util-src/strbitop.c
author Kim Alvefur <zash@zash.se>
Mon, 17 Oct 2022 15:20:06 +0200
changeset 12779 1dd468c63a3d
parent 12579 1f6f05a98fcd
child 12980 a187600ec7d6
permissions -rw-r--r--
mod_blocklist: Add option 'migrate_legacy_blocking' to disable migration from mod_privacy Tiny performance improvement for new users by skipping this check. Most servers should have gone trough the migration for all active users long ago. As a suitable first step of phasing out this code, we make it possible to disable it first. Later it can be disabled by default, before finally the code is deleted.

/*
 * This project is MIT licensed. Please see the
 * COPYING file in the source package for more information.
 *
 * Copyright (C) 2016 Kim Alvefur
 */

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


/* TODO Deduplicate code somehow */

static int strop_and(lua_State *L) {
	luaL_Buffer buf;
	size_t a, b, i;
	const char *str_a = luaL_checklstring(L, 1, &a);
	const char *str_b = luaL_checklstring(L, 2, &b);

	luaL_buffinit(L, &buf);

	if(a == 0 || b == 0) {
		lua_settop(L, 1);
		return 1;
	}

	for(i = 0; i < a; i++) {
		luaL_addchar(&buf, str_a[i] & str_b[i % b]);
	}

	luaL_pushresult(&buf);
	return 1;
}

static int strop_or(lua_State *L) {
	luaL_Buffer buf;
	size_t a, b, i;
	const char *str_a = luaL_checklstring(L, 1, &a);
	const char *str_b = luaL_checklstring(L, 2, &b);

	luaL_buffinit(L, &buf);

	if(a == 0 || b == 0) {
		lua_settop(L, 1);
		return 1;
	}

	for(i = 0; i < a; i++) {
		luaL_addchar(&buf, str_a[i] | str_b[i % b]);
	}

	luaL_pushresult(&buf);
	return 1;
}

static int strop_xor(lua_State *L) {
	luaL_Buffer buf;
	size_t a, b, i;
	const char *str_a = luaL_checklstring(L, 1, &a);
	const char *str_b = luaL_checklstring(L, 2, &b);

	luaL_buffinit(L, &buf);

	if(a == 0 || b == 0) {
		lua_settop(L, 1);
		return 1;
	}

	for(i = 0; i < a; i++) {
		luaL_addchar(&buf, str_a[i] ^ str_b[i % b]);
	}

	luaL_pushresult(&buf);
	return 1;
}

LUA_API int luaopen_util_strbitop(lua_State *L) {
	luaL_Reg exports[] = {
		{ "sand", strop_and },
		{ "sor",  strop_or },
		{ "sxor", strop_xor },
		{ NULL, NULL }
	};

	lua_newtable(L);
	luaL_setfuncs(L, exports, 0);
	return 1;
}