private List<Entry> appendResults(
ByteBuffer key,
ByteBuffer columnStart,
ByteBuffer columnEnd,
List<Entry> entries,
LimitTracker limit,
TransactionHandle txh) {
if (limit.limitExhausted()) return null;
List<Entry> results = null;
for (int readAttempt = 0; readAttempt < maxReadRetryAttempts; readAttempt++) {
try {
results = edgeStore.getSlice(key, columnStart, columnEnd, limit.getLimit(), txh);
break;
} catch (StorageException e) {
if (e instanceof TemporaryStorageException) {
if (readAttempt < maxReadRetryAttempts - 1) temporaryStorageException(e);
else throw readException(e, maxReadRetryAttempts);
} else throw readException(e);
}
}
limit.retrieved(results.size());
if (entries == null) return results;
else {
entries.addAll(results);
return entries;
}
}
@Override
public long[] indexRetrieval(Object key, TitanKey pt, InternalTitanTransaction tx) {
Preconditions.checkArgument(
pt.isSimple(), "Currently, only simple properties are supported for index retrieval");
Preconditions.checkArgument(
pt.hasIndex(), "Cannot retrieve for given property key - it does not have an index");
long[] vertices = null;
Preconditions.checkArgument(
pt.getDataType().isInstance(key),
"Specified object is incompatible with property data type [" + pt.getName() + "]");
for (int readAttempt = 0; readAttempt < maxReadRetryAttempts; readAttempt++) {
try {
if (pt.isUnique()) {
ByteBuffer value =
propertyIndex.get(getIndexKey(key), getKeyedIndexColumn(pt), tx.getTxHandle());
if (value != null) {
vertices = new long[1];
vertices[0] = VariableLong.readPositive(value);
}
} else {
ByteBuffer startColumn = VariableLong.positiveByteBuffer(pt.getID());
List<Entry> entries =
propertyIndex.getSlice(
getIndexKey(key),
startColumn,
ByteBufferUtil.nextBiggerBuffer(startColumn),
tx.getTxHandle());
vertices = new long[entries.size()];
int i = 0;
for (Entry ent : entries) {
vertices[i++] = VariableLong.readPositive(ent.getValue());
}
}
break;
} catch (StorageException e) {
if (e instanceof TemporaryStorageException) {
if (readAttempt < maxReadRetryAttempts - 1) temporaryStorageException(e);
else throw readException(e, maxReadRetryAttempts);
} else throw readException(e);
}
}
if (vertices == null) return new long[0];
else return vertices;
}
@Override
public boolean containsVertexID(long id, InternalTitanTransaction tx) {
log.trace("Checking node existence for {}", id);
for (int readAttempt = 0; readAttempt < maxReadRetryAttempts; readAttempt++) {
try {
return edgeStore.containsKey(IDHandler.getKey(id), tx.getTxHandle());
} catch (StorageException e) {
if (e instanceof TemporaryStorageException) {
if (readAttempt < maxReadRetryAttempts - 1) temporaryStorageException(e);
else throw readException(e, maxReadRetryAttempts);
} else throw readException(e);
}
}
throw new AssertionError("Illegal program state");
}
@Override
public RecordIterator<Long> getVertexIDs(final InternalTitanTransaction tx) {
if (!(edgeStore instanceof ScanKeyColumnValueStore))
throw new UnsupportedOperationException(
"The configured storage backend does not support global graph operations - use Faunus instead");
for (int readAttempt = 0; readAttempt < maxReadRetryAttempts; readAttempt++) {
try {
final RecordIterator<ByteBuffer> keyiter =
((ScanKeyColumnValueStore) edgeStore).getKeys(tx.getTxHandle());
return new RecordIterator<Long>() {
@Override
public boolean hasNext() throws StorageException {
return keyiter.hasNext();
}
@Override
public Long next() throws StorageException {
return IDHandler.getKeyID(keyiter.next());
}
@Override
public void close() throws StorageException {
keyiter.close();
}
};
} catch (StorageException e) {
if (e instanceof TemporaryStorageException) {
if (readAttempt < maxReadRetryAttempts - 1) temporaryStorageException(e);
else throw readException(e, maxReadRetryAttempts);
} else throw readException(e);
}
}
throw new AssertionError("Illegal program state");
}
@Override
public void save(
final Collection<InternalRelation> addedRelations,
final Collection<InternalRelation> deletedRelations,
