Fix DBTest.SuggestCompactRangeTest for disable jemalloc case

Summary: DBTest.SuggestCompactRangeTest fails for the case when jemalloc is disabled, including ASAN and valgrind builds. It is caused by the improvement of skip list, which allocates different size of nodes for a new records. Fix it by using a special mem table that triggers a flush by number of entries. In that way the behavior will be consistent for all allocators.

Test Plan: Run the test with both of DISABLE_JEMALLOC=1 and 0

Reviewers: anthony, rven, yhchiang, kradhakrishnan, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51423

db/db_test.cc

@@ -8626,10 +8626,12 @@ TEST_F(DBTest, SuggestCompactRangeTest) {
   };
 
   Options options = CurrentOptions();
+  options.memtable_factory.reset(
+      new SpecialSkipListFactory(DBTestBase::kNumKeysByGenerateNewRandomFile));
   options.compaction_style = kCompactionStyleLevel;
   options.compaction_filter_factory.reset(
       new CompactionFilterFactoryGetContext());
-  options.write_buffer_size = 100 << 10;
+  options.write_buffer_size = 200 << 10;
   options.arena_block_size = 4 << 10;
   options.level0_file_num_compaction_trigger = 4;
   options.num_levels = 4;

db/db_test_util.cc

@@ -855,8 +855,10 @@ void DBTestBase::GenerateNewFile(Random* rnd, int* key_idx, bool nowait) {
   }
 }
 
+const int DBTestBase::kNumKeysByGenerateNewRandomFile = 51;
+
 void DBTestBase::GenerateNewRandomFile(Random* rnd, bool nowait) {
-  for (int i = 0; i < 51; i++) {
+  for (int i = 0; i < kNumKeysByGenerateNewRandomFile; i++) {
     ASSERT_OK(Put("key" + RandomString(rnd, 7), RandomString(rnd, 2000)));
   }
   ASSERT_OK(Put("key" + RandomString(rnd, 7), RandomString(rnd, 200)));

db/db_test_util.h

@@ -118,6 +118,84 @@ struct OptionsOverride {
 
 }  // namespace anon
 
+// A hacky skip list mem table that triggers flush after number of entries.
+class SpecialMemTableRep : public MemTableRep {
+ public:
+  explicit SpecialMemTableRep(MemTableAllocator* allocator,
+                              MemTableRep* memtable, int num_entries_flush)
+      : MemTableRep(allocator),
+        memtable_(memtable),
+        num_entries_flush_(num_entries_flush),
+        num_entries_(0) {}
+
+  virtual KeyHandle Allocate(const size_t len, char** buf) override {
+    return memtable_->Allocate(len, buf);
+  }
+
+  // Insert key into the list.
+  // REQUIRES: nothing that compares equal to key is currently in the list.
+  virtual void Insert(KeyHandle handle) override {
+    memtable_->Insert(handle);
+    num_entries_++;
+  }
+
+  // Returns true iff an entry that compares equal to key is in the list.
+  virtual bool Contains(const char* key) const override {
+    return memtable_->Contains(key);
+  }
+
+  virtual size_t ApproximateMemoryUsage() override {
+    // Return a high memory usage when number of entries exceeds the threshold
+    // to trigger a flush.
+    return (num_entries_ < num_entries_flush_) ? 0 : 1024 * 1024 * 1024;
+  }
+
+  virtual void Get(const LookupKey& k, void* callback_args,
+                   bool (*callback_func)(void* arg,
+                                         const char* entry)) override {
+    memtable_->Get(k, callback_args, callback_func);
+  }
+
+  uint64_t ApproximateNumEntries(const Slice& start_ikey,
+                                 const Slice& end_ikey) override {
+    return memtable_->ApproximateNumEntries(start_ikey, end_ikey);
+  }
+
+  virtual MemTableRep::Iterator* GetIterator(Arena* arena = nullptr) override {
+    return memtable_->GetIterator(arena);
+  }
+
+  virtual ~SpecialMemTableRep() override {}
+
+ private:
+  unique_ptr<MemTableRep> memtable_;
+  int num_entries_flush_;
+  int num_entries_;
+};
+
+// The factory for the hacky skip list mem table that triggers flush after
+// number of entries exceeds a threshold.
+class SpecialSkipListFactory : public MemTableRepFactory {
+ public:
+  // After number of inserts exceeds `num_entries_flush` in a mem table, trigger
+  // flush.
+  explicit SpecialSkipListFactory(int num_entries_flush)
+      : num_entries_flush_(num_entries_flush) {}
+
+  virtual MemTableRep* CreateMemTableRep(
+      const MemTableRep::KeyComparator& compare, MemTableAllocator* allocator,
+      const SliceTransform* transform, Logger* logger) {
+    return new SpecialMemTableRep(
+        allocator, factory_.CreateMemTableRep(compare, allocator, transform, 0),
+        num_entries_flush_);
+  }
+  virtual const char* Name() const override { return "SkipListFactory"; }
+
+ private:
+  SkipListFactory factory_;
+  int num_entries_flush_;
+};
+
 // Special Env used to delay background operations
 class SpecialEnv : public EnvWrapper {
  public:
@@ -631,6 +709,8 @@ class DBTestBase : public testing::Test {
 
   void GenerateNewFile(int fd, Random* rnd, int* key_idx, bool nowait = false);
 
+  static const int kNumKeysByGenerateNewRandomFile;
+
   void GenerateNewRandomFile(Random* rnd, bool nowait = false);
 
   std::string IterStatus(Iterator* iter);