File

util-src/table.c @ 12480:7e9ebdc75ce4

net: isolate LuaSec-specifics For this, various accessor functions are now provided directly on the sockets, which reach down into the LuaSec implementation to obtain the information. While this may seem of little gain at first, it hides the implementation detail of the LuaSec+LuaSocket combination that the actual socket and the TLS layer are separate objects. The net gain here is that an alternative implementation does not have to emulate that specific implementation detail and "only" has to expose LuaSec-compatible data structures on the new functions.
author Jonas Schäfer <jonas@wielicki.name>
date Wed, 27 Apr 2022 17:44:14 +0200
parent 12405:308ed64dc69b
child 12575:1f6f05a98fcd
line wrap: on
line source

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

#ifndef LUA_MAXINTEGER
#include <stdint.h>
#define LUA_MAXINTEGER PTRDIFF_MAX
#endif

#if (LUA_VERSION_NUM > 501)
#define lua_equal(L, A, B) lua_compare(L, A, B, LUA_OPEQ)
#endif

static int Lcreate_table(lua_State *L) {
	lua_createtable(L, luaL_checkinteger(L, 1), luaL_checkinteger(L, 2));
	return 1;
}

/* COMPAT: w/ Lua pre-5.4 */
static int Lpack(lua_State *L) {
	unsigned int n_args = lua_gettop(L);
	lua_createtable(L, n_args, 1);
	lua_insert(L, 1);

	for(int arg = n_args; arg >= 1; arg--) {
		lua_rawseti(L, 1, arg);
	}

	lua_pushinteger(L, n_args);
	lua_setfield(L, -2, "n");
	return 1;
}

/* COMPAT: w/ Lua pre-5.4 */
static int Lmove (lua_State *L) {
	lua_Integer f = luaL_checkinteger(L, 2);
	lua_Integer e = luaL_checkinteger(L, 3);
	lua_Integer t = luaL_checkinteger(L, 4);

	int tt = !lua_isnoneornil(L, 5) ? 5 : 1;  /* destination table */
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_checktype(L, tt, LUA_TTABLE);

	if (e >= f) {  /* otherwise, nothing to move */
		lua_Integer n, i;
		luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
		  "too many elements to move");
		n = e - f + 1;  /* number of elements to move */
		luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4,
		"destination wrap around");
		if (t > e || t <= f || (tt != 1 && !lua_equal(L, 1, tt))) {
			for (i = 0; i < n; i++) {
				lua_rawgeti(L, 1, f + i);
				lua_rawseti(L, tt, t + i);
			}
		} else {
			for (i = n - 1; i >= 0; i--) {
				lua_rawgeti(L, 1, f + i);
				lua_rawseti(L, tt, t + i);
			}
		}
	}

	lua_pushvalue(L, tt);  /* return destination table */
	return 1;
}

int luaopen_util_table(lua_State *L) {
#if (LUA_VERSION_NUM > 501)
	luaL_checkversion(L);
#endif
	lua_createtable(L, 0, 2);
	lua_pushcfunction(L, Lcreate_table);
	lua_setfield(L, -2, "create");
	lua_pushcfunction(L, Lpack);
	lua_setfield(L, -2, "pack");
	lua_pushcfunction(L, Lmove);
	lua_setfield(L, -2, "move");
	return 1;
}