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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault
#include "mongo/client/dbclient_connection.h"
#include "mongo/client/dbclient_cursor.h"
#include "mongo/db/query/cursor_response.h"
#include "mongo/logv2/log.h"
#include "mongo/unittest/unittest.h"
#include "mongo/util/assert_util.h"
namespace mongo {
namespace {
/**
* This DBClientConnection mock allows us to intercept outgoing client requests and to simulate a
* remote server's responses to these requests. We use this to test DBClientCursor, since a
* DBClientConnection is how a DBClientCursor interacts with the rest of the world. By mocking the
* behavior of the DBClientConnection (i.e. the network) we can make sure that DBClientCursor
* behaves correctly, assuming correct behavior of DBClientConnection.
*/
class DBClientConnectionForTest : public DBClientConnection {
public:
DBClientConnectionForTest() {
_setServerRPCProtocols(rpc::supports::kAll); // allow all protocol types by default.
_serverAddress = HostAndPort("localhost", 27017); // dummy server address.
}
bool call(Message& toSend,
Message& response,
bool assertOk,
std::string* actualServer) override {
// Intercept request.
const auto reqId = nextMessageId();
toSend.header().setId(reqId);
toSend.header().setResponseToMsgId(0);
OpMsg::appendChecksum(&toSend);
_lastSent = toSend;
// Mock response.
response = _mockCallResponse;
response.header().setId(nextMessageId());
response.header().setResponseToMsgId(reqId);
OpMsg::appendChecksum(&response);
return true;
}
Status recv(Message& m, int lastRequestId) override {
m = _mockRecvResponse;
return Status::OK();
}
// No-op.
void killCursor(const NamespaceString& ns, long long cursorID) override {
LOGV2(20131, "Killing cursor in DBClientConnectionForTest");
}
void setSupportedProtocols(rpc::ProtocolSet protocols) {
_setServerRPCProtocols(protocols);
}
void setCallResponse(Message reply) {
_mockCallResponse = reply;
}
void setRecvResponse(Message reply) {
_mockRecvResponse = reply;
}
Message getLastSentMessage() {
return _lastSent;
}
void clearLastSentMessage() {
_lastSent = Message();
}
private:
Message _mockCallResponse;
Message _mockRecvResponse;
Message _lastSent;
};
class DBClientCursorTest : public unittest::Test {
protected:
/**
* An OP_MSG response to a 'find' command.
*/
Message mockFindResponse(NamespaceString nss,
long long cursorId,
std::vector<BSONObj> firstBatch) {
auto cursorRes = CursorResponse(nss, cursorId, firstBatch);
return OpMsg{cursorRes.toBSON(CursorResponse::ResponseType::InitialResponse)}.serialize();
}
/**
* An OP_MSG response to a 'getMore' command.
*/
Message mockGetMoreResponse(NamespaceString nss,
long long cursorId,
std::vector<BSONObj> batch) {
auto cursorRes = CursorResponse(nss, cursorId, batch);
return OpMsg{cursorRes.toBSON(CursorResponse::ResponseType::SubsequentResponse)}
.serialize();
}
/**
* A generic non-ok OP_MSG command response.
*/
Message mockErrorResponse(ErrorCodes::Error err) {
OpMsgBuilder builder;
BSONObjBuilder bodyBob;
bodyBob.append("ok", 0);
bodyBob.append("code", err);
builder.setBody(bodyBob.done());
return builder.finish();
}
BSONObj docObj(int id) {
return BSON("_id" << id);
}
};
TEST_F(DBClientCursorTest, DBClientCursorCallsMetaDataReaderOncePerBatch) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(&conn, NamespaceStringOrUUID(nss), Query().obj, 0, 0, nullptr, 0, 0);
cursor.setBatchSize(2);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {docObj(1), docObj(2)});
conn.setCallResponse(findResponseMsg);
int numMetaRead = 0;
conn.setReplyMetadataReader(
[&](OperationContext* opCtx, const BSONObj& metadataObj, StringData target) {
numMetaRead++;
return Status::OK();
});
// Trigger a find command.
ASSERT(cursor.init());
// First batch from the initial find command.
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
// Test that the metadata reader callback is called once.
