File

util-src/windows.c @ 13552:f0b2c026e542

net.server_epoll: Improve efficiency of sending much buffered data Problem: The string slice operations when a lot of data gets buffered ends up being expensive and memory-consuming. We have util.dbuffer for precisely this kind of thing. I want to keep the behavior of writebuffer being upgraded from nil to a string to full buffer since the last step involves three table allocations, where the previous buffer method only used one. Avoiding those allocations for simple writes like white space keep alive feels like it would keep memory churn down. This work was started in 2020
author Kim Alvefur <zash@zash.se>
date Sat, 09 Nov 2024 00:37:15 +0100
parent 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 < 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) {
	luaL_checkversion(L);
	lua_newtable(L);
	luaL_setfuncs(L, Reg, 0);
	lua_pushliteral(L, "-3.14");
	lua_setfield(L, -2, "version");
	return 1;
}