@Test
public void testExplain() {
DBCollection c = _db.getCollection("explain1");
c.drop();
for (int i = 0; i < 100; i++) c.save(new BasicDBObject("x", i));
DBObject q = BasicDBObjectBuilder.start().push("x").add("$gt", 50).get();
assertEquals(49, c.find(q).count());
assertEquals(49, c.find(q).itcount());
assertEquals(49, c.find(q).toArray().size());
assertEquals(49, c.find(q).itcount());
assertEquals(20, c.find(q).limit(20).itcount());
assertEquals(20, c.find(q).limit(-20).itcount());
c.ensureIndex(new BasicDBObject("x", 1));
assertEquals(49, c.find(q).count());
assertEquals(49, c.find(q).toArray().size());
assertEquals(49, c.find(q).itcount());
assertEquals(20, c.find(q).limit(20).itcount());
assertEquals(20, c.find(q).limit(-20).itcount());
assertEquals(49, c.find(q).explain().get("n"));
assertEquals(20, c.find(q).limit(20).explain().get("n"));
assertEquals(20, c.find(q).limit(-20).explain().get("n"));
}
@Test
public void testBig() {
DBCollection c = _db.getCollection("big1");
c.drop();
String bigString;
{
StringBuilder buf = new StringBuilder(16000);
for (int i = 0; i < 16000; i++) buf.append("x");
bigString = buf.toString();
}
int numToInsert = (15 * 1024 * 1024) / bigString.length();
for (int i = 0; i < numToInsert; i++)
c.save(BasicDBObjectBuilder.start().add("x", i).add("s", bigString).get());
assert (800 < numToInsert);
assertEquals(numToInsert, c.find().count());
assertEquals(numToInsert, c.find().toArray().size());
assertEquals(numToInsert, c.find().limit(800).count());
assertEquals(800, c.find().limit(800).toArray().size());
// negative limit works like negative batchsize, for legacy reason
int x = c.find().limit(-800).toArray().size();
assertLess(x, 800);
DBCursor a = c.find();
assertEquals(numToInsert, a.itcount());
DBCursor b = c.find().batchSize(10);
assertEquals(numToInsert, b.itcount());
assertEquals(10, b.getSizes().get(0).intValue());
assertLess(a.numGetMores(), b.numGetMores());
assertEquals(numToInsert, c.find().batchSize(2).itcount());
assertEquals(numToInsert, c.find().batchSize(1).itcount());
assertEquals(numToInsert, _count(c.find(null, null).skip(0).batchSize(5)));
assertEquals(5, _count(c.find(null, null).skip(0).batchSize(-5)));
}
@Test
public void testLimitAndBatchSize() {
DBCollection c = _db.getCollection("LimitAndBatchSize");
c.drop();
for (int i = 0; i < 1000; i++) c.save(new BasicDBObject("x", i));
DBObject q = BasicDBObjectBuilder.start().push("x").add("$lt", 200).get();
DBCursor cur = c.find(q);
assertEquals(0, cur.getCursorId());
assertEquals(200, cur.itcount());
cur = c.find(q).limit(50);
assertEquals(0, cur.getCursorId());
assertEquals(50, cur.itcount());
cur = c.find(q).batchSize(50);
assertEquals(0, cur.getCursorId());
assertEquals(200, cur.itcount());
cur = c.find(q).batchSize(100).limit(50);
assertEquals(0, cur.getCursorId());
assertEquals(50, cur.itcount());
cur = c.find(q).batchSize(-40);
assertEquals(0, cur.getCursorId());
assertEquals(40, cur.itcount());
cur = c.find(q).limit(-100);
assertEquals(0, cur.getCursorId());
assertEquals(100, cur.itcount());
cur = c.find(q).batchSize(-40).limit(20);
assertEquals(0, cur.getCursorId());
assertEquals(20, cur.itcount());
cur = c.find(q).batchSize(-20).limit(100);
assertEquals(0, cur.getCursorId());
assertEquals(20, cur.itcount());
}