com.bigdata.rdf.spo.SPORelation 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 Jun 21, 2008
*/
package com.bigdata.rdf.spo;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.log4j.Logger;
import com.bigdata.bop.BOp;
import com.bigdata.bop.Constant;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.IPredicate;
import com.bigdata.bop.IVariableOrConstant;
import com.bigdata.bop.NV;
import com.bigdata.bop.Var;
import com.bigdata.bop.ap.Predicate;
import com.bigdata.btree.BTree;
import com.bigdata.btree.BloomFilterFactory;
import com.bigdata.btree.DefaultTupleSerializer;
import com.bigdata.btree.IIndex;
import com.bigdata.btree.IRangeQuery;
import com.bigdata.btree.ITuple;
import com.bigdata.btree.IndexMetadata;
import com.bigdata.btree.filter.TupleFilter;
import com.bigdata.btree.isolation.IConflictResolver;
import com.bigdata.btree.keys.IKeyBuilder;
import com.bigdata.btree.keys.KeyBuilder;
import com.bigdata.btree.keys.SuccessorUtil;
import com.bigdata.btree.proc.LongAggregator;
import com.bigdata.btree.raba.codec.EmptyRabaValueCoder;
import com.bigdata.btree.raba.codec.FixedLengthValueRabaCoder;
import com.bigdata.btree.raba.codec.IRabaCoder;
import com.bigdata.journal.AbstractTask;
import com.bigdata.journal.IIndexManager;
import com.bigdata.journal.IResourceLock;
import com.bigdata.journal.ITx;
import com.bigdata.journal.TemporaryStore;
import com.bigdata.journal.TimestampUtility;
import com.bigdata.rdf.axioms.NoAxioms;
import com.bigdata.rdf.changesets.IChangeLog;
import com.bigdata.rdf.inf.Justification;
import com.bigdata.rdf.internal.IV;
import com.bigdata.rdf.internal.IVUtility;
import com.bigdata.rdf.internal.constraints.RangeBOp;
import com.bigdata.rdf.internal.impl.bnode.SidIV;
import com.bigdata.rdf.lexicon.ITermIVFilter;
import com.bigdata.rdf.lexicon.LexiconRelation;
import com.bigdata.rdf.model.StatementEnum;
import com.bigdata.rdf.sparql.ast.QuadsOperationInTriplesModeException;
import com.bigdata.rdf.sparql.ast.service.history.HistoryIndexTupleSerializer;
import com.bigdata.rdf.spo.JustIndexWriteProc.WriteJustificationsProcConstructor;
import com.bigdata.rdf.store.AbstractTripleStore;
import com.bigdata.rdf.store.IRawTripleStore;
import com.bigdata.rdf.store.LocalTripleStore;
import com.bigdata.relation.AbstractRelation;
import com.bigdata.relation.accesspath.ArrayAccessPath;
import com.bigdata.relation.accesspath.ElementFilter;
import com.bigdata.relation.accesspath.EmptyAccessPath;
import com.bigdata.relation.accesspath.IAccessPath;
import com.bigdata.relation.accesspath.IElementFilter;
import com.bigdata.relation.rule.eval.AbstractSolutionBuffer.InsertSolutionBuffer;
import com.bigdata.relation.rule.eval.ISolution;
import com.bigdata.service.IBigdataFederation;
import com.bigdata.striterator.ChunkedWrappedIterator;
import com.bigdata.striterator.EmptyChunkedIterator;
import com.bigdata.striterator.IChunkedIterator;
import com.bigdata.striterator.IChunkedOrderedIterator;
import com.bigdata.striterator.IKeyOrder;
import cutthecrap.utils.striterators.ICloseableIterator;
import cutthecrap.utils.striterators.Resolver;
import cutthecrap.utils.striterators.Striterator;
/**
* The {@link SPORelation} handles all things related to the indices
* representing the triples stored in the database. Statements are first
* converted to term identifiers using the {@link LexiconRelation} and then
* inserted into the statement indices in parallel. There is one statement index
* for each of the three possible access paths for a triple store. The key is
* formed from the corresponding permutation of the subject, predicate, and
* object, e.g., {s,p,o}, {p,o,s}, and {o,s,p} for triples or {s,p,o,c}, etc for
* quads. The statement type (inferred, axiom, or explicit) and the optional
* statement identifier are stored under the key. All state for a statement is
* replicated in each of the statement indices.
*
* @author Bryan Thompson
* @version $Id$
*/
public class SPORelation extends AbstractRelation {
protected static final transient Logger log = Logger
.getLogger(SPORelation.class);
private final Set indexNames;
private final List keyOrders;
private final int keyArity;
/**
* The arity of the key for the statement indices: 3 is a
* triple store, with or without statement identifiers; 4 is a
* quad store, which does not support statement identifiers as the 4th
* position of the (s,p,o,c) is interpreted as context and located in the
* B+Tree statement index key rather than the value associated with the key.
*/
public int getKeyArity() {
return keyArity;
}
/**
* Hard references for the possible statement indices. The index into the
* array is {@link SPOKeyOrder#index()}.
*/
private final IIndex[] indices;
/** Hard reference to the justifications index iff used. */
private volatile IIndex just;
/**
* Constant for the {@link SPORelation} namespace component.
*
* Note: To obtain the fully qualified name of an index in the
* {@link SPORelation} you need to append a "." to the relation's namespace,
* then this constant, then a "." and then the local name of the index.
*
* @see AbstractRelation#getFQN(IKeyOrder)
*/
public static final String NAME_SPO_RELATION = "spo";
private static final transient String NAME_JUST = "JUST";
/**
* This is used to conditionally enable the logic to retract justifications
* when the corresponding statements is retracted.
*/
final public boolean justify;
/**
* This is used to conditionally disable all but a single statement index
* (aka access path).
*/
final public boolean oneAccessPath;
/**
* true iff the SPO index will maintain a bloom filter.
*
* @see Options#BLOOM_FILTER
*/
final protected boolean bloomFilter;
/**
* This is used to conditionally index the {@link IChangeLog}.
*/
final private boolean historyService;
/**
* When true, SPOs will never be removed from the indices, only downgraded
* to {@link StatementEnum#History}.
*/
final private boolean history;
/**
* When true the database will support statement identifiers.
* A statement identifier is a unique 64-bit integer taken from the same
* space as the term identifiers and which uniquely identifiers a statement
* in the database regardless of the graph in which that statement appears.
* The purpose of statement identifiers is to allow statements about
* statements without recourse to RDF style reification.
*/
final private boolean statementIdentifiers;
/**
* When true the database will support statement identifiers.
*
* A statement identifier is a unique 64-bit integer taken from the same
* space as the term identifiers and which uniquely identifiers a statement
* in the database regardless of the graph in which that statement appears.
* The purpose of statement identifiers is to allow statements about
* statements without recourse to RDF style reification.
*
* Only explicit statements will have a statement identifier. Statements
* made about statements using their statement identifiers will
* automatically be retracted if a statement they describe is retracted (a
* micro form of truth maintenance that is always enabled when statement
* identifiers are enabled).
*/
public boolean getStatementIdentifiers() {
return statementIdentifiers;
}
public SPORelation(final IIndexManager indexManager,
final String namespace, final Long timestamp,
final Properties properties) {
this(null/* container */, indexManager, namespace, timestamp,
properties);
}
public SPORelation(final AbstractTripleStore container,
final IIndexManager indexManager, final String namespace,
final Long timestamp, final Properties properties) {
super(container, indexManager, namespace, timestamp, properties);
/*
* Reads off the property for the inference engine that tells us whether
* or not the justification index is being used. This is used to
* conditionally enable the logic to retract justifications when the
* corresponding statements is retracted.
*/
this.justify = Boolean.parseBoolean(getProperty(
AbstractTripleStore.Options.JUSTIFY,
AbstractTripleStore.Options.DEFAULT_JUSTIFY));
this.oneAccessPath = Boolean.parseBoolean(getProperty(
AbstractTripleStore.Options.ONE_ACCESS_PATH,
AbstractTripleStore.Options.DEFAULT_ONE_ACCESS_PATH));
this.statementIdentifiers = Boolean.parseBoolean(getProperty(
AbstractTripleStore.Options.STATEMENT_IDENTIFIERS,
AbstractTripleStore.Options.DEFAULT_STATEMENT_IDENTIFIERS));
this.historyService= Boolean.parseBoolean(getProperty(
AbstractTripleStore.Options.HISTORY_SERVICE,
AbstractTripleStore.Options.DEFAULT_HISTORY_SERVICE));
this.keyArity = Boolean.valueOf(getProperty(
AbstractTripleStore.Options.QUADS,
AbstractTripleStore.Options.DEFAULT_QUADS)) ? 4 : 3;
if (statementIdentifiers && keyArity == 4) {
throw new UnsupportedOperationException(
AbstractTripleStore.Options.QUADS
+ " does not support the provenance mode ("
+ AbstractTripleStore.Options.STATEMENT_IDENTIFIERS
+ ")");
}
this.bloomFilter = Boolean.parseBoolean(getProperty(
AbstractTripleStore.Options.BLOOM_FILTER,
AbstractTripleStore.Options.DEFAULT_BLOOM_FILTER));
final String historyClass = getProperty(
AbstractTripleStore.Options.RDR_HISTORY_CLASS,
null);
this.history = historyClass != null && historyClass.length() > 0;
// declare the various indices.
