/**
* collectd - src/lua.c
* Copyright (C) 2010 Julien Ammous
+ * Copyright (C) 2010 Florian Forster
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
*
* Authors:
* Julien Ammous
+ * Florian Forster <octo at collectd.org>
**/
+/* <lua5.1/luaconf.h> defines a macro using "sprintf". Although not used here,
+ * GCC will complain about the macro definition. */
+#define DONT_POISON_SPRINTF_YET
+
#include "collectd.h"
#include "plugin.h"
#include "common.h"
#include <lauxlib.h>
#include <lualib.h>
-#include "lua_exports.c"
+#if defined(COLLECT_DEBUG) && COLLECT_DEBUG && defined(__GNUC__) && __GNUC__
+# undef sprintf
+# pragma GCC poison sprintf
+#endif
typedef struct lua_script_s {
char *script_path;
struct lua_script_s *next;
} lua_script_t;
+struct clua_read_function_s
+{
+ lua_State *lua_state;
+ char *lua_function_name;
+};
+typedef struct clua_read_function_s clua_read_function_t;
+
+struct lua_c_functions_s
+{
+ char *name;
+ lua_CFunction func;
+};
+typedef struct lua_c_functions_s lua_c_functions_t;
+
static char base_path[PATH_MAX + 1] = "";
static lua_script_t *scripts = NULL;
-/* Declare the Lua libraries we wish to use.
- * Note: If you are opening and running a file containing Lua code using
- * 'lua_dofile(l, "myfile.lua") - you must delcare all the libraries used in
- * that file here also. */
-static const luaL_reg lua_load_libs[] =
+static int clua_read (user_data_t *ud) /* {{{ */
{
-#if COLLECT_DEBUG
- { LUA_DBLIBNAME, luaopen_debug },
-#endif
- { LUA_TABLIBNAME, luaopen_table },
- { LUA_IOLIBNAME, luaopen_io },
- { LUA_STRLIBNAME, luaopen_string },
- { LUA_MATHLIBNAME, luaopen_math }
+ clua_read_function_t *rf = ud->data;
+ int status;
+
+ /* Load the function to the stack */
+ lua_pushstring (rf->lua_state, rf->lua_function_name);
+ lua_gettable (rf->lua_state, LUA_REGISTRYINDEX);
+
+ if (!lua_isfunction (rf->lua_state, /* stack pos = */ -1))
+ {
+ ERROR ("lua plugin: Unable to lookup the read function \"%s\".",
+ rf->lua_function_name);
+ /* pop the value again */
+ lua_settop (rf->lua_state, -2);
+ return (-1);
+ }
+
+ lua_call (rf->lua_state, /* nargs = */ 0, /* nresults = */ 1);
+
+ if (lua_isnumber (rf->lua_state, -1))
+ {
+ status = (int) lua_tonumber (rf->lua_state, -1);
+ }
+ else
+ {
+ ERROR ("lua plugin: Read function \"%s\" did not return a numeric status.",
+ rf->lua_function_name);
+ status = -1;
+ }
+ /* pop the value */
+ lua_settop (rf->lua_state, -2);
+
+ return (status);
+} /* }}} int clua_read */
+
+/* Cleans up the stack, pushes the return value as a number onto the stack and
+ * returns the number of values returned (1). */
+#define RETURN_LUA(l,status) do { \
+ lua_State *_l_state = (l); \
+ lua_settop (_l_state, 0); \
+ lua_pushnumber (_l_state, (lua_Number) (status)); \
+ return (1); \
+} while (0)
+
+/*
+ * Exported functions
+ */
+static int lua_cb_log (lua_State *l) /* {{{ */
+{
+ int nargs = lua_gettop (l); /* number of arguments */
+ int severity;
+ const char *msg;
+
+ if (nargs != 2)
+ {
+ WARNING ("lua plugin: collectd_log() called with an invalid number of arguments (%i).",
+ nargs);
+ RETURN_LUA (l, -1);
+ }
+
+ if (!lua_isnumber (l, 1))
+ {
+ WARNING ("lua plugin: The first argument to collectd_log() must be a number.");
+ RETURN_LUA (l, -1);
+ }
+
+ if (!lua_isstring (l, 2))
+ {
+ WARNING ("lua plugin: The second argument to collectd_log() must be a string.");
+ RETURN_LUA (l, -1);
+ }
+
+ severity = (int) lua_tonumber (l, /* stack pos = */ 1);
+ if ((severity != LOG_ERR)
+ && (severity != LOG_WARNING)
+ && (severity != LOG_NOTICE)
+ && (severity != LOG_INFO)
+ && (severity != LOG_DEBUG))
+ severity = LOG_ERR;
+
+ msg = lua_tostring (l, 2);
+ if (msg == NULL)
+ {
+ ERROR ("lua plugin: lua_tostring failed.");
+ RETURN_LUA (l, -1);
+ }
+
+ plugin_log (severity, "%s", msg);
+
+ RETURN_LUA (l, 0);
