SERVER-41496 Remove Database::getCollection() and replace with CollectionCatalog::get().lookupCollectionByNamespace()

14 files changed, 65 insertions, 63 deletions

diff --git a/src/mongo/dbtests/counttests.cpp b/src/mongo/dbtests/counttests.cpp
index 41ad97c5203..a5a614016da 100644
--- a/src/mongo/dbtests/counttests.cpp
+++ b/src/mongo/dbtests/counttests.cpp
@@ -51,7 +51,7 @@ public:
         {
             WriteUnitOfWork wunit(&_opCtx);
 
-            _collection = _database->getCollection(&_opCtx, nss());
+            _collection = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
             if (_collection) {
                 _database->dropCollection(&_opCtx, nss()).transitional_ignore();
             }
diff --git a/src/mongo/dbtests/dbtests.cpp b/src/mongo/dbtests/dbtests.cpp
index 62238c52cf7..bba6a636a30 100644
--- a/src/mongo/dbtests/dbtests.cpp
+++ b/src/mongo/dbtests/dbtests.cpp
@@ -99,7 +99,10 @@ Status createIndexFromSpec(OperationContext* opCtx, StringData ns, const BSONObj
     Collection* coll;
     {
         WriteUnitOfWork wunit(opCtx);
-        coll = autoDb.getDb()->getOrCreateCollection(opCtx, NamespaceString(ns));
+        coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(NamespaceString(ns));
+        if (!coll) {
+            coll = autoDb.getDb()->createCollection(opCtx, NamespaceString(ns));
+        }
         invariant(coll);
         wunit.commit();
     }
diff --git a/src/mongo/dbtests/dbtests.h b/src/mongo/dbtests/dbtests.h
index e64772a11b7..f0b0166aecb 100644
--- a/src/mongo/dbtests/dbtests.h
+++ b/src/mongo/dbtests/dbtests.h
@@ -80,7 +80,7 @@ public:
     }
 
     Collection* getCollection() const {
-        return db()->getCollection(_opCtx, _nss);
+        return CollectionCatalog::get(_opCtx).lookupCollectionByNamespace(_nss);
     }
 
 private:
diff --git a/src/mongo/dbtests/pdfiletests.cpp b/src/mongo/dbtests/pdfiletests.cpp
index b4f09c83c52..a57a3fb0619 100644
--- a/src/mongo/dbtests/pdfiletests.cpp
+++ b/src/mongo/dbtests/pdfiletests.cpp
@@ -60,7 +60,7 @@ protected:
         return NamespaceString("unittests.pdfiletests.Insert");
     }
     Collection* collection() {
-        return _context.db()->getCollection(&_opCtx, nss());
+        return CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
     }
 
     const ServiceContext::UniqueOperationContext _opCtxPtr = cc().makeOperationContext();
@@ -75,15 +75,19 @@ public:
         WriteUnitOfWork wunit(&_opCtx);
         BSONObj x = BSON("x" << 1);
         ASSERT(x["_id"].type() == 0);
-        Collection* collection = _context.db()->getOrCreateCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
+        if (!coll) {
+            coll = _context.db()->createCollection(&_opCtx, nss());
+        }
+        ASSERT(coll);
         OpDebug* const nullOpDebug = nullptr;
-        ASSERT(!collection->insertDocument(&_opCtx, InsertStatement(x), nullOpDebug, true).isOK());
+        ASSERT(!coll->insertDocument(&_opCtx, InsertStatement(x), nullOpDebug, true).isOK());
 
         StatusWith<BSONObj> fixed = fixDocumentForInsert(_opCtx.getServiceContext(), x);
         ASSERT(fixed.isOK());
         x = fixed.getValue();
         ASSERT(x["_id"].type() == jstOID);
-        ASSERT(collection->insertDocument(&_opCtx, InsertStatement(x), nullOpDebug, true).isOK());
+        ASSERT(coll->insertDocument(&_opCtx, InsertStatement(x), nullOpDebug, true).isOK());
         wunit.commit();
     }
 };
diff --git a/src/mongo/dbtests/plan_executor_invalidation_test.cpp b/src/mongo/dbtests/plan_executor_invalidation_test.cpp
index 590d518feae..8cb1e1401d9 100644
--- a/src/mongo/dbtests/plan_executor_invalidation_test.cpp
+++ b/src/mongo/dbtests/plan_executor_invalidation_test.cpp
@@ -85,11 +85,13 @@ public:
         std::unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
 