{
final Set set = new HashSet();
if (keyArity == 3) {
// three indices for a triple store and the have ids in [0:2].
this.indices = new IIndex[3];
if (oneAccessPath) {
set.add(getFQN(SPOKeyOrder.SPO));
keyOrders = Collections.unmodifiableList(Arrays
.asList(new SPOKeyOrder[] { SPOKeyOrder.SPO }));
} else {
set.add(getFQN(SPOKeyOrder.SPO));
set.add(getFQN(SPOKeyOrder.POS));
set.add(getFQN(SPOKeyOrder.OSP));
keyOrders = Collections.unmodifiableList(Arrays
.asList(new SPOKeyOrder[] { SPOKeyOrder.SPO,
SPOKeyOrder.POS, SPOKeyOrder.OSP }));
}
} else {
// six indices for a quad store w/ ids in [3:8].
this.indices = new IIndex[SPOKeyOrder.MAX_INDEX_COUNT];
if (oneAccessPath) {
set.add(getFQN(SPOKeyOrder.SPOC));
keyOrders = Collections.unmodifiableList(Arrays
.asList(new SPOKeyOrder[] { SPOKeyOrder.SPOC }));
} else {
final List tmp = new ArrayList(6);
for (int i = SPOKeyOrder.FIRST_QUAD_INDEX; i <= SPOKeyOrder.LAST_QUAD_INDEX; i++) {
set.add(getFQN(SPOKeyOrder.valueOf(i)));
tmp.add(SPOKeyOrder.valueOf(i));
}
keyOrders = Collections.unmodifiableList(tmp);
}
}
/*
* Note: We need the justifications index in the [indexNames] set
* since that information is used to request the appropriate index
* locks when running rules as mutation program in the LDS mode.
*/
if (justify) {
set.add(getNamespace() + "." + NAME_JUST);
}
this.indexNames = Collections.unmodifiableSet(set);
}
// Note: Do not eagerly resolve the indices.
// {
//
// final boolean inlineTerms = Boolean.parseBoolean(getProperty(
// AbstractTripleStore.Options.INLINE_TERMS,
// AbstractTripleStore.Options.DEFAULT_INLINE_TERMS));
//
// lexiconConfiguration = new LexiconConfiguration(inlineTerms);
//
// }
}
/**
* Strengthened return type.
*/
@Override
public AbstractTripleStore getContainer() {
return (AbstractTripleStore) super.getContainer();
}
/**
* @todo This should use GRS row scan in the GRS for the SPORelation
* namespace. It is only used by the {@link LocalTripleStore}
* constructor and a unit test's main() method. This method
* IS NOT part of any public API at this time.
*/
public boolean exists() {
for(String name : getIndexNames()) {
if (getIndex(name) == null)
return false;
}
return true;
}
public void create() {
final IResourceLock resourceLock = acquireExclusiveLock();
try {
// create the relation declaration metadata.
super.create();
final IIndexManager indexManager = getIndexManager();
final boolean triples = keyArity == 3;
if (triples) {
// triples
if (oneAccessPath) {
indexManager
.registerIndex(getStatementIndexMetadata(SPOKeyOrder.SPO));
} else {
for (int i = SPOKeyOrder.FIRST_TRIPLE_INDEX; i <= SPOKeyOrder.LAST_TRIPLE_INDEX; i++) {
indexManager
.registerIndex(getStatementIndexMetadata(SPOKeyOrder
.valueOf(i)));
}
}
} else {
// quads
if(oneAccessPath) {
indexManager
.registerIndex(getStatementIndexMetadata(SPOKeyOrder.SPOC));
} else {
for (int i = SPOKeyOrder.FIRST_QUAD_INDEX; i <= SPOKeyOrder.LAST_QUAD_INDEX; i++) {
indexManager
.registerIndex(getStatementIndexMetadata(SPOKeyOrder
.valueOf(i)));
}
}
}
if (justify) {
final String fqn = getNamespace() + "." + NAME_JUST;
indexManager.registerIndex(getJustIndexMetadata(fqn));
}
if (historyService) {
final SPOKeyOrder keyOrder = triples //
? SPOKeyOrder.POS//
: SPOKeyOrder.PCSO//
;
indexManager.registerIndex(getHistoryIndexMetadata(keyOrder));
}
// lookupIndices();
} finally {
unlock(resourceLock);
}
}
/*
* @todo force drop of all indices rather than throwing an exception if an
* index does not exist?
*/
@Override
public void destroy() {
final IResourceLock resourceLock = acquireExclusiveLock();
try {
final IIndexManager indexManager = getIndexManager();
// clear hard references.
for (int i = 0; i < indices.length; i++) {
indices[i] = null;
}
// drop indices.
for(String name : getIndexNames()) {
indexManager.dropIndex(name);
}
// if (justify) {
//
// indexManager.dropIndex(getNamespace() + "."+ NAME_JUST);
just = null;
//
// }
// destroy the relation declaration metadata.
super.destroy();
} finally {
unlock(resourceLock);
}
}
/**
* Overridden to return the hard reference for the index, which is cached
* the first time it is resolved. This class does not eagerly resolve the
* indices to (a) avoid a performance hit when running in a context where
* the index view is not required; and (b) to avoid exceptions when running
* as an {@link ITx#UNISOLATED} {@link AbstractTask} where the index was not
* declared and hence can not be materialized.
*/
@Override
public IIndex getIndex(final IKeyOrder keyOrder) {
final int n = ((SPOKeyOrder) keyOrder).index();
IIndex ndx = indices[n];
if (ndx == null) {
synchronized (indices) {
if ((ndx = indices[n] = super.getIndex(keyOrder)) == null) {
throw new IllegalArgumentException(keyOrder.toString());
}
}
}
return ndx;
}
final public SPOKeyOrder getPrimaryKeyOrder() {
return keyArity == 3 ? SPOKeyOrder.SPO : SPOKeyOrder.SPOC;
}
final public IIndex getPrimaryIndex() {
return getIndex(getPrimaryKeyOrder());
}
/**
* The optional index on which {@link Justification}s are stored.
*
* @todo The Justifications index is not a regular index of the SPORelation.
* In fact, it is a relation for proof chains and is not really of the
* SPORelation at all and should probably be moved onto its own
* JRelation. The presence of the Justification index on the
* SPORelation would cause problems for methods which would like to
* enumerate the indices, except that we just silently ignore its
* presence in those methods (it is not in the index[] for example).
*
* This would cause the justification index namespace to change to be
* a peer of the SPORelation namespace.
*/
final public IIndex getJustificationIndex() {
if (!justify)
return null;
if (just == null) {
synchronized (this) {
// attempt to resolve the index and set the index reference.
if ((just = super.getIndex(getNamespace() + "." + NAME_JUST)) == null) {
throw new IllegalStateException();
}
}
}
return just;
}
/**
* Return an iterator that will visit the distinct (s,p,o) tuples in the
* source iterator. The context and statement type information will be
* stripped from the visited {@link ISPO}s. The iterator will be backed by a
* {@link BTree} on a {@link TemporaryStore} and will use a bloom filter for
* fast point tests. The {@link BTree} and the source iterator will be
* closed when the returned iterator is closed.
*
* @param src
* The source iterator.
*
* @return The filtered iterator.
*/
public ICloseableIterator distinctSPOIterator(
final ICloseableIterator src) {
if (!src.hasNext())
return new EmptyChunkedIterator(SPOKeyOrder.SPO);
return new DistinctSPOIterator(this, src);
}
/**
* Return a new unnamed {@link BTree} instance for the
* {@link SPOKeyOrder#SPO} key order backed by a {@link TemporaryStore}. The
* index will only store (s,p,o) triples (not quads) and will not store
* either the SID or {@link StatementEnum}. This is a good choice when you
* need to impose a "distinct" filter on (s,p,o) triples.
*
* @param bloomFilter
* When true, a bloom filter is enabled for the
* index. The bloom filter provides fast correct rejection tests
* for point lookups up to ~2M triples and then shuts off
* automatically. See {@link BloomFilterFactory#DEFAULT} for more
* details.
*
* @return The SPO index.
*
* @deprecated Comment out when we drop the {@link DistinctSPOIterator}.
*/
public BTree getSPOOnlyBTree(final boolean bloomFilter) {
final TemporaryStore tempStore = getIndexManager().getTempStore();
final IndexMetadata metadata = new IndexMetadata(UUID.randomUUID());
// leading key compression works great.
final IRabaCoder leafKeySer = DefaultTupleSerializer
.getDefaultLeafKeysCoder();
// nothing is stored under the values.
final IRabaCoder leafValSer = EmptyRabaValueCoder.INSTANCE;
// setup the tuple serializer.
metadata.setTupleSerializer(new SPOTupleSerializer(
SPOKeyOrder.SPO, false/* sids */, leafKeySer, leafValSer));
if(bloomFilter) {
// optionally enable the bloom filter.
metadata.setBloomFilterFactory(BloomFilterFactory.DEFAULT);
}
final BTree ndx = BTree.create(tempStore, metadata);
return ndx;
}
/**
* Overrides for the statement indices.
