dobrograd-13-06-2022/garrysmod/addons/admin-sg/lua/modules/bitbuf_glua/read.lua

--[[local config = include "./config.lua"
if (SERVER) then
	if (config and config.netstreamcompat) then
		util.AddNetworkString "BITBUF_NETSTREAM"
	end
	AddCSLuaFile()
end
]]
if (SERVER) then
	AddCSLuaFile()
end
local function bad(val, argn, name, err)
	if (not val) then
		error(("bad argument #%i to '%s' (%s)"):format(argn, name, err), 2)
	end
end

local mt = {
	__index = function(self, k)
	  return getmetatable(self)[k]
	end,
	__call = function(self, data)
		return setmetatable({}, getmetatable(self)):Init(data)
	end
}

local function nop() end

local bb_read = setmetatable({
	SetupQueuedCallback = function(name, cb, filter)
		bad(isfunction(cb), 2, "SetupQueuedCallback", "expected function")
		local states = {}
		net.Receive(name, function(len, cl)
			states[cl] = states[cl] or {}
			local ID = net.ReadUInt(32)
			len = len - 32
			local state = states[cl][ID] or (function()
				len = len - 32
				local datalen = net.ReadUInt(32)
				;(filter or nop)(cl, datalen)
				return {len = datalen, current = 0}
			end)()
			
			table.insert(state, net.ReadData(len / 8))
			
			states[cl][ID] = state
			state.current = state.current + len / 8
			if (state.current >= state.len) then
				states[cl][ID] = nil
				cb(table.concat(state), cl)
			end
		
			
		end)
	end
}, mt)

function mt:Init(data)
	bad(isstring(data), 1, "Init", "string expected")
	self:SetData(data)
	return self
end

function mt:SetData(data)
	self.RawData = {}
	data:gsub("().", function(match)
		self.RawData[match] = data:byte(match, match)
	end)
	self.Bits = 0
	self.Bytes = 1
	return self
end

function mt:Byte()
	return self:UInt(8)
end

function mt:Data(len)
	local dat = {}
	for i = 1, len do
		dat[i] = string.char(self:Byte())
	end
	
	return table.concat(dat)
end

function mt:String()
	local b = self:Byte()
	local dat = { n = 0 }
	while (b ~= 0) do
		dat[dat.n + 1] = string.char(b)
		dat.n = dat.n + 1
		b = self:Byte()
	end
	
	return table.concat(dat)
end

function mt:Int(totalbits)
	bad(isnumber(totalbits), 1, "Int", "number expected")
	bad(totalbits <= 32 and totalbits > 0, 1, "Int", "a number 1 through 32 expected")
	
	local retnum = 0
	
	for i = 1, totalbits do 
		local bitread = self.Bits % 8
		
		local byte = self.RawData[self.Bytes]
		
		-- retnum |= ((byte & (1 << bitread)) >> bitread) << (totalbits - i)
		local bitmask = bit.lshift(1, 7-bitread)
		local bitn = bit.rshift(bit.band(byte, bitmask), 7 - bitread)
		retnum = bit.bor(retnum, bit.lshift(bitn, totalbits - i))
		
		self.Bits = self.Bits + 1
		if (self.Bits % 8 == 0) then
			self.Bytes = self.Bytes + 1
		end
	end
	
	if (retnum > 0 and bit.band(retnum, 2^(totalbits - 1)) ~= 0) then
		retnum = retnum - 2^totalbits
	end
	
	return retnum
end

function mt:UInt(bits)
	local r = self:Int(bits)
	if (r < 0) then
		r = r + 2^bits
	end
	return r
end

--[[ THE NEXT TWO FUNCTIONS ARE GIVEN RIGHTS TO ME FOR USAGE UNDER MIT LICENSE BY THE CREATOR ]]

local function UInt32sToDouble (low, high)
	local negative = false
	
	if high >= 0x80000000 then
		negative = true
		high = high - 0x80000000
	end
	
	local biasedExponent = bit.rshift (bit.band (high, 0x7FF00000), 20)
	local mantissa = (bit.band (high, 0x000FFFFF) * 4294967296 + low) / 2 ^ 52
	
	local f
	if biasedExponent == 0x0000 then
		f = mantissa == 0 and 0 or math.ldexp (mantissa, -1022)
	elseif biasedExponent == 0x07FF then
		f = mantissa == 0 and math.huge or (math.huge - math.huge)
	else
		f = math.ldexp (1 + mantissa, biasedExponent - 1023)
	end
	
	return negative and -f or f
end

local function UInt32ToFloat (n)
	-- 1 sign bit
	-- 8 biased exponent bits (bias of 127, biased value of 0 if 0 or denormal)
	-- 23 mantissa bits (implicit 1, unless biased exponent is 0)
	
	local negative = false
	
	if n >= 0x80000000 then
		negative = true
		n = n - 0x80000000
	end
	
	local biasedExponent = bit.rshift (bit.band (n, 0x7F800000), 23)
	local mantissa = bit.band (n, 0x007FFFFF) / (2 ^ 23)
	
	local f
	if biasedExponent == 0x00 then
		f = mantissa == 0 and 0 or math.ldexp (mantissa, -126)
	elseif biasedExponent == 0xFF then
		f = mantissa == 0 and math.huge or (math.huge - math.huge)
	else
		f = math.ldexp (1 + mantissa, biasedExponent - 127)
	end
	
	return negative and -f or f
end

function mt:Float()
	return UInt32ToFloat(self:UInt(32))
end

function mt:Double(dbl) 
	local low = self:UInt(32)
	local high = self:UInt(32)
	return UInt32sToDouble(low, high)
end

function mt:Write()
	
	net.Start(self.Name)
	
end

return bb_read