         // Takes ownership of 'ws', 'scan', and 'cq'.
-        auto statusWithPlanExecutor = PlanExecutor::make(std::move(cq),
-                                                         std::move(ws),
-                                                         std::move(scan),
-                                                         _ctx->db()->getCollection(&_opCtx, nss),
-                                                         PlanExecutor::YIELD_MANUAL);
+        auto statusWithPlanExecutor =
+            PlanExecutor::make(std::move(cq),
+                               std::move(ws),
+                               std::move(scan),
+                               CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss),
+                               PlanExecutor::YIELD_MANUAL);
+
         ASSERT_OK(statusWithPlanExecutor.getStatus());
         return std::move(statusWithPlanExecutor.getValue());
     }
@@ -115,7 +117,7 @@ public:
     }
 
     Collection* collection() {
-        return _ctx->db()->getCollection(&_opCtx, nss);
+        return CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss);
     }
 
     void truncateCollection(Collection* collection) const {
diff --git a/src/mongo/dbtests/query_plan_executor.cpp b/src/mongo/dbtests/query_plan_executor.cpp
index be1b3448555..1726b5c994f 100644
--- a/src/mongo/dbtests/query_plan_executor.cpp
+++ b/src/mongo/dbtests/query_plan_executor.cpp
@@ -148,7 +148,8 @@ public:
         ixparams.bounds.endKey = BSON("" << end);
         ixparams.bounds.boundInclusion = BoundInclusion::kIncludeBothStartAndEndKeys;
 
-        const Collection* coll = db->getCollection(&_opCtx, nss);
+        const Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss);
+
 
         unique_ptr<WorkingSet> ws(new WorkingSet());
         auto ixscan = std::make_unique<IndexScan>(&_opCtx, ixparams, ws.get(), nullptr);
@@ -174,7 +175,7 @@ protected:
 
 private:
     const IndexDescriptor* getIndex(Database* db, const BSONObj& obj) {
-        Collection* collection = db->getCollection(&_opCtx, nss);
+        Collection* collection = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss);
         std::vector<const IndexDescriptor*> indexes;
         collection->getIndexCatalog()->findIndexesByKeyPattern(&_opCtx, obj, false, &indexes);
         ASSERT_LTE(indexes.size(), 1U);
diff --git a/src/mongo/dbtests/query_stage_count_scan.cpp b/src/mongo/dbtests/query_stage_count_scan.cpp
index 9b6a4f94383..0b3e05c5cba 100644
--- a/src/mongo/dbtests/query_stage_count_scan.cpp
+++ b/src/mongo/dbtests/query_stage_count_scan.cpp
@@ -92,7 +92,8 @@ public:
     }
 
     const IndexDescriptor* getIndex(Database* db, const BSONObj& obj) {
-        Collection* collection = db->getCollection(&_opCtx, NamespaceString(ns()));
+        Collection* collection =
+            CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(NamespaceString(ns()));
         std::vector<const IndexDescriptor*> indexes;
         collection->getIndexCatalog()->findIndexesByKeyPattern(&_opCtx, obj, false, &indexes);
         return indexes.empty() ? nullptr : indexes[0];
diff --git a/src/mongo/dbtests/query_stage_fetch.cpp b/src/mongo/dbtests/query_stage_fetch.cpp
index 8e6b0930e90..61a472f82e2 100644
--- a/src/mongo/dbtests/query_stage_fetch.cpp
+++ b/src/mongo/dbtests/query_stage_fetch.cpp
@@ -99,7 +99,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -165,7 +165,7 @@ public:
         Lock::DBLock lk(&_opCtx, nss().db(), MODE_X);
         OldClientContext ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
diff --git a/src/mongo/dbtests/query_stage_merge_sort.cpp b/src/mongo/dbtests/query_stage_merge_sort.cpp
index 14a0d2019d8..75795c5978e 100644
--- a/src/mongo/dbtests/query_stage_merge_sort.cpp
+++ b/src/mongo/dbtests/query_stage_merge_sort.cpp
@@ -145,7 +145,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -210,7 +210,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -274,7 +274,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -339,7 +339,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -408,7 +408,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -471,7 +471,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -523,7 +523,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -640,7 +640,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -742,7 +742,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -808,7 +808,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
diff --git a/src/mongo/dbtests/query_stage_sort.cpp b/src/mongo/dbtests/query_stage_sort.cpp
index 1bb68145894..db699ced854 100644
--- a/src/mongo/dbtests/query_stage_sort.cpp
+++ b/src/mongo/dbtests/query_stage_sort.cpp
@@ -241,7 +241,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -263,7 +263,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -294,7 +294,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -319,7 +319,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -428,7 +428,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -526,7 +526,7 @@ public:
     void run() {
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wuow(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
diff --git a/src/mongo/dbtests/query_stage_update.cpp b/src/mongo/dbtests/query_stage_update.cpp
index 0ce3c6cbe37..665ae70f031 100644
--- a/src/mongo/dbtests/query_stage_update.cpp
+++ b/src/mongo/dbtests/query_stage_update.cpp
@@ -272,8 +272,7 @@ public:
             OpDebug* opDebug = &curOp.debug();
             const CollatorInterface* collator = nullptr;
             UpdateDriver driver(new ExpressionContext(&_opCtx, collator));
-            Database* db = ctx.db();
-            Collection* coll = db->getCollection(&_opCtx, nss);
+            Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss);
             ASSERT(coll);
 
