From 5ef9478a2ebbbfa9a3c2a67867369e9f8d555a03 Mon Sep 17 00:00:00 2001
From: Mikhail Koviazin <mikhail.koviazin@aiven.io>
Date: Wed, 10 Jan 2024 09:21:06 +0000
Subject: [PATCH] SensitiveDataMasker: replace shared_ptr with MultiVersion

---
 src/Common/SensitiveDataMasker.cpp | 13 ++++++-------
 src/Common/SensitiveDataMasker.h   |  8 +++++---
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/Common/SensitiveDataMasker.cpp b/src/Common/SensitiveDataMasker.cpp
index 1d8b1a9bc72..33770c3e78a 100644
--- a/src/Common/SensitiveDataMasker.cpp
+++ b/src/Common/SensitiveDataMasker.cpp
@@ -85,9 +85,9 @@ public:
 
 SensitiveDataMasker::~SensitiveDataMasker() = default;
 
-std::shared_ptr<SensitiveDataMasker> SensitiveDataMasker::sensitive_data_masker = nullptr;
+SensitiveDataMasker::MaskerMultiVersion SensitiveDataMasker::sensitive_data_masker{};
 
-void SensitiveDataMasker::setInstance(std::shared_ptr<SensitiveDataMasker> sensitive_data_masker_)
+void SensitiveDataMasker::setInstance(std::unique_ptr<SensitiveDataMasker>&& sensitive_data_masker_)
 {
 
     if (!sensitive_data_masker_)
@@ -95,18 +95,17 @@ void SensitiveDataMasker::setInstance(std::shared_ptr<SensitiveDataMasker> sensi
 
     if (sensitive_data_masker_->rulesCount() > 0)
     {
-        std::atomic_store(&sensitive_data_masker, std::move(sensitive_data_masker_));
+        sensitive_data_masker.set(std::move(sensitive_data_masker_));
     }
     else
     {
-        std::atomic_store(&sensitive_data_masker, std::shared_ptr<SensitiveDataMasker>(nullptr));
+        sensitive_data_masker.set(nullptr);
     }
 }
 
-std::shared_ptr<SensitiveDataMasker> SensitiveDataMasker::getInstance()
+SensitiveDataMasker::MaskerMultiVersion::Version SensitiveDataMasker::getInstance()
 {
-    // TODO: use std::atomic<std::shared_ptr> when compiler supports it
-    return std::atomic_load(&sensitive_data_masker);
+    return sensitive_data_masker.get();
 }
 
 SensitiveDataMasker::SensitiveDataMasker(const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix)
diff --git a/src/Common/SensitiveDataMasker.h b/src/Common/SensitiveDataMasker.h
index afddd52a56c..a153575cdbd 100644
--- a/src/Common/SensitiveDataMasker.h
+++ b/src/Common/SensitiveDataMasker.h
@@ -2,6 +2,7 @@
 
 #include <memory>
 #include <vector>
+#include "Common/MultiVersion.h"
 
 namespace Poco
 {
@@ -44,7 +45,8 @@ class SensitiveDataMasker
 private:
     class MaskingRule;
     std::vector<std::unique_ptr<MaskingRule>> all_masking_rules;
-    static std::shared_ptr<SensitiveDataMasker> sensitive_data_masker;
+    using MaskerMultiVersion = MultiVersion<SensitiveDataMasker>;
+    static MaskerMultiVersion sensitive_data_masker;
 
 public:
     SensitiveDataMasker(const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix);
@@ -55,8 +57,8 @@ public:
 
     /// setInstance is not thread-safe and should be called once in single-thread mode.
     /// https://github.com/ClickHouse/ClickHouse/pull/6810#discussion_r321183367
-    static void setInstance(std::shared_ptr<SensitiveDataMasker> sensitive_data_masker_);
-    static std::shared_ptr<SensitiveDataMasker> getInstance();
+    static void setInstance(std::unique_ptr<SensitiveDataMasker>&& sensitive_data_masker_);
+    static MaskerMultiVersion::Version getInstance();
 
     /// Used in tests.
     void addMaskingRule(const std::string & name, const std::string & regexp_string, const std::string & replacement_string);