final InternalTitanTransaction tx)
throws StorageException {
// Setup
log.debug(
"Saving transaction. Added {}, removed {}", addedRelations.size(), deletedRelations.size());
final Map<TitanType, TypeSignature> signatures = new HashMap<TitanType, TypeSignature>();
final TransactionHandle txh = tx.getTxHandle();
final StoreMutator mutator = getStoreMutator(txh);
final boolean acquireLocks = tx.getTxConfiguration().hasAcquireLocks();
// 1. Assign TitanVertex IDs
assignIDs(addedRelations, tx);
for (int saveAttempt = 0; saveAttempt < maxWriteRetryAttempts; saveAttempt++) {
// while (true) { //Indefinite loop, broken if no exception occurs, otherwise retried
// or failed immediately
try {
// 2. Collect deleted edges
ListMultimap<InternalTitanVertex, InternalRelation> mutations = ArrayListMultimap.create();
if (deletedRelations != null && !deletedRelations.isEmpty()) {
for (InternalRelation del : deletedRelations) {
assert del.isRemoved();
for (int pos = 0; pos < del.getArity(); pos++) {
InternalTitanVertex node = del.getVertex(pos);
if (pos == 0 || !del.isUnidirected()) {
mutations.put(node, del);
}
if (pos == 0
&& acquireLocks
&& del.getType().isFunctional()
&& ((InternalTitanType) del.getType()).isFunctionalLocking()) {
Entry entry = getEntry(tx, del, node, signatures);
mutator.acquireEdgeLock(
IDHandler.getKey(node.getID()), entry.getColumn(), entry.getValue());
}
}
if (acquireLocks && del.isProperty()) {
lockKeyedProperty((TitanProperty) del, mutator);
}
}
}
ListMultimap<InternalTitanType, InternalRelation> simpleEdgeTypes = null;
ListMultimap<InternalTitanType, InternalRelation> otherEdgeTypes = null;
// 3. Sort Added Edges
for (InternalRelation edge : addedRelations) {
if (edge.isRemoved()) continue;
assert edge.isNew();
TitanType et = edge.getType();
// Give special treatment to edge type definitions
if (SystemTypeManager.prepersistedSystemTypes.contains(et)) {
assert edge.getVertex(0) instanceof InternalTitanType;
InternalTitanType node = (InternalTitanType) edge.getVertex(0);
assert node.hasID();
if (node.isSimple()) {
if (simpleEdgeTypes == null) simpleEdgeTypes = ArrayListMultimap.create();
simpleEdgeTypes.put(node, edge);
} else {
if (otherEdgeTypes == null) otherEdgeTypes = ArrayListMultimap.create();
otherEdgeTypes.put(node, edge);
}
} else { // STANDARD TitanRelation
assert (edge.getArity() == 1 && edge.isProperty())
|| (edge.getArity() == 2 && edge.isEdge());
for (int pos = 0; pos < edge.getArity(); pos++) {
InternalTitanVertex node = edge.getVertex(pos);
assert node.hasID();
if (pos == 0 || !edge.isUnidirected()) {
mutations.put(node, edge);
}
if (pos == 0
&& acquireLocks
&& edge.getType().isFunctional()
&& !node.isNew()
&& ((InternalTitanType) edge.getType()).isFunctionalLocking()) {
Entry entry = getEntry(tx, edge, node, signatures, true);
mutator.acquireEdgeLock(IDHandler.getKey(node.getID()), entry.getColumn(), null);
}
}
}
if (acquireLocks && edge.isProperty()) {
lockKeyedProperty((TitanProperty) edge, mutator);
}
}
// 3. Persist
if (simpleEdgeTypes != null) persist(simpleEdgeTypes, signatures, tx, mutator);
if (otherEdgeTypes != null) persist(otherEdgeTypes, signatures, tx, mutator);
mutator.flush();
// Commit saved EdgeTypes to TypeManager
if (simpleEdgeTypes != null) commitEdgeTypes(simpleEdgeTypes.keySet());
if (otherEdgeTypes != null) commitEdgeTypes(otherEdgeTypes.keySet());
if (!mutations.isEmpty()) persist(mutations, signatures, tx, mutator);
mutator.flush();
// Successfully completed - return to break out of loop
break;
} catch (Throwable e) {
if (e instanceof TemporaryStorageException) {
if (saveAttempt < maxWriteRetryAttempts - 1) temporaryStorageException(e);
else
throw new PermanentStorageException(
"Tried committing "
+ maxWriteRetryAttempts
+ " times on temporary exception without success",
e);
} else if (e instanceof StorageException) {
throw (StorageException) e;
} else {
throw new PermanentStorageException(
"Unidentified exception occurred during persistence", e);
}
}
}
}
