Changes for supporting cross functional tests for inplace_update

Summary:
This diff containes the changes to the code and db_test
for supporting cross functional tests for inplace_update

Test Plan: Run XF with inplace_test and also without

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32367

db/db_test.cc

@@ -2432,8 +2432,10 @@ TEST(DBTest, IterPrevMaxSkip) {
 }
 
 TEST(DBTest, IterWithSnapshot) {
+  anon::OptionsOverride options_override;
+  options_override.skip_policy = kSkipNoSnapshot;
   do {
-    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
+    CreateAndReopenWithCF({"pikachu"}, CurrentOptions(options_override));
     ASSERT_OK(Put(1, "key1", "val1"));
     ASSERT_OK(Put(1, "key2", "val2"));
     ASSERT_OK(Put(1, "key3", "val3"));
@@ -8098,9 +8100,11 @@ static bool CompareIterators(int step,
 }
 
 TEST(DBTest, Randomized) {
+  anon::OptionsOverride options_override;
+  options_override.skip_policy = kSkipNoSnapshot;
   Random rnd(test::RandomSeed());
   do {
-    ModelDB model(CurrentOptions());
+    ModelDB model(CurrentOptions(options_override));
     const int N = 10000;
     const Snapshot* model_snap = nullptr;
     const Snapshot* db_snap = nullptr;
@@ -8170,7 +8174,7 @@ TEST(DBTest, Randomized) {
         if (db_snap != nullptr) db_->ReleaseSnapshot(db_snap);
 
 
-        auto options = CurrentOptions();
+        auto options = CurrentOptions(options_override);
         Reopen(options);
         ASSERT_TRUE(CompareIterators(step, &model, db_, nullptr, nullptr));
 

db/memtable.h

@@ -196,7 +196,10 @@ class MemTable {
   }
 
   // return true if the current MemTableRep supports snapshots.
-  bool IsSnapshotSupported() const { return table_->IsSnapshotSupported(); }
+  // inplace update prevents snapshots,
+  bool IsSnapshotSupported() const {
+    return table_->IsSnapshotSupported() && !moptions_.inplace_update_support;
+  }
 
   // Get the lock associated for the key
   port::RWMutex* GetLock(const Slice& key);