lua_converter.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>

#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>

#include "libretrodb.h"
#include "lua_common.h"

int master_key = 1;

const char * LUA_COMMON = " \
function binary(s) if s ~= nil then return {binary = s} else return nil end end \
function uint(s) if s ~= nil then return {uint = s} else return nil end end \
";

static int call_init(
        lua_State * L,
        int argc,
        const char ** argv
) {
	int rv = -1;
	int i;

	lua_getglobal(L, "init");
	for (i = 0; i < argc; i++) {
		lua_pushstring(L, argv[i]);
	}

	if (lua_pcall(L, argc, 0, 0) != 0) {
		printf(
		        "error running function `init': %s\n",
		        lua_tostring(L, -1)
		);
	}

	return rv;
}

static int value_provider(
        void * ctx,
        struct rmsgpack_dom_value * out
) {
	int rv;
	lua_State * L = ctx;

	lua_getglobal(L, "get_value");

	if (lua_pcall(L, 0, 1, 0) != 0) {
		printf(
		        "error running function `get_value': %s\n",
		        lua_tostring(L, -1)
		);
	}

	if (lua_isnil(L, -1)) {
		rv = 1;
	} else if (lua_istable(L, -1)) {
		rv = libretrodb_lua_to_rmsgpack_value(L, -1, out);
	} else {
		printf("function `get_value' must return a table or nil\n");
	}
	lua_pop(L, 1);
	return rv;
}

int main(
        int argc,
        char ** argv
){
	const char * db_file;
	const char * lua_file;
	int dst = -1;
	int rv = 0;

	if (argc < 3) {
		printf("usage:\n%s <db file> <lua file> [args ...]\n", argv[0]);
		return 1;
	}

	db_file = argv[1];
	lua_file = argv[2];

	lua_State * L = luaL_newstate();
	luaL_openlibs(L);
	luaL_dostring(L, LUA_COMMON);

	if (luaL_dofile(L, lua_file) != 0) {
		return 1;
	}

	call_init(L, argc - 2, (const char **) argv + 2);

	dst = open(db_file, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
	if (dst == -1) {
		printf(
		        "Could not open destination file '%s': %s\n",
		        db_file,
		        strerror(errno)
		);
		rv = errno;
		goto clean;
	}

	rv = libretrodb_create(dst, &value_provider, L);
clean:
	lua_close(L);
	if (dst != -1) {
		close(dst);
	}
	return rv;
}