MyRocks: Fixing stats collection assuming Deletes are rows (issue#100)

Summary:
MyRocks statistics assumed all operation types (including Delete, SingleDelete,
Merge) as incrementing rows. This diff changes behavior -- incrementing
rows for Put only.

Test Plan: new test case rocksdb.issue100_delete

Reviewers: spetrunia, hermanlee4, jkedgar

Reviewed By: jkedgar

Subscribers: webscalesql-eng

Differential Revision: https://reviews.facebook.net/D51315

Author: yoshinorim

storage/rocksdb/properties_collector.cc

@@ -98,7 +98,10 @@ MyRocksTablePropertiesCollector::AddUserKey(
     }
     auto& stats = stats_.back();
     stats.data_size += key.size()+value.size();
-    stats.rows++;
+    if (type == rocksdb::kEntryPut)
+    {
+      stats.rows++;
+    }
     stats.actual_disk_size += file_size-file_size_;
 
     if (params_.window_ > 0) {