SERVER-50329 Make ChunkManager be passed by value everywhere

... instead of shared_ptr.

15 files changed, 48 insertions, 56 deletions

diff --git a/src/mongo/db/s/balancer/balancer.cpp b/src/mongo/db/s/balancer/balancer.cpp
index d7b6dc884bc..d91670c60d8 100644
--- a/src/mongo/db/s/balancer/balancer.cpp
+++ b/src/mongo/db/s/balancer/balancer.cpp
@@ -703,8 +703,7 @@ void Balancer::_splitOrMarkJumbo(OperationContext* opCtx,
                                  const BSONObj& minKey) {
     auto routingInfo = uassertStatusOK(
         Grid::get(opCtx)->catalogCache()->getShardedCollectionRoutingInfoWithRefresh(opCtx, nss));
-    const auto cm = routingInfo.cm().get();
-
+    const auto cm = routingInfo.cm();
     auto chunk = cm->findIntersectingChunkWithSimpleCollation(minKey);
 
     try {
diff --git a/src/mongo/db/s/balancer/balancer_chunk_selection_policy_impl.cpp b/src/mongo/db/s/balancer/balancer_chunk_selection_policy_impl.cpp
index 61cf7e2525c..e41e0f977f1 100644
--- a/src/mongo/db/s/balancer/balancer_chunk_selection_policy_impl.cpp
+++ b/src/mongo/db/s/balancer/balancer_chunk_selection_policy_impl.cpp
@@ -65,7 +65,7 @@ namespace {
  * distribution and chunk placement information which is needed by the balancer policy.
  */
 StatusWith<DistributionStatus> createCollectionDistributionStatus(
-    OperationContext* opCtx, const ShardStatisticsVector& allShards, ChunkManager* chunkMgr) {
+    OperationContext* opCtx, const ShardStatisticsVector& allShards, const ChunkManager& chunkMgr) {
     ShardToChunksMap shardToChunksMap;
 
     // Makes sure there is an entry in shardToChunksMap for every shard, so empty shards will also
@@ -74,9 +74,9 @@ StatusWith<DistributionStatus> createCollectionDistributionStatus(
         shardToChunksMap[stat.shardId];
     }
 
-    chunkMgr->forEachChunk([&](const auto& chunkEntry) {
+    chunkMgr.forEachChunk([&](const auto& chunkEntry) {
         ChunkType chunk;
-        chunk.setNS(chunkMgr->getns());
+        chunk.setNS(chunkMgr.getns());
         chunk.setMin(chunkEntry.getMin());
         chunk.setMax(chunkEntry.getMax());
         chunk.setJumbo(chunkEntry.isJumbo());
@@ -89,17 +89,17 @@ StatusWith<DistributionStatus> createCollectionDistributionStatus(
     });
 
     const auto swCollectionTags =
-        Grid::get(opCtx)->catalogClient()->getTagsForCollection(opCtx, chunkMgr->getns());
+        Grid::get(opCtx)->catalogClient()->getTagsForCollection(opCtx, chunkMgr.getns());
     if (!swCollectionTags.isOK()) {
         return swCollectionTags.getStatus().withContext(
-            str::stream() << "Unable to load tags for collection " << chunkMgr->getns().ns());
+            str::stream() << "Unable to load tags for collection " << chunkMgr.getns());
     }
     const auto& collectionTags = swCollectionTags.getValue();
 
-    DistributionStatus distribution(chunkMgr->getns(), std::move(shardToChunksMap));
+    DistributionStatus distribution(chunkMgr.getns(), std::move(shardToChunksMap));
 
     // Cache the collection tags
-    const auto& keyPattern = chunkMgr->getShardKeyPattern().getKeyPattern();
+    const auto& keyPattern = chunkMgr.getShardKeyPattern().getKeyPattern();
 
     for (const auto& tag : collectionTags) {
         auto status = distribution.addRangeToZone(
@@ -465,9 +465,9 @@ BalancerChunkSelectionPolicyImpl::selectSpecificChunkToMove(OperationContext* op
         return routingInfoStatus.getStatus();
     }
 
-    const auto cm = routingInfoStatus.getValue().cm().get();
+    const auto cm = routingInfoStatus.getValue().cm();
 