             // Get the RecordIds that would be returned by an in-order scan.
diff --git a/src/mongo/dbtests/querytests.cpp b/src/mongo/dbtests/querytests.cpp
index 9792bfcb7b4..47cb3f55f4d 100644
--- a/src/mongo/dbtests/querytests.cpp
+++ b/src/mongo/dbtests/querytests.cpp
@@ -68,7 +68,7 @@ public:
         {
             WriteUnitOfWork wunit(&_opCtx);
             _database = _context.db();
-            _collection = _database->getCollection(&_opCtx, nss());
+            _collection = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
             if (_collection) {
                 _database->dropCollection(&_opCtx, nss()).transitional_ignore();
             }
@@ -219,7 +219,7 @@ public:
         {
             WriteUnitOfWork wunit(&_opCtx);
             Database* db = ctx.db();
-            if (db->getCollection(&_opCtx, nss())) {
+            if (CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss())) {
                 _collection = nullptr;
                 db->dropCollection(&_opCtx, nss()).transitional_ignore();
             }
diff --git a/src/mongo/dbtests/repltests.cpp b/src/mongo/dbtests/repltests.cpp
index 7ca7eb19d80..638e339766a 100644
--- a/src/mongo/dbtests/repltests.cpp
+++ b/src/mongo/dbtests/repltests.cpp
@@ -138,7 +138,7 @@ public:
         dbtests::WriteContextForTests ctx(&_opCtx, ns());
         WriteUnitOfWork wuow(&_opCtx);
 
-        Collection* c = ctx.db()->getCollection(&_opCtx, nss());
+        Collection* c = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!c) {
             c = ctx.db()->createCollection(&_opCtx, nss());
         }
@@ -208,7 +208,7 @@ protected:
         Lock::GlobalWrite lk(&_opCtx);
         OldClientContext ctx(&_opCtx, ns());
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             WriteUnitOfWork wunit(&_opCtx);
             coll = db->createCollection(&_opCtx, nss());
@@ -265,7 +265,7 @@ protected:
         NamespaceString nss(ns);
 
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss);
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss);
         if (!coll) {
             WriteUnitOfWork wunit(&_opCtx);
             coll = db->createCollection(&_opCtx, nss);
@@ -286,7 +286,7 @@ protected:
             OldClientContext ctx(&_opCtx, ns);
             WriteUnitOfWork wunit(&_opCtx);
             Database* db = ctx.db();
-            Collection* coll = db->getCollection(&_opCtx, nss);
+            Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss);
             if (!coll) {
                 coll = db->createCollection(&_opCtx, nss);
             }
@@ -300,7 +300,7 @@ protected:
         OldClientContext ctx(&_opCtx, ns());
         WriteUnitOfWork wunit(&_opCtx);
         Database* db = ctx.db();
-        Collection* coll = db->getCollection(&_opCtx, nss());
+        Collection* coll = CollectionCatalog::get(&_opCtx).lookupCollectionByNamespace(nss());
         if (!coll) {
             coll = db->createCollection(&_opCtx, nss());
         }
diff --git a/src/mongo/dbtests/rollbacktests.cpp b/src/mongo/dbtests/rollbacktests.cpp
index cd8f785d99b..d9417770b49 100644
--- a/src/mongo/dbtests/rollbacktests.cpp
+++ b/src/mongo/dbtests/rollbacktests.cpp
@@ -87,20 +87,17 @@ Status renameCollection(OperationContext* opCtx,
     return renameCollection(opCtx, source, target, {});
 }
 Status truncateCollection(OperationContext* opCtx, const NamespaceString& nss) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     return coll->truncate(opCtx);
 }
 