*
* @see
* Choosing the index for testing fully bound access paths based on
* index locality
*/
protected IndexMetadata getStatementIndexMetadata(final SPOKeyOrder keyOrder) {
final IndexMetadata metadata = newIndexMetadata(getFQN(keyOrder));
// leading key compression works great.
final IRabaCoder leafKeySer = DefaultTupleSerializer
.getDefaultLeafKeysCoder();
// final IRabaCoder leafValSer;
// if (!statementIdentifiers) {
//
// /*
// * Note: this value coder does not know about statement identifiers.
// * Therefore it is turned off if statement identifiers are enabled.
// */
//
// leafValSer = new FastRDFValueCoder2();
//// leafValSer = SimpleRabaCoder.INSTANCE;
//
// } else {
//
// /*
// * The default is canonical huffman coding, which is relatively slow
// * and does not achieve very good compression on term identifiers.
// */
// leafValSer = DefaultTupleSerializer.getDefaultValuesCoder();
//
// /*
// * @todo This is much faster than huffman coding, but less space
// * efficient. However, it appears that there are some cases where
// * SIDs are enabled but only the flag bits are persisted. What
// * gives?
// */
//// leafValSer = new FixedLengthValueRabaCoder(1 + 8);
//
// }
/*
* We can just always use the FastRDFValueCoder now that sids are
* inlined into the statement indices and we don't store a term id
* for them in the SPO tuple value.
*/
final IRabaCoder leafValSer = new FastRDFValueCoder2();
metadata.setTupleSerializer(new SPOTupleSerializer(
keyOrder, statementIdentifiers, leafKeySer, leafValSer));
if ((getIndexManager() instanceof IBigdataFederation)
&& ((IBigdataFederation) getIndexManager()).isScaleOut()
&& keyOrder.getKeyArity() == 4
&& getContainer().isConstrainXXXCShards()
&& keyOrder.getIndexName().endsWith("C")) {
/*
* Apply a constraint to an xxxC index such that all quads for the
* same triple are in the same shard.
*/
metadata.setSplitHandler(new XXXCShardSplitHandler());
}
if (bloomFilter
&& (keyOrder.equals(SPOKeyOrder.SPO) || keyOrder
.equals(SPOKeyOrder.SPOC))) {
// * Enable the bloom filter for the SPO index only.
// *
// * Note: This SPO index is used any time we have an access path that
// * is a point test. Therefore this is the only index for which it
// * makes sense to maintain a bloom filter.
/*
* Enable the bloom filter.
*
* Historically, the bloom filter was only enabled in for the SPO
* index because the SPO index was always used for a point test.
* Further, by oversight, it was never enabled for a quads mode KB
* instance. However, in order to improve the locality of reference
* for point tests, the SPOKeyOrder#getKeyOrder() method was
* modified to use the index which would be used if we evaluated the
* original predicate rather than the "as-bound" predicate. This
* change provides better locality of access since the variables
* indicate the region of variability in the index while the
* constants indicate the region of locality. Therefore, fully bound
* (aka point tests) can now occur on ANY statement index and the
* bloom filter is now enabled on all statement indices.
*
* @see https://sourceforge.net/apps/trac/bigdata/ticket/150
* (chosing the index for testing fully bound access paths based on
* index locality)
*/
/*
* Note: The maximum error rate (maxP) applies to the mutable BTree
* only. For scale-out indices, there is one mutable BTree per index
* partition and a new (empty) BTree is allocated each time the live
* journal for the index partitions overflows.
*
* Note: The bloom filter is disabled once the error rate grows too
* large. However, in scale-out, we are able to put a perfect fit
* bloom filter in each index segment. This can significantly reduce
* the IO costs associated with point tests. This can not be done in
* the single machine database mode because the error rate of the
* bloom filter is a function of the size of the bloom filter and
* the #of entries in the index.
*/
// // good performance up to ~2M triples.
// final int n = 1000000; // 1M
// final double p = 0.01;
// final double maxP = 0.20;
// // good performance up to ~20M triples.
// final int n = 10000000; // 10M
// final double p = 0.05;
// final double maxP = 0.20;
// final BloomFilterFactory factory = new BloomFilterFactory(n, p, maxP);
final BloomFilterFactory factory = BloomFilterFactory.DEFAULT;
if (log.isInfoEnabled())
log.info("Enabling bloom filter for SPO index: " + factory);
metadata.setBloomFilterFactory( factory );
}
if(TimestampUtility.isReadWriteTx(getTimestamp())) {
// enable isolatable indices.
metadata.setIsolatable(true);
/*
* This tests to see whether or not the axiomsClass is NoAxioms. If
* so, then we understand inference to be disabled and can use a
* conflict resolver for plain triples, plain quads, or even plain
* sids (SIDs are assigned by the lexicon using unisolated
* operations).
*
* @todo we should have an explicit "no inference" property. this
* jumps through hoops since we can not call getAxioms() on the
* AbstractTripleStore has been created, and SPORelation#create()
* is invoked from within AbstractTripleStore#create(). When
* adding that property, update a bunch of unit tests and code
* which tests on the axioms class or BaseAxioms#isNone().
*/
if (NoAxioms.class.getName().equals(
getContainer().getProperties().getProperty(
AbstractTripleStore.Options.AXIOMS_CLASS,
AbstractTripleStore.Options.DEFAULT_AXIOMS_CLASS))) {
metadata.setConflictResolver(new SPOWriteWriteResolver());
}
}
return metadata;
}
/**
* Overrides for the statement indices.
*
* @see
* History Service
*/
protected IndexMetadata getHistoryIndexMetadata(final SPOKeyOrder keyOrder) {
final IndexMetadata metadata = newIndexMetadata(getFQN(this, NAME_HISTORY));
// leading key compression works great.
final IRabaCoder leafKeySer = DefaultTupleSerializer
.getDefaultLeafKeysCoder();
/*
* There is one byte per tuple. The low nibble is the flags and
* statement enum. The high nibble is the ChangeAction.
*/
final IRabaCoder leafValSer = new FixedLengthValueRabaCoder(1/* len */);
metadata.setTupleSerializer(new HistoryIndexTupleSerializer(keyOrder,
statementIdentifiers, leafKeySer, leafValSer));
if (TimestampUtility.isReadWriteTx(getTimestamp())) {
/*
* Enable isolatable indices.
*
* Note: we can not use an unisolated history index since changes
* could become committed before a given tx commits due to a
* concurrent tx commit. That would break the semantics of the
* history index if the tx then fails rather than committing since
* some of its changes would have become visible and durable anyway.
*/
metadata.setIsolatable(true);
/*
* TODO We might need to add a write-write resolver for the history
* index.
*/
// metadata.setConflictResolver(new HistoryWriteWriteResolver());
}
return metadata;
}
public static transient final String NAME_HISTORY = "HIST";
/**
* Conflict resolver for add/add conflicts and retract/retract conflicts for
* any of (triple store, triple store with SIDs or quad store) but without
* inference. For an add/retract conflict, the writes can not be reconciled
* and the transaction can not be validated. Write-write conflict
* reconciliation is not supported if inference is enabled. The truth
* maintenance behavior makes this too complex.
*
* @todo It is really TM, not inference, which makes this complicated.
* However, if we allow statement type information into the statement
* index values then we must also deal with that information in the
* conflict resolver.
*
* @todo In both cases where we can resolve the conflict, the tuple could be
* withdrawn from the writeSet since the desired tuple is already in
* the unisolated index rather than causing it to be touched on the
* unisolated index. This would have the advantage of minimizing
* writes on the unisolated index.
*/
private static class SPOWriteWriteResolver implements IConflictResolver {
/**
*
*/
private static final long serialVersionUID = -1591732801502917983L;
public SPOWriteWriteResolver() {
}
public boolean resolveConflict(IIndex writeSet, ITuple txTuple,
ITuple currentTuple) throws Exception {
/*
* Note: In fact, retract-retract conflicts SHOULD NOT be resolved
* because retracts are often used to remove an old property value
* when a new value will be assigned for that property. For example,
*
* tx1: -red, +green
*
* tx2: -red, +blue
*
* if we resolve the retract-retract conflict, then we will get
* {green,blue} after the transactions run, rather than either
* {green} or {blue}.
*/
// if (txTuple.isDeletedVersion() && currentTuple.isDeletedVersion()) {
//
//// System.err.println("Resolved retract/retract conflict");
//
// // retract/retract is not a conflict.
// return true;
//
// }
if (!txTuple.isDeletedVersion() && !currentTuple.isDeletedVersion()) {
// System.err.println("Resolved add/add conflict");
// add/add is not a conflict.
return true;
}
/*
* Note: We don't need to materialize the SPOs to resolve the
* conflict, but this is how you would do that.
*/
// final ISPO txSPO = (ISPO) txTuple.getObject();
//
// final ISPO currentSPO = (ISPO) txTuple.getObject();
// either delete/add or add/delete is a conflict.
return false;
}
}
/**
* Overrides for the {@link IRawTripleStore#getJustificationIndex()}.