-    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, cm);
+    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, *cm);
     if (!collInfoStatus.isOK()) {
         return collInfoStatus.getStatus();
     }
@@ -494,9 +494,9 @@ Status BalancerChunkSelectionPolicyImpl::checkMoveAllowed(OperationContext* opCt
         return routingInfoStatus.getStatus();
     }
 
-    const auto cm = routingInfoStatus.getValue().cm().get();
+    const auto cm = routingInfoStatus.getValue().cm();
 
-    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, cm);
+    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, *cm);
     if (!collInfoStatus.isOK()) {
         return collInfoStatus.getStatus();
     }
@@ -527,9 +527,9 @@ StatusWith<SplitInfoVector> BalancerChunkSelectionPolicyImpl::_getSplitCandidate
         return routingInfoStatus.getStatus();
     }
 
-    const auto cm = routingInfoStatus.getValue().cm().get();
+    const auto cm = routingInfoStatus.getValue().cm();
 
-    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, cm);
+    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, *cm);
     if (!collInfoStatus.isOK()) {
         return collInfoStatus.getStatus();
     }
@@ -565,11 +565,11 @@ StatusWith<MigrateInfoVector> BalancerChunkSelectionPolicyImpl::_getMigrateCandi
         return routingInfoStatus.getStatus();
     }
 
-    const auto cm = routingInfoStatus.getValue().cm().get();
+    const auto cm = routingInfoStatus.getValue().cm();
 
     const auto& shardKeyPattern = cm->getShardKeyPattern().getKeyPattern();
 
-    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, cm);
+    const auto collInfoStatus = createCollectionDistributionStatus(opCtx, shardStats, *cm);
     if (!collInfoStatus.isOK()) {
         return collInfoStatus.getStatus();
     }
diff --git a/src/mongo/db/s/collection_metadata.cpp b/src/mongo/db/s/collection_metadata.cpp
index 984fa6a1059..ccb0a5a4050 100644
--- a/src/mongo/db/s/collection_metadata.cpp
+++ b/src/mongo/db/s/collection_metadata.cpp
@@ -33,8 +33,6 @@
 
 #include "mongo/db/s/collection_metadata.h"
 
-#include <memory>
-
 #include "mongo/bson/simple_bsonobj_comparator.h"
 #include "mongo/bson/util/builder.h"
 #include "mongo/db/bson/dotted_path_support.h"
@@ -43,7 +41,7 @@
 
 namespace mongo {
 
-CollectionMetadata::CollectionMetadata(std::shared_ptr<ChunkManager> cm, const ShardId& thisShardId)
+CollectionMetadata::CollectionMetadata(ChunkManager cm, const ShardId& thisShardId)
     : _cm(std::move(cm)), _thisShardId(thisShardId) {}
 
 BSONObj CollectionMetadata::extractDocumentKey(const BSONObj& doc) const {
diff --git a/src/mongo/db/s/collection_metadata.h b/src/mongo/db/s/collection_metadata.h
index 792dbb208b0..5ac597eaa95 100644
--- a/src/mongo/db/s/collection_metadata.h
+++ b/src/mongo/db/s/collection_metadata.h
@@ -60,7 +60,7 @@ public:
      * "thisShardId" is the shard identity of this shard for purposes of answering questions like
      * "does this key belong to this shard"?
      */
-    CollectionMetadata(std::shared_ptr<ChunkManager> cm, const ShardId& thisShardId);
+    CollectionMetadata(ChunkManager cm, const ShardId& thisShardId);
 
     /**
      * Returns whether this metadata object represents a sharded or unsharded collection.
@@ -158,9 +158,9 @@ public:
     // Methods used for orphan filtering and general introspection of the chunks owned by the shard
     //
 
-    ChunkManager* getChunkManager() const {
+    const ChunkManager* getChunkManager() const {
         invariant(isSharded());
-        return _cm.get();
+        return _cm.get_ptr();
     }
 
     /**
@@ -225,11 +225,11 @@ public:
     void toBSONChunks(BSONArrayBuilder* builder) const;
 
 private:
-    // The full routing table for the collection or nullptr if the collection is not sharded
-    std::shared_ptr<ChunkManager> _cm;
+    // The full routing table for the collection or boost::none if the collection is not sharded
+    boost::optional<ChunkManager> _cm;
 