 void insertRecord(OperationContext* opCtx, const NamespaceString& nss, const BSONObj& data) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     OpDebug* const nullOpDebug = nullptr;
     ASSERT_OK(coll->insertDocument(opCtx, InsertStatement(data), nullOpDebug, false));
 }
 void assertOnlyRecord(OperationContext* opCtx, const NamespaceString& nss, const BSONObj& data) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     auto cursor = coll->getCursor(opCtx);
 
     auto record = cursor->next();
@@ -110,18 +107,15 @@ void assertOnlyRecord(OperationContext* opCtx, const NamespaceString& nss, const
     ASSERT(!cursor->next());
 }
 void assertEmpty(OperationContext* opCtx, const NamespaceString& nss) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     ASSERT(!coll->getCursor(opCtx)->next());
 }
 bool indexExists(OperationContext* opCtx, const NamespaceString& nss, const string& idxName) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     return coll->getIndexCatalog()->findIndexByName(opCtx, idxName, true) != nullptr;
 }
 bool indexReady(OperationContext* opCtx, const NamespaceString& nss, const string& idxName) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     return coll->getIndexCatalog()->findIndexByName(opCtx, idxName, false) != nullptr;
 }
 size_t getNumIndexEntries(OperationContext* opCtx,
@@ -129,8 +123,7 @@ size_t getNumIndexEntries(OperationContext* opCtx,
                           const string& idxName) {
     size_t numEntries = 0;
 
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     IndexCatalog* catalog = coll->getIndexCatalog();
     auto desc = catalog->findIndexByName(opCtx, idxName, false);
 
@@ -152,8 +145,7 @@ size_t getNumIndexEntries(OperationContext* opCtx,
 }
 
 void dropIndex(OperationContext* opCtx, const NamespaceString& nss, const string& idxName) {
-    auto databaseHolder = DatabaseHolder::get(opCtx);
-    auto coll = databaseHolder->getDb(opCtx, nss.db())->getCollection(opCtx, nss);
+    auto coll = CollectionCatalog::get(opCtx).lookupCollectionByNamespace(nss);
     auto desc = coll->getIndexCatalog()->findIndexByName(opCtx, idxName);
     ASSERT(desc);
     ASSERT_OK(coll->getIndexCatalog()->dropIndex(opCtx, desc));
@@ -543,7 +535,7 @@ public:
 
         AutoGetDb autoDb(&opCtx, nss.db(), MODE_X);
 
-        Collection* coll = autoDb.getDb()->getCollection(&opCtx, nss);
+        Collection* coll = CollectionCatalog::get(&opCtx).lookupCollectionByNamespace(nss);
         IndexCatalog* catalog = coll->getIndexCatalog();
 
         string idxName = "a";
@@ -584,7 +576,7 @@ public:
 
         AutoGetDb autoDb(&opCtx, nss.db(), MODE_X);
 
-        Collection* coll = autoDb.getDb()->getCollection(&opCtx, nss);
+        Collection* coll = CollectionCatalog::get(&opCtx).lookupCollectionByNamespace(nss);
         IndexCatalog* catalog = coll->getIndexCatalog();
 
         string idxName = "a";
@@ -637,7 +629,7 @@ public:
 
         AutoGetDb autoDb(&opCtx, nss.db(), MODE_X);
 
-        Collection* coll = autoDb.getDb()->getCollection(&opCtx, nss);
+        Collection* coll = CollectionCatalog::get(&opCtx).lookupCollectionByNamespace(nss);
         IndexCatalog* catalog = coll->getIndexCatalog();
 
         string idxName = "a";
@@ -700,7 +692,7 @@ public:
                 assertGet(CollectionOptions::parse(BSONObj(), CollectionOptions::parseForCommand));
             ASSERT_OK(ctx.db()->userCreateNS(&opCtx, nss, collectionOptions, false));
             ASSERT(collectionExists(&opCtx, &ctx, nss.ns()));
-            Collection* coll = ctx.db()->getCollection(&opCtx, nss);
+            Collection* coll = CollectionCatalog::get(&opCtx).lookupCollectionByNamespace(nss);
             IndexCatalog* catalog = coll->getIndexCatalog();
 
             ASSERT_OK(catalog->createIndexOnEmptyCollection(&opCtx, specA));