feat use short log level

src/ulib/log/level.h

@@ -42,6 +42,26 @@ public:
         FATAL = ULOG_LEVEL_FATAL
     };
 
+    static const char *ToShortString(int level)
+    {
+        switch (level) {
+        case kTrace:
+            return "T";
+        case kDebug:
+            return "D";
+        case kInfo:
+            return "I";
+        case kWarn:
+            return "W";
+        case kError:
+            return "E";
+        case kFatal:
+            return "F";
+        default:
+            return "UNKNOWN";
+        }
+    }
+
     static const char *ToString(int level)
     {
         switch (level) {

src/ulib/log/logger.cpp

@@ -53,7 +53,7 @@ Logger::Log(int32_t level,
             const char *msg)
 {
     if (level < level_) { return; }
-    const char *level_name = Level::ToString(level);
+    const char *level_name = Level::ToShortString(level);
     /**
      * @brief time file:line@func tag level_name msg
      */
@@ -62,7 +62,7 @@ Logger::Log(int32_t level,
     /**
     * @brief time level_name tag file:line@func msg
       */
-    std::string pattern = "{} [{}] {} {}:{}@{}: {}";
+    std::string pattern = "{} {} {} {}:{}@{}: {}";
     std::string log_time;
     {
         std::time_t now = time(NULL);