1 files changed, 8 insertions, 1 deletions
diff --git a/db/db_impl.h b/db/db_impl.h
index 3c8d711ae0..75fd30abe9 100644
--- a/db/db_impl.h
+++ b/db/db_impl.h
@@ -59,13 +59,19 @@ class DBImpl : public DB {
   // file at a level >= 1.
   int64_t TEST_MaxNextLevelOverlappingBytes();
 
+  // Record a sample of bytes read at the specified internal key.
+  // Samples are taken approximately once every config::kReadBytesPeriod
+  // bytes.
+  void RecordReadSample(Slice key);
+
  private:
   friend class DB;
   struct CompactionState;
   struct Writer;
 
   Iterator* NewInternalIterator(const ReadOptions&,
-                                SequenceNumber* latest_snapshot);
+                                SequenceNumber* latest_snapshot,
+                                uint32_t* seed);
 
   Status NewDB();
 
@@ -135,6 +141,7 @@ class DBImpl : public DB {
   WritableFile* logfile_;
   uint64_t logfile_number_;
   log::Writer* log_;
+  uint32_t seed_;                // For sampling.
 
   // Queue of writers.
   std::deque<Writer*> writers_;