ASSERT_EQ(1, numMetaRead);
// Set a terminal getMore response with cursorId 0.
auto getMoreResponseMsg = mockGetMoreResponse(nss, 0, {docObj(3), docObj(4)});
conn.setCallResponse(getMoreResponseMsg);
// Trigger a subsequent getMore command.
ASSERT_TRUE(cursor.more());
// Second batch from the getMore command.
ASSERT_BSONOBJ_EQ(docObj(3), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(4), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_TRUE(cursor.isDead());
// Test that the metadata reader callback is called twice.
ASSERT_EQ(2, numMetaRead);
}
TEST_F(DBClientCursorTest, DBClientCursorHandlesOpMsgExhaustCorrectly) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(
&conn, NamespaceStringOrUUID(nss), Query().obj, 0, 0, nullptr, QueryOption_Exhaust, 0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
// Create a 'getMore' response and set it as the mock response. The 'moreToCome' flag is set on
// the response to indicate this is an exhaust message.
cursor.setBatchSize(2);
std::vector<BSONObj> docs = {docObj(1), docObj(2)};
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, docs);
OpMsg::setFlag(&getMoreResponseMsg, OpMsg::kMoreToCome);
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the first 'getMore' request with exhaust
// flag set.
conn.clearLastSentMessage();
ASSERT(cursor.more());
m = conn.getLastSentMessage();
ASSERT(!m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT(OpMsg::isFlagSet(m, OpMsg::kExhaustSupported));
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
// Create and set a terminal 'getMore' response. The 'moreToCome' flag is not set, since this is
// the last message of the stream.
auto terminalDoc = BSON("_id"
<< "terminal");
auto getMoreTerminalResponseMsg = mockGetMoreResponse(nss, 0, {terminalDoc});
conn.setRecvResponse(getMoreTerminalResponseMsg);
// Request more results. This call to 'more' should not trigger a new 'getMore' request, since
// the remote server should already be streaming results to us. After getting the final batch,
// the cursor should be exhausted i.e. "dead".
conn.clearLastSentMessage();
ASSERT(cursor.more());
ASSERT(conn.getLastSentMessage().empty());
ASSERT_BSONOBJ_EQ(terminalDoc, cursor.next());
ASSERT(cursor.isDead());
}
TEST_F(DBClientCursorTest, DBClientCursorResendsGetMoreIfMoreToComeFlagIsOmittedInExhaustMessage) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(
&conn, NamespaceStringOrUUID(nss), Query().obj, 0, 0, nullptr, QueryOption_Exhaust, 0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
// Create and set a mock 'getMore' response. The 'moreToCome' flag is NOT set on the response,
// even though exhaust mode was requested by the client. It is legal for a server to do this,
// even if the cursor is not exhausted. In response, the client should resend a 'getMore' to
// restart the stream.
cursor.setBatchSize(2);
std::vector<BSONObj> docs = {docObj(1), docObj(2)};
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, docs);
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the first 'getMore' request with exhaust
// flag set.
conn.clearLastSentMessage();
ASSERT(cursor.more());
m = conn.getLastSentMessage();
ASSERT(!m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT_EQ(msg.body["batchSize"].number(), 2);
ASSERT(OpMsg::isFlagSet(m, OpMsg::kExhaustSupported));
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
// Create another mock 'getMore' response. This one has the 'moreToCome' flag set.
docs = {docObj(3), docObj(4)};
getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, docs);
OpMsg::setFlag(&getMoreResponseMsg, OpMsg::kMoreToCome);
conn.setCallResponse(getMoreResponseMsg);
// Request more results again. This call should trigger another 'getMore' request, since the
// previous response had no 'moreToCome' flag set. This time the mock server will respond with
// the 'moreToCome' flag set.
conn.clearLastSentMessage();
ASSERT(cursor.more());
m = conn.getLastSentMessage();
ASSERT(!m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT(OpMsg::isFlagSet(m, OpMsg::kExhaustSupported));
ASSERT_BSONOBJ_EQ(docObj(3), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(4), cursor.next());
// Exhaust the cursor with a terminal 'getMore' response.
auto terminalDoc = BSON("_id"
<< "terminal");
auto terminalGetMoreResponseMsg = mockGetMoreResponse(nss, 0, {terminalDoc});
conn.setRecvResponse(terminalGetMoreResponseMsg);
// Get the last returned document.
conn.clearLastSentMessage();
ASSERT(cursor.more());
ASSERT_BSONOBJ_EQ(terminalDoc, cursor.next());
// The cursor should now be exhausted.