     // The identity of this shard, for the purpose of answering "key belongs to me" queries. If the
-    // collection is not sharded (_cm is nullptr), then this value will be empty.
+    // collection is not sharded (_cm is boost::none), then this value will be empty.
     ShardId _thisShardId;
 };
 
diff --git a/src/mongo/db/s/collection_metadata_filtering_test.cpp b/src/mongo/db/s/collection_metadata_filtering_test.cpp
index ebb0d564bea..c275530b384 100644
--- a/src/mongo/db/s/collection_metadata_filtering_test.cpp
+++ b/src/mongo/db/s/collection_metadata_filtering_test.cpp
@@ -96,8 +96,8 @@ protected:
                 return std::vector<ChunkType>{chunk1, chunk2, chunk3, chunk4};
             }());
 
-        auto cm = std::make_shared<ChunkManager>(rt, boost::none);
-        ASSERT_EQ(4, cm->numChunks());
+        ChunkManager cm(rt, boost::none);
+        ASSERT_EQ(4, cm.numChunks());
 
         {
             AutoGetCollection autoColl(operationContext(), kNss, MODE_X);
@@ -109,7 +109,7 @@ protected:
             getServiceContext(), kNss, executor(), CollectionMetadata(cm, ShardId("0")));
 
         auto& oss = OperationShardingState::get(operationContext());
-        const auto version = cm->getVersion(ShardId("0"));
+        const auto version = cm.getVersion(ShardId("0"));
         BSONObjBuilder builder;
         version.appendToCommand(&builder);
         oss.initializeClientRoutingVersionsFromCommand(kNss, builder.obj());
diff --git a/src/mongo/db/s/collection_metadata_test.cpp b/src/mongo/db/s/collection_metadata_test.cpp
index 035bd4777f8..eaa5d5bcf79 100644
--- a/src/mongo/db/s/collection_metadata_test.cpp
+++ b/src/mongo/db/s/collection_metadata_test.cpp
@@ -82,8 +82,7 @@ std::unique_ptr<CollectionMetadata> makeCollectionMetadataImpl(
     UUID uuid(UUID::gen());
     auto rt =
         RoutingTableHistory::makeNew(kNss, uuid, shardKeyPattern, nullptr, false, epoch, allChunks);
-    std::shared_ptr<ChunkManager> cm = std::make_shared<ChunkManager>(rt, kChunkManager);
-    return std::make_unique<CollectionMetadata>(cm, kThisShard);
+    return std::make_unique<CollectionMetadata>(ChunkManager(rt, kChunkManager), kThisShard);
 }
 
 struct ConstructedRangeMap : public RangeMap {
diff --git a/src/mongo/db/s/collection_sharding_runtime_test.cpp b/src/mongo/db/s/collection_sharding_runtime_test.cpp
index 71ea4afab44..58415ae97eb 100644
--- a/src/mongo/db/s/collection_sharding_runtime_test.cpp
+++ b/src/mongo/db/s/collection_sharding_runtime_test.cpp
@@ -51,12 +51,13 @@ CollectionMetadata makeShardedMetadata(OperationContext* opCtx, UUID uuid = UUID
     const OID epoch = OID::gen();
     auto range = ChunkRange(BSON(kShardKey << MINKEY), BSON(kShardKey << MAXKEY));
     auto chunk = ChunkType(kTestNss, std::move(range), ChunkVersion(1, 0, epoch), ShardId("other"));
-    auto rt = RoutingTableHistory::makeNew(
-        kTestNss, uuid, kShardKeyPattern, nullptr, false, epoch, {std::move(chunk)});
-    std::shared_ptr<ChunkManager> cm = std::make_shared<ChunkManager>(rt, boost::none);
+    ChunkManager cm(
+        RoutingTableHistory::makeNew(
+            kTestNss, uuid, kShardKeyPattern, nullptr, false, epoch, {std::move(chunk)}),
+        boost::none);
 
     if (!OperationShardingState::isOperationVersioned(opCtx)) {
-        const auto version = cm->getVersion(ShardId("0"));
+        const auto version = cm.getVersion(ShardId("0"));
         BSONObjBuilder builder;
         version.appendToCommand(&builder);
 
