improve logging facility

we have a log viewer within the program now

src/ta-log.h

@@ -19,8 +19,12 @@
 
 #ifndef _TA_LOG_H
 #define _TA_LOG_H
+#include <chrono>
 #include <stdio.h>
 #include <stdarg.h>
+#include <atomic>
+#include <string>
+#include <fmt/printf.h>
 
 #define LOGLEVEL_ERROR 0
 #define LOGLEVEL_WARN 1
@@ -28,11 +32,51 @@
 #define LOGLEVEL_DEBUG 3
 #define LOGLEVEL_TRACE 4
 
+// this has to be a power of 2
+#define TA_LOG_SIZE 2048
+
 extern int logLevel;
 
-int logV(const char* format, ...);
-int logD(const char* format, ...);
-int logI(const char* format, ...);
-int logW(const char* format, ...);
-int logE(const char* format, ...);
+extern std::atomic<unsigned short> logPosition;
+
+struct LogEntry {
+  int loglevel;
+  std::chrono::system_clock::time_point time;
+  std::string text;
+  bool ready;
+  LogEntry():
+    loglevel(0),
+    ready(false) {}
+};
+
+int writeLog(int level, const char* msg, fmt::printf_args& args);
+
+extern LogEntry logEntries[TA_LOG_SIZE];
+
+template<typename... T> int logV(const char* msg, const T&... args) {
+  fmt::printf_args a=fmt::make_printf_args(args...);
+  return writeLog(LOGLEVEL_TRACE,msg,a);
+}
+
+template<typename... T> int logD(const char* msg, const T&... args) {
+  fmt::printf_args a=fmt::make_printf_args(args...);
+  return writeLog(LOGLEVEL_DEBUG,msg,a);
+}
+
+template<typename... T> int logI(const char* msg, const T&... args) {
+  fmt::printf_args a=fmt::make_printf_args(args...);
+  return writeLog(LOGLEVEL_INFO,msg,a);
+}
+
+template<typename... T> int logW(const char* msg, const T&... args) {
+  fmt::printf_args a=fmt::make_printf_args(args...);
+  return writeLog(LOGLEVEL_WARN,msg,a);
+}
+
+template<typename... T> int logE(const char* msg, const T&... args) {
+  fmt::printf_args a=fmt::make_printf_args(args...);
+  return writeLog(LOGLEVEL_ERROR,msg,a);
+}
+
+void initLog();
 #endif