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author | Charlie Swanson <charlie.swanson@mongodb.com> | 2018-02-14 15:48:53 -0500 |
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committer | Charlie Swanson <charlie.swanson@mongodb.com> | 2018-03-06 12:18:27 -0500 |
commit | a7106b407cecdcfa8ba6c8765c9874bce65a6d5a (patch) | |
tree | ae17d3d93617f04af362627bd656ecd82e67840a /src/mongo/db/pipeline/document_source_merge_cursors_test.cpp | |
parent | 29be917dd176b883880198347d872fa10d1ad701 (diff) | |
download | mongo-a7106b407cecdcfa8ba6c8765c9874bce65a6d5a.tar.gz |
SERVER-24978 Use AsyncResultsMerger in $mergeCursors
Diffstat (limited to 'src/mongo/db/pipeline/document_source_merge_cursors_test.cpp')
-rw-r--r-- | src/mongo/db/pipeline/document_source_merge_cursors_test.cpp | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/document_source_merge_cursors_test.cpp b/src/mongo/db/pipeline/document_source_merge_cursors_test.cpp new file mode 100644 index 00000000000..8007aea0db0 --- /dev/null +++ b/src/mongo/db/pipeline/document_source_merge_cursors_test.cpp @@ -0,0 +1,488 @@ +/** + * Copyright (C) 2018 MongoDB Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License, version 3, + * as published by the Free Software Foundation. + * + * 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 + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * 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 GNU Affero General 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. + */ + +#include "mongo/platform/basic.h" + +#include "mongo/db/pipeline/document_source_merge_cursors.h" + +#include "mongo/client/remote_command_targeter_factory_mock.h" +#include "mongo/client/remote_command_targeter_mock.h" +#include "mongo/db/json.h" +#include "mongo/db/pipeline/aggregation_context_fixture.h" +#include "mongo/db/pipeline/document_source_limit.h" +#include "mongo/db/pipeline/document_source_sort.h" +#include "mongo/db/pipeline/document_value_test_util.h" +#include "mongo/db/pipeline/expression_context_for_test.h" +#include "mongo/db/query/cursor_response.h" +#include "mongo/db/query/getmore_request.h" +#include "mongo/db/query/query_request.h" +#include "mongo/executor/network_interface_mock.h" +#include "mongo/executor/task_executor.h" +#include "mongo/executor/thread_pool_task_executor_test_fixture.h" +#include "mongo/s/catalog/type_shard.h" +#include "mongo/s/client/shard_registry.h" +#include "mongo/s/sharding_test_fixture.h" +#include "mongo/stdx/memory.h" +#include "mongo/stdx/thread.h" +#include "mongo/unittest/unittest.h" + +namespace mongo { +namespace { + +using executor::NetworkInterfaceMock; +using executor::RemoteCommandRequest; +using executor::RemoteCommandResponse; + +using ResponseStatus = executor::TaskExecutor::ResponseStatus; + +const HostAndPort kTestConfigShardHost = HostAndPort("FakeConfigHost", 12345); +const std::vector<ShardId> kTestShardIds = { + ShardId("FakeShard1"), ShardId("FakeShard2"), ShardId("FakeShard3")}; +const std::vector<HostAndPort> kTestShardHosts = {HostAndPort("FakeShard1Host", 12345), + HostAndPort("FakeShard2Host", 12345), + HostAndPort("FakeShard3Host", 12345)}; + +const NamespaceString kTestNss = NamespaceString("test.mergeCursors"_sd); +const HostAndPort kTestHost = HostAndPort("localhost:27017"_sd); + +const CursorId kExhaustedCursorID = 0; + +class DocumentSourceMergeCursorsTest : public ShardingTestFixture { +public: + DocumentSourceMergeCursorsTest() : _expCtx(new ExpressionContextForTest(kTestNss)) {} + + void setUp() override { + ShardingTestFixture::setUp(); + setRemote(HostAndPort("ClientHost", 12345)); + + configTargeter()->setFindHostReturnValue(kTestConfigShardHost); + + std::vector<ShardType> shards; + for (size_t i = 0; i < kTestShardIds.size(); i++) { + ShardType shardType; + shardType.setName(kTestShardIds[i].toString()); + shardType.setHost(kTestShardHosts[i].toString()); + + shards.push_back(shardType); + + std::unique_ptr<RemoteCommandTargeterMock> targeter( + stdx::make_unique<RemoteCommandTargeterMock>()); + targeter->setConnectionStringReturnValue(ConnectionString(kTestShardHosts[i])); + targeter->setFindHostReturnValue(kTestShardHosts[i]); + + targeterFactory()->addTargeterToReturn(ConnectionString(kTestShardHosts[i]), + std::move(targeter)); + } + + setupShards(shards); + } + + boost::intrusive_ptr<ExpressionContextForTest> getExpCtx() { + return _expCtx.get(); + } + +private: + boost::intrusive_ptr<ExpressionContextForTest> _expCtx; +}; + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectNonArray) { + auto spec = BSON("$mergeCursors" << BSON( + "cursors" << BSON_ARRAY(BSON("ns" << kTestNss.ns() << "id" << 0LL << "host" + << kTestHost.toString())))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 17026); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectEmptyArray) { + auto spec = BSON("$mergeCursors" << BSONArray()); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50729); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorWithNoNamespace) { + auto spec = + BSON("$mergeCursors" << BSON_ARRAY(BSON("id" << 0LL << "host" << kTestHost.toString()))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50731); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorWithNonStringNamespace) { + auto spec = BSON("$mergeCursors" << BSON_ARRAY( + BSON("ns" << 4 << "id" << 0LL << "host" << kTestHost.toString()))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50731); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorsWithDifferentNamespaces) { + auto spec = BSON( + "$mergeCursors" + << BSON_ARRAY(BSON("ns" << kTestNss.ns() << "id" << 0LL << "host" << kTestHost.toString()) + << BSON("ns" + << "test.other"_sd + << "id" + << 0LL + << "host" + << kTestHost.toString()))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50720); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorWithNoHost) { + auto spec = BSON("$mergeCursors" << BSON_ARRAY(BSON("ns" << kTestNss.ns() << "id" << 0LL))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50721); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorWithNonStringHost) { + auto spec = BSON("$mergeCursors" + << BSON_ARRAY(BSON("ns" << kTestNss.ns() << "id" << 0LL << "host" << 4LL))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50721); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorWithNonLongId) { + auto spec = BSON("$mergeCursors" << BSON_ARRAY(BSON("ns" << kTestNss.ns() << "id" + << "zero" + << "host" + << kTestHost.toString()))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50722); + spec = BSON("$mergeCursors" << BSON_ARRAY( + BSON("ns" << kTestNss.ns() << "id" << 0 << "host" << kTestHost.toString()))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50722); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldRejectCursorWithExtraField) { + auto spec = + BSON("$mergeCursors" << BSON_ARRAY(BSON( + "ns" << kTestNss.ns() << "id" << 0LL << "host" << kTestHost.toString() << "extra" + << "unexpected"))); + ASSERT_THROWS_CODE(DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()), + AssertionException, + 50730); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldBeAbleToParseTheSerializedVersionOfItself) { + auto spec = + BSON("$mergeCursors" << BSON_ARRAY( + BSON("ns" << kTestNss.ns() << "id" << 1LL << "host" << kTestHost.toString()) + << BSON("ns" << kTestNss.ns() << "id" << 2LL << "host" << kTestHost.toString()))); + auto mergeCursors = + DocumentSourceMergeCursors::createFromBson(spec.firstElement(), getExpCtx()); + std::vector<Value> serializationArray; + mergeCursors->serializeToArray(serializationArray); + ASSERT_EQ(serializationArray.size(), 1UL); + // The serialized version might not be identical to 'spec', the fields might be in a different + // order, etc. Here we just make sure that the final parse doesn't throw. + auto newSpec = serializationArray[0].getDocument().toBson(); + ASSERT(DocumentSourceMergeCursors::createFromBson(newSpec.firstElement(), getExpCtx())); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldReportEOFWithNoCursors) { + auto expCtx = getExpCtx(); + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back( + kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, kExhaustedCursorID, {})); + cursors.emplace_back( + kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, kExhaustedCursorID, {})); + auto pipeline = uassertStatusOK(Pipeline::create({}, expCtx)); + auto mergeCursorsStage = + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx); + + ASSERT_TRUE(mergeCursorsStage->getNext().isEOF()); +} + +BSONObj cursorResponseObj(const NamespaceString& nss, + CursorId cursorId, + std::vector<BSONObj> batch) { + return CursorResponse{nss, cursorId, std::move(batch)}.toBSON( + CursorResponse::ResponseType::SubsequentResponse); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldBeAbleToIterateCursorsUntilEOF) { + auto expCtx = getExpCtx(); + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back(kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, 1, {})); + cursors.emplace_back(kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, 2, {})); + auto pipeline = uassertStatusOK(Pipeline::create({}, expCtx)); + pipeline->addInitialSource( + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx)); + + // Iterate the $mergeCursors stage asynchronously on a different thread, since it will block + // waiting for network responses, which we will manually schedule below. + auto future = launchAsync([&pipeline]() { + for (int i = 0; i < 5; ++i) { + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", 1}})); + } + ASSERT_FALSE(static_cast<bool>(pipeline->getNext())); + }); + + + // Schedule responses to two getMores which keep the cursor open. + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["getMore"]); + return cursorResponseObj( + expCtx->ns, request.cmdObj["getMore"].Long(), {BSON("x" << 1), BSON("x" << 1)}); + }); + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["getMore"]); + return cursorResponseObj( + expCtx->ns, request.cmdObj["getMore"].Long(), {BSON("x" << 1), BSON("x" << 1)}); + }); + + // Schedule responses to two getMores which report the cursor is exhausted. + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["getMore"]); + return cursorResponseObj(expCtx->ns, kExhaustedCursorID, {}); + }); + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["getMore"]); + return cursorResponseObj(expCtx->ns, kExhaustedCursorID, {BSON("x" << 1)}); + }); + + future.timed_get(kFutureTimeout); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldNotKillCursorsIfNeverIterated) { + auto expCtx = getExpCtx(); + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back(kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, 1, {})); + cursors.emplace_back(kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, 2, {})); + auto pipeline = uassertStatusOK(Pipeline::create({}, expCtx)); + pipeline->addInitialSource( + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx)); + + pipeline.reset(); // Delete the pipeline before using it. + + network()->enterNetwork(); + ASSERT_FALSE(network()->hasReadyRequests()); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldKillCursorsIfPartiallyIterated) { + auto expCtx = getExpCtx(); + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back(kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, 1, {})); + cursors.emplace_back(kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, 2, {})); + auto pipeline = uassertStatusOK(Pipeline::create({}, expCtx)); + pipeline->addInitialSource( + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx)); + + // Iterate the pipeline asynchronously on a different thread, since it will block waiting for + // network responses, which we will manually schedule below. + auto future = launchAsync([&pipeline]() { + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", 1}})); + pipeline.reset(); // Stop iterating and delete the pipeline. + }); + + // Note we do not use 'kExhaustedCursorID' here, so the cursors are still open. + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["getMore"]); + return cursorResponseObj(expCtx->ns, 1, {BSON("x" << 1), BSON("x" << 1)}); + }); + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["getMore"]); + return cursorResponseObj(expCtx->ns, 2, {BSON("x" << 1), BSON("x" << 1)}); + }); + + // Here we're looking for the killCursors requests to be scheduled. + std::set<CursorId> killedCursors; + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["killCursors"]); + auto cursors = request.cmdObj["cursors"]; + ASSERT_EQ(cursors.type(), BSONType::Array); + auto cursorsArray = cursors.Array(); + ASSERT_FALSE(cursorsArray.empty()); + auto cursorId = cursorsArray[0].Long(); + ASSERT(cursorId == 1 || cursorId == 2); + killedCursors.insert(cursorId); + // The ARM doesn't actually inspect the response of the killCursors, so we don't have to put + // anything except {ok: 1}. + return BSON("ok" << 1); + }); + onCommand([&](const auto& request) { + ASSERT(request.cmdObj["killCursors"]); + auto cursors = request.cmdObj["cursors"]; + ASSERT_EQ(cursors.type(), BSONType::Array); + auto cursorsArray = cursors.Array(); + ASSERT_FALSE(cursorsArray.empty()); + auto cursorId = cursorsArray[0].Long(); + ASSERT(cursorId == 1 || cursorId == 2); + killedCursors.insert(cursorId); + // The ARM doesn't actually inspect the response of the killCursors, so we don't have to put + // anything except {ok: 1}. + return BSON("ok" << 1); + }); + + future.timed_get(kFutureTimeout); + ASSERT_EQ(killedCursors.size(), 2UL); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldOptimizeWithASortToEnsureCorrectOrder) { + auto expCtx = getExpCtx(); + + // Make a pipeline with a single $sort stage that is merging pre-sorted results. + const bool mergingPresorted = true; + const long long noLimit = -1; + auto sortStage = DocumentSourceSort::create(expCtx, + BSON("x" << 1), + noLimit, + DocumentSourceSort::kMaxMemoryUsageBytes, + mergingPresorted); + auto pipeline = uassertStatusOK(Pipeline::create({std::move(sortStage)}, expCtx)); + + // Make a $mergeCursors stage and add it to the front of the pipeline. + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back(kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, 1, {})); + cursors.emplace_back(kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, 2, {})); + auto mergeCursorsStage = + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx); + pipeline->addInitialSource(std::move(mergeCursorsStage)); + + // After optimization we should only have a $mergeCursors