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|
/* Copyright (c) 2014, Vsevolod Stakhov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file lua ucl bindings
*/
#include "ucl.h"
#include "ucl_internal.h"
#include "lua_ucl.h"
#include <strings.h>
/***
* @module ucl
* This lua module allows to parse objects from strings and to store data into
* ucl objects. It uses `libucl` C library to parse and manipulate with ucl objects.
* @example
local ucl = require("ucl")
local parser = ucl.parser()
local res,err = parser:parse_string('{key=value}')
if not res then
print('parser error: ' .. err)
else
local obj = parser:get_object()
local got = ucl.to_format(obj, 'json')
endif
local table = {
str = 'value',
num = 100500,
null = ucl.null,
func = function ()
return 'huh'
end
}
print(ucl.to_format(table, 'ucl'))
-- Output:
--[[
num = 100500;
str = "value";
null = null;
func = "huh";
--]]
*/
#define PARSER_META "ucl.parser.meta"
#define EMITTER_META "ucl.emitter.meta"
#define NULL_META "null.emitter.meta"
static int ucl_object_lua_push_array (lua_State *L, const ucl_object_t *obj);
static int ucl_object_lua_push_scalar (lua_State *L, const ucl_object_t *obj, bool allow_array);
static ucl_object_t* ucl_object_lua_fromtable (lua_State *L, int idx);
static ucl_object_t* ucl_object_lua_fromelt (lua_State *L, int idx);
static void *ucl_null;
struct ucl_lua_funcdata {
lua_State *L;
int idx;
char *ret;
};
/**
* Push a single element of an object to lua
* @param L
* @param key
* @param obj
*/
static void
ucl_object_lua_push_element (lua_State *L, const char *key,
const ucl_object_t *obj)
{
lua_pushstring (L, key);
ucl_object_push_lua (L, obj, true);
lua_settable (L, -3);
}
static void
lua_ucl_userdata_dtor (void *ud)
{
struct ucl_lua_funcdata *fd = (struct ucl_lua_funcdata *)ud;
luaL_unref (fd->L, LUA_REGISTRYINDEX, fd->idx);
if (fd->ret != NULL) {
free (fd->ret);
}
free (fd);
}
static const char *
lua_ucl_userdata_emitter (void *ud)
{
struct ucl_lua_funcdata *fd = (struct ucl_lua_funcdata *)ud;
const char *out = "";
lua_rawgeti (fd->L, LUA_REGISTRYINDEX, fd->idx);
lua_pcall (fd->L, 0, 1, 0);
out = lua_tostring (fd->L, -1);
if (out != NULL) {
/* We need to store temporary string in a more appropriate place */
if (fd->ret) {
free (fd->ret);
}
fd->ret = strdup (out);
}
lua_settop (fd->L, 0);
return fd->ret;
}
/**
* Push a single object to lua
* @param L
* @param obj
* @return
*/
static int
ucl_object_lua_push_object (lua_State *L, const ucl_object_t *obj,
bool allow_array)
{
const ucl_object_t *cur;
ucl_object_iter_t it = NULL;
int nelt = 0;
if (allow_array && obj->next != NULL) {
/* Actually we need to push this as an array */
return ucl_object_lua_push_array (L, obj);
}
/* Optimize allocation by preallocation of table */
while (ucl_iterate_object (obj, &it, true) != NULL) {
nelt ++;
}
lua_createtable (L, 0, nelt);
it = NULL;
while ((cur = ucl_iterate_object (obj, &it, true)) != NULL) {
ucl_object_lua_push_element (L, ucl_object_key (cur), cur);
}
return 1;
}
/**
* Push an array to lua as table indexed by integers
* @param L
* @param obj
* @return
*/
static int
ucl_object_lua_push_array (lua_State *L, const ucl_object_t *obj)
{
const ucl_object_t *cur;
int i = 1, nelt = 0;
/* Optimize allocation by preallocation of table */
LL_FOREACH (obj, cur) {
nelt ++;
}
lua_createtable (L, nelt, 0);
LL_FOREACH (obj, cur) {
ucl_object_push_lua (L, cur, false);
lua_rawseti (L, -2, i);
i ++;
}
return 1;
}
/**
* Push a simple object to lua depending on its actual type
*/
static int
ucl_object_lua_push_scalar (lua_State *L, const ucl_object_t *obj,
bool allow_array)
{
struct ucl_lua_funcdata *fd;
if (allow_array && obj->next != NULL) {
/* Actually we need to push this as an array */
return ucl_object_lua_push_array (L, obj);
}
switch (obj->type) {
case UCL_BOOLEAN:
lua_pushboolean (L, ucl_obj_toboolean (obj));
break;
case UCL_STRING:
lua_pushstring (L, ucl_obj_tostring (obj));
break;
case UCL_INT:
#if LUA_VERSION_NUM >= 501
lua_pushinteger (L, ucl_obj_toint (obj));
#else
lua_pushnumber (L, ucl_obj_toint (obj));
#endif
break;
case UCL_FLOAT:
case UCL_TIME:
lua_pushnumber (L, ucl_obj_todouble (obj));
break;
case UCL_NULL:
lua_getfield (L, LUA_REGISTRYINDEX, "ucl.null");
break;
case UCL_USERDATA:
fd = (struct ucl_lua_funcdata *)obj->value.ud;
lua_rawgeti (L, LUA_REGISTRYINDEX, fd->idx);
break;
default:
lua_pushnil (L);
break;
}
return 1;
}
/***
* @function ucl_object_push_lua(L, obj, allow_array)
* This is a `C` function to push `UCL` object as lua variable. This function
* converts `obj` to lua representation using the following conversions:
*
* - *scalar* values are directly presented by lua objects
* - *userdata* values are converted to lua function objects using `LUA_REGISTRYINDEX`,
* this can be used to pass functions from lua to c and vice-versa
* - *arrays* are converted to lua tables with numeric indicies suitable for `ipairs` iterations
* - *objects* are converted to lua tables with string indicies
* @param {lua_State} L lua state pointer
* @param {ucl_object_t} obj object to push
* @param {bool} allow_array expand implicit arrays (should be true for all but partial arrays)
* @return {int} `1` if an object is pushed to lua
*/
int
ucl_object_push_lua (lua_State *L, const ucl_object_t *obj, bool allow_array)
{
switch (obj->type) {
case UCL_OBJECT:
return ucl_object_lua_push_object (L, obj, allow_array);
case UCL_ARRAY:
return ucl_object_lua_push_array (L, obj->value.av);
default:
return ucl_object_lua_push_scalar (L, obj, allow_array);
}
}
/**
* Parse lua table into object top
* @param L
* @param top
* @param idx
*/
static ucl_object_t *
ucl_object_lua_fromtable (lua_State *L, int idx)
{
ucl_object_t *obj, *top = NULL;
size_t keylen;
const char *k;
bool is_array = true;
int max = INT_MIN;
if (idx < 0) {
/* For negative indicies we want to invert them */
idx = lua_gettop (L) + idx + 1;
}
/* Check for array */
lua_pushnil (L);
while (lua_next (L, idx) != 0) {
if (lua_type (L, -2) == LUA_TNUMBER) {
double num = lua_tonumber (L, -2);
if (num == (int)num) {
if (num > max) {
max = num;
}
}
else {
/* Keys are not integer */
lua_pop (L, 2);
is_array = false;
break;
}
}
else {
/* Keys are not numeric */
lua_pop (L, 2);
is_array = false;
break;
}
lua_pop (L, 1);
}
/* Table iterate */
if (is_array) {
int i;
top = ucl_object_typed_new (UCL_ARRAY);
for (i = 1; i <= max; i ++) {
lua_pushinteger (L, i);
lua_gettable (L, idx);
obj = ucl_object_lua_fromelt (L, lua_gettop (L));
if (obj != NULL) {
ucl_array_append (top, obj);
}
}
}
else {
lua_pushnil (L);
top = ucl_object_typed_new (UCL_OBJECT);
while (lua_next (L, idx) != 0) {
/* copy key to avoid modifications */
k = lua_tolstring (L, -2, &keylen);
obj = ucl_object_lua_fromelt (L, lua_gettop (L));
if (obj != NULL) {
ucl_object_insert_key (top, obj, k, keylen, true);
}
lua_pop (L, 1);
}
}
return top;
}
/**
* Get a single element from lua to object obj
* @param L
* @param obj
* @param idx
*/
static ucl_object_t *
ucl_object_lua_fromelt (lua_State *L, int idx)
{
int type;
double num;
ucl_object_t *obj = NULL;
struct ucl_lua_funcdata *fd;
type = lua_type (L, idx);
switch (type) {
case LUA_TSTRING:
obj = ucl_object_fromstring_common (lua_tostring (L, idx), 0, 0);
break;
case LUA_TNUMBER:
num = lua_tonumber (L, idx);
if (num == (int64_t)num) {
obj = ucl_object_fromint (num);
}
else {
obj = ucl_object_fromdouble (num);
}
break;
case LUA_TBOOLEAN:
obj = ucl_object_frombool (lua_toboolean (L, idx));
break;
case LUA_TUSERDATA:
if (lua_topointer (L, idx) == ucl_null) {
obj = ucl_object_typed_new (UCL_NULL);
}
break;
case LUA_TTABLE:
case LUA_TFUNCTION:
case LUA_TTHREAD:
if (luaL_getmetafield (L, idx, "__gen_ucl")) {
if (lua_isfunction (L, -1)) {
lua_settop (L, 3); /* gen, obj, func */
lua_insert (L, 1); /* func, gen, obj */
lua_insert (L, 2); /* func, obj, gen */
lua_call(L, 2, 1);
obj = ucl_object_lua_fromelt (L, 1);
}
lua_pop (L, 2);
}
else {
if (type == LUA_TTABLE) {
obj = ucl_object_lua_fromtable (L, idx);
}
else if (type == LUA_TFUNCTION) {
fd = malloc (sizeof (*fd));
if (fd != NULL) {
lua_pushvalue (L, idx);
fd->L = L;
fd->ret = NULL;
fd->idx = luaL_ref (L, LUA_REGISTRYINDEX);
obj = ucl_object_new_userdata (lua_ucl_userdata_dtor,
lua_ucl_userdata_emitter);
obj->type = UCL_USERDATA;
obj->value.ud = (void *)fd;
}
}
}
break;
}
return obj;
}
/**
* @function ucl_object_lua_import(L, idx)
* Extracts ucl object from lua variable at `idx` position,
* @see ucl_object_push_lua for conversion definitions
* @param {lua_state} L lua state machine pointer
* @param {int} idx index where the source variable is placed
* @return {ucl_object_t} new ucl object extracted from lua variable. Reference count of this object is 1,
* this object thus needs to be unref'ed after usage.
*/
ucl_object_t *
ucl_object_lua_import (lua_State *L, int idx)
{
ucl_object_t *obj;
int t;
t = lua_type (L, idx);
switch (t) {
case LUA_TTABLE:
obj = ucl_object_lua_fromtable (L, idx);
break;
default:
obj = ucl_object_lua_fromelt (L, idx);
break;
}
return obj;
}
static int
lua_ucl_parser_init (lua_State *L)
{
struct ucl_parser *parser, **pparser;
int flags = 0;
if (lua_gettop (L) >= 1) {
flags = lua_tonumber (L, 1);
}
parser = ucl_parser_new (flags);
if (parser == NULL) {
lua_pushnil (L);
}
pparser = lua_newuserdata (L, sizeof (parser));
*pparser = parser;
luaL_getmetatable (L, PARSER_META);
lua_setmetatable (L, -2);
return 1;
}
static struct ucl_parser *
lua_ucl_parser_get (lua_State *L, int index)
{
return *((struct ucl_parser **) luaL_checkudata(L, index, PARSER_META));
}
/***
* @method parser:parse_file(name)
* Parse UCL object from file.
