/**
* Limits the number of elements returned. Note: parameter <tt>n</tt> should be positive, although
* a negative value is supported for legacy reason. Passing a negative value will call {@link
* DBCursor#batchSize(int)} which is the preferred method.
*
* @param n the number of elements to return
* @return a cursor to iterate the results
* @dochub limit
*/
public DBCursor limit(int n) {
if (_it != null) throw new IllegalStateException("can't set limit after executing query");
if (n > 0) _limit = n;
else if (n < 0) batchSize(n);
return this;
}
@Test
public void testBatchWithActiveCursor() {
DBCollection c = _db.getCollection("testBatchWithActiveCursor");
c.drop();
for (int i = 0; i < 100; i++) c.save(new BasicDBObject("x", i));
try {
DBCursor cursor = c.find().batchSize(2); // setting to 1, actually sets to 2 (why, oh why?)
cursor.next(); // creates real cursor on server.
cursor.next();
assertEquals(0, cursor.numGetMores());
cursor.next();
assertEquals(1, cursor.numGetMores());
cursor.next();
cursor.next();
assertEquals(2, cursor.numGetMores());
cursor.next();
cursor.next();
assertEquals(3, cursor.numGetMores());
cursor.batchSize(20);
cursor.next();
cursor.next();
cursor.next();
assertEquals(4, cursor.numGetMores());
} catch (IllegalStateException e) {
assertNotNull(e); // there must be a better way to detect this.
}
}
protected void doFindAll(Exchange exchange) throws Exception {
DBCollection dbCol = calculateCollection(exchange);
// do not use getMandatoryBody, because if the body is empty we want to retrieve all objects in
// the collection
DBObject query = null;
// do not run around looking for a type converter unless there is a need for it
if (exchange.getIn().getBody() != null) {
query = exchange.getIn().getBody(DBObject.class);
}
DBObject fieldFilter =
exchange.getIn().getHeader(MongoDbConstants.FIELDS_FILTER, DBObject.class);
// get the batch size and number to skip
Integer batchSize = exchange.getIn().getHeader(MongoDbConstants.BATCH_SIZE, Integer.class);
Integer numToSkip = exchange.getIn().getHeader(MongoDbConstants.NUM_TO_SKIP, Integer.class);
Integer limit = exchange.getIn().getHeader(MongoDbConstants.LIMIT, Integer.class);
DBObject sortBy = exchange.getIn().getHeader(MongoDbConstants.SORT_BY, DBObject.class);
DBCursor ret = null;
try {
if (query == null && fieldFilter == null) {
ret = dbCol.find(new BasicDBObject());
} else if (fieldFilter == null) {
ret = dbCol.find(query);
} else {
ret = dbCol.find(query, fieldFilter);
}
if (sortBy != null) {
ret.sort(sortBy);
}
if (batchSize != null) {
ret.batchSize(batchSize.intValue());
}
if (numToSkip != null) {
ret.skip(numToSkip.intValue());
}
if (limit != null) {
ret.limit(limit.intValue());
}
Message resultMessage = prepareResponseMessage(exchange, MongoDbOperation.findAll);
resultMessage.setBody(ret.toArray());
resultMessage.setHeader(MongoDbConstants.RESULT_TOTAL_SIZE, ret.count());
resultMessage.setHeader(MongoDbConstants.RESULT_PAGE_SIZE, ret.size());
} finally {
// make sure the cursor is closed
if (ret != null) {
ret.close();
}
}
}
@Test
public void testHasFinalizer() throws UnknownHostException {
DBCollection c = _db.getCollection("HasFinalizerTest");
c.drop();
for (int i = 0; i < 1000; i++) c.save(new BasicDBObject("_id", i), WriteConcern.SAFE);
// finalizer is on by default so after calling hasNext should report that it has one
DBCursor cursor = c.find();
assertFalse(cursor.hasFinalizer());
cursor.hasNext();
assertTrue(cursor.hasFinalizer());
cursor.close();
// no finalizer if there is no cursor, as there should not be for a query with only one result
cursor = c.find(new BasicDBObject("_id", 1));
cursor.hasNext();
assertFalse(cursor.hasFinalizer());
cursor.close();
// no finalizer if there is no cursor, as there should not be for a query with negative batch
// size
cursor = c.find();
cursor.batchSize(-1);
cursor.hasNext();
assertFalse(cursor.hasFinalizer());
cursor.close();
// finally, no finalizer if disabled in mongo options
MongoOptions mongoOptions = new MongoOptions();
mongoOptions.cursorFinalizerEnabled = false;
Mongo m = new Mongo("127.0.0.1", mongoOptions);
try {
c = m.getDB(cleanupDB).getCollection("HasFinalizerTest");
cursor = c.find();
cursor.hasNext();
assertFalse(cursor.hasFinalizer());
cursor.close();
} finally {
m.close();
}
}
/**
* Execute the interaction and return output record. The spec is either GET, PUT or DELETE
* interaction.
