com.bigdata.btree.DefaultTupleSerializer Maven / Gradle / Ivy
/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
This program 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; version 2 of the License.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on May 28, 2008
*/
package com.bigdata.btree;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Properties;
import com.bigdata.btree.keys.DefaultKeyBuilderFactory;
import com.bigdata.btree.keys.IKeyBuilder;
import com.bigdata.btree.keys.IKeyBuilderFactory;
import com.bigdata.btree.keys.KeyBuilder;
import com.bigdata.btree.keys.ThreadLocalKeyBuilderFactory;
import com.bigdata.btree.raba.codec.CanonicalHuffmanRabaCoder;
import com.bigdata.btree.raba.codec.IRabaCoder;
import com.bigdata.btree.raba.codec.FrontCodedRabaCoder.DefaultFrontCodedRabaCoder;
import com.bigdata.io.SerializerUtil;
/**
* Default implementation uses the {@link KeyBuilder} to format the object as a
* key and uses Java default serialization for the value. You only need to
* subclass this if you want to use custom (de-)serialization of the value,
* custom conversion of the application key to an unsigned byte[], or if you
* have a special type of application key such that you are able to decode the
* unsigned byte[] and materialize the corresponding application key.
*
* @author Bryan Thompson
* @version $Id$
*/
public class DefaultTupleSerializer
implements ITupleSerializer, Externalizable {
/**
*
*/
private static final long serialVersionUID = 2211020411074955099L;
/**
* The default for {@link IKeyBuilderFactory}.
*
* @deprecated by {@link IndexMetadata.Options#KEY_BUILDER_FACTORY}
*/
static public final IKeyBuilderFactory getDefaultKeyBuilderFactory() {
return new DefaultKeyBuilderFactory(new Properties());
}
/**
* The default for {@link #getLeafKeysCoder()} (compression for the keys
* stored in a leaf).
*
* @deprecated by {@link IndexMetadata.Options#LEAF_KEYS_CODER}
*/
static public final IRabaCoder getDefaultLeafKeysCoder() {
return DefaultFrontCodedRabaCoder.INSTANCE;
// return PrefixSerializer.INSTANCE;
}
/**
* The default for {@link #getLeafValuesCoder()} (compression for
* the values stored in a leaf).
*
* @deprecated by {@link IndexMetadata.Options#LEAF_VALUES_CODER}
*/
static public final IRabaCoder getDefaultValuesCoder() {
return CanonicalHuffmanRabaCoder.INSTANCE;
// return DefaultDataSerializer.INSTANCE;
}
private IRabaCoder leafKeysCoder;
private IRabaCoder leafValsCoder;
@Override
final public IRabaCoder getLeafKeysCoder() {
return leafKeysCoder;
}
@Override
final public IRabaCoder getLeafValuesCoder() {
return leafValsCoder;
}
/**
* Override the {@link #getLeafKeysCoder()}. It is NOT safe to change
* this value once data have been stored in an {@link IIndex} using another
* value as existing data MAY become unreadable.
*
* @param leafKeysCoder
* The new value.
*/
final public void setLeafKeysCoder(final IRabaCoder leafKeysCoder) {
if (leafKeysCoder == null)
throw new IllegalArgumentException();
this.leafKeysCoder = leafKeysCoder;
}
/**
* Override the {@link #getLeafValuesCoder()}. It is NOT safe to change
* this value once data have been stored in an {@link IIndex} using another
* value as existing data MAY become unreadable.
*
* @param valuesCoder
* The new value.
*/
final public void setLeafValuesCoder(final IRabaCoder valuesCoder) {
if (valuesCoder == null)
throw new IllegalArgumentException();
this.leafValsCoder = valuesCoder;
}
/**
* Factory for a new instance using default values for the
* {@link #getKeyBuilder()}, the {@link #getLeafKeysCoder()}, and the
* {@link #getLeafValuesCoder()}.
*/
public static ITupleSerializer newInstance() {
return new DefaultTupleSerializer(getDefaultKeyBuilderFactory());
}
/**
* The factory specified to the ctor.
*/
private IKeyBuilderFactory delegateKeyBuilderFactory;
/**
* The {@link #delegateKeyBuilderFactory} wrapped up in thread-local
* factory.
*/
private transient IKeyBuilderFactory threadLocalKeyBuilderFactory;
/**
* De-serialization ctor only.
*/
public DefaultTupleSerializer() {
}
/**
*
* @param keyBuilderFactory
* The {@link IKeyBuilderFactory}, which will be automatically
* wrapped up by a {@link ThreadLocalKeyBuilderFactory}.
