SERVER-32645 Create a shim helper framework.

The `MONGO_DECLARE_SHIM`, `MONGO_DEFINE_SHIM`, and `MONGO_REGISTER_SHIM`
macros can be used to create specialized types which are customization
and auto-registration points for late-binding functions.  In some
sense they work like weak-symbols; however, they also are useful for
tracking dependencies upon shimmed-out implementations.

10 files changed, 19 insertions, 18 deletions

diff --git a/src/mongo/db/repl/apply_ops.cpp b/src/mongo/db/repl/apply_ops.cpp
index 3a732c407ec..81ebf365c62 100644
--- a/src/mongo/db/repl/apply_ops.cpp
+++ b/src/mongo/db/repl/apply_ops.cpp
@@ -137,7 +137,7 @@ Status _applyOps(OperationContext* opCtx,
             invariant(opCtx->lockState()->isW());
             invariant(*opType != 'c');
 
-            auto db = dbHolder().get(opCtx, nss.ns());
+            auto db = DatabaseHolder::getDatabaseHolder().get(opCtx, nss.ns());
             if (!db) {
                 // Retry in non-atomic mode, since MMAP cannot implicitly create a new database
                 // within an active WriteUnitOfWork.
@@ -339,7 +339,7 @@ Status _checkPrecondition(OperationContext* opCtx,
         BSONObj realres = db.findOne(nss.ns(), preCondition["q"].Obj());
 
         // Get collection default collation.
-        Database* database = dbHolder().get(opCtx, nss.db());
+        Database* database = DatabaseHolder::getDatabaseHolder().get(opCtx, nss.db());
         if (!database) {
             return {ErrorCodes::NamespaceNotFound, "database in ns does not exist: " + nss.ns()};
         }
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index 6e083990f4e..2c6f4395590 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -227,7 +227,7 @@ void createIndexForApplyOps(OperationContext* opCtx,
                             IncrementOpsAppliedStatsFn incrementOpsAppliedStats,
                             OplogApplication::Mode mode) {
     // Check if collection exists.
-    Database* db = dbHolder().get(opCtx, indexNss.ns());
+    Database* db = DatabaseHolder::getDatabaseHolder().get(opCtx, indexNss.ns());
     auto indexCollection = db ? db->getCollection(opCtx, indexNss) : nullptr;
     uassert(ErrorCodes::NamespaceNotFound,
             str::stream() << "Failed to create index due to missing collection: " << indexNss.ns(),
@@ -1516,7 +1516,7 @@ Status applyCommand_inlock(OperationContext* opCtx,
         return {ErrorCodes::InvalidNamespace, "invalid ns: " + std::string(nss.ns())};
     }
     {
-        Database* db = dbHolder().get(opCtx, nss.ns());
+        Database* db = DatabaseHolder::getDatabaseHolder().get(opCtx, nss.ns());
         if (db && !db->getCollection(opCtx, nss) && db->getViewCatalog()->lookup(opCtx, nss.ns())) {
             return {ErrorCodes::CommandNotSupportedOnView,
                     str::stream() << "applyOps not supported on view:" << nss.ns()};
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index bb87c7312d7..1fb7bea1adf 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -394,7 +394,7 @@ Status ReplicationCoordinatorExternalStateImpl::runRepairOnLocalDB(OperationCont
         Status status = repairDatabase(opCtx, engine, localDbName, false, false);
 
