File

util-src/windows.c @ 11661:735b8f4a6d7e

net.http: Send entire HTTP request header as one write When opportunistic writes are enabled this reduces the number of syscalls and TCP packets sent on the wire. Experiments with TCP Fast Open made this even more obvious. That table trick probably wasn't as efficient. Lua generates bytecode for a table with zero array slots and space for two entries in the hash part, plus code to set [2] and [4]. I didn't verify but I suspect it would have had to resize the table when setting [1] and [3], although probably only once. Concatenating the strings directly in Lua is easier to read and involves no extra table or function call.
author Kim Alvefur <zash@zash.se>
date Thu, 08 Jul 2021 18:21:59 +0200
parent 10921:6eb5d2bb11af
child 12575:1f6f05a98fcd
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/* Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
*/

/*
* windows.c
* Windows support functions for Lua
*/

#include <stdio.h>
#include <windows.h>
#include <windns.h>

#include "lua.h"
#include "lauxlib.h"

#if (LUA_VERSION_NUM == 501)
#define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
#endif
#if (LUA_VERSION_NUM < 504)
#define luaL_pushfail lua_pushnil
#endif

static int Lget_nameservers(lua_State *L) {
	char stack_buffer[1024]; // stack allocated buffer
	IP4_ARRAY *ips = (IP4_ARRAY *) stack_buffer;
	DWORD len = sizeof(stack_buffer);
	DNS_STATUS status;

	status = DnsQueryConfig(DnsConfigDnsServerList, FALSE, NULL, NULL, ips, &len);

	if(status == 0) {
		DWORD i;
		lua_createtable(L, ips->AddrCount, 0);

		for(i = 0; i < ips->AddrCount; i++) {
			DWORD ip = ips->AddrArray[i];
			char ip_str[16] = "";
			sprintf_s(ip_str, sizeof(ip_str), "%d.%d.%d.%d", (ip >> 0) & 255, (ip >> 8) & 255, (ip >> 16) & 255, (ip >> 24) & 255);
			lua_pushstring(L, ip_str);
			lua_rawseti(L, -2, i + 1);
		}

		return 1;
	} else {
		luaL_pushfail(L);
		lua_pushfstring(L, "DnsQueryConfig returned %d", status);
		return 2;
	}
}

static int lerror(lua_State *L, char *string) {
	luaL_pushfail(L);
	lua_pushfstring(L, "%s: %d", string, GetLastError());
	return 2;
}

static int Lget_consolecolor(lua_State *L) {
	HWND console = GetStdHandle(STD_OUTPUT_HANDLE);
	WORD color;
	DWORD read_len;

	CONSOLE_SCREEN_BUFFER_INFO info;

	if(console == INVALID_HANDLE_VALUE) {
		return lerror(L, "GetStdHandle");
	}

	if(!GetConsoleScreenBufferInfo(console, &info)) {
		return lerror(L, "GetConsoleScreenBufferInfo");
	}

	if(!ReadConsoleOutputAttribute(console, &color, 1, info.dwCursorPosition, &read_len)) {
		return lerror(L, "ReadConsoleOutputAttribute");
	}

	lua_pushnumber(L, color);
	return 1;
}
static int Lset_consolecolor(lua_State *L) {
	int color = luaL_checkint(L, 1);
	HWND console = GetStdHandle(STD_OUTPUT_HANDLE);

	if(console == INVALID_HANDLE_VALUE) {
		return lerror(L, "GetStdHandle");
	}

	if(!SetConsoleTextAttribute(console, color)) {
		return lerror(L, "SetConsoleTextAttribute");
	}

	lua_pushboolean(L, 1);
	return 1;
}

static const luaL_Reg Reg[] = {
	{ "get_nameservers",	Lget_nameservers	},
	{ "get_consolecolor",	Lget_consolecolor	},
	{ "set_consolecolor",	Lset_consolecolor	},
	{ NULL,		NULL	}
};

LUALIB_API int luaopen_util_windows(lua_State *L) {
#if (LUA_VERSION_NUM > 501)
	luaL_checkversion(L);
#endif
	lua_newtable(L);
	luaL_setfuncs(L, Reg, 0);
	lua_pushliteral(L, "-3.14");
	lua_setfield(L, -2, "version");
	return 1;
}