LevelDB: Add WriteBatch::ApproximateSize().

This can be used to report metrics on LevelDB usage.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=156934930

1 files changed, 6 insertions, 0 deletions

diff --git a/include/leveldb/write_batch.h b/include/leveldb/write_batch.h
index ee9aab6..65a76d8 100644
--- a/include/leveldb/write_batch.h
+++ b/include/leveldb/write_batch.h
@@ -42,6 +42,12 @@ class WriteBatch {
   // Clear all updates buffered in this batch.
   void Clear();
 
+  // The size of the database changes caused by this batch.
+  //
+  // This number is tied to implementation details, and may change across
+  // releases. It is intended for LevelDB usage metrics.
+  size_t ApproximateSize();
+
   // Support for iterating over the contents of a batch.
   class Handler {
    public: