SERVER-71644: Avoid parsing durable catalog entry when we only need to compare as BSON

8 files changed, 37 insertions, 17 deletions

diff --git a/src/mongo/db/catalog/collection.h b/src/mongo/db/catalog/collection.h
index 6e76150d554..75595c5fdaa 100644
--- a/src/mongo/db/catalog/collection.h
+++ b/src/mongo/db/catalog/collection.h
@@ -559,7 +559,7 @@ public:
     virtual void replaceMetadata(OperationContext* opCtx,
                                  std::shared_ptr<BSONCollectionCatalogEntry::MetaData> md) = 0;
 
-    virtual bool isMetadataEqual(const BSONCollectionCatalogEntry::MetaData& md) const = 0;
+    virtual bool isMetadataEqual(const BSONObj& otherMetadata) const = 0;
 
     /**
      * Specifies whether writes to this collection should X-lock the metadata resource. It is only
diff --git a/src/mongo/db/catalog/collection_catalog.cpp b/src/mongo/db/catalog/collection_catalog.cpp
index 2c936194ca6..28453d2c900 100644
--- a/src/mongo/db/catalog/collection_catalog.cpp
+++ b/src/mongo/db/catalog/collection_catalog.cpp
@@ -793,22 +793,27 @@ CollectionPtr CollectionCatalog::openCollection(OperationContext* opCtx,
             catalogId = lookupResult.id;
         }
 
-        auto catalogEntry = DurableCatalog::get(opCtx)->getParsedCatalogEntry(opCtx, catalogId);
-        if (!catalogEntry || nss != catalogEntry->metadata->nss) {
+        auto catalogEntry = DurableCatalog::get(opCtx)->getCatalogEntry(opCtx, catalogId);
+        if (catalogEntry.isEmpty() ||
+            nss != DurableCatalog::getNamespaceFromCatalogEntry(catalogEntry)) {
             return CollectionPtr();
         }
-        auto latestCollection = _lookupCollectionByUUID(*catalogEntry->metadata->options.uuid);
+
+        auto latestCollection = lookupCollectionByNamespaceForRead(opCtx, nss);
+        auto metadata = DurableCatalog::getMetadataFromCatalogEntry(catalogEntry);
 
         // Use the pendingCollection if there is no latestCollection or if the metadata of the
         // latestCollection doesn't match the durable catalogEntry.
-        if (!latestCollection || !latestCollection->isMetadataEqual(*catalogEntry->metadata)) {
-            invariant(pendingCollection->isMetadataEqual(*catalogEntry->metadata));
+        if (!latestCollection || !latestCollection->isMetadataEqual(metadata)) {
+            invariant(pendingCollection->isMetadataEqual(metadata));
             uncommittedCatalogUpdates.openCollection(opCtx, pendingCollection);
             return CollectionPtr(pendingCollection.get(), CollectionPtr::NoYieldTag{});
         }
 
-        invariant(latestCollection->isMetadataEqual(*catalogEntry->metadata));
-        uncommittedCatalogUpdates.openCollection(opCtx, latestCollection);
+        invariant(latestCollection->isMetadataEqual(metadata));
+        // TODO SERVER-71817 remove const cast
+        uncommittedCatalogUpdates.openCollection(
+            opCtx, std::const_pointer_cast<Collection>(latestCollection));
         return CollectionPtr(latestCollection.get(), CollectionPtr::NoYieldTag{});
     }
 
diff --git a/src/mongo/db/catalog/collection_catalog_test.cpp b/src/mongo/db/catalog/collection_catalog_test.cpp
index d701426fd8c..496bac3b10e 100644
--- a/src/mongo/db/catalog/collection_catalog_test.cpp
+++ b/src/mongo/db/catalog/collection_catalog_test.cpp
@@ -1204,9 +1204,10 @@ private:
             ASSERT_EQ(coll->getIndexCatalog()->numIndexesTotal(), expectedNumIndexes);
 