ASSERT(!cursor.more());
ASSERT(cursor.isDead());
}
TEST_F(DBClientCursorTest, DBClientCursorMoreThrowsExceptionOnNonOKResponse) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(
&conn, NamespaceStringOrUUID(nss), Query().obj, 0, 0, nullptr, QueryOption_Exhaust, 0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
// Create and set a mock error response.
cursor.setBatchSize(2);
auto errResponseMsg = mockErrorResponse(ErrorCodes::Interrupted);
conn.setCallResponse(errResponseMsg);
// Try to request more results, and expect an error.
conn.clearLastSentMessage();
ASSERT_THROWS_CODE(cursor.more(), DBException, ErrorCodes::Interrupted);
}
TEST_F(DBClientCursorTest, DBClientCursorMoreThrowsExceptionWhenMoreToComeFlagSetWithZeroCursorId) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(
&conn, NamespaceStringOrUUID(nss), Query().obj, 0, 0, nullptr, QueryOption_Exhaust, 0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
// Create and set a getMore response that has the 'moreToCome' flag but also a cursor id of
// zero.
cursor.setBatchSize(2);
auto getMoreResponseMsg = mockGetMoreResponse(nss, 0, {});
OpMsg::setFlag(&getMoreResponseMsg, OpMsg::kMoreToCome);
conn.setCallResponse(getMoreResponseMsg);
// Try to request more results, and expect an error.
conn.clearLastSentMessage();
ASSERT_THROWS_CODE(cursor.more(), DBException, 50935);
}
TEST_F(DBClientCursorTest, DBClientCursorIgnoresExhaustForOpQueryMessages) {
// Set up the DBClientCursor and a mock client connection. If we set the server RPC protocol to
// OpQuery, then when we assemble a command request in DBClientCursor, we will make a command
// style OpQuery request, as opposed to an OpMsg request. We want to make sure that for command
// style OpQuery requests, we ignore the exhaust option, and that cursor queries work normally.
DBClientConnectionForTest conn;
conn.setSupportedProtocols(rpc::supports::kOpQueryOnly);
const NamespaceString nss("test", "coll");
DBClientCursor cursor(
&conn, NamespaceStringOrUUID(nss), Query().obj, 0, 0, nullptr, QueryOption_Exhaust, 0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
QueryMessage queryMsg(m);
ASSERT_EQ(queryMsg.query.getStringField("find"), nss.coll());
ASSERT_EQ(queryMsg.query["batchSize"].number(), 0);
ASSERT_EQ(0, queryMsg.queryOptions);
// Create and set a non-exhaust getMore response.
cursor.setBatchSize(2);
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {docObj(1), docObj(2)});
conn.setCallResponse(getMoreResponseMsg);
// Trigger another 'getMore' request.
conn.clearLastSentMessage();
ASSERT(cursor.more());
// Make sure the sent request has no exhaust query options set.
m = conn.getLastSentMessage();
ASSERT(!m.empty());
queryMsg = QueryMessage(m);
ASSERT_EQ(queryMsg.query["getMore"].number(), cursorId);
ASSERT_EQ(queryMsg.query["collection"].str(), nss.coll());
ASSERT_EQ(0, queryMsg.queryOptions);
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
}
TEST_F(DBClientCursorTest, DBClientCursorPassesReadOnceFlag) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(&conn,
NamespaceStringOrUUID(nss),
QUERY("query" << BSONObj() << "$readOnce" << true).obj,
0,
0,
nullptr,
/*QueryOption*/ 0,
0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the 'find' request was sent with readOnce.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
ASSERT_TRUE(msg.body.getBoolField("readOnce")) << msg.body;
}
// "Resume fields" refers to $_requestResumeToken and $_resumeAfter.