*/
public Record execute(InteractionSpec spec, Record record) throws ResourceException {
if (!(spec instanceof MongoInteractionSpec)) {
throw EISException.invalidInteractionSpecType();
}
if (!(record instanceof MongoRecord)) {
throw EISException.invalidRecordType();
}
MongoInteractionSpec mongoSpec = (MongoInteractionSpec) spec;
MongoRecord input = (MongoRecord) record;
MongoOperation operation = mongoSpec.getOperation();
String collectionName = mongoSpec.getCollection();
if (operation == null) {
ResourceException resourceException = new ResourceException("Mongo operation must be set");
throw resourceException;
}
if (operation == MongoOperation.EVAL) {
Object result = this.connection.getDB().eval(mongoSpec.getCode());
return buildRecordFromDBObject((DBObject) result);
}
if (collectionName == null) {
ResourceException resourceException = new ResourceException("DB Collection name must be set");
throw resourceException;
}
try {
DBCollection collection = this.connection.getDB().getCollection(collectionName);
if (mongoSpec.getOptions() > 0) {
collection.setOptions(mongoSpec.getOptions());
}
if (mongoSpec.getReadPreference() != null) {
collection.setReadPreference(mongoSpec.getReadPreference());
}
if (mongoSpec.getWriteConcern() != null) {
collection.setWriteConcern(mongoSpec.getWriteConcern());
}
if (operation == MongoOperation.INSERT) {
DBObject object = buildDBObject(input);
collection.insert(object);
} else if (operation == MongoOperation.REMOVE) {
DBObject object = buildDBObject(input);
collection.remove(object);
} else if (operation == MongoOperation.FIND) {
DBObject sort = null;
if (input.containsKey(MongoRecord.SORT)) {
sort = buildDBObject((MongoRecord) input.get(MongoRecord.SORT));
input.remove(MongoRecord.SORT);
}
DBObject select = null;
if (input.containsKey("$select")) {
select = buildDBObject((MongoRecord) input.get("$select"));
input.remove("$select");
}
DBObject object = buildDBObject(input);
DBCursor cursor = collection.find(object, select);
if (sort != null) {
cursor.sort(sort);
}
try {
if (mongoSpec.getSkip() > 0) {
cursor.skip(mongoSpec.getSkip());
}
if (mongoSpec.getLimit() != 0) {
cursor.limit(mongoSpec.getLimit());
}
if (mongoSpec.getBatchSize() != 0) {
cursor.batchSize(mongoSpec.getBatchSize());
}
if (!cursor.hasNext()) {
return null;
}
MongoListRecord results = new MongoListRecord();
while (cursor.hasNext()) {
DBObject result = cursor.next();
results.add(buildRecordFromDBObject(result));
}
return results;
} finally {
cursor.close();
}
} else {
throw new ResourceException("Invalid operation: " + operation);
}
} catch (Exception exception) {
ResourceException resourceException = new ResourceException(exception.toString());
resourceException.initCause(exception);
throw resourceException;
}
return null;
}