*/
protected IndexMetadata getJustIndexMetadata(final String name) {
final IndexMetadata metadata = newIndexMetadata(name);
metadata.setTupleSerializer(new JustificationTupleSerializer(keyArity));
return metadata;
}
@Override
public Set getIndexNames() {
return indexNames;
}
@Override
@SuppressWarnings({ "unchecked", "rawtypes" })
public Iterator> getKeyOrders() {
return (Iterator) keyOrders.iterator();
}
/**
* Return an iterator visiting each {@link IKeyOrder} maintained by this
* relation.
*/
public Iterator statementKeyOrderIterator() {
switch(keyArity) {
case 3:
if (oneAccessPath)
return SPOKeyOrder.spoOnlyKeyOrderIterator();
return SPOKeyOrder.tripleStoreKeyOrderIterator();
case 4:
if (oneAccessPath)
return SPOKeyOrder.spocOnlyKeyOrderIterator();
return SPOKeyOrder.quadStoreKeyOrderIterator();
default:
throw new AssertionError();
}
}
/**
* Return the access path for a triple pattern.
*
* @param s
* @param p
* @param o
* @throws UnsupportedOperationException
* unless the {@link #getKeyArity()} is 3.
*
* @deprecated by {@link #getAccessPath(IV, IV, IV, IV)}
*/
public IAccessPath getAccessPath(final IV s, final IV p, final IV o) {
if (keyArity != 3)
throw new UnsupportedOperationException();
return getAccessPath(s, p, o, null/* c */, null/* filter */, null/* range */);
}
/**
* Return the access path for a triple or quad pattern.
*/
public IAccessPath getAccessPath(final IV s, final IV p,
final IV o, final IV c) {
return getAccessPath(s, p, o, c, null/*filter*/, null/*range*/);
}
/**
* Return the access path for a triple or quad pattern with a range.
*/
public IAccessPath getAccessPath(final IV s, final IV p,
final IV o, final IV c, final RangeBOp range) {
return getAccessPath(s, p, o, c, null/*filter*/, range);
}
/**
* Return the access path for a triple or quad pattern with a filter.
*/
public IAccessPath getAccessPath(final IV s, final IV p,
final IV o, final IV c, IElementFilter filter) {
return getAccessPath(s, p, o, c, filter, null);
}
/**
* Return the access path for a triple or quad pattern with an optional
* filter (core implementation). All arguments are optional. Any bound
* argument will restrict the returned access path. For a triple pattern,
* c WILL BE IGNORED as there is no index over the statement
* identifiers, even when they are enabled. For a quad pattern, any argument
* MAY be bound.
*
* @param s
* The subject position (optional).
* @param p
* The predicate position (optional).
* @param o
* The object position (optional).
* @param c
* The context position (optional and ignored for a triple
* store).
* @param filter
* The filter (optional).
* @param range
* The range (optional).
*
* @return The best access path for that triple or quad pattern.
*
* @throws UnsupportedOperationException
* for a triple store without statement identifiers if the
* c is non-{@link #NULL}.
*/
public IAccessPath getAccessPath(final IV s, final IV p,
final IV o, final IV c, IElementFilter filter,
final RangeBOp range) {
final IPredicate pred = getPredicate(s, p, o, c, filter, range);
return getAccessPath(pred);
}
/**
* Return the predicate for a triple or quad pattern filter (core
* implementation). All arguments are optional. Any bound argument will
* restrict the returned access path. For a triple pattern, c WILL BE
* IGNORED as there is no index over the statement identifiers, even when
* they are enabled. For a quad pattern, any argument MAY be bound.
*
* @param s
* The subject position (optional).
* @param p
* The predicate position (optional).
* @param o
* The object position (optional).
* @param c
* The context position (optional and ignored for a triple
* store).
*
* @return The predicate for that triple or quad pattern.
*
* @throws UnsupportedOperationException
* for a triple store without statement identifiers if the
* c is non-{@link #NULL}.
*/
public IPredicate getPredicate(final IV s, final IV p,
final IV o, final IV c) {
return getPredicate(s, p, o, c, null, null);
}
/**
* Return the predicate for a triple or quad pattern with an optional
* filter (core implementation). All arguments are optional. Any bound
* argument will restrict the returned access path. For a triple pattern,
* c WILL BE IGNORED as there is no index over the statement
* identifiers, even when they are enabled. For a quad pattern, any argument
* MAY be bound.
*
* @param s
* The subject position (optional).
* @param p
* The predicate position (optional).
* @param o
* The object position (optional).
* @param c
* The context position (optional and ignored for a triple
* store).
* @param filter
* The filter (optional).
* @param range
* The range (optional).
*
* @return The predicate for that triple or quad pattern.
*
* @throws UnsupportedOperationException
* for a triple store without statement identifiers if the
* c is non-{@link #NULL}.
*/
public IPredicate getPredicate(final IV s, final IV p,
final IV o, final IV c, IElementFilter filter,
final RangeBOp range) {
final IVariableOrConstant S = (s == null ? Var.var("s")
: new Constant(s));
final IVariableOrConstant P = (p == null ? Var.var("p")
: new Constant(p));
final IVariableOrConstant O = (o == null ? Var.var("o")
: new Constant(o));
IVariableOrConstant C = null;
switch (keyArity) {
case 3:
if (statementIdentifiers) {
C = (c == null ? Var.var("c") : new Constant(c));
} else if (c != null) {
/*
* The 4th position should never become bound for a triple store
* without statement identifiers.
*/
throw new RuntimeException(
new QuadsOperationInTriplesModeException(
"Predicate lookup with bound context, but DB is initialized"
+ " in triples mode. Please do either re-init your database"
+ " in quads mode or use operations over triples only."));
}
break;
case 4:
C = (c == null ? Var.var("c") : new Constant(c));
break;
default:
throw new AssertionError();
}
final Map anns = new LinkedHashMap();
anns.put(IPredicate.Annotations.RELATION_NAME,
new String[] { getNamespace() });
if (range != null) {
anns.put(IPredicate.Annotations.RANGE, range);
}
Predicate pred = new SPOPredicate(
// keyArity == 4 ?
(keyArity == 4 || statementIdentifiers) ?
new BOp[] { S, P, O, C } : new BOp[] { S, P, O },
anns);
if (filter != null) {
// Layer on an optional filter.
pred = pred.addIndexLocalFilter(ElementFilter.newInstance(filter));
}
return pred;
}
// /**
// * Return the {@link IAccessPath} that is most efficient for the specified
// * predicate based on an analysis of the bound and unbound positions in the
// * predicate.
// *
// * Note: When statement identifiers are enabled, the only way to bind the
// * context position is to already have an {@link SPO} on hand. There is no
// * index which can be used to look up an {@link SPO} by its context and the
// * context is always a blank node.
// *
// * Note: This method is a hot spot, especially when the maximum parallelism
// * for subqueries is large. A variety of caching techniques are being
// * evaluated to address this.
// *
// * @param pred
// * The predicate.
// *
// * @return The best access path for that predicate.
// */
// public IAccessPath getAccessPath(final IPredicate predicate) {
//
// /*
// * Note: Query is faster w/o cache on all LUBM queries.
// *
// * @todo Optimization could reuse a caller's SPOAccessPath instance,
// * setting only the changed data on the fromKey/toKey. That could
// * be done with setS(long), setO(long), setP(long) methods. The
// * filter could be modified in the same manner. That could cut down
// * on allocation costs, formatting the from/to keys, etc.
// */
//
//// if (predicate.getPartitionId() != -1) {
////
//// /*
//// * Note: This handles a read against a local index partition.
//// *
//// * Note: This does not work here because it has the federation's
//// * index manager rather than the data service's index manager. That
//// * is because we always resolve relations against the federation
//// * since their metadata is stored in the global row store. Maybe
//// * this could be changed if we developed the concept of a
//// * "relation shard" accessed the metadata via a catalog and which
//// * was aware that only one index shard could be resolved locally.
//// */
////
//// return getAccessPathForIndexPartition(predicate);
////
//// }
//
// return _getAccessPath(predicate);
//
// }
// /**
// * Isolates the logic for selecting the {@link SPOKeyOrder} from the
// * {@link SPOPredicate} and then delegates to
// * {@link #getAccessPath(IKeyOrder, IPredicate)}.
// */
// final private SPOAccessPath _getAccessPath(final IPredicate predicate) {
//
// final SPOKeyOrder keyOrder = getKeyOrder(predicate);
//
// final SPOAccessPath accessPath = getAccessPath(keyOrder, predicate);
//
// if (log.isDebugEnabled())
// log.debug(accessPath.toString());
//
// // System.err.println("new access path: pred="+predicate);
//
// return accessPath;
//
// }
/**
* Implementation chooses a quads or triples index as appropriate.
*
* {@inheritDoc}
*
* @todo This should recognize when only the primary index is available and
* then use it for all access paths.
*/
public SPOKeyOrder getKeyOrder(final IPredicate predicate) {
return SPOKeyOrder.getKeyOrder(predicate, keyArity);
}
// /**
// * This handles a request for an access path that is restricted to a
// * specific index partition.
// *
// * Note: This path is used with the scale-out JOIN strategy, which
// * distributes join tasks onto each index partition from which it needs to
// * read. Those tasks constrain the predicate to only read from the index
// * partition which is being serviced by that join task.