TEST_F(DBClientCursorTest, DBClientCursorPassesResumeFields) {
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(&conn,
NamespaceStringOrUUID(nss),
QUERY("query" << BSONObj() << "$_requestResumeToken" << true
<< "$_resumeAfter" << BSON("$recordId" << 5LL))
.obj,
0,
0,
nullptr,
/*QueryOption*/ 0,
0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// Verify that the 'find' request was sent with $_requestResumeToken and $_resumeAfter.
auto m = conn.getLastSentMessage();
ASSERT(!m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
ASSERT_TRUE(msg.body.getBoolField("$_requestResumeToken")) << msg.body;
ASSERT_TRUE(msg.body.hasField("$_resumeAfter")) << msg.body;
ASSERT_TRUE(msg.body.getObjectField("$_resumeAfter").hasField("$recordId")) << msg.body;
ASSERT_EQ(msg.body.getObjectField("$_resumeAfter")["$recordId"].numberLong(), 5LL) << msg.body;
}
TEST_F(DBClientCursorTest, DBClientCursorTailable) {
// This tests DBClientCursor in tailable mode. Cases to test are:
// 1. Initial find command has {tailable: true} set.
// 2. A getMore can handle a normal batch correctly.
// 3. A getMore can handle an empty batch correctly.
// 4. The tailable cursor is not dead until the cursorId is 0 in the response.
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(&conn,
NamespaceStringOrUUID(nss),
Query().obj,
0,
0,
nullptr,
QueryOption_CursorTailable,
0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// --- Test 1 ---
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
ASSERT_TRUE(msg.body.getBoolField("tailable")) << msg.body;
// --- Test 2 ---
// Create a 'getMore' response with two documents and set it as the mock response.
cursor.setBatchSize(2);
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {docObj(1), docObj(2)});
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the first 'getMore' request.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
// --- Test 3 ---
// Create a 'getMore' response with an empty batch and set it as the mock response.
getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {});
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the second 'getMore' request.
// more() should return false on an empty batch.
conn.clearLastSentMessage();
ASSERT_FALSE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT_FALSE(cursor.moreInCurrentBatch());
// But the cursor should be still valid.
ASSERT_FALSE(cursor.isDead());
// --- Test 4 ---
// Create a 'getMore' response with cursorId = 0 and set it as the mock response.
getMoreResponseMsg = mockGetMoreResponse(nss, 0, {docObj(3)});
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the third 'getMore' request.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT_BSONOBJ_EQ(docObj(3), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
// Cursor is dead if the cursorId is 0.
ASSERT_TRUE(cursor.isDead());
// Request more results. This should not trigger a new 'getMore' request as the cursor is dead.
conn.clearLastSentMessage();
ASSERT_FALSE(cursor.more());
ASSERT_TRUE(conn.getLastSentMessage().empty());
}
TEST_F(DBClientCursorTest, DBClientCursorTailableAwaitData) {
// This tests DBClientCursor in tailable awaitData mode. Cases to test are:
// 1. Initial find command has {tailable: true} and {awaitData: true} set.
// 2. A subsequent getMore command sets awaitData timeout correctly.
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(&conn,
NamespaceStringOrUUID(nss),
Query().obj,
0,
0,
nullptr,
QueryOption_CursorTailable | QueryOption_AwaitData,
0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// --- Test 1 ---
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
ASSERT_TRUE(msg.body.getBoolField("tailable")) << msg.body;
ASSERT_TRUE(msg.body.getBoolField("awaitData")) << msg.body;
cursor.setAwaitDataTimeoutMS(Milliseconds{5000});
ASSERT_EQ(cursor.getAwaitDataTimeoutMS(), Milliseconds{5000});
// --- Test 2 ---
// Create a 'getMore' response with two documents and set it as the mock response.
cursor.setBatchSize(2);
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {docObj(1), docObj(2)});
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the first 'getMore' request.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
// Make sure the correct awaitData timeout is sent.
ASSERT_EQ(msg.body["maxTimeMS"].number(), 5000);
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
}
TEST_F(DBClientCursorTest, DBClientCursorTailableAwaitDataExhaust) {
// This tests DBClientCursor in tailable awaitData exhaust mode. Cases to test are:
// 1. Initial find command has {tailable: true} and {awaitData: true} set.
// 2. The first getMore command sets awaitData timeout correctly and has kExhaustSupported flag.
// 3. Exhaust receive can handle a normal batch correctly.
// 4. Exhaust receive can handle an empty batch correctly.
// 5. Cursor resends a new 'getMore' command if the previous response had no 'moreToCome' flag.
// 6. The tailable cursor is not dead until the cursorId is 0 in the response.
