@Override
public UniqueValueSet load(
final ApplicationScope appScope,
final ConsistencyLevel consistencyLevel,
final String type,
final Collection<Field> fields)
throws ConnectionException {
Preconditions.checkNotNull(fields, "fields are required");
Preconditions.checkArgument(fields.size() > 0, "More than 1 field must be specified");
final List<ScopedRowKey<FieldKey>> keys = new ArrayList<>(fields.size());
final Id applicationId = appScope.getApplication();
for (Field field : fields) {
final FieldKey key = createUniqueValueKey(applicationId, type, field);
final ScopedRowKey<FieldKey> rowKey = ScopedRowKey.fromKey(applicationId, key);
keys.add(rowKey);
}
final UniqueValueSetImpl uniqueValueSet = new UniqueValueSetImpl(fields.size());
Iterator<Row<ScopedRowKey<FieldKey>, EntityVersion>> results =
keyspace
.prepareQuery(CF_UNIQUE_VALUES)
.setConsistencyLevel(consistencyLevel)
.getKeySlice(keys)
.withColumnRange(new RangeBuilder().setLimit(1).build())
.execute()
.getResult()
.iterator();
while (results.hasNext()) {
final Row<ScopedRowKey<FieldKey>, EntityVersion> unique = results.next();
final Field field = parseRowKey(unique.getKey());
final Iterator<Column<EntityVersion>> columnList = unique.getColumns().iterator();
// sanity check, nothing to do, skip it
if (!columnList.hasNext()) {
continue;
}
final EntityVersion entityVersion = columnList.next().getName();
final UniqueValueImpl uniqueValue =
new UniqueValueImpl(field, entityVersion.getEntityId(), entityVersion.getEntityVersion());
uniqueValueSet.addValue(uniqueValue);
}
return uniqueValueSet;
}