// *
// * Note: Since the relation may materialize the index views for its various
// * access paths, and since we are restricted to a single index partition and
// * (presumably) an index manager that only sees the index partitions local
// * to a specific data service, we create an access path view for an index
// * partition without forcing the relation to be materialized.
// *
// * Note: Expanders ARE NOT applied in this code path. Expanders require a
// * total view of the relation, which is not available during scale-out
// * pipeline joins.
// *
// * @param indexManager
// * This MUST be the data service local index manager so that the
// * returned access path will read against the local shard.
// * @param predicate
// * The predicate. {@link IPredicate#getPartitionId()} MUST return
// * a valid index partition identifier.
// *
// * @throws IllegalArgumentException
// * if either argument is null.
// * @throws IllegalArgumentException
// * unless the {@link IIndexManager} is a local index
// * manager providing direct access to the specified shard.
// * @throws IllegalArgumentException
// * unless the predicate identifies a specific shard using
// * {@link IPredicate#getPartitionId()}.
// *
// * @deprecated {@link AccessPath} is handling this directly based on the
// * {@link IPredicate.Annotations#PARTITION_ID}.
// */
// @Override
// public IAccessPath getAccessPathForIndexPartition(
// final IIndexManager indexManager, //
// final IPredicate predicate//
// ) {
//
// return getAccessPath(indexManager,getKeyOrder(predicate),predicate);
//
//// /*
//// * Note: getIndexManager() _always_ returns the federation's index
//// * manager because that is how we materialize an ILocatableResource when
//// * we locate it. However, the federation's index manager can not be used
//// * here because it addresses the scale-out indices. Instead, the caller
//// * must pass in the IIndexManager which has access to the local index
//// * objects so we can directly read on the shard.
//// */
////// final IIndexManager indexManager = getIndexManager();
////
//// if (indexManager == null)
//// throw new IllegalArgumentException();
////
//// if (indexManager instanceof IBigdataFederation) {
////
//// /*
//// * This will happen if you fail to re-create the JoinNexus within
//// * the target execution environment.
//// *
//// * This is disallowed because the predicate specifies an index
//// * partition and expects to have access to the local index objects
//// * for that index partition. However, the index partition is only
//// * available when running inside of the ConcurrencyManager and when
//// * using the IndexManager exposed by the ConcurrencyManager to its
//// * tasks.
//// */
////
//// throw new IllegalArgumentException(
//// "Expecting a local index manager, not: "
//// + indexManager.getClass().toString());
////
//// }
////
//// if (predicate == null)
//// throw new IllegalArgumentException();
////
//// final int partitionId = predicate.getPartitionId();
////
//// if (partitionId == -1) // must be a valid partition identifier.
//// throw new IllegalArgumentException();
////
//// /*
//// * @todo This condition should probably be an error since the expander
//// * will be ignored.
//// */
////// if (predicate.getSolutionExpander() != null)
////// throw new IllegalArgumentException();
////
//// if (predicate.getRelationCount() != 1) {
////
//// /*
//// * This is disallowed. The predicate must be reading on a single
//// * local index partition, not a view comprised of more than one
//// * index partition.
//// *
//// * @todo In fact, we could allow a view here as long as all parts of
//// * the view are local. That could be relevant when the other view
//// * component was a shard of a focusStore for parallel decomposition
//// * of RDFS closure, etc. The best way to handle such views when the
//// * components are not local is to use a UNION of the JOIN. When both
//// * parts are local we can do better using a UNION of the
//// * IAccessPath.
//// */
////
//// throw new IllegalStateException();
////
//// }
////
//// final String namespace = getNamespace();//predicate.getOnlyRelationName();
////
//// /*
//// * Find the best access path for that predicate.
//// */
//// final SPOKeyOrder keyOrder = getKeyOrder(predicate);
////
//// // The name of the desired index partition.
//// final String name = DataService.getIndexPartitionName(namespace + "."
//// + keyOrder.getIndexName(), predicate.getPartitionId());
////
//// /*
//// * Note: whether or not we need both keys and values depends on the
//// * specific index/predicate.
//// *
//// * Note: If the timestamp is a historical read, then the iterator will
//// * be read only regardless of whether we specify that flag here or not.
//// */
////// * Note: We can specify READ_ONLY here since the tail predicates are not
////// * mutable for rule execution.
//// final int flags = IRangeQuery.KEYS | IRangeQuery.VALS;// | IRangeQuery.READONLY;
////
//// final long timestamp = getTimestamp();//getReadTimestamp();
////
//// // MUST be a local index view.
//// final ILocalBTreeView ndx = (ILocalBTreeView) indexManager
//// .getIndex(name, timestamp);
////
//// return newAccessPath(this/* relation */, indexManager, timestamp,
//// predicate, keyOrder, ndx, flags, getChunkOfChunksCapacity(),
//// getChunkCapacity(), getFullyBufferedReadThreshold());
//
// }
// /**
// * Core impl.
// *
// * @param keyOrder
// * The natural order of the selected index (this identifies the
// * index).
// * @param predicate
// * The predicate specifying the query constraint on the access
// * path.
// *
// * @return The access path.
// */
// public SPOAccessPath getAccessPath(final IIndexManager localIndexManager,
// final IKeyOrder keyOrder, final IPredicate predicate) {
//
// if (keyOrder == null)
// throw new IllegalArgumentException();
//
// if (predicate == null)
// throw new IllegalArgumentException();
//
// final IIndex ndx = getIndex(keyOrder);
//
// if (ndx == null) {
//
// throw new IllegalArgumentException("no index? relation="
// + getNamespace() + ", timestamp=" + getTimestamp()
// + ", keyOrder=" + keyOrder + ", pred=" + predicate
// + ", indexManager=" + getIndexManager());
//
// }
//
// /*
// * Note: The PARALLEL flag here is an indication that the iterator may
// * run in parallel across the index partitions. This only effects
// * scale-out and only for simple triple patterns since the pipeline join
// * does something different (it runs inside the index partition using
// * the local index, not the client's view of a distributed index).
// *
// * @todo Introducing the PARALLEL flag here will break semantics when
// * the rule is supposed to be "stable" (repeatable order) or when the
// * access path is supposed to be fully ordered. What we really need to
// * do is take the "stable" flag from the rule and transfer it onto the
// * predicates in that rule so we can enforce stable execution for
// * scale-out. Of course, that would kill any parallelism for scale-out
// * :-) This shows up as an issue when using SLICEs since the rule that
// * we execute has to have stable results for someone to page through
// * those results using LIMIT/OFFSET.
// */
// final int flags = IRangeQuery.KEYS
// | IRangeQuery.VALS
// | (TimestampUtility.isReadOnly(getTimestamp()) ? IRangeQuery.READONLY
// : 0)
// | IRangeQuery.PARALLEL
// ;
//
// final AbstractTripleStore container = getContainer();
//
// final int chunkOfChunksCapacity = container.getChunkOfChunksCapacity();
//
// final int chunkCapacity = container.getChunkCapacity();
//
// final int fullyBufferedReadThreshold = container.getFullyBufferedReadThreshold();
//
// return newAccessPath(this, getIndexManager(), getTimestamp(),
// predicate, keyOrder, ndx, flags, chunkOfChunksCapacity,
// chunkCapacity, fullyBufferedReadThreshold);
//
// }
@Override
public IAccessPath newAccessPath(
// final IRelation relation,
final IIndexManager localIndexManager,
// final long timestamp,
final IPredicate predicate,
final IKeyOrder keyOrder
// final IIndex ndx,
// final int flags,
// final int chunkOfChunksCapacity,
// final int chunkCapacity,
// final int fullyBufferedReadThreshold
) {
if (statementIdentifiers && predicate.arity() == 4) {
/*
* Since sids are inlined into the statement indices and the SidIV
* can materialize the SPO to which it refers directly, we may be
* able to avoid going to the indices altogether in the case when
* the C position is bound in the predicate.
*/
final IVariableOrConstant sid = predicate.get(3);
if (sid != null && sid.isConstant() && sid.get() instanceof SidIV) {
final SidIV sidIV = (SidIV) sid.get();
final ISPO spo = sidIV.getInlineValue();
/*
* We need to check the inline SPO against the predicate to
* make sure it matches the triple pattern implied by the
* predicate. Usually in this case s, p, and o are unbound
* (reverse lookup from SID to spo), but occasionally there
* will be a bound term inside the predicate. In this case
* we should return an empty access path if the SPO does not
* match the triple pattern.
*/
for (int i = 0; i <= 2; i++) {
final IVariableOrConstant t = predicate.get(i);
if (t != null && t.isConstant()) {
final IV iv = t.get();
if (!spo.get(i).equals(iv)) {
return new EmptyAccessPath(
predicate, SPOKeyOrder.SPO);
}
}
}
if (log.isDebugEnabled()) {
log.debug("materializing an inline SID access path: " + spo);
}
return new ArrayAccessPath(new ISPO[] { spo },
predicate, SPOKeyOrder.SPO);
}
}
final IPredicate historyFiltered;
/*
* If we are in history mode and the predicate does not have the
* include history annotation, attached an index local filter to filter
* out SPOs where type == StatementEnum.History.
