How to bind a Set in TupleBinding

Question

If I have a record:
class Record{
long o
long a
Set<Integer> v
}o,a are part of the primary key and
Set<Integer> v is the data portion.
When I create a primaryIndex, I need to provide an entity class (in this case Record) and entity binding ( that will bind the Set<Integer> v into the data portion)
What is the best way( in terms of performance) to to use custom TupleBinding to convert objects to entry and entry to objects for the 'Set'.
More specifically how do we handle the lines with ?? in the below code.
public Record entryToObject(TupleInput input) {
          long o = input.readLong();
          long a = input.readLong();
          int v = input.??
public void objectToEntry(Record object, TupleOutput output) {
          output.writeLong(object.getO());
          output.writeLong(object.getA());
          // Need to figure this one out
          output.??;
     }If you can provide an example that would be great.

Answer 1

Hi PD,
You should be implementing an EntityBinding instead of an EntryBinding. Because both key and data are tuples, you can extend the TupleTupleBinding abstract class.
import java.util.HashSet;
import java.util.Set;
import com.sleepycat.bind.tuple.TupleInput;
import com.sleepycat.bind.tuple.TupleOutput;
import com.sleepycat.bind.tuple.TupleTupleBinding;
class Record {
    long o;
    long a;
    Set<Integer> v;
class RecordBinding extends TupleTupleBinding<Record> {
    public Record entryToObject(TupleInput keyInput, TupleInput dataInput) {
        Record object = new Record();
        object.o = keyInput.readLong();
        object.a = keyInput.readLong();
        int size = dataInput.readInt();
        object.v = new HashSet<Integer>(size);
        for (int i = 0; i < size; i += 1) {
            object.v.add(dataInput.readInt());
        return object;
    public void objectToKey(Record object, TupleOutput output) {
        output.writeLong(object.o);
        output.writeLong(object.a);
    public void objectToData(Record object, TupleOutput output) {
        output.writeInt(object.v.size());
        for (Integer i : object.v) {
            output.writeInt(i);
}In general, you can build any complex data structure on top of the primitives in TupleInput and TupleOutput. It's up to you to do that in a way that works best for your application.
--mark