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;
}