*/
if (history &&
!predicate.getProperty(SPOPredicate.Annotations.INCLUDE_HISTORY, false)) {
historyFiltered = ((Predicate) predicate).addIndexLocalFilter(
ElementFilter.newInstance(HistorySPOFilter.INSTANCE));
} else {
historyFiltered = predicate;
}
return new SPOAccessPath(this/*relation*/, localIndexManager, //timestamp,
historyFiltered, keyOrder
// , ndx, flags, chunkOfChunksCapacity,
// chunkCapacity, fullyBufferedReadThreshold
).init();
}
// public long getElementCount(boolean exact) {
//
// final IIndex ndx = getIndex(SPOKeyOrder.SPO);
//
// if (exact) {
//
// return ndx.rangeCountExact(null/* fromKey */, null/* toKey */);
//
// } else {
//
// return ndx.rangeCount(null/* fromKey */, null/* toKey */);
//
// }
//
// }
/**
* Efficient scan of the distinct term identifiers that appear in the first
* position of the keys for the statement index corresponding to the
* specified {@link IKeyOrder}. For example, using {@link SPOKeyOrder#POS}
* will give you the term identifiers for the distinct predicates actually
* in use within statements in the {@link SPORelation}.
*
* @param keyOrder
* The selected index order.
*
* @return An iterator visiting the distinct term identifiers.
*/
public IChunkedIterator distinctTermScan(final IKeyOrder keyOrder) {
return distinctTermScan(keyOrder,/* termIdFilter */null);
}
/**
* Efficient scan of the distinct term identifiers that appear in the first
* position of the keys for the statement index corresponding to the
* specified {@link IKeyOrder}. For example, using {@link SPOKeyOrder#POS}
* will give you the term identifiers for the distinct predicates actually
* in use within statements in the {@link SPORelation}.
*
* @param keyOrder
* The selected index order.
* @param filter
* An optional filter on the visited {@link IV}s.
*
* @return An iterator visiting the distinct term identifiers.
*
* @todo add the ability to specify {@link IRangeQuery#PARALLEL} here for
* fast scans across multiple shards when chunk-wise order is Ok.
*/
public IChunkedIterator distinctTermScan(
final IKeyOrder keyOrder, final ITermIVFilter filter) {
return distinctTermScan(keyOrder, null/* fromKey */, null/* toKey */,
filter);
}
/**
* Efficient scan of the distinct term identifiers that appear in the first
* position of the keys for the statement index corresponding to the
* specified {@link IKeyOrder}. For example, using {@link SPOKeyOrder#POS}
* will give you the term identifiers for the distinct predicates actually
* in use within statements in the {@link SPORelation}.
*
* @param keyOrder
* The selected index order.
* @param fromKey
* The first key for the scan -or- null to start the
* scan at the head of the index.
* @param toKey
* The last key (exclusive upper bound) for the scan -or-
* null to scan until the end of the index.
* @param termIdFilter
* An optional filter on the visited {@link IV}s.
*
* @return An iterator visiting the distinct term identifiers.
*
* @todo add the ability to specify {@link IRangeQuery#PARALLEL} here for
* fast scans across multiple shards when chunk-wise order is Ok.
*/
public IChunkedIterator distinctTermScan(
final IKeyOrder keyOrder, final byte[] fromKey,
final byte[] toKey, final ITermIVFilter termIdFilter) {
final DistinctTermAdvancer filter = new DistinctTermAdvancer(keyArity);
/*
* Layer in the logic to advance to the tuple that will have the
* next distinct term identifier in the first position of the key.
*/
if (termIdFilter != null) {
/*
* Layer in a filter for only the desired term types.
*/
filter.addFilter(new TupleFilter() {
private static final long serialVersionUID = 1L;
@Override
protected boolean isValid(final ITuple tuple) {
final byte[] key = tuple.getKey();
final IV iv = IVUtility.decode(key);
return termIdFilter.isValid(iv);
}
});
}
@SuppressWarnings("unchecked")
final Iterator itr = new Striterator(getIndex(keyOrder)
.rangeIterator(fromKey, toKey,//
0/* capacity */, IRangeQuery.KEYS | IRangeQuery.CURSOR,
filter)).addFilter(new Resolver() {
private static final long serialVersionUID = 1L;
/**
* Resolve SPO key to IV.
*/
@Override
protected IV resolve(Object obj) {
final byte[] key = ((ITuple) obj).getKey();
return IVUtility.decode(key);
}
});
// return new ChunkedWrappedIterator(itr);
return new ChunkedWrappedIterator(itr,
IChunkedIterator.DEFAULT_CHUNK_SIZE, IV.class);
}
/**
* Efficient scan of the distinct term identifiers that appear in the first
* position of the keys for the statement index corresponding to the
* specified {@link IKeyOrder}. For example, using {@link SPOKeyOrder#POS}
* will give you the term identifiers for the distinct predicates actually
* in use within statements in the {@link SPORelation}.
*
* @param keyOrder
* The selected index order.
*
* @return An iterator visiting the distinct term identifiers.
*/
public IChunkedIterator distinctMultiTermScan(
final IKeyOrder keyOrder, IV[] knownTerms) {
return distinctMultiTermScan(keyOrder, knownTerms,/* termIdFilter */null);
}
/**
* Efficient scan of the distinct term identifiers that appear in the first
* position of the keys for the statement index corresponding to the
* specified {@link IKeyOrder}. For example, using {@link SPOKeyOrder#POS}
* will give you the term identifiers for the distinct predicates actually
* in use within statements in the {@link SPORelation}.
*
* @param keyOrder
* The selected index order.
* @param knownTerms
* An array of term identifiers to be interpreted as bindings
* using the keyOrder.
* @param termIdFilter
* An optional filter.
*
* @return An iterator visiting the distinct term identifiers.
*
* @todo add the ability to specify {@link IRangeQuery#PARALLEL} here for
* fast scans across multiple shards when chunk-wise order is Ok.
*/
public IChunkedIterator distinctMultiTermScan(
final IKeyOrder keyOrder, final IV[] knownTerms,
final ITermIVFilter termIdFilter) {
final int nterms = knownTerms.length;
final IKeyBuilder keyBuilder = KeyBuilder.newInstance();
for (int i = 0; i < knownTerms.length; i++) {
knownTerms[i].encode(keyBuilder);
}
final byte[] fromKey = knownTerms.length == 0 ? null
: keyBuilder.getKey();
final byte[] toKey = fromKey == null ? null
: SuccessorUtil.successor(fromKey.clone());
/*
* Layer in the logic to advance to the tuple that will have the next
* distinct term identifier in the first position of the key.
*/
final DistinctMultiTermAdvancer filter = new DistinctMultiTermAdvancer(
getKeyArity(), nterms);
if (termIdFilter != null) {
/*
* Layer in a filter for only the desired term types.
*/
filter.addFilter(new TupleFilter() {
private static final long serialVersionUID = 1L;
@Override
protected boolean isValid(final ITuple tuple) {
final byte[] key = tuple.getKey();
final int pos = knownTerms.length;
final IV iv = IVUtility.decode(key, pos+1)[pos];
return termIdFilter.isValid(iv);
}
});
}
@SuppressWarnings("unchecked")
final Iterator itr = new Striterator(getIndex(keyOrder)
.rangeIterator(fromKey, toKey,
0/* capacity */, IRangeQuery.KEYS | IRangeQuery.CURSOR,
filter)).addFilter(new Resolver() {
private static final long serialVersionUID = 1L;
/**
* Resolve SPO key to IV.
*/
@Override
protected IV resolve(Object obj) {
final byte[] key = ((ITuple) obj).getKey();
final int pos = knownTerms.length;
return IVUtility.decode(key, pos+1)[pos];
}
});
return new ChunkedWrappedIterator(itr,//
ChunkedWrappedIterator.DEFAULT_CHUNK_SIZE,// chunkSize
IV.class// elementClass
);
}
// /**
// * @todo This implementation was written early on and works for creating new
// * SPOs licensed by inference against a triple store. It does not
// * allow us to specify the statement type, which is always set to
// * [inferred]. It also does not capture the context if one exists, but
// * that could be done by inspection of the arity of the predicate. It
// * might be better to have an explicit "CONSTRUCT" operator rather
// * than having this implicit relationship between the head of a rule
// * and the element created from that rule. For example, that might let
// * us capture the distinction of inferred versus explicit within the
// * CONSTRUCT operator.
// */
// public SPO newElement(final IPredicate predicate,
// final IBindingSet bindingSet) {
//
// if (predicate == null)
// throw new IllegalArgumentException();
//
// if (bindingSet == null)
// throw new IllegalArgumentException();
//
// final IV s = (IV) predicate.asBound(0, bindingSet);
//
// final IV p = (IV) predicate.asBound(1, bindingSet);
//
// final IV o = (IV) predicate.asBound(2, bindingSet);
//
// final SPO spo = new SPO(s, p, o, StatementEnum.Inferred);
//
// if(log.isDebugEnabled())
// log.debug(spo.toString());
//
// return spo;
//
// }
/**
* @todo This works for creating new SPOs licensed by inference against a
* triple store. However, it does not allow us to specify the
* statement type, which is always set to [inferred]. It also does not
* capture the context if one exists, but that could be done by
* inspection of the arity of the predicate. It might be better to
* have an explicit "CONSTRUCT" operator rather than having this
* implicit relationship between the head of a rule and the element
* created from that rule. For example, that might let us capture the
* distinction of inferred versus explicit within the CONSTRUCT
* operator.
