@Override
public void prepare() throws Exception {
final TaskConfig config = this.taskContext.getTaskConfig();
if (config.getDriverStrategy() != DriverStrategy.ALL_REDUCE) {
throw new Exception(
"Unrecognized driver strategy for AllReduce driver: "
+ config.getDriverStrategy().name());
}
TypeSerializerFactory<T> serializerFactory = this.taskContext.getInputSerializer(0);
this.serializer = serializerFactory.getSerializer();
this.input = this.taskContext.getInput(0);
}
@Override
public void prepare() throws Exception {
final TaskConfig config = this.taskContext.getTaskConfig();
if (config.getDriverStrategy() != DriverStrategy.CO_GROUP) {
throw new Exception(
"Unrecognized driver strategy for CoGoup driver: " + config.getDriverStrategy().name());
}
final MutableObjectIterator<IT1> in1 = this.taskContext.getInput(0);
final MutableObjectIterator<IT2> in2 = this.taskContext.getInput(1);
// get the key positions and types
final TypeSerializer<IT1> serializer1 =
this.taskContext.<IT1>getInputSerializer(0).getSerializer();
final TypeSerializer<IT2> serializer2 =
this.taskContext.<IT2>getInputSerializer(1).getSerializer();
final TypeComparator<IT1> groupComparator1 = this.taskContext.getInputComparator(0);
final TypeComparator<IT2> groupComparator2 = this.taskContext.getInputComparator(1);
final TypePairComparatorFactory<IT1, IT2> pairComparatorFactory =
config.getPairComparatorFactory(this.taskContext.getUserCodeClassLoader());
if (pairComparatorFactory == null) {
throw new Exception("Missing pair comparator factory for CoGroup driver");
}
// create CoGropuTaskIterator according to provided local strategy.
this.coGroupIterator =
new SortMergeCoGroupIterator<IT1, IT2>(
in1,
in2,
serializer1,
groupComparator1,
serializer2,
groupComparator2,
pairComparatorFactory.createComparator12(groupComparator1, groupComparator2));
// open CoGroupTaskIterator - this triggers the sorting and blocks until the iterator is ready
this.coGroupIterator.open();
if (LOG.isDebugEnabled()) {
LOG.debug(this.taskContext.formatLogString("CoGroup task iterator ready."));
}
}