         // Open database before returning
-        dbHolder().openDb(opCtx, localDbName);
+        DatabaseHolder::getDatabaseHolder().openDb(opCtx, localDbName);
     } catch (const DBException& ex) {
         return ex.toStatus();
     }
@@ -787,7 +787,7 @@ void ReplicationCoordinatorExternalStateImpl::_dropAllTempCollections(OperationC
         if (*it == "local")
             continue;
         LOG(2) << "Removing temporary collections from " << *it;
-        Database* db = dbHolder().get(opCtx, *it);
+        Database* db = DatabaseHolder::getDatabaseHolder().get(opCtx, *it);
         // Since we must be holding the global lock during this function, if listDatabases
         // returned this dbname, we should be able to get a reference to it - it can't have
         // been dropped.
diff --git a/src/mongo/db/repl/rollback_impl.cpp b/src/mongo/db/repl/rollback_impl.cpp
index e92b0c9ab2d..6e96e6d0237 100644
--- a/src/mongo/db/repl/rollback_impl.cpp
+++ b/src/mongo/db/repl/rollback_impl.cpp
@@ -857,7 +857,7 @@ void RollbackImpl::_resetDropPendingState(OperationContext* opCtx) {
     opCtx->getServiceContext()->getGlobalStorageEngine()->listDatabases(&dbNames);
     for (const auto& dbName : dbNames) {
         Lock::DBLock dbLock(opCtx, dbName, MODE_X);
-        Database* db = dbHolder().openDb(opCtx, dbName);
+        Database* db = DatabaseHolder::getDatabaseHolder().openDb(opCtx, dbName);
         checkForIdIndexesAndDropPendingCollections(opCtx, db);
     }
 }
diff --git a/src/mongo/db/repl/rollback_test_fixture.cpp b/src/mongo/db/repl/rollback_test_fixture.cpp
index 2e9c4f47889..b0d49b1473a 100644
--- a/src/mongo/db/repl/rollback_test_fixture.cpp
+++ b/src/mongo/db/repl/rollback_test_fixture.cpp
@@ -102,8 +102,8 @@ void RollbackTest::tearDown() {
     SessionCatalog::get(_serviceContextMongoDTest.getServiceContext())->reset_forTest();
 
     // We cannot unset the global replication coordinator because ServiceContextMongoD::tearDown()
-    // calls dropAllDatabasesExceptLocal() which requires the replication coordinator to clear all
-    // snapshots.
+    // calls Databse::dropAllDatabasesExceptLocal() which requires the replication coordinator to
+    // clear all snapshots.
     _serviceContextMongoDTest.tearDown();
 
     // ServiceContextMongoD::tearDown() does not destroy service context so it is okay
@@ -179,7 +179,7 @@ Collection* RollbackTest::_createCollection(OperationContext* opCtx,
                                             const CollectionOptions& options) {
     Lock::DBLock dbLock(opCtx, nss.db(), MODE_X);
     mongo::WriteUnitOfWork wuow(opCtx);
-    auto db = dbHolder().openDb(opCtx, nss.db());
+    auto db = DatabaseHolder::getDatabaseHolder().openDb(opCtx, nss.db());
     ASSERT_TRUE(db);
     db->dropCollection(opCtx, nss.ns()).transitional_ignore();
     auto coll = db->createCollection(opCtx, nss.ns(), options);
diff --git a/src/mongo/db/repl/rs_rollback.cpp b/src/mongo/db/repl/rs_rollback.cpp
index 3e9944988ba..eae8c70a468 100644
--- a/src/mongo/db/repl/rs_rollback.cpp
+++ b/src/mongo/db/repl/rs_rollback.cpp
@@ -844,7 +844,7 @@ void rollbackRenameCollection(OperationContext* opCtx, UUID uuid, RenameCollecti
     log() << "Attempting to rename collection with UUID: " << uuid << ", from: " << info.renameFrom
           << ", to: " << info.renameTo;
     Lock::DBLock dbLock(opCtx, dbName, MODE_X);
-    auto db = dbHolder().openDb(opCtx, dbName);
+    auto db = DatabaseHolder::getDatabaseHolder().openDb(opCtx, dbName);
     invariant(db);
 
     auto status = renameCollectionForRollback(opCtx, info.renameTo, uuid);
@@ -1138,7 +1138,7 @@ void rollback_internal::syncFixUp(OperationContext* opCtx,
 
             Lock::DBLock dbLock(opCtx, nss.db(), MODE_X);
 
-            auto db = dbHolder().openDb(opCtx, nss.db().toString());
+            auto db = DatabaseHolder::getDatabaseHolder().openDb(opCtx, nss.db().toString());
             invariant(db);
 
             Collection* collection = UUIDCatalog::get(opCtx).lookupCollectionByUUID(uuid);
diff --git a/src/mongo/db/repl/rs_rollback_test.cpp b/src/mongo/db/repl/rs_rollback_test.cpp
index b4858df9cba..93a47ec8044 100644
--- a/src/mongo/db/repl/rs_rollback_test.cpp
+++ b/src/mongo/db/repl/rs_rollback_test.cpp
@@ -357,7 +357,7 @@ int _testRollbackDelete(OperationContext* opCtx,
 