diff --git a/src/mongo/db/s/metadata_manager.cpp b/src/mongo/db/s/metadata_manager.cpp
index feb943e2462..7f83dfaca1d 100644
--- a/src/mongo/db/s/metadata_manager.cpp
+++ b/src/mongo/db/s/metadata_manager.cpp
@@ -137,8 +137,8 @@ std::shared_ptr<ScopedCollectionDescription::Impl> MetadataManager::getActiveMet
     }
 
     auto chunkManager = activeMetadata->getChunkManager();
-    auto chunkManagerAtClusterTime = std::make_shared<ChunkManager>(
-        chunkManager->getRoutingHistory(), atClusterTime->asTimestamp());
+    ChunkManager chunkManagerAtClusterTime =
+        ChunkManager(chunkManager->getRoutingHistory(), atClusterTime->asTimestamp());
 
     class MetadataAtTimestamp : public ScopedCollectionDescription::Impl {
     public:
diff --git a/src/mongo/db/s/metadata_manager_test.cpp b/src/mongo/db/s/metadata_manager_test.cpp
index e2693e9de1a..6ec878a9bc1 100644
--- a/src/mongo/db/s/metadata_manager_test.cpp
+++ b/src/mongo/db/s/metadata_manager_test.cpp
@@ -87,9 +87,7 @@ protected:
             epoch,
             {ChunkType{kNss, range, ChunkVersion(1, 0, epoch), kOtherShard}});
 
-        std::shared_ptr<ChunkManager> cm = std::make_shared<ChunkManager>(rt, boost::none);
-
-        return CollectionMetadata(cm, kThisShard);
+        return CollectionMetadata(ChunkManager(rt, boost::none), kThisShard);
     }
 
     /**
@@ -131,7 +129,7 @@ protected:
 
         auto rt = cm->getRoutingHistory()->makeUpdated(splitChunks);
 
-        return CollectionMetadata(std::make_shared<ChunkManager>(rt, boost::none), kThisShard);
+        return CollectionMetadata(ChunkManager(rt, boost::none), kThisShard);
     }
 
     static CollectionMetadata cloneMetadataMinusChunk(const CollectionMetadata& metadata,
@@ -152,7 +150,7 @@ protected:
         auto rt = cm->getRoutingHistory()->makeUpdated(
             {ChunkType(kNss, ChunkRange(minKey, maxKey), chunkVersion, kOtherShard)});
 
-        return CollectionMetadata(std::make_shared<ChunkManager>(rt, boost::none), kThisShard);
+        return CollectionMetadata(ChunkManager(rt, boost::none), kThisShard);
     }
 
     std::shared_ptr<MetadataManager> _manager;
diff --git a/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp b/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp
index 446b5984c68..7d8b0d1c6f3 100644
--- a/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp
+++ b/src/mongo/db/s/migration_chunk_cloner_source_legacy_test.cpp
@@ -159,13 +159,12 @@ protected:
                            ChunkVersion(1, 0, epoch),
                            ShardId("dummyShardId")}});
 
-            std::shared_ptr<ChunkManager> cm = std::make_shared<ChunkManager>(rt, boost::none);
-
             AutoGetDb autoDb(operationContext(), kNss.db(), MODE_IX);
             Lock::CollectionLock collLock(operationContext(), kNss, MODE_IX);
             CollectionShardingRuntime::get(operationContext(), kNss)
-                ->setFilteringMetadata(operationContext(),
-                                       CollectionMetadata(cm, ShardId("dummyShardId")));
+                ->setFilteringMetadata(
+                    operationContext(),
+                    CollectionMetadata(ChunkManager(rt, boost::none), ShardId("dummyShardId")));
         }();
 
         _client->createIndex(kNss.ns(), kShardKeyPattern);
diff --git a/src/mongo/db/s/op_observer_sharding_test.cpp b/src/mongo/db/s/op_observer_sharding_test.cpp
index 4c328b6936f..0d8597e9e98 100644
--- a/src/mongo/db/s/op_observer_sharding_test.cpp
+++ b/src/mongo/db/s/op_observer_sharding_test.cpp
@@ -65,9 +65,8 @@ CollectionMetadata makeAMetadata(BSONObj const& keyPattern) {
     auto chunk = ChunkType(kTestNss, std::move(range), ChunkVersion(1, 0, epoch), ShardId("other"));
     auto rt = RoutingTableHistory::makeNew(
         kTestNss, UUID::gen(), KeyPattern(keyPattern), nullptr, false, epoch, {std::move(chunk)});
-    std::shared_ptr<ChunkManager> cm = std::make_shared<ChunkManager>(rt, Timestamp(100, 0));
 
