Trace function for Lua (Step 1/?)

src/mod_lua.inl

@@ -1588,6 +1588,67 @@ lsp_get_option(lua_State *L)
 	return luaL_error(L, "invalid get_option() call");
 }
 
+static int s_lua_traceLevel = 1;
+static FILE *s_lua_traceFile = NULL;
+static pthread_mutex_t s_lua_traceMutex;
+
+
+/* mg.trace */
+static int
+lsp_trace(lua_State *L)
+{
+	int num_args = lua_gettop(L);
+	int arg_type[8];
+	int trace_level = 0;
+	int firstarg = 1;
+	int i;
+
+	for (i=0; i<8; i++) {
+		if (num_args >= (i + 1)) {
+			arg_type[i] = lua_type(L, (i + 1));
+		}
+		else {
+			arg_type[i] = LUA_TNIL;
+		}
+	}
+
+	if (arg_type[0] == LUA_TNUMBER) {
+		trace_level = lua_tointeger(L, 1);
+		if (num_args == 1) {
+			/* Set a new trace level, return the current one. */
+			lua_pushinteger(L, s_lua_traceLevel);
+			s_lua_traceLevel = trace_level;
+			if (s_lua_traceFile) {
+				pthread_mutex_lock(&s_lua_traceMutex);
+				fflush(s_lua_traceFile);
+				pthread_mutex_unlock(&s_lua_traceMutex);
+			}
+			return 1;
+		}
+		firstarg = 2;
+	}
+
+	if (trace_level > s_lua_traceLevel) {
+		/* If this trace request has a higher trace level than the global trace level, do not trace. */
+		lua_pushboolean(L, 0);
+		return 1;
+	}
+
+	/* Print to file */
+	if (s_lua_traceFile) {
+		pthread_mutex_lock(&s_lua_traceMutex);
+		for (i = firstarg; i <= num_args; i++) {
+			if (arg_type[i - 1] == LUA_TSTRING) {
+				const char *arg = lua_tostring(L, i);
+				fprintf(s_lua_traceFile, "%s\n", arg);
+			}
+		}
+		pthread_mutex_unlock(&s_lua_traceMutex);
+	}
+	lua_pushboolean(L, 1);
+	return 1;
+}
+
 
 /* UUID library and function pointer */
 union {
@@ -2232,6 +2293,7 @@ prepare_lua_environment(struct mg_context *ctx,
 	reg_function(L, "get_response_code_text", lsp_get_response_code_text);
 	reg_function(L, "random", lsp_random);
 	reg_function(L, "get_info", lsp_get_info);
+	reg_function(L, "trace", lsp_trace);
 
 	if (pf_uuid_generate.f) {
 		reg_function(L, "uuid", lsp_uuid);
@@ -2875,6 +2937,9 @@ static void *lib_handle_uuid = NULL;
 static void
 lua_init_optional_libraries(void)
 {
+	/* Create logging mutex */
+	pthread_mutex_init(&s_lua_traceMutex, &pthread_mutex_attr);
+	
 	/* shared Lua state */
 	lua_shared_init();
 
@@ -2903,6 +2968,9 @@ lua_exit_optional_libraries(void)
 
 	/* shared Lua state */
 	lua_shared_exit();
+
+	/* Delete logging mutex */
+	pthread_mutex_destroy(&s_lua_traceMutex);
 }