+} /* }}} int lua_cb_log */
+
+static int lua_cb_register_read (lua_State *l) /* {{{ */
+{
+ static int count = 0;
+ int nargs = lua_gettop (l); /* number of arguments */
+ clua_read_function_t *rf;
+
+ int num = count++; /* XXX FIXME: Not thread-safe! */
+ char function_name[64];
+
+ if (nargs != 1)
+ {
+ WARNING ("lua plugin: collectd_register_read() called with an invalid "
+ "number of arguments (%i).", nargs);
+ RETURN_LUA (l, -1);
+ }
+
+ /* If the argument is a string, assume it's a global function and try to look
+ * it up. */
+ if (lua_isstring (l, /* stack pos = */ 1))
+ lua_gettable (l, LUA_GLOBALSINDEX);
+
+ if (!lua_isfunction (l, /* stack pos = */ 1))
+ {
+ WARNING ("lua plugin: The first argument of collectd_register_read() "
+ "must be a function.");
+ RETURN_LUA (l, -1);
+ }
+
+ ssnprintf (function_name, sizeof (function_name), "collectd.read_func_%i", num);
+
+ /* Push the name of the global variable */
+ lua_pushstring (l, function_name);
+ /* Push the name down to the first position */
+ lua_insert (l, 1);
+ /* Now set the global variable called "collectd". */
+ lua_settable (l, LUA_REGISTRYINDEX);
+
+ rf = malloc (sizeof (*rf));
+ if (rf == NULL)
+ {
+ ERROR ("lua plugin: malloc failed.");
+ RETURN_LUA (l, -1);
+ }
+ else
+ {
+ user_data_t ud = { rf, /* free func */ NULL /* FIXME */ };
+ char cb_name[DATA_MAX_NAME_LEN];
+
+ memset (rf, 0, sizeof (*rf));
+ rf->lua_state = l;
+ rf->lua_function_name = strdup (function_name);
+
+ ssnprintf (cb_name, sizeof (cb_name), "lua/read_func_%i", num);
+
+ plugin_register_complex_read (/* group = */ "lua",
+ /* name = */ cb_name,
+ /* callback = */ clua_read,
+ /* interval = */ NULL,
+ /* user_data = */ &ud);
+ }
+
+ DEBUG ("lua plugin: Successful call to lua_cb_register_read().");
+
+ RETURN_LUA (l, 0);
+} /* }}} int lua_cb_register_read */
+
+static lua_c_functions_t lua_c_functions[] =
+{
+ { "collectd_log", lua_cb_log },
+ { "collectd_register_read", lua_cb_register_read }
};
static void lua_script_free (lua_script_t *script) /* {{{ */
return (-1);
}
- /* Open up all the Lua libraries declared above. */
- for (i = 0; i < STATIC_ARRAY_SIZE (lua_load_libs); i++)
- {
- int status;
-
- status = (*lua_load_libs[i].func) (script->lua_state);
- if (status != 0)
- WARNING ("lua plugin: Loading library \"%s\" failed.",
- lua_load_libs[i].name);
- }
+ /* Open up all the standard Lua libraries. */
+ luaL_openlibs (script->lua_state);
/* Register all the functions we implement in C */
- register_exported_functions (script->lua_state);
+ for (i = 0; i < STATIC_ARRAY_SIZE (lua_c_functions); i++)
+ lua_register (script->lua_state,
+ lua_c_functions[i].name, lua_c_functions[i].func);
return (0);
} /* }}} int lua_script_init */
status = luaL_loadfile (script->lua_state, script->script_path);
if (status != 0)
{
+ ERROR ("lua plugin: luaL_loadfile failed with status %i", status);
+ lua_script_free (script);
+ return (-1);
+ }
+
+ status = lua_pcall (script->lua_state,
+ /* nargs = */ 0,
+ /* nresults = */ LUA_MULTRET,
+ /* errfunc = */ 0);
+ if (status != 0)
+ {
const char *errmsg;
- switch (status)
- {
- case LUA_ERRSYNTAX: errmsg = "Syntax error"; break;
- case LUA_ERRFILE: errmsg = "File I/O error"; break;
- case LUA_ERRMEM: errmsg = "Memory allocation error"; break;
- default: errmsg = "Unexpected error";
- }
+ errmsg = lua_tostring (script->lua_state, /* stack pos = */ -1);
- ERROR ("lua plugin: Loading script \"%s\" failed: %s",
- script->script_path, errmsg);
+ if (errmsg == NULL)
+ ERROR ("lua plugin: lua_pcall failed with status %i. "
+ "In addition, no error message could be retrieved from the stack.",
+ status);
+ else
+ ERROR ("lua plugin: Executing script \"%s\" failed:\n%s",
+ script->script_path, errmsg);
lua_script_free (script);
return (-1);
projects / collectd.git / blobdiff