public boolean setNextStem() {
pos = 0;
if (sit.hasNext()) {
stemString = sit.next();
return true;
} else {
return false;
}
}
/**
* Create a compound non-unique index, each pair is a {@link String} field and a {@link
* Direction}.
*
* @param fieldsAndDirections Must be even number of arguments.
* @return
*/
public static Index compound(Object... fieldsAndDirections) {
final BasicDBObject indexObj = new BasicDBObject();
final UnmodifiableIterator<Object> iter = Iterators.forArray(fieldsAndDirections);
while (iter.hasNext()) {
final String field = (String) iter.next();
final Sort.Direction dir = (Direction) iter.next();
indexObj.put(field, dir == Direction.ASC ? 1 : -1);
}
return new Index(indexObj, false);
}
private RelationPlan planCrossJoinUnnest(RelationPlan leftPlan, Join joinNode, Unnest node) {
TupleDescriptor outputDescriptor = analysis.getOutputDescriptor(joinNode);
TupleDescriptor unnestOutputDescriptor = analysis.getOutputDescriptor(node);
// Create symbols for the result of unnesting
ImmutableList.Builder<Symbol> unnestedSymbolsBuilder = ImmutableList.builder();
for (Field field : unnestOutputDescriptor.getVisibleFields()) {
Symbol symbol = symbolAllocator.newSymbol(field);
unnestedSymbolsBuilder.add(symbol);
}
ImmutableList<Symbol> unnestedSymbols = unnestedSymbolsBuilder.build();
// Add a projection for all the unnest arguments
PlanBuilder planBuilder = initializePlanBuilder(leftPlan);
planBuilder = appendProjections(planBuilder, node.getExpressions());
TranslationMap translations = planBuilder.getTranslations();
ProjectNode projectNode =
checkType(planBuilder.getRoot(), ProjectNode.class, "planBuilder.getRoot()");
ImmutableMap.Builder<Symbol, List<Symbol>> unnestSymbols = ImmutableMap.builder();
UnmodifiableIterator<Symbol> unnestedSymbolsIterator = unnestedSymbols.iterator();
for (Expression expression : node.getExpressions()) {
Type type = analysis.getType(expression);
Symbol inputSymbol = translations.get(expression);
if (type instanceof ArrayType) {
unnestSymbols.put(inputSymbol, ImmutableList.of(unnestedSymbolsIterator.next()));
} else if (type instanceof MapType) {
unnestSymbols.put(
inputSymbol,
ImmutableList.of(unnestedSymbolsIterator.next(), unnestedSymbolsIterator.next()));
} else {
throw new IllegalArgumentException("Unsupported type for UNNEST: " + type);
}
}
Optional<Symbol> ordinalitySymbol =
node.isWithOrdinality() ? Optional.of(unnestedSymbolsIterator.next()) : Optional.empty();
checkState(
!unnestedSymbolsIterator.hasNext(),
"Not all output symbols were matched with input symbols");
UnnestNode unnestNode =
new UnnestNode(
idAllocator.getNextId(),
projectNode,
leftPlan.getOutputSymbols(),
unnestSymbols.build(),
ordinalitySymbol);
return new RelationPlan(
unnestNode, outputDescriptor, unnestNode.getOutputSymbols(), Optional.empty());
}
@Override
public String next() {
return values.get(0).apply(sit.next());
}
@Override
public boolean hasNext() {
return sit.hasNext();
}