--[[
	Public functions:
		CreateStream(data_or_nil)
	A stream object, has the methods:
		stream:WriteString(string)	::		nil
		stream:WriteInt(num,bytes)	::		nil

		stream:ReadString()			::		string
		stream:ReadInt(bytes)		::		number

		stream:ToString()			::		string
]]

local ss = {}

local function WriteString(self,string)
	local buflen = #self.buf
	for i=1,#string do
		self.buf[buflen+i] = string.byte(string,i)
	end
	self.buf[#self.buf + 1] = 0
end

local function WriteInt(self,num,bytes)
	local buflen = #self.buf
	local byte = 255
	for i = 1,bytes do
		--[[
		pack[i] = (num & byte) >> (i-1)*8
		byte = 255 << i*8
		]]
		self.buf[buflen + i] = bit.rshift(bit.band(num,byte),(i-1)*8)
		byte = bit.lshift(255,i*8)
	end
end

local function ReadInt(self,len)
	local tbl = {}
	for i = 1, len do
		tbl[i] = self.buf[i]
	end
	for i = 1, #self.buf do
		self.buf[i] = self.buf[i+len]
	end
	local byte = 1
	local num = 0
	for i = 1, #tbl do
		num = num + (tbl[i] * byte)
		byte = 2 ^ (i*8)
	end
	return num
end

local function ReadString(self)
	local str = {}
	local strlen = 1
	while self.buf[strlen] ~= 0 do
		str[#str + 1] = string.char(self.buf[strlen])
		strlen = strlen + 1
	end
	for i = 1,strlen do
		self.buf[i] = self.buf[i+strlen]
	end
	return table.concat(str)
end

local function ToString(self)
	return table.concat(self.buf)
end

function ss.CreateStream(str)
	local ns = {}
	ns.buf = {}
	if str ~= nil then
		for i = 1, #str do
			ns[i] = str[i]
		end
	end
	ns.ReadString = ReadString
	ns.ReadInt = ReadInt
	ns.WriteString = WriteString
	ns.WriteInt = WriteInt
	ns.ToString = ToString
	return ns
end

return ss