*/
@SuppressWarnings("unchecked")
public SPO newElement(final List a, final IBindingSet bindingSet) {
if (a == null)
throw new IllegalArgumentException();
if (bindingSet == null)
throw new IllegalArgumentException();
final IV s = (IV) ((IVariableOrConstant) a.get(0)).get(bindingSet);
final IV p = (IV) ((IVariableOrConstant) a.get(1)).get(bindingSet);
final IV o = (IV) ((IVariableOrConstant) a.get(2)).get(bindingSet);
final SPO spo = new SPO(s, p, o, StatementEnum.Inferred);
if(log.isDebugEnabled())
log.debug(spo.toString());
return spo;
}
public Class getElementClass() {
return ISPO.class;
}
/**
* Inserts {@link SPO}s, writing on the statement indices in parallel.
*
* Note: This does NOT write on the justifications index. If justifications
* are being maintained then the {@link ISolution}s MUST report binding
* sets and an {@link InsertSolutionBuffer} MUST be used that knows how to
* write on the justifications index AND delegate writes on the statement
* indices to this method.
*
* Note: This does NOT assign statement identifiers. The {@link SPORelation}
* does not have direct access to the {@link LexiconRelation} and the latter
* is responsible for assigning term identifiers. Code that writes explicit
* statements onto the statement indices MUST use
* {@link AbstractTripleStore#addStatements(AbstractTripleStore, boolean, IChunkedOrderedIterator, IElementFilter)},
* which knows how to generate the statement identifiers. In turn, that
* method will delegate each "chunk" to this method.
*/
public long insert(final IChunkedOrderedIterator itr) {
try {
long n = 0;
while(itr.hasNext()) {
final ISPO[] a = itr.nextChunk();
n += insert( a, a.length, null/*filter*/ );
}
return n;
} finally {
itr.close();
}
}
/**
* Deletes {@link SPO}s, writing on the statement indices in parallel.
*
* Note: The {@link ISPO#isModified()} flag is set by this method.
*
* Note: This does NOT write on the justifications index. If justifications
* are being maintained then the {@link ISolution}s MUST report binding sets
* and an {@link InsertSolutionBuffer} MUST be used that knows how to write
* on the justifications index AND delegate writes on the statement indices
* to this method.
*
* Note: This does NOT perform truth maintenance!
*
* Note: This does NOT compute the closure for statement identifiers
* (statements that need to be deleted because they are about a statement
* that is being deleted).
*
* @see AbstractTripleStore#removeStatements(IChunkedOrderedIterator,
* boolean)
* @see SPOAccessPath#removeAll()
*/
public long delete(final IChunkedOrderedIterator itr) {
try {
long n = 0;
while(itr.hasNext()) {
final ISPO[] a = itr.nextChunk();
n += delete(a, a.length);
}
return n;
} finally {
itr.close();
}
}
/**
* Inserts {@link SPO}s, writing on the statement indices in parallel.
*
* Note: The {@link ISPO#isModified()} flag is set by this method.
*
* Note: This does NOT write on the justifications index. If justifications
* are being maintained then the {@link ISolution}s MUST report binding sets
* and an {@link InsertSolutionBuffer} MUST be used that knows how to write
* on the justifications index AND delegate writes on the statement indices
* to this method.
*
* Note: This does NOT perform truth maintenance!
*
* Note: This does NOT compute the closure for statement identifiers
* (statements that need to be deleted because they are about a statement
* that is being deleted).
*
* Note: The statements are inserted into each index in parallel. We clone
* the statement[] and sort and bulk load each statement index in parallel
* using a thread pool. All mutation to the statement indices goes through
* this method.
*
* @param a
* An {@link ISPO}[] of the statements to be written onto the
* statement indices. For each {@link ISPO}, the
* {@link ISPO#isModified()} flag will be set iff the tuple
* corresponding to the statement was : (a) inserted; (b) updated
* (state change, such as to the {@link StatementEnum} value), or
* (c) removed.
* @param numStmts
* The #of elements of that array that will be written.
* @param filter
* An optional filter on the elements to be written.
*
* @return The mutation count.
*/
public long insert(final ISPO[] a, final int numStmts,
final IElementFilter filter) {
if (a == null)
throw new IllegalArgumentException();
if (numStmts > a.length)
throw new IllegalArgumentException();
if (numStmts == 0)
return 0L;
final long begin = System.currentTimeMillis();
if(log.isDebugEnabled()) {
log.debug("indexManager="+getIndexManager());
}
// time to sort the statements.
final AtomicLong sortTime = new AtomicLong(0);
// time to generate the keys and load the statements into the
// indices.
final AtomicLong insertTime = new AtomicLong(0);
final AtomicLong mutationCount = new AtomicLong(0);
final List> tasks = new ArrayList>(3);
/*
* When true, mutations on the primary index (SPO or SPOC) will be
* reported. That metadata is used to set the isModified flag IFF the
* tuple corresponding to the statement in the indices was (a) inserted;
* (b) modified; or (c) removed.
*/
final boolean reportMutation = true;
if (keyArity == 3) {
tasks.add(new SPOIndexWriter(this, a, numStmts, false/* clone */,
SPOKeyOrder.SPO, SPOKeyOrder.SPO.isPrimaryIndex(),
filter, sortTime, insertTime, mutationCount,
reportMutation));
if (!oneAccessPath) {
tasks.add(new SPOIndexWriter(this, a, numStmts, true/* clone */,
SPOKeyOrder.POS, SPOKeyOrder.POS.isPrimaryIndex(),
filter, sortTime, insertTime, mutationCount,
false/*reportMutation*/));
tasks.add(new SPOIndexWriter(this, a, numStmts, true/* clone */,
SPOKeyOrder.OSP, SPOKeyOrder.OSP.isPrimaryIndex(),
filter, sortTime, insertTime, mutationCount,
false/*reportMutation*/));
}
} else {
tasks.add(new SPOIndexWriter(this, a, numStmts, false/* clone */,
SPOKeyOrder.SPOC, SPOKeyOrder.SPOC.isPrimaryIndex(),
filter, sortTime, insertTime,
mutationCount, reportMutation));
if (!oneAccessPath) {
tasks.add(new SPOIndexWriter(this, a, numStmts,
true/* clone */, SPOKeyOrder.POCS,
SPOKeyOrder.POCS.isPrimaryIndex(),
filter, sortTime,
insertTime, mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexWriter(this, a, numStmts,
true/* clone */, SPOKeyOrder.OCSP,
SPOKeyOrder.OCSP.isPrimaryIndex(),
filter, sortTime,
insertTime, mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexWriter(this, a, numStmts,
true/* clone */, SPOKeyOrder.CSPO,
SPOKeyOrder.CSPO.isPrimaryIndex(),
filter, sortTime,
insertTime, mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexWriter(this, a, numStmts,
true/* clone */, SPOKeyOrder.PCSO,
SPOKeyOrder.PCSO.isPrimaryIndex(),
filter, sortTime,
insertTime, mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexWriter(this, a, numStmts,
true/* clone */, SPOKeyOrder.SOPC,
SPOKeyOrder.SOPC.isPrimaryIndex(),
filter, sortTime,
insertTime, mutationCount, false/* reportMutation */));
}
}
// if(numStmts>1000) {
//
// log.info("Writing " + numStmts + " statements...");
//
// }
final List> futures;
/*
final long elapsed_SPO;
final long elapsed_POS;
final long elapsed_OSP;
*/
try {
futures = getExecutorService().invokeAll(tasks);
for (int i = 0; i < tasks.size(); i++) {
// futures.get(i).get();
logFuture(futures.get(i));
}
/*
elapsed_SPO = futures.get(0).get();
if (!oneAccessPath) {
elapsed_POS = futures.get(1).get();
elapsed_OSP = futures.get(2).get();
} else {
elapsed_POS = 0;
elapsed_OSP = 0;
}
*/
} catch (InterruptedException ex) {
throw new RuntimeException(ex);
} catch (ExecutionException ex) {
throw new RuntimeException(ex);
}
final long elapsed = System.currentTimeMillis() - begin;
if (log.isInfoEnabled() && numStmts > 1000) {
log.info("Wrote " + numStmts + " statements (mutationCount="
+ mutationCount + ") in " + elapsed + "ms" //
+ "; sort=" + sortTime + "ms" //
+ ", keyGen+insert=" + insertTime + "ms" //
// + "; spo=" + elapsed_SPO + "ms" //
// + ", pos=" + elapsed_POS + "ms" //
// + ", osp=" + elapsed_OSP + "ms" //
);
}
return mutationCount.get();
}
private T logFuture(final Future f) throws ExecutionException,
InterruptedException {
try {
return f.get();
} catch (InterruptedException e) {
log.warn(e, e);
throw e;
} catch (ExecutionException e) {
log.error(e, e);
throw e;
}
}
/**
* Delete the {@link SPO}s from the statement indices. Any justifications
* for those statements will also be deleted. The {@link ISPO#isModified()}
* flag is set by this method if the {@link ISPO} was pre-existing in the
* database and was therefore deleted by this operation.
