A lua library by zengrong.net

Dependences

Following libraries are dependented:

• lpack
• BitOp
• LuaSocket

1. For pure lua

For some reason in my server development, I moved some packages that my wrote in to zr package (They were in cc package ago).

2. For quick-cocos2d-x

All of the dependences were included in quick-cocos2d-x.

This library has already been merged into quick-cocos2d-x framework.

In quick-cocos2d-x framework, these librares still use "cc" package name, and I won't update them.

3. Usage

You can import them by lib.zrong.init, it can import all of zrong's packages into a global table named zr , and also import some necessary global functions:

require("lib.zrong.init")

or if you have had these necessary global functions, you can require them in your code selectively:

utils = require("lib.zrong.zr.utils.init")
net = {}
net.SocketTCP = require("lib.zrong.zr.net.SocketTCP")

The necessary global functions are:

In functions.lua

• class
• import
• iskindof

4. API list

• zr.utils.Gettext
• zr.utils.ByteArray
• zr.utils.ByteArrayVarint
• zr.net.SocketTCP
• zr.log

## zr.utils.Gettext

A detailed example about GNU gettext and Poedit (in chinese): http://zengrong.net/post/1986.htm

Usage:

local Gettext = require("utils.Gettext")

-- Use lua io, cannot use in Android
local fd,err=io.open("main.mo","rb")
if not fd then return nil,err end
local raw_data=fd:read("*all")
fd:close()

local mo_data=assert(Gettext.parseData(raw_data))
print(mo_data["hello"])
-- 你好
print(mo_data["world"])
-- nil

-- Then you'll get a kind of gettext function:
local gettext= Gettext.gettext(raw_data)
print(gettext("hello"))
-- 你好
print(gettext("world"))
-- world

-- With a slight modification this will be ready-to-use for the xgettext tool:

_ = Gettext.gettext(raw_data)
print(_("hello"))
print(_("world"))

## zr.utils.ByteArray

It can serialize bytes stream like ActionScript flash.utils.ByteArray

It depends on lpack.

Usage:

local ByteArray = zr.utils.ByteArray
-- use lpack to write a pack
local __pack = string.pack("<bihP2", 0x59, 11, 1101, "", "中文")

-- create a ByteArray
local __ba = ByteArray.new()

-- ByteArray can write a lpack buffer directly
__ba:writeBuf(__pack)

-- remember, lua array started from 1
__ba:setPos(1)

-- now, you can read it like actionscript
print("ba.len:", __ba:getLen())
print("ba.readByte:", __ba:readByte())
print("ba.readInt:", __ba:readInt())
print("ba.readShort:", __ba:readShort())
print("ba.readString:", __ba:readStringUShort())
print("ba.available:", __ba:getAvailable())
-- dump it
print("ba.toString(16):", __ba:toString(16))

-- create a ByteArray
local __ba2 = ByteArray.new()

-- you can write some values like actionscript
-- also, you can use chaining calls.
__ba2:writeByte(0x59)
    :writeInt(11)
    :writeShort(1101)
-- write a empty string
__ba2:writeStringUShort("")
-- write some chinese string
__ba2:writeStringUShort("中文")

-- dump it
print("ba2.toString(10):", __ba2:toString(10))

Above codes will print like these:

## zr.utils.ByteArrayVarint

ByteArrayVarint depends on BitOP.

ByteArrayVarint implements the Varint encoding in google protocol buffer.

See following:

To understand your simple protocol buffer encoding, you first need to understand varints. Varints are a method of serializing integers using one or more bytes. Smaller numbers take a smaller number of bytes.

Each byte in a varint, except the last byte, has the most significant bit (msb) set – this indicates that there are further bytes to come. The lower 7 bits of each byte are used to store the two's complement representation of the number in groups of 7 bits, least significant group first.

Your can use these methods(and all ByteArray methods) in ByteArrayVarint:

Method Name	Description
ByteArrayVarint.readUVInt()	read a unsigned varint int
ByteArrayVarint.writeUVInt()	write a unsigned varint int
ByteArrayVarint.readVInt()	read varint int
ByteArrayVarint.writeVInt()	write varint int
ByteArrayVarint.readStringUVInt()	read a string preceding a unsigned varint int
ByteArrayVarint.writeStringUVInt()	write a string preceding a unsigned varint int

On account of a BitOP limitation, ByteArrayVarint will read a unsigned int as a minus.

## zr.net.SocketTCP

The SocketTCP depends on LuaSocket

Usage:

local SocketTCP = zr.net.SocketTCP
local ByteArray = zr.utils.ByteArray

socket = SocketTCP.new("127.0.0.1", 12001, false)
socket:addEventListener(SocketTCP.EVENT_CONNECTED, onStatus)
socket:addEventListener(SocketTCP.EVENT_CLOSE, onStatus)
socket:addEventListener(SocketTCP.EVENT_CLOSED, onStatus)
socket:addEventListener(SocketTCP.EVENT_CONNECT_FAILURE, onStatus)
socket:addEventListener(SocketTCP.EVENT_DATA, onData)

socket:send(ByteArray.new():writeByte(0x59):getPack())

function onStatus(__event)
    echoInfo("socket status: %s", __event.name)
end

function onData(__event)
    echoInfo("socket status: %s, data:%s", __event.name, ByteArray.toString(__event.data))
end

## zr.log

zr.log package is very similar to python logging package.

local logFilePath = 'log.txt'
local flogh = nil
local logFileHandler = io.open(logFilePath, 'w+b')

-- FileHandler can accept a file handler or a file name.
if logFileHandler then
    flogh = zr.log.FileHandler.new(logFileHandler, nil, true, true)
    flogh.filename = logFilePath
else
    flogh = zr.log.FileHandler.new(logFilePath, 'w+b', true, true)
end

local echo = print
-- A logger can accept one or more handler.
log = zr.log.Logger.new(zr.log.Logger.NOTSET, 
    zr.log.PrintHandler.new(echo), 
    flogh)
log:debug('You name?', 'zrong')
log:debug('My name is %s.', 'zrong')

-- Following contents will appear in console and log.txt.
-- [5.3278] You name?  zrong
-- [5.3279] My name is zrong.