Allow copy for PerfContext objects (facebook#4919)

Summary: Existing implementation of PerfContext does not define copy constructor or assignment operator, which could potentially cause problems when user create copies and resets the builtin one. This PR address the issue by providing these two constructors with deep copy semantics. Pull Request resolved: facebook#4919 Differential Revision: D13960406 Pulled By: miasantreble fbshipit-source-id: 36aab5aaee65d4480f537e4e22148faa45e8e334
katherinez · Feb 5, 2019 · 00ed41d · 00ed41d
1 parent c9a52cb
commit 00ed41d
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Showing 3 changed files with 371 additions and 2 deletions.
diff --git a/db/perf_context_test.cc b/db/perf_context_test.cc
@@ -688,6 +688,89 @@ TEST_F(PerfContextTest, MergeOperatorTime) {
   delete db;
 }
 
+TEST_F(PerfContextTest, CopyAndMove) {
+  // Assignment operator
+  {
+    get_perf_context()->Reset();
+    get_perf_context()->EnablePerLevelPerfContext();
+    PERF_COUNTER_BY_LEVEL_ADD(bloom_filter_useful, 1, 5);
+    ASSERT_EQ(
+        1,
+        (*(get_perf_context()->level_to_perf_context))[5].bloom_filter_useful);
+    PerfContext perf_context_assign;
+    perf_context_assign = *get_perf_context();
+    ASSERT_EQ(
+        1,
+        (*(perf_context_assign.level_to_perf_context))[5].bloom_filter_useful);
+    get_perf_context()->ClearPerLevelPerfContext();
+    get_perf_context()->Reset();
+    ASSERT_EQ(
+        1,
+        (*(perf_context_assign.level_to_perf_context))[5].bloom_filter_useful);
+    perf_context_assign.ClearPerLevelPerfContext();
+    perf_context_assign.Reset();
+  }
+  // Copy constructor
+  {
+    get_perf_context()->Reset();
+    get_perf_context()->EnablePerLevelPerfContext();
+    PERF_COUNTER_BY_LEVEL_ADD(bloom_filter_useful, 1, 5);
+    ASSERT_EQ(
+        1,
+        (*(get_perf_context()->level_to_perf_context))[5].bloom_filter_useful);
+    PerfContext perf_context_copy(*get_perf_context());
+    ASSERT_EQ(
+        1, (*(perf_context_copy.level_to_perf_context))[5].bloom_filter_useful);
+    get_perf_context()->ClearPerLevelPerfContext();
+    get_perf_context()->Reset();
+    ASSERT_EQ(
+        1, (*(perf_context_copy.level_to_perf_context))[5].bloom_filter_useful);
+    perf_context_copy.ClearPerLevelPerfContext();
+    perf_context_copy.Reset();
+  }
+  // Move constructor
+  {
+    get_perf_context()->Reset();
+    get_perf_context()->EnablePerLevelPerfContext();
+    PERF_COUNTER_BY_LEVEL_ADD(bloom_filter_useful, 1, 5);
+    ASSERT_EQ(
+        1,
+        (*(get_perf_context()->level_to_perf_context))[5].bloom_filter_useful);
+    PerfContext perf_context_move = std::move(*get_perf_context());
+    ASSERT_EQ(
+        1, (*(perf_context_move.level_to_perf_context))[5].bloom_filter_useful);
+    get_perf_context()->ClearPerLevelPerfContext();
+    get_perf_context()->Reset();
+    ASSERT_EQ(
+        1, (*(perf_context_move.level_to_perf_context))[5].bloom_filter_useful);
+    perf_context_move.ClearPerLevelPerfContext();
+    perf_context_move.Reset();
+  }
+}
+
+TEST_F(PerfContextTest, PerfContextDisableEnable) {
+  get_perf_context()->Reset();
+  get_perf_context()->EnablePerLevelPerfContext();
+  PERF_COUNTER_BY_LEVEL_ADD(bloom_filter_full_positive, 1, 0);
+  get_perf_context()->DisablePerLevelPerfContext();
+  PERF_COUNTER_BY_LEVEL_ADD(bloom_filter_useful, 1, 5);
+  get_perf_context()->EnablePerLevelPerfContext();
+  PERF_COUNTER_BY_LEVEL_ADD(block_cache_hit_count, 1, 0);
+  get_perf_context()->DisablePerLevelPerfContext();
+  PerfContext perf_context_copy(*get_perf_context());
+  ASSERT_EQ(1, (*(perf_context_copy.level_to_perf_context))[0]
+                   .bloom_filter_full_positive);
+  // this was set when per level perf context is disabled, should not be copied
+  ASSERT_NE(
+      1, (*(perf_context_copy.level_to_perf_context))[5].bloom_filter_useful);
+  ASSERT_EQ(
+      1, (*(perf_context_copy.level_to_perf_context))[0].block_cache_hit_count);
+  perf_context_copy.ClearPerLevelPerfContext();
+  perf_context_copy.Reset();
+  get_perf_context()->ClearPerLevelPerfContext();
+  get_perf_context()->Reset();
+}
+
 TEST_F(PerfContextTest, PerfContextByLevelGetSet) {
   get_perf_context()->Reset();
   get_perf_context()->EnablePerLevelPerfContext();

diff --git a/include/rocksdb/perf_context.h b/include/rocksdb/perf_context.h
@@ -45,6 +45,12 @@ struct PerfContext {
 
   ~PerfContext();
 
+  PerfContext() {}
+
+  PerfContext(const PerfContext&);
+  PerfContext& operator=(const PerfContext&);
+  PerfContext(PerfContext&&) noexcept;
+
   void Reset(); // reset all performance counters to zero
 
   std::string ToString(bool exclude_zero_counters = false) const;