From 3d7f9ca15e55829f9141728079a55f6a2f767082 Mon Sep 17 00:00:00 2001
From: Artemkin Pavel <artpaul@users.noreply.github.com>
Date: Tue, 18 Jun 2019 19:03:44 +0500
Subject: [PATCH] #55 thread safe ast cache (#74)

---
 clickhouse/types/type_parser.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/clickhouse/types/type_parser.cpp b/clickhouse/types/type_parser.cpp
index 0b1fa20..62d471d 100644
--- a/clickhouse/types/type_parser.cpp
+++ b/clickhouse/types/type_parser.cpp
@@ -1,6 +1,8 @@
 #include "type_parser.h"
 #include "../base/string_utils.h"
 
+#include <map>
+#include <mutex>
 #include <unordered_map>
 
 namespace clickhouse {
@@ -167,8 +169,10 @@ const TypeAst* ParseTypeName(const std::string& type_name) {
     // Cache for type_name.
     // Usually we won't have too many type names in the cache, so do not try to
     // limit cache size.
-    static std::unordered_map<std::string, TypeAst> ast_cache;
+    static std::map<std::string, TypeAst> ast_cache;
+    static std::mutex lock;
 
+    std::lock_guard<std::mutex> guard(lock);
     auto it = ast_cache.find(type_name);
     if (it != ast_cache.end()) {
         return &it->second;