Total memtables size counter

Summary: Added one new counter for GetProperty

Test Plan: Not sure if needs a test case. compiles

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D25023

db/internal_stats.cc

@@ -133,6 +133,8 @@ DBPropertyType GetPropertyType(const Slice& property, bool* is_int_property,
     return kBackgroundErrors;
   } else if (in == "cur-size-active-mem-table") {
     return kCurSizeActiveMemTable;
+  } else if (in == "cur-size-all-mem-tables") {
+    return kCurSizeAllMemTables;
   } else if (in == "num-entries-active-mem-table") {
     return kNumEntriesInMutableMemtable;
   } else if (in == "num-entries-imm-mem-tables") {
@@ -250,12 +252,17 @@ bool InternalStats::GetIntProperty(DBPropertyType property_type,
       // Current size of the active memtable
       *value = cfd_->mem()->ApproximateMemoryUsage();
       return true;
+    case kCurSizeAllMemTables:
+      // Current size of the active memtable + immutable memtables
+      *value = cfd_->mem()->ApproximateMemoryUsage() +
+               cfd_->imm()->ApproximateMemoryUsage();
+      return true;
     case kNumEntriesInMutableMemtable:
-      // Current size of the active memtable
+      // Current number of entires in the active memtable
       *value = cfd_->mem()->GetNumEntries();
       return true;
     case kNumEntriesInImmutableMemtable:
-      // Current size of the active memtable
+      // Current number of entries in the immutable memtables
       *value = cfd_->imm()->current()->GetTotalNumEntries();
       return true;
     case kEstimatedNumKeys:

db/internal_stats.h

@@ -36,6 +36,8 @@ enum DBPropertyType : uint32_t {
   kCompactionPending,      // Return 1 if a compaction is pending. Otherwise 0.
   kBackgroundErrors,       // Return accumulated background errors encountered.
   kCurSizeActiveMemTable,  // Return current size of the active memtable
+  kCurSizeAllMemTables,    // Return current size of all (active + immutable)
+                           // memtables
   kNumEntriesInMutableMemtable,    // Return number of entries in the mutable
                                    // memtable.
   kNumEntriesInImmutableMemtable,  // Return sum of number of entries in all