* @param {string} name filename to parse
* @return {bool[, string]} if res is `true` then file has been parsed successfully, otherwise an error string is also returned
@example
local parser = ucl.parser()
local res,err = parser:parse_file('/some/file.conf')
if not res then
print('parser error: ' .. err)
else
-- Do something with object
end
*/
static int
lua_ucl_parser_parse_file (lua_State *L)
{
struct ucl_parser *parser;
const char *file;
int ret = 2;
parser = lua_ucl_parser_get (L, 1);
file = luaL_checkstring (L, 2);
if (parser != NULL && file != NULL) {
if (ucl_parser_add_file (parser, file)) {
lua_pushboolean (L, true);
ret = 1;
}
else {
lua_pushboolean (L, false);
lua_pushstring (L, ucl_parser_get_error (parser));
}
}
else {
lua_pushboolean (L, false);
lua_pushstring (L, "invalid arguments");
}
return ret;
}
/***
* @method parser:parse_string(input)
* Parse UCL object from file.
* @param {string} input string to parse
* @return {bool[, string]} if res is `true` then file has been parsed successfully, otherwise an error string is also returned
*/
static int
lua_ucl_parser_parse_string (lua_State *L)
{
struct ucl_parser *parser;
const char *string;
size_t llen;
int ret = 2;
parser = lua_ucl_parser_get (L, 1);
string = luaL_checklstring (L, 2, &llen);
if (parser != NULL && string != NULL) {
if (ucl_parser_add_chunk (parser, (const unsigned char *)string, llen)) {
lua_pushboolean (L, true);
ret = 1;
}
else {
lua_pushboolean (L, false);
lua_pushstring (L, ucl_parser_get_error (parser));
}
}
else {
lua_pushboolean (L, false);
lua_pushstring (L, "invalid arguments");
}
return ret;
}
/***
* @method parser:get_object()
* Get top object from parser and export it to lua representation.
* @return {variant or nil} ucl object as lua native variable
*/
static int
lua_ucl_parser_get_object (lua_State *L)
{
struct ucl_parser *parser;
ucl_object_t *obj;
int ret = 1;
parser = lua_ucl_parser_get (L, 1);
obj = ucl_parser_get_object (parser);
if (obj != NULL) {
ret = ucl_object_push_lua (L, obj, false);
/* no need to keep reference */
ucl_object_unref (obj);
}
else {
lua_pushnil (L);
}
return ret;
}
static int
lua_ucl_parser_gc (lua_State *L)
{
struct ucl_parser *parser;
parser = lua_ucl_parser_get (L, 1);
ucl_parser_free (parser);
return 0;
}
static void
lua_ucl_parser_mt (lua_State *L)
{
luaL_newmetatable (L, PARSER_META);
lua_pushvalue(L, -1);
lua_setfield(L, -2, "__index");
lua_pushcfunction (L, lua_ucl_parser_gc);
lua_setfield (L, -2, "__gc");
lua_pushcfunction (L, lua_ucl_parser_parse_file);
lua_setfield (L, -2, "parse_file");
lua_pushcfunction (L, lua_ucl_parser_parse_string);
lua_setfield (L, -2, "parse_string");
lua_pushcfunction (L, lua_ucl_parser_get_object);
lua_setfield (L, -2, "get_object");
lua_pop (L, 1);
}
static int
lua_ucl_to_string (lua_State *L, const ucl_object_t *obj, enum ucl_emitter type)
{
unsigned char *result;
result = ucl_object_emit (obj, type);
if (result != NULL) {
lua_pushstring (L, (const char *)result);
free (result);
}
else {
lua_pushnil (L);
}
return 1;
}
static int
lua_ucl_to_json (lua_State *L)
{
ucl_object_t *obj;
int format = UCL_EMIT_JSON;
if (lua_gettop (L) > 1) {
if (lua_toboolean (L, 2)) {
format = UCL_EMIT_JSON_COMPACT;
}
}
obj = ucl_object_lua_import (L, 1);
if (obj != NULL) {
lua_ucl_to_string (L, obj, format);
ucl_object_unref (obj);
}
else {
lua_pushnil (L);
}
return 1;
}
static int
lua_ucl_to_config (lua_State *L)
{
ucl_object_t *obj;
obj = ucl_object_lua_import (L, 1);
if (obj != NULL) {
lua_ucl_to_string (L, obj, UCL_EMIT_CONFIG);
ucl_object_unref (obj);
}
else {
lua_pushnil (L);
}
return 1;
}
/***
* @function ucl.to_format(var, format)
* Converts lua variable `var` to the specified `format`. Formats supported are:
*
* - `json` - fine printed json
* - `json-compact` - compacted json
* - `config` - fine printed configuration
* - `ucl` - same as `config`
* - `yaml` - embedded yaml
*
* If `var` contains function, they are called during output formatting and if
* they return string value, then this value is used for ouptut.