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss("test", "coll");
DBClientCursor cursor(&conn,
NamespaceStringOrUUID(nss),
Query().obj,
0,
0,
nullptr,
QueryOption_CursorTailable | QueryOption_AwaitData | QueryOption_Exhaust,
0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// --- Test 1 ---
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll());
ASSERT_EQ(msg.body["batchSize"].number(), 0);
ASSERT_TRUE(msg.body.getBoolField("tailable")) << msg.body;
ASSERT_TRUE(msg.body.getBoolField("awaitData")) << msg.body;
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
ASSERT_FALSE(cursor.connectionHasPendingReplies());
// --- Test 2 ---
cursor.setAwaitDataTimeoutMS(Milliseconds{5000});
ASSERT_EQ(cursor.getAwaitDataTimeoutMS(), Milliseconds{5000});
// Create a 'getMore' response and set it as the mock response. The 'moreToCome' flag is set on
// the response to indicate this is an exhaust message.
cursor.setBatchSize(2);
std::vector<BSONObj> docs = {docObj(1), docObj(2)};
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, docs);
OpMsg::setFlag(&getMoreResponseMsg, OpMsg::kMoreToCome);
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the first 'getMore' request with exhaust
// flag set.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT_EQ(msg.body["maxTimeMS"].number(), 5000);
ASSERT_TRUE(OpMsg::isFlagSet(m, OpMsg::kExhaustSupported));
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
ASSERT_TRUE(cursor.connectionHasPendingReplies());
// --- Test 3 ---
// Create a 'getMore' response with the 'moreToCome' flag set and set it as the mock response.
getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {docObj(3)});
OpMsg::setFlag(&getMoreResponseMsg, OpMsg::kMoreToCome);
conn.setRecvResponse(getMoreResponseMsg);
// Request more results. But this should not trigger a new 'getMore' request because the
// previous response had the 'moreToCome' flag set.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
ASSERT_TRUE(conn.getLastSentMessage().empty());
ASSERT_BSONOBJ_EQ(docObj(3), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
ASSERT_TRUE(cursor.connectionHasPendingReplies());
// --- Test 4 ---
// Create a 'getMore' response with an empty batch and the 'moreToCome' flag set and set it as
// the mock response.
getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {});
OpMsg::setFlag(&getMoreResponseMsg, OpMsg::kMoreToCome);
conn.setRecvResponse(getMoreResponseMsg);
// Request more results. But this should not trigger a new 'getMore' request because the
// previous response had the 'moreToCome' flag set.
conn.clearLastSentMessage();
// more() should return false on an empty batch.
ASSERT_FALSE(cursor.more());
ASSERT_TRUE(conn.getLastSentMessage().empty());
ASSERT_FALSE(cursor.moreInCurrentBatch());
// But the cursor should be still valid.
ASSERT_FALSE(cursor.isDead());
ASSERT_TRUE(cursor.connectionHasPendingReplies());
// --- Test 5 ---
// Create a 'getMore' response without the 'moreToCome' flag and set it as the mock response.
getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {docObj(4)});
conn.setRecvResponse(getMoreResponseMsg);
// Request more results. But this should not trigger a new 'getMore' request because the
// previous response had the 'moreToCome' flag set.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
ASSERT_TRUE(conn.getLastSentMessage().empty());
ASSERT_BSONOBJ_EQ(docObj(4), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
ASSERT_FALSE(cursor.connectionHasPendingReplies());
// --- Test 6 ---
// Create a 'getMore' response with cursorId 0 and set it as the mock response.
getMoreResponseMsg = mockGetMoreResponse(nss, 0, {docObj(5)});
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This should trigger a new 'getMore' request because the previous
// response had no 'moreToCome' flag.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore");
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong);
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId);
ASSERT_EQ(msg.body["maxTimeMS"].number(), 5000);
ASSERT_BSONOBJ_EQ(docObj(5), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
// Cursor is dead if the cursorId is 0.
ASSERT_TRUE(cursor.isDead());
ASSERT_FALSE(cursor.connectionHasPendingReplies());
// Request more results. This should not trigger a new 'getMore' request as the cursor is dead.
conn.clearLastSentMessage();
ASSERT_FALSE(cursor.more());
ASSERT_TRUE(conn.getLastSentMessage().empty());
}
TEST_F(DBClientCursorTest, DBClientCursorOplogQuery) {
// This tests DBClientCursor supports oplog query with special fields in the command request.
