private static ResultSet exec(String pattern, Graph graph) {
Op op = SSE.parseOp(pattern, pmap);
List<Var> vars = new ArrayList<>();
vars.addAll(OpVars.visibleVars(op));
QueryIterator qIter = Algebra.exec(op, graph);
return ResultSetFactory.create(qIter, Var.varNames(vars));
}
/**
* Tests whether a query gives the same results when run both with and without a given optimizer
*
* @param queryStr Query
* @param ds Dataset
* @param opt Optimizer
* @param expected Expected number of results
*/
public static void test(String queryStr, Dataset ds, Symbol opt, int expected) {
Query q = QueryFactory.create(queryStr);
if (!q.isSelectType()) Assert.fail("Only SELECT queries are testable with this method");
Op op = Algebra.compile(q);
// Track current state
boolean isEnabled = ARQ.isTrue(opt);
boolean isDisabled = ARQ.isFalse(opt);
try {
// Run first without optimization
ARQ.set(opt, false);
ResultSetRewindable rs;
try (QueryExecution qe = QueryExecutionFactory.create(q, ds)) {
rs = ResultSetFactory.makeRewindable(qe.execSelect());
if (expected != rs.size()) {
System.err.println("Non-optimized results not as expected");
TextOutput output = new TextOutput((SerializationContext) null);
output.format(System.out, rs);
rs.reset();
}
Assert.assertEquals(expected, rs.size());
}
// Run with optimization
ARQ.set(opt, true);
ResultSetRewindable rsOpt;
try (QueryExecution qeOpt = QueryExecutionFactory.create(q, ds)) {
rsOpt = ResultSetFactory.makeRewindable(qeOpt.execSelect());
if (expected != rsOpt.size()) {
System.err.println("Optimized results not as expected");
TextOutput output = new TextOutput((SerializationContext) null);
output.format(System.out, rsOpt);
rsOpt.reset();
}
Assert.assertEquals(expected, rsOpt.size());
}
Assert.assertTrue(ResultSetCompare.isomorphic(rs, rsOpt));
} finally {
// Restore previous state
if (isEnabled) {
ARQ.set(opt, true);
} else if (isDisabled) {
ARQ.set(opt, false);
} else {
ARQ.unset(opt);
}
}
}
protected Binding moveToNextBindingOrNull() {
// iterCurrent is the iterator of entries in the
// probe hashed table for the current stream row.
// iterStream is the stream of incoming rows.
switch (state) {
case DONE:
return null;
case HASH:
case INIT:
throw new IllegalStateException();
case TRAILER:
return doOneTail();
case STREAM:
}
for (; ; ) {
// Ensure we are processing a row.
while (iterCurrent == null) {
// Move on to the next row from the right.
if (!iterStream.hasNext()) {
state = Phase.TRAILER;
iterTail = joinFinished();
if (iterTail != null) return doOneTail();
return null;
}
rowStream = iterStream.next();
s_countScan++;
iterCurrent = hashTable.getCandidates(rowStream);
yielded = false;
}
// Emit one row using the rightRow and the current matched left rows.
if (!iterCurrent.hasNext()) {
iterCurrent = null;
if (!yielded) {
Binding b = noYieldedRows(rowStream);
if (b != null) {
s_countScan++;
return b;
}
}
continue;
}
// Nested loop join, only on less.
// Iterator<Binding> iter = nestedLoop(iterCurrent, rowStream) ;
Binding rowCurrentProbe = iterCurrent.next();
Binding r = Algebra.merge(rowCurrentProbe, rowStream);
Binding r2 = null;
if (r != null) r2 = yieldOneResult(rowCurrentProbe, rowStream, r);
if (r2 == null) {
// Reject
} else {
yielded = true;
s_countResults++;
return r2;
}
}
}