stage. + pipeline->optimizePipeline(); + ASSERT_EQ(pipeline->getSources().size(), 1UL); + ASSERT_TRUE(dynamic_cast<DocumentSourceMergeCursors*>(pipeline->getSources().front().get())); + + // Iterate the pipeline asynchronously on a different thread, since it will block waiting for + // network responses, which we will manually schedule below. + auto future = launchAsync([&pipeline]() { + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", 1}})); + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", 2}})); + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", 3}})); + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", 4}})); + ASSERT_FALSE(static_cast<bool>(pipeline->getNext())); + }); + + onCommand([&](const auto& request) { + return cursorResponseObj(expCtx->ns, + kExhaustedCursorID, + {BSON("x" << 1 << "$sortKey" << BSON("" << 1)), + BSON("x" << 3 << "$sortKey" << BSON("" << 3))}); + }); + onCommand([&](const auto& request) { + return cursorResponseObj(expCtx->ns, + kExhaustedCursorID, + {BSON("x" << 2 << "$sortKey" << BSON("" << 2)), + BSON("x" << 4 << "$sortKey" << BSON("" << 4))}); + }); + + future.timed_get(kFutureTimeout); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldNotRemoveLimitWhenOptimizingWithLeadingSort) { + auto expCtx = getExpCtx(); + + // Make a pipeline with a single $sort stage that is merging pre-sorted results. + const bool mergingPresorted = true; + const long long limit = 3; + auto sortStage = DocumentSourceSort::create( + expCtx, BSON("x" << 1), limit, DocumentSourceSort::kMaxMemoryUsageBytes, mergingPresorted); + auto pipeline = uassertStatusOK(Pipeline::create({std::move(sortStage)}, expCtx)); + + // Make a $mergeCursors stage and add it to the front of the pipeline. + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back(kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, 1, {})); + cursors.emplace_back(kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, 2, {})); + auto mergeCursorsStage = + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx); + pipeline->addInitialSource(std::move(mergeCursorsStage)); + + // After optimization, we should still have a $limit stage. + pipeline->optimizePipeline(); + ASSERT_EQ(pipeline->getSources().size(), 2UL); + ASSERT_TRUE(dynamic_cast<DocumentSourceMergeCursors*>(pipeline->getSources().front().get())); + ASSERT_TRUE(dynamic_cast<DocumentSourceLimit*>(pipeline->getSources().back().get())); + + // Iterate the pipeline asynchronously on a different thread, since it will block waiting for + // network responses, which we will manually schedule below. + auto future = launchAsync([&]() { + for (int i = 1; i <= limit; ++i) { + ASSERT_DOCUMENT_EQ(*pipeline->getNext(), (Document{{"x", i}})); + } + ASSERT_FALSE(static_cast<bool>(pipeline->getNext())); + }); + + onCommand([&](const auto& request) { + return cursorResponseObj(expCtx->ns, + kExhaustedCursorID, + {BSON("x" << 1 << "$sortKey" << BSON("" << 1)), + BSON("x" << 3 << "$sortKey" << BSON("" << 3))}); + }); + onCommand([&](const auto& request) { + return cursorResponseObj(expCtx->ns, + kExhaustedCursorID, + {BSON("x" << 2 << "$sortKey" << BSON("" << 2)), + BSON("x" << 4 << "$sortKey" << BSON("" << 4))}); + }); + + future.timed_get(kFutureTimeout); +} + +TEST_F(DocumentSourceMergeCursorsTest, ShouldSerializeSortIfAbsorbedViaOptimize) { + auto expCtx = getExpCtx(); + + // Make a pipeline with a single $sort stage that is merging pre-sorted results. + const bool mergingPresorted = true; + const long long limit = 3; + auto sortStage = DocumentSourceSort::create( + expCtx, BSON("x" << 1), limit, DocumentSourceSort::kMaxMemoryUsageBytes, mergingPresorted); + auto pipeline = uassertStatusOK(Pipeline::create({std::move(sortStage)}, expCtx)); + + // Make a $mergeCursors stage and add it to the front of the pipeline. + std::vector<ClusterClientCursorParams::RemoteCursor> cursors; + cursors.emplace_back(kTestShardIds[0], kTestShardHosts[0], CursorResponse(expCtx->ns, 1, {})); + cursors.emplace_back(kTestShardIds[1], kTestShardHosts[1], CursorResponse(expCtx->ns, 2, {})); + auto mergeCursorsStage = + DocumentSourceMergeCursors::create(std::move(cursors), executor(), expCtx); + pipeline->addInitialSource(std::move(mergeCursorsStage)); + + // After optimization, we should still have a $limit stage. + pipeline->optimizePipeline(); + ASSERT_EQ(pipeline->getSources().size(), 2UL); + ASSERT_TRUE(dynamic_cast<DocumentSourceMergeCursors*>(pipeline->getSources().front().get())); + ASSERT_TRUE(dynamic_cast<DocumentSourceLimit*>(pipeline->getSources().back().get())); + + auto serialized = pipeline->serialize(); + ASSERT_EQ(serialized.size(), 3UL); + ASSERT_FALSE(serialized[0]["$mergeCursors"].missing()); + ASSERT_FALSE(serialized[1]["$sort"].missing()); + ASSERT_FALSE(serialized[2]["$limit"].missing()); +} + +} // namespace +} // namespace mongo |