-    return CollectionMetadata(std::move(cm), ShardId("this"));
+    return CollectionMetadata(ChunkManager(rt, Timestamp(100, 0)), ShardId("this"));
 }
 
 class DeleteStateTest : public ShardServerTestFixture {};
diff --git a/src/mongo/db/s/range_deletion_util_test.cpp b/src/mongo/db/s/range_deletion_util_test.cpp
index b4a80b9a25d..a8bdd46cf56 100644
--- a/src/mongo/db/s/range_deletion_util_test.cpp
+++ b/src/mongo/db/s/range_deletion_util_test.cpp
@@ -101,13 +101,12 @@ public:
                        ChunkVersion(1, 0, epoch),
                        ShardId("dummyShardId")}});
 
-        std::shared_ptr<ChunkManager> cm = std::make_shared<ChunkManager>(rt, boost::none);
-
         AutoGetDb autoDb(operationContext(), kNss.db(), MODE_IX);
         Lock::CollectionLock collLock(operationContext(), kNss, MODE_IX);
         CollectionShardingRuntime::get(operationContext(), kNss)
-            ->setFilteringMetadata(operationContext(),
-                                   CollectionMetadata(cm, ShardId("dummyShardId")));
+            ->setFilteringMetadata(
+                operationContext(),
+                CollectionMetadata(ChunkManager(rt, boost::none), ShardId("dummyShardId")));
     }
 
     UUID uuid() const {
diff --git a/src/mongo/db/s/shard_filtering_metadata_refresh.cpp b/src/mongo/db/s/shard_filtering_metadata_refresh.cpp
index ac01d337e6c..d7115e5b294 100644
--- a/src/mongo/db/s/shard_filtering_metadata_refresh.cpp
+++ b/src/mongo/db/s/shard_filtering_metadata_refresh.cpp
@@ -328,7 +328,7 @@ CollectionMetadata forceGetCurrentMetadata(OperationContext* opCtx, const Namesp
         return CollectionMetadata();
     }
 
-    return CollectionMetadata(routingInfo.cm(), shardingState->shardId());
+    return CollectionMetadata(*routingInfo.cm(), shardingState->shardId());
 }
 
 ChunkVersion forceShardFilteringMetadataRefresh(OperationContext* opCtx,
@@ -421,7 +421,7 @@ ChunkVersion forceShardFilteringMetadataRefresh(OperationContext* opCtx,
         }
     }
 
-    CollectionMetadata metadata(std::move(cm), shardingState->shardId());
+    CollectionMetadata metadata(*cm, shardingState->shardId());
     const auto newShardVersion = metadata.getShardVersion();
 
     csr->setFilteringMetadata(opCtx, std::move(metadata));
diff --git a/src/mongo/db/s/shard_key_util.cpp b/src/mongo/db/s/shard_key_util.cpp
index 7bbeed2614d..2cae3071624 100644
--- a/src/mongo/db/s/shard_key_util.cpp
+++ b/src/mongo/db/s/shard_key_util.cpp
@@ -240,7 +240,7 @@ ValidationBehaviorsRefineShardKey::ValidationBehaviorsRefineShardKey(OperationCo
     const auto minKeyShardId = routingInfo.cm()->getMinKeyShardIdWithSimpleCollation();
     _indexShard =
         uassertStatusOK(Grid::get(opCtx)->shardRegistry()->getShard(opCtx, minKeyShardId));
-    _cm = routingInfo.cm();
+    _cm.emplace(*routingInfo.cm());
 }
 
 std::vector<BSONObj> ValidationBehaviorsRefineShardKey::loadIndexes(
diff --git a/src/mongo/db/s/shard_key_util.h b/src/mongo/db/s/shard_key_util.h
index 494ef5bce04..d6e1802549c 100644
--- a/src/mongo/db/s/shard_key_util.h
+++ b/src/mongo/db/s/shard_key_util.h
@@ -105,7 +105,7 @@ public:
 private:
     OperationContext* _opCtx;
     std::shared_ptr<Shard> _indexShard;
-    std::shared_ptr<ChunkManager> _cm;
+    boost::optional<ChunkManager> _cm;
 };
 
 /**