*
* @param stmts
* The {@link SPO}s.
* @param numStmts
* The #of elements in that array to be processed.
*
* @return The #of statements that were removed (mutationCount).
*/
public long delete(final ISPO[] stmts, final int numStmts) {
if (stmts == null)
throw new IllegalArgumentException();
if (numStmts < 0 || numStmts > stmts.length)
throw new IllegalArgumentException();
if (numStmts == 0)
return 0L;
final long begin = System.currentTimeMillis();
/*
* Downgrade statements to StatementEnum.History instead of actually
* removing them.
*/
if (history) {
final ISPO[] a = new ISPO[numStmts];
for (int i = 0; i < numStmts; i++) {
a[i] = new SPO(stmts[i].s(), stmts[i].p(), stmts[i].o(),
StatementEnum.History);
}
final long nmodified = insert(a, numStmts, null);
for (int i = 0; i < numStmts; i++) {
stmts[i].setModified(a[i].getModified());
}
return nmodified;
}
// The time to sort the data.
final AtomicLong sortTime = new AtomicLong(0);
// The time to delete the statements from the indices.
final AtomicLong writeTime = new AtomicLong(0);
// The mutation count.
final AtomicLong mutationCount = new AtomicLong(0);
final List> tasks = new ArrayList>(3);
/*
* When true, mutations on the primary index (SPO or SPOC) will be
* reported. That metadata is used to set the isModified flag IFF the
* tuple corresponding to the statement in the indices was (a) inserted;
* (b) modified; or (c) removed.
*/
final boolean reportMutation = true;
if (keyArity == 3) {
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.SPO, SPOKeyOrder.SPO.isPrimaryIndex(),
false/* clone */, sortTime, writeTime,
mutationCount, reportMutation));
if (!oneAccessPath) {
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.POS, SPOKeyOrder.POS.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount,
false/* reportMutation */));
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.OSP, SPOKeyOrder.OSP.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount, false/* reportMutation */));
}
} else {
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.SPOC, SPOKeyOrder.SPOC.isPrimaryIndex(),
false/* clone */, sortTime, writeTime,
mutationCount, reportMutation));
if (!oneAccessPath) {
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.POCS,SPOKeyOrder.POCS.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.OCSP, SPOKeyOrder.OCSP.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.CSPO, SPOKeyOrder.CSPO.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.PCSO, SPOKeyOrder.PCSO.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount, false/* reportMutation */));
tasks.add(new SPOIndexRemover(this, stmts, numStmts,
SPOKeyOrder.SOPC, SPOKeyOrder.SOPC.isPrimaryIndex(),
true/* clone */, sortTime, writeTime,
mutationCount, false/* reportMutation */));
}
}
if (justify) {
/*
* Also retract the justifications for the statements.
*/
tasks.add(new JustificationRemover(this, stmts, numStmts,
true/* clone */, sortTime, writeTime));
}
final List> futures;
/*
final long elapsed_SPO;
final long elapsed_POS;
final long elapsed_OSP;
final long elapsed_JST;
*/
try {
futures = getExecutorService().invokeAll(tasks);
for (int i = 0; i < tasks.size(); i++) {
futures.get(i).get();
}
/*
elapsed_SPO = futures.get(0).get();
if (!oneAccessPath) {
elapsed_POS = futures.get(1).get();
elapsed_OSP = futures.get(2).get();
} else {
elapsed_POS = 0;
elapsed_OSP = 0;
}
if (justify) {
elapsed_JST = futures.get(3).get();
} else {
elapsed_JST = 0;
}
*/
} catch (InterruptedException ex) {
throw new RuntimeException(ex);
} catch (ExecutionException ex) {
throw new RuntimeException(ex);
}
final long elapsed = System.currentTimeMillis() - begin;
if (log.isInfoEnabled() && numStmts > 1000) {
log.info("Removed " + numStmts + " in " + elapsed
+ "ms; sort=" + sortTime + "ms, keyGen+delete="
+ writeTime + "ms"
// + "; spo=" + elapsed_SPO + "ms, pos="
// + elapsed_POS + "ms, osp=" + elapsed_OSP
// + "ms, jst=" + elapsed_JST
);
}
return mutationCount.get();
}
/**
* Adds justifications to the store.
*
* @param itr
* The iterator from which we will read the {@link Justification}s
* to be added. The iterator is closed by this operation.
*
* @return The #of {@link Justification}s written on the justifications
* index.
*
* @todo a lot of the cost of loading data is writing the justifications.
* SLD/magic sets will relieve us of the need to write the
* justifications since we can efficiently prove whether or not the
* statements being removed can be entailed from the remaining
* statements. Any statement which can still be proven is converted to
* an inference. Since writing the justification chains is such a
* source of latency, SLD/magic sets will translate into an immediate
* performance boost for data load.
*/
public long addJustifications(final IChunkedIterator itr) {
try {
if (!itr.hasNext())
return 0;
final long begin = System.currentTimeMillis();
// /*
// * Note: This capacity estimate is based on N longs per SPO, one
// * head, and 2-3 SPOs in the tail. The capacity will be extended
// * automatically if necessary.
// */
//
// final KeyBuilder keyBuilder = new KeyBuilder(IRawTripleStore.N
// * (1 + 3) * Bytes.SIZEOF_LONG);
long nwritten = 0;
final IIndex ndx = getJustificationIndex();
final JustificationTupleSerializer tupleSer = (JustificationTupleSerializer) ndx
.getIndexMetadata().getTupleSerializer();
while (itr.hasNext()) {
final Justification[] a = itr.nextChunk();
final int n = a.length;
// sort into their natural order.
Arrays.sort(a);
final byte[][] keys = new byte[n][];
for (int i = 0; i < n; i++) {
// final Justification jst = a[i];
keys[i] = tupleSer.serializeKey(a[i]);//jst.getKey(keyBuilder);
}
/*
* sort into their natural order.
*
* @todo is it faster to sort the Justification[] or the keys[]?
* See above for the alternative.
*/
// Arrays.sort(keys,UnsignedByteArrayComparator.INSTANCE);
final LongAggregator aggregator = new LongAggregator();
ndx.submit(0/* fromIndex */, n/* toIndex */, keys,
null/* vals */,
WriteJustificationsProcConstructor.INSTANCE,
aggregator);
nwritten += aggregator.getResult();
}
final long elapsed = System.currentTimeMillis() - begin;
if (log.isInfoEnabled())
log.info("Wrote " + nwritten + " justifications in " + elapsed
+ " ms");
return nwritten;
} finally {
itr.close();
}
}
/**
* Dumps the specified index.
*/
// @SuppressWarnings("unchecked")
public StringBuilder dump(final IKeyOrder keyOrder) {
final StringBuilder sb = new StringBuilder();
final IPredicate pred = new SPOPredicate(
keyArity==4?new BOp[]{//
Var.var("s"),//
Var.var("p"),//
Var.var("o"),//
Var.var("c"),//
}:new BOp[] {
Var.var("s"),//
Var.var("p"),//
Var.var("o"),//
},//
NV.asMap(new NV[] {//
new NV(IPredicate.Annotations.RELATION_NAME,
new String[] { getNamespace() }),//
// new NV(IPredicate.Annotations.KEY_ORDER,
// keyOrder),//
}));
// final IPredicate pred = new SPOPredicate(
// new String[] { getNamespace() }, -1, // partitionId
// Var.var("s"),//
// Var.var("p"),//
// Var.var("o"),//
// keyArity == 3 ? null : Var.var("c"),//
// false, // optional
// null, // filter,
// null // expander
// );
final IChunkedOrderedIterator itr = getAccessPath(
keyOrder, pred).iterator();
try {
while (itr.hasNext()) {
sb.append(itr.next());
sb.append("\n");
}
} finally {
itr.close();
}
return sb;
}
/**
* Checks whether one of the associated triple indices uses delete markers.
*
* @return true if some index uses delete markers
*/
public boolean indicesHaveDeleteMarkers() {
/**
* actually, either none of the triple indices or all of them uses
* delete markers, so it suffices to probe the primary index
*/
return getPrimaryIndex().getIndexMetadata().getDeleteMarkers();
}
/**
* The {@link ILexiconConfiguration} instance, which will determine how
* terms are encoded and decoded in the key space.
private ILexiconConfiguration lexiconConfiguration;
*/
/**
* See {@link ILexiconConfiguration#isInline(DTE)}. Delegates to the
* {@link #lexiconConfiguration} instance.
public boolean isInline(DTE dte) {
return lexiconConfiguration.isInline(dte);
}
*/
/**
* See {@link ILexiconConfiguration#isLegacyEncoding()}. Delegates to the
* {@link #lexiconConfiguration} instance.
public boolean isLegacyEncoding() {
return lexiconConfiguration.isLegacyEncoding();
}
*/
/**
* Return the {@link #lexiconConfiguration} instance. Used to determine
* how to encode and decode terms in the key space.
public ILexiconConfiguration getLexiconConfiguration() {
return lexiconConfiguration;
}
*/
}