Add named constants for remaining properties

Summary:
There were just these two properties that didn't have any named
constant.

Test Plan:
build and below test

  $ ./db_properties_test --gtest_filter=DBPropertiesTest.NumImmutableMemTable

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D53103

db/db_properties_test.cc

@@ -428,7 +428,7 @@ TEST_F(DBPropertiesTest, NumImmutableMemTable) {
     writeOpt.disableWAL = true;
     options.max_write_buffer_number = 4;
     options.min_write_buffer_number_to_merge = 3;
-    options.max_write_buffer_number_to_maintain = 0;
+    options.max_write_buffer_number_to_maintain = 4;
     options.write_buffer_size = 1000000;
     CreateAndReopenWithCF({"pikachu"}, options);
 
@@ -441,6 +441,9 @@ TEST_F(DBPropertiesTest, NumImmutableMemTable) {
     ASSERT_TRUE(dbfull()->GetProperty(handles_[1],
                                       "rocksdb.num-immutable-mem-table", &num));
     ASSERT_EQ(num, "0");
+    ASSERT_TRUE(dbfull()->GetProperty(
+        handles_[1], DB::Properties::kNumImmutableMemTableFlushed, &num));
+    ASSERT_EQ(num, "0");
     ASSERT_TRUE(dbfull()->GetProperty(
         handles_[1], "rocksdb.num-entries-active-mem-table", &num));
     ASSERT_EQ(num, "1");
@@ -492,6 +495,9 @@ TEST_F(DBPropertiesTest, NumImmutableMemTable) {
     ASSERT_TRUE(dbfull()->GetProperty(handles_[1],
                                       "rocksdb.num-immutable-mem-table", &num));
     ASSERT_EQ(num, "0");
+    ASSERT_TRUE(dbfull()->GetProperty(
+        handles_[1], DB::Properties::kNumImmutableMemTableFlushed, &num));
+    ASSERT_EQ(num, "3");
     ASSERT_TRUE(dbfull()->GetProperty(
         handles_[1], "rocksdb.cur-size-active-mem-table", &num));
     // "192" is the size of the metadata of an empty skiplist, this would

db/internal_stats.cc

@@ -136,8 +136,11 @@ const std::string DB::Properties::kStats = rocksdb_prefix + allstats;
 const std::string DB::Properties::kSSTables = rocksdb_prefix + sstables;
 const std::string DB::Properties::kCFStats = rocksdb_prefix + cfstats;
 const std::string DB::Properties::kDBStats = rocksdb_prefix + dbstats;
+const std::string DB::Properties::kLevelStats = rocksdb_prefix + levelstats;
 const std::string DB::Properties::kNumImmutableMemTable =
                       rocksdb_prefix + num_immutable_mem_table;
+const std::string DB::Properties::kNumImmutableMemTableFlushed =
+                      rocksdb_prefix + num_immutable_mem_table_flushed;
 const std::string DB::Properties::kMemTableFlushPending =
                       rocksdb_prefix + mem_table_flush_pending;
 const std::string DB::Properties::kCompactionPending =

include/rocksdb/db.h

@@ -343,11 +343,14 @@ class DB {
   //     of the sstables that make up the db contents.
   //  "rocksdb.cfstats"
   //  "rocksdb.dbstats"
+  //  "rocksdb.levelstats"
   //  "rocksdb.num-immutable-mem-table"
   //  "rocksdb.mem-table-flush-pending"
+  //  "rocksdb.num-immutable-mem-table-flushed"
   //  "rocksdb.compaction-pending" - 1 if at least one compaction is pending
   //  "rocksdb.background-errors" - accumulated number of background errors
   //  "rocksdb.cur-size-active-mem-table"
+  //  "rocksdb.cur-size-all-mem-tables"
   //  "rocksdb.size-all-mem-tables"
   //  "rocksdb.num-entries-active-mem-table"
   //  "rocksdb.num-entries-imm-mem-tables"
@@ -386,7 +389,9 @@ class DB {
     static const std::string kSSTables;
     static const std::string kCFStats;
     static const std::string kDBStats;
+    static const std::string kLevelStats;
     static const std::string kNumImmutableMemTable;
+    static const std::string kNumImmutableMemTableFlushed;
     static const std::string kMemTableFlushPending;
     static const std::string kNumRunningFlushes;
     static const std::string kCompactionPending;