     Lock::DBLock dbLock(opCtx, "test", MODE_S);
     Lock::CollectionLock collLock(opCtx->lockState(), "test.t", MODE_S);
-    auto db = dbHolder().get(opCtx, "test");
+    auto db = DatabaseHolder::getDatabaseHolder().get(opCtx, "test");
     ASSERT_TRUE(db);
     auto collection = db->getCollection(opCtx, "test.t");
     if (!collection) {
@@ -1777,7 +1777,7 @@ TEST_F(RSRollbackTest, RollbackCreateCollectionCommand) {
                            _replicationProcess.get()));
     {
         Lock::DBLock dbLock(_opCtx.get(), "test", MODE_S);
-        auto db = dbHolder().get(_opCtx.get(), "test");
+        auto db = DatabaseHolder::getDatabaseHolder().get(_opCtx.get(), "test");
         ASSERT_TRUE(db);
         ASSERT_FALSE(db->getCollection(_opCtx.get(), "test.t"));
     }
diff --git a/src/mongo/db/repl/storage_interface_impl.cpp b/src/mongo/db/repl/storage_interface_impl.cpp
index e4a53344305..cd9dbcc1fd1 100644
--- a/src/mongo/db/repl/storage_interface_impl.cpp
+++ b/src/mongo/db/repl/storage_interface_impl.cpp
@@ -370,7 +370,7 @@ Status StorageInterfaceImpl::insertDocuments(OperationContext* opCtx,
 }
 
 Status StorageInterfaceImpl::dropReplicatedDatabases(OperationContext* opCtx) {
-    dropAllDatabasesExceptLocal(opCtx);
+    Database::dropAllDatabasesExceptLocal(opCtx);
     return Status::OK();
 }
 
diff --git a/src/mongo/db/repl/sync_tail.cpp b/src/mongo/db/repl/sync_tail.cpp
index 1dd997ce5a8..b70f3c56793 100644
--- a/src/mongo/db/repl/sync_tail.cpp
+++ b/src/mongo/db/repl/sync_tail.cpp
@@ -542,7 +542,7 @@ private:
         CollectionProperties collProperties;
 
         Lock::DBLock dbLock(opCtx, nsToDatabaseSubstring(ns), MODE_IS);
-        auto db = dbHolder().get(opCtx, ns);
+        auto db = DatabaseHolder::getDatabaseHolder().get(opCtx, ns);
         if (!db) {
             return collProperties;
         }
diff --git a/src/mongo/db/repl/sync_tail_test.cpp b/src/mongo/db/repl/sync_tail_test.cpp
index 3740407529a..d995e4f61e2 100644
--- a/src/mongo/db/repl/sync_tail_test.cpp
+++ b/src/mongo/db/repl/sync_tail_test.cpp
@@ -193,7 +193,7 @@ auto createCollectionWithUuid(OperationContext* opCtx, const NamespaceString& ns
 void createDatabase(OperationContext* opCtx, StringData dbName) {
     Lock::GlobalWrite globalLock(opCtx);
     bool justCreated;
-    Database* db = dbHolder().openDb(opCtx, dbName, &justCreated);
+    Database* db = DatabaseHolder::getDatabaseHolder().openDb(opCtx, dbName, &justCreated);
     ASSERT_TRUE(db);
     ASSERT_TRUE(justCreated);
 }
@@ -991,7 +991,8 @@ TEST_F(SyncTailTest, MultiInitialSyncApplyIgnoresUpdateOperationIfDocumentIsMiss
     {
         Lock::GlobalWrite globalLock(_opCtx.get());
         bool justCreated = false;
-        Database* db = dbHolder().openDb(_opCtx.get(), nss.db(), &justCreated);
+        Database* db =
+            DatabaseHolder::getDatabaseHolder().openDb(_opCtx.get(), nss.db(), &justCreated);
         ASSERT_TRUE(db);
         ASSERT_TRUE(justCreated);
     }