*/
public DefaultTupleSerializer(final IKeyBuilderFactory keyBuilderFactory) {
this(keyBuilderFactory, getDefaultLeafKeysCoder(),
getDefaultValuesCoder());
}
public DefaultTupleSerializer(final IKeyBuilderFactory keyBuilderFactory,
final IRabaCoder leafKeysCoder, final IRabaCoder leafValsCoder) {
if (keyBuilderFactory == null)
throw new IllegalArgumentException();
if (leafKeysCoder == null)
throw new IllegalArgumentException();
if (leafValsCoder == null)
throw new IllegalArgumentException();
threadLocalKeyBuilderFactory = new ThreadLocalKeyBuilderFactory(
keyBuilderFactory);
this.delegateKeyBuilderFactory = keyBuilderFactory;
this.leafKeysCoder = leafKeysCoder;
this.leafValsCoder = leafValsCoder;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append(getClass().getName()+"{");
sb.append(", keyBuilderFactory="+delegateKeyBuilderFactory);
sb.append(", leafKeysCoder=" + leafKeysCoder);//.getClass().getName());
sb.append(", leafValuesCoder=" + leafValsCoder);//.getClass().getName());
sb.append("}");
return sb.toString();
}
/**
* A thread-local {@link IKeyBuilder} instance.
*
* Note: By default, the {@link #getKeyBuilder()} uses whatever default is
* in place on the host/JVM where the {@link DefaultTupleSerializer}
* instance was first created. That backing {@link IKeyBuilderFactory}
* object is serialized along with the {@link DefaultTupleSerializer} so
* that the specific configuration values are persisted, even when the
* {@link DefaultTupleSerializer} is de-serialized on a different host.
*/
@Override
final public IKeyBuilder getKeyBuilder() {
if(threadLocalKeyBuilderFactory == null) {
/*
* This can happen if you use the de-serialization ctor by mistake.
*/
throw new IllegalStateException();
}
/*
* TODO This should probably to a reset() before returning the object.
* However, we need to verify that no callers are assuming that it does
* NOT do a reset and implicitly relying on passing the intermediate key
* via the return value (which would be very bad style).
*/
return threadLocalKeyBuilderFactory.getKeyBuilder();
}
@Override
final public IKeyBuilder getPrimaryKeyBuilder() {
if(threadLocalKeyBuilderFactory == null) {
/*
* This can happen if you use the de-serialization ctor by mistake.
*/
throw new IllegalStateException();
}
/*
* TODO This should probably to a reset() before returning the object.
* However, we need to verify that no callers are assuming that it does
* NOT do a reset and implicitly relying on passing the intermediate key
* via the return value (which would be very bad style).
*/
return threadLocalKeyBuilderFactory.getPrimaryKeyBuilder();
}
@Override
public byte[] serializeKey(final Object obj) {
if (obj == null)
throw new IllegalArgumentException();
return getKeyBuilder().reset().append(obj).getKey();
}
/**
* Serializes the object as a byte[] using Java default serialization.
*
* @param obj
* The object to be serialized (MAY be null).
*
* @return The serialized representation of the object as a byte[] -or-
* null if the reference is null.
*/
@Override
public byte[] serializeVal(final V obj) {
return SerializerUtil.serialize(obj);
}
/**
* De-serializes an object from the {@link ITuple#getValue() value} stored
* in the tuple (ignores the key stored in the tuple).
*/
@Override
public V deserialize(ITuple tuple) {
if (tuple == null)
throw new IllegalArgumentException();
// @todo tuple.getValueStream()
return (V)SerializerUtil.deserialize(tuple.getValue());
}
/**
* This is an unsupported operation. Additional information is required to
* either decode the internal unsigned byte[] keys or to extract the key
* from the de-serialized value (if it is being stored in that value). You
* can either write your own {@link ITupleSerializer} or you can specialize
* this one so that it can de-serialize your keys using whichever approach
* makes the most sense for your data.
*
* @throws UnsupportedOperationException
* always.
*/
@Override
public K deserializeKey(ITuple tuple) {
throw new UnsupportedOperationException();
}
/**
* The initial version.
*
* Note: Explicit versioning for the {@link DefaultTupleSerializer} was
* introduced with inlining of datatype literals for the RDF database.
*/
private final static transient byte VERSION0 = 0;
/**
* The current version.
*/
private final static transient byte VERSION = VERSION0;
@Override
public void readExternal(final ObjectInput in) throws IOException,
ClassNotFoundException {
final byte version = in.readByte();
switch (version) {
case VERSION0:
delegateKeyBuilderFactory = (IKeyBuilderFactory) in.readObject();
threadLocalKeyBuilderFactory = new ThreadLocalKeyBuilderFactory(
delegateKeyBuilderFactory);
leafKeysCoder = (IRabaCoder) in.readObject();
leafValsCoder = (IRabaCoder) in.readObject();
break;
default:
throw new UnsupportedOperationException("Unknown version: "
+ version);
}
}
@Override
public void writeExternal(final ObjectOutput out) throws IOException {
out.writeByte(VERSION);
out.writeObject(delegateKeyBuilderFactory);
out.writeObject(leafKeysCoder);
out.writeObject(leafValsCoder);
}
}