Make all std::regex instances static

Per [1] we really shouldn't be using regex.  In the cases we do, it's a
HUUUUUGE performance benefit to be compiling the regex ONCE.

The only downside is a slight increase in memory usage.

[1]: #176

Signed-off-by: Ed Tanous <[email protected]>
Change-Id: I8644b8a07810349fb60bfa0258a13e815912a38e

Author: edtanous

include/dbus_monitor.hpp

@@ -173,8 +173,8 @@ inline void requestRoutes(App& app)
 
         // These regexes derived on the rules here:
         // https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names
-        std::regex validPath("^/([A-Za-z0-9_]+/?)*$");
-        std::regex validInterface(
+        static std::regex validPath("^/([A-Za-z0-9_]+/?)*$");
+        static std::regex validInterface(
             "^[A-Za-z_][A-Za-z0-9_]*(\\.[A-Za-z_][A-Za-z0-9_]*)+$");
 
         for (const auto& thisPath : *paths)

include/dbus_utility.hpp

@@ -103,7 +103,7 @@ using MapperEndPoints = std::vector<std::string>;
 
 inline void escapePathForDbus(std::string& path)
 {
-    const std::regex reg("[^A-Za-z0-9_/]");
+    const static std::regex reg("[^A-Za-z0-9_/]");
     std::regex_replace(path.begin(), path.begin(), path.end(), reg, "_");
 }
 

include/openbmc_dbus_rest.hpp

@@ -101,7 +101,7 @@ const constexpr char* forbiddenResDesc =
 
 inline bool validateFilename(const std::string& filename)
 {
-    std::regex validFilename(R"(^[\w\- ]+(\.?[\w\- ]*)$)");
+    static std::regex validFilename(R"(^[\w\- ]+(\.?[\w\- ]*)$)");
 
     return std::regex_match(filename, validFilename);
 }
@@ -2562,7 +2562,7 @@ inline void requestRoutes(App& app)
             // Filename should be in alphanumeric, dot and underscore
             // Its based on phosphor-debug-collector application
             // dumpfile format
-            std::regex dumpFileRegex("[a-zA-Z0-9\\._]+");
+            static std::regex dumpFileRegex("[a-zA-Z0-9\\._]+");
             if (!std::regex_match(dumpFileName, dumpFileRegex))
             {
                 BMCWEB_LOG_ERROR << "Invalid dump filename " << dumpFileName;

redfish-core/lib/ethernet.hpp

@@ -949,7 +949,7 @@ inline bool isHostnameValid(const std::string& hostname)
     // MUST handle host names of up to 63 characters (RFC 1123)
     // labels cannot start or end with hyphens (RFC 952)
     // labels can start with numbers (RFC 1123)
-    const std::regex pattern(
+    const static std::regex pattern(
         "^[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9]$");
 
     return std::regex_match(hostname, pattern);
@@ -959,7 +959,7 @@ inline bool isDomainnameValid(const std::string& domainname)
 {
     // Can have multiple subdomains
     // Top Level Domain's min length is 2 character
-    const std::regex pattern(
+    const static std::regex pattern(
         "^([A-Za-z0-9][a-zA-Z0-9\\-]{1,61}|[a-zA-Z0-9]{1,30}\\.)*[a-zA-Z]{2,}$");
 
     return std::regex_match(domainname, pattern);