Implement simple caching for compiled regular expressions

1 files changed, 9 insertions, 4 deletions

diff --git a/src/stringutils.cpp b/src/stringutils.cpp
index fc80017..e7c8b5b 100644
--- a/src/stringutils.cpp
+++ b/src/stringutils.cpp
@@ -28,6 +28,7 @@
 #include <cstdio>
 #include <ctime>
 #include <list>
+#include <unordered_map>
 
 #include <sys/stat.h>
 
@@ -709,16 +710,20 @@ void secureChatCommand(std::string &str)
 bool isMatch(const std::string &str,
              const std::string &exp)
 {
-    std::regex regExp(exp);
-    return std::regex_match(str, regExp);
+    static std::unordered_map<std::string, std::regex> re_cache;
+    if (re_cache.find(exp) == re_cache.end())
+        re_cache.emplace(exp, exp);
+    return std::regex_match(str, re_cache[exp]);
 }
 
 bool isMatch(const std::string &str,
              const std::string &exp,
              std::smatch &m)
 {
-    std::regex regExp(exp);
-    return std::regex_match(str, m, regExp);
+    static std::unordered_map<std::string, std::regex> re_cache;
+    if (re_cache.find(exp) == re_cache.end())
+        re_cache.emplace(exp, exp);
+    return std::regex_match(str, m, re_cache[exp]);
 }
 
 bool fileExists(const std::string &name)