// 1. Initial find command has "filter", "tailable", "awaitData", "maxTimeMS", "batchSize",
// "term" and "readConcern" fields set.
// 2. A subsequent getMore command sets awaitData timeout and lastKnownCommittedOpTime
// correctly.
// Set up the DBClientCursor and a mock client connection.
DBClientConnectionForTest conn;
const NamespaceString nss = NamespaceString::kRsOplogNamespace;
const BSONObj filterObj = BSON("ts" << BSON("$gte" << Timestamp(123, 4)));
const BSONObj readConcernObj = BSON("afterClusterTime" << Timestamp(0, 1));
const long long maxTimeMS = 5000LL;
const long long term = 5;
const auto oplogQuery = QUERY("query" << filterObj << "readConcern" << readConcernObj
<< "$maxTimeMS" << maxTimeMS << "term" << term);
DBClientCursor cursor(&conn,
NamespaceStringOrUUID(nss),
oplogQuery.obj,
0,
0,
nullptr,
QueryOption_CursorTailable | QueryOption_AwaitData,
0);
cursor.setBatchSize(0);
// Set up mock 'find' response.
const long long cursorId = 42;
Message findResponseMsg = mockFindResponse(nss, cursorId, {});
conn.setCallResponse(findResponseMsg);
ASSERT(cursor.init());
// --- Test 1 ---
// Verify that the initial 'find' request was sent.
auto m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
auto msg = OpMsg::parse(m);
ASSERT_EQ(OpMsg::flags(m), OpMsg::kChecksumPresent);
ASSERT_EQ(msg.body.getStringField("find"), nss.coll()) << msg.body;
ASSERT_BSONOBJ_EQ(msg.body["filter"].Obj(), filterObj);
ASSERT_TRUE(msg.body.getBoolField("tailable")) << msg.body;
ASSERT_TRUE(msg.body.getBoolField("awaitData")) << msg.body;
ASSERT_EQ(msg.body["maxTimeMS"].numberLong(), maxTimeMS) << msg.body;
ASSERT_EQ(msg.body["batchSize"].number(), 0) << msg.body;
ASSERT_EQ(msg.body["term"].numberLong(), term) << msg.body;
ASSERT_BSONOBJ_EQ(msg.body["readConcern"].Obj(), readConcernObj);
cursor.setAwaitDataTimeoutMS(Milliseconds{5000});
ASSERT_EQ(cursor.getAwaitDataTimeoutMS(), Milliseconds{5000});
cursor.setCurrentTermAndLastCommittedOpTime(term, repl::OpTime(Timestamp(123, 4), term));
// --- Test 2 ---
// Create a 'getMore' response with two documents and set it as the mock response.
cursor.setBatchSize(2);
auto getMoreResponseMsg = mockGetMoreResponse(nss, cursorId, {docObj(1), docObj(2)});
conn.setCallResponse(getMoreResponseMsg);
// Request more results. This call should trigger the first 'getMore' request.
conn.clearLastSentMessage();
ASSERT_TRUE(cursor.more());
m = conn.getLastSentMessage();
ASSERT_FALSE(m.empty());
msg = OpMsg::parse(m);
ASSERT_EQ(StringData(msg.body.firstElement().fieldName()), "getMore") << msg.body;
ASSERT_EQ(msg.body["getMore"].type(), BSONType::NumberLong) << msg.body;
ASSERT_EQ(msg.body["getMore"].numberLong(), cursorId) << msg.body;
// Make sure the correct awaitData timeout is sent.
ASSERT_EQ(msg.body["maxTimeMS"].number(), 5000) << msg.body;
// Make sure the correct term is sent.
ASSERT_EQ(msg.body["term"].numberLong(), term) << msg.body;
// Make sure the correct lastKnownCommittedOpTime is sent.
ASSERT_EQ(msg.body["lastKnownCommittedOpTime"]["ts"].timestamp(), Timestamp(123, 4))
<< msg.body;
ASSERT_EQ(msg.body["lastKnownCommittedOpTime"]["t"].numberLong(), term) << msg.body;
ASSERT_BSONOBJ_EQ(docObj(1), cursor.next());
ASSERT_BSONOBJ_EQ(docObj(2), cursor.next());
ASSERT_FALSE(cursor.moreInCurrentBatch());
ASSERT_FALSE(cursor.isDead());
}
} // namespace
} // namespace mongo
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