
byte[] hash2 = null;
// We don't have access to a binary factory, so do this brute force.
// Conver the non-binary value to a string, then compute the hash of the string ...
if (type1 == PropertyType.BINARY) {
value2 = stringFactory.create(o2);
hash2 = SecureHash.getHash(SecureHash.Algorithm.SHA_1, value2.getBytes());
hash1 = ((Binary)o1).getHash();
} else {
assert type2 == PropertyType.BINARY;
value1 = stringFactory.create(o1);
hash1 = SecureHash.getHash(SecureHash.Algorithm.SHA_1, value1.getBytes());
hash2 = ((Binary)o2).getHash();
}
// Compute the difference in the hashes ...
if (hash1.length == hash2.length) {
for (int i = 0; i != hash1.length; ++i) {
int diff = hash1[i] - hash2[i];
if (diff != 0) return diff;
}
return 0;
}
} catch (Throwable error) {
// If anything went wrong, just continue with the string comparison
}
}
// The types are different and must be converted ...
if (value1 == null) value1 = stringFactory.create(o1);
if (value2 == null) value2 = stringFactory.create(o2);
return value1.compareTo(value2);
}
};
// This is loaded lazily so that there is not a circular dependency between PropertyType (depends on this),
// StringValueFactory (depends on PropertyType), and OBJECT_COMPARATOR (which depends on StringValueFactory) ...
private static ValueFactory<String> STRING_VALUE_FACTORY;
protected static final ValueFactory<String> getStringValueFactory() {
// No locking is required, because it doesn't matter if we create several instances during initialization ...
if (STRING_VALUE_FACTORY == null) {
STRING_VALUE_FACTORY = new StringValueFactory(Path.NO_OP_DECODER, Path.NO_OP_ENCODER);
}
return STRING_VALUE_FACTORY;
}
}