* @param {variant} var any sort of lua variable (if userdata then metafield `__to_ucl` is searched for output)
* @param {string} format any available format
* @return {string} string representation of `var` in the specific `format`.
* @example
local table = {
str = 'value',
num = 100500,
null = ucl.null,
func = function ()
return 'huh'
end
}
print(ucl.to_format(table, 'ucl'))
-- Output:
--[[
num = 100500;
str = "value";
null = null;
func = "huh";
--]]
*/
static int
lua_ucl_to_format (lua_State *L)
{
ucl_object_t *obj;
int format = UCL_EMIT_JSON;
if (lua_gettop (L) > 1) {
if (lua_type (L, 2) == LUA_TNUMBER) {
format = lua_tonumber (L, 2);
if (format < 0 || format >= UCL_EMIT_YAML) {
lua_pushnil (L);
return 1;
}
}
else if (lua_type (L, 2) == LUA_TSTRING) {
const char *strtype = lua_tostring (L, 2);
if (strcasecmp (strtype, "json") == 0) {
format = UCL_EMIT_JSON;
}
else if (strcasecmp (strtype, "json-compact") == 0) {
format = UCL_EMIT_JSON_COMPACT;
}
else if (strcasecmp (strtype, "yaml") == 0) {
format = UCL_EMIT_YAML;
}
else if (strcasecmp (strtype, "config") == 0 ||
strcasecmp (strtype, "ucl") == 0) {
format = UCL_EMIT_CONFIG;
}
}
}
obj = ucl_object_lua_import (L, 1);
if (obj != NULL) {
lua_ucl_to_string (L, obj, format);
ucl_object_unref (obj);
}
else {
lua_pushnil (L);
}
return 1;
}
static int
lua_ucl_null_tostring (lua_State* L)
{
lua_pushstring (L, "null");
return 1;
}
static void
lua_ucl_null_mt (lua_State *L)
{
luaL_newmetatable (L, NULL_META);
lua_pushcfunction (L, lua_ucl_null_tostring);
lua_setfield (L, -2, "__tostring");
lua_pop (L, 1);
}
int
luaopen_ucl (lua_State *L)
{
lua_ucl_parser_mt (L);
lua_ucl_null_mt (L);
/* Create the refs weak table: */
lua_createtable (L, 0, 2);
lua_pushliteral (L, "v"); /* tbl, "v" */
lua_setfield (L, -2, "__mode");
lua_pushvalue (L, -1); /* tbl, tbl */
lua_setmetatable (L, -2); /* tbl */
lua_setfield (L, LUA_REGISTRYINDEX, "ucl.refs");
lua_newtable (L);
lua_pushcfunction (L, lua_ucl_parser_init);
lua_setfield (L, -2, "parser");
lua_pushcfunction (L, lua_ucl_to_json);
lua_setfield (L, -2, "to_json");
lua_pushcfunction (L, lua_ucl_to_config);
lua_setfield (L, -2, "to_config");
lua_pushcfunction (L, lua_ucl_to_format);
lua_setfield (L, -2, "to_format");
ucl_null = lua_newuserdata (L, 0);
luaL_getmetatable (L, NULL_META);
lua_setmetatable (L, -2);
lua_pushvalue (L, -1);
lua_setfield (L, LUA_REGISTRYINDEX, "ucl.null");
lua_setfield (L, -2, "null");
return 1;
}
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