             auto catalogEntry =
-                DurableCatalog::get(opCtx)->getParsedCatalogEntry(opCtx, coll->getCatalogId());
-            ASSERT(catalogEntry);
-            ASSERT(coll->isMetadataEqual(*catalogEntry->metadata.get()));
+                DurableCatalog::get(opCtx)->getCatalogEntry(opCtx, coll->getCatalogId());
+            ASSERT(!catalogEntry.isEmpty());
+            ASSERT(
+                coll->isMetadataEqual(DurableCatalog::getMetadataFromCatalogEntry(catalogEntry)));
         } else {
             ASSERT(!coll);
             auto catalogEntry = DurableCatalog::get(opCtx)->scanForCatalogEntryByNss(opCtx, nss);
diff --git a/src/mongo/db/catalog/collection_impl.cpp b/src/mongo/db/catalog/collection_impl.cpp
index 22e78c3e8c4..c5d39ff8723 100644
--- a/src/mongo/db/catalog/collection_impl.cpp
+++ b/src/mongo/db/catalog/collection_impl.cpp
@@ -1771,9 +1771,8 @@ void CollectionImpl::replaceMetadata(OperationContext* opCtx,
     _metadata = std::move(md);
 }
 
-bool CollectionImpl::isMetadataEqual(
-    const BSONCollectionCatalogEntry::MetaData& otherMetadata) const {
-    return !_metadata->toBSON().woCompare(otherMetadata.toBSON());
+bool CollectionImpl::isMetadataEqual(const BSONObj& otherMetadata) const {
+    return !_metadata->toBSON().woCompare(otherMetadata);
 }
 
 template <typename Func>
diff --git a/src/mongo/db/catalog/collection_impl.h b/src/mongo/db/catalog/collection_impl.h
index d50462158a2..fd1c854bbce 100644
--- a/src/mongo/db/catalog/collection_impl.h
+++ b/src/mongo/db/catalog/collection_impl.h
@@ -368,7 +368,7 @@ public:
     void replaceMetadata(OperationContext* opCtx,
                          std::shared_ptr<BSONCollectionCatalogEntry::MetaData> md) final;
 
-    bool isMetadataEqual(const BSONCollectionCatalogEntry::MetaData& md) const final;
+    bool isMetadataEqual(const BSONObj& otherMetadata) const final;
 
     bool needsCappedLock() const final;
 
diff --git a/src/mongo/db/catalog/collection_mock.h b/src/mongo/db/catalog/collection_mock.h
index b1343d38c87..4cc17cf983a 100644
--- a/src/mongo/db/catalog/collection_mock.h
+++ b/src/mongo/db/catalog/collection_mock.h
@@ -437,7 +437,7 @@ public:
         MONGO_UNREACHABLE;
     }
 
-    bool isMetadataEqual(const BSONCollectionCatalogEntry::MetaData& md) const {
+    bool isMetadataEqual(const BSONObj& otherMetadata) const {
         MONGO_UNREACHABLE;
     }
 
diff --git a/src/mongo/db/catalog/virtual_collection_impl.h b/src/mongo/db/catalog/virtual_collection_impl.h
index 0f4f14a5c56..d45b46bd380 100644
--- a/src/mongo/db/catalog/virtual_collection_impl.h
+++ b/src/mongo/db/catalog/virtual_collection_impl.h
@@ -374,7 +374,7 @@ public:
         unimplementedTasserted();
     }
 
-    bool isMetadataEqual(const BSONCollectionCatalogEntry::MetaData& md) const final {
+    bool isMetadataEqual(const BSONObj& otherMetadata) const final {
         unimplementedTasserted();
         return false;
     }
diff --git a/src/mongo/db/storage/durable_catalog.h b/src/mongo/db/storage/durable_catalog.h
index 8c45922b95b..5167a8d681b 100644
--- a/src/mongo/db/storage/durable_catalog.h
+++ b/src/mongo/db/storage/durable_catalog.h
@@ -84,6 +84,21 @@ public:
         return false;
     }
 
+    /**
+     * Gets the parsed namespace from a raw BSON catalog entry.
+     */
+    static NamespaceString getNamespaceFromCatalogEntry(const BSONObj& catalogEntry) {
+        return NamespaceString::parseFromStringExpectTenantIdInMultitenancyMode(
+            catalogEntry["ns"].checkAndGetStringData());
+    }
+
+    /**
+     * Gets the metadata as BSON from a raw BSON catalog entry.
+     */
+    static BSONObj getMetadataFromCatalogEntry(const BSONObj& catalogEntry) {
+        return catalogEntry["md"].Obj();
+    }
+
     virtual void init(OperationContext* opCtx) = 0;
 
     virtual std::vector<EntryIdentifier> getAllCatalogEntries(OperationContext* opCtx) const = 0;