SERVER-27257 Deduplicate symbol `newHarnessHelper`

The `newHarnessHelper` function was defined by multiple test driver
modules, each one specializing it to return a specific kind of
storage test driver's `HarnessHelper`.  The two different kinds
of `HarnessHelper` class were given a common base class, and the
`newHarnessHelper` function was changed to a single implementation.
This new implementation returns the results of a `HarnessHelper`
factory function which can be registered by a MONGO_INITIALIZER
statement.

2 files changed, 27 insertions, 8 deletions

diff --git a/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_btree_impl_test.cpp b/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_btree_impl_test.cpp
index 5a91de906f2..49cbc6d1762 100644
--- a/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_btree_impl_test.cpp
+++ b/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_btree_impl_test.cpp
@@ -31,16 +31,19 @@
 #include "mongo/db/storage/ephemeral_for_test/ephemeral_for_test_btree_impl.h"
 
 
+#include "mongo/base/init.h"
 #include "mongo/db/storage/ephemeral_for_test/ephemeral_for_test_recovery_unit.h"
 #include "mongo/db/storage/sorted_data_interface_test_harness.h"
 #include "mongo/stdx/memory.h"
 #include "mongo/unittest/unittest.h"
 
 namespace mongo {
+namespace {
 
-class EphemeralForTestHarnessHelper final : public HarnessHelper {
+class EphemeralForBtreeImplTestHarnessHelper final
+    : public virtual SortedDataInterfaceHarnessHelper {
 public:
-    EphemeralForTestHarnessHelper() : _order(Ordering::make(BSONObj())) {}
+    EphemeralForBtreeImplTestHarnessHelper() : _order(Ordering::make(BSONObj())) {}
 
     std::unique_ptr<SortedDataInterface> newSortedDataInterface(bool unique) final {
         return std::unique_ptr<SortedDataInterface>(
@@ -56,7 +59,13 @@ private:
     Ordering _order;
 };
 
-std::unique_ptr<HarnessHelper> newHarnessHelper() {
-    return stdx::make_unique<EphemeralForTestHarnessHelper>();
+std::unique_ptr<HarnessHelper> makeHarnessHelper() {
+    return stdx::make_unique<EphemeralForBtreeImplTestHarnessHelper>();
 }
+
+MONGO_INITIALIZER(RegisterHarnessFactory)(InitializerContext* const) {
+    mongo::registerHarnessHelperFactory(makeHarnessHelper);
+    return Status::OK();
 }
+}  // namespace
+}  // namespace mongo
diff --git a/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_record_store_test.cpp b/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_record_store_test.cpp
index 5fa803ea2e0..153c34e2779 100644
--- a/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_record_store_test.cpp
+++ b/src/mongo/db/storage/ephemeral_for_test/ephemeral_for_test_record_store_test.cpp
@@ -32,27 +32,31 @@
 
 #include "mongo/db/storage/ephemeral_for_test/ephemeral_for_test_record_store.h"
 
+#include "mongo/base/init.h"
 #include "mongo/db/storage/ephemeral_for_test/ephemeral_for_test_recovery_unit.h"
 #include "mongo/db/storage/record_store_test_harness.h"
+#include "mongo/stdx/memory.h"
 #include "mongo/unittest/unittest.h"
 
 namespace mongo {
+namespace {
 
-class EphemeralForTestHarnessHelper final : public HarnessHelper {
+class EphemeralForTestHarnessHelper final : public RecordStoreHarnessHelper {
 public:
     EphemeralForTestHarnessHelper() {}
 
     std::unique_ptr<RecordStore> newNonCappedRecordStore() final {
         return stdx::make_unique<EphemeralForTestRecordStore>("a.b", &data);
     }
+
     std::unique_ptr<RecordStore> newCappedRecordStore(int64_t cappedSizeBytes,
                                                       int64_t cappedMaxDocs) final {
         return stdx::make_unique<EphemeralForTestRecordStore>(
             "a.b", &data, true, cappedSizeBytes, cappedMaxDocs);
     }
 
-    RecoveryUnit* newRecoveryUnit() final {
-        return new EphemeralForTestRecoveryUnit();
+    std::unique_ptr<RecoveryUnit> newRecoveryUnit() final {
+        return stdx::make_unique<EphemeralForTestRecoveryUnit>();
     }
 
     bool supportsDocLocking() final {
@@ -62,7 +66,13 @@ public:
     std::shared_ptr<void> data;
 };
 
-std::unique_ptr<HarnessHelper> newHarnessHelper() {
+std::unique_ptr<HarnessHelper> makeHarnessHelper() {
     return stdx::make_unique<EphemeralForTestHarnessHelper>();
 }
+
+MONGO_INITIALIZER(RegisterHarnessFactory)(InitializerContext* const) {
+    mongo::registerHarnessHelperFactory(makeHarnessHelper);
+    return Status::OK();
 }
+}  // namespace
+}  // namespace mongo