conversion to/from bytes and data buffer modules

res/modules/data_buffer.lua

@@ -0,0 +1,148 @@
+local bit_converter = require "core:bit_converter"
+
+-- Data buffer
+
+local data_buffer = { }
+
+function data_buffer.__call(bytes)
+	return setmetatable({ pos = 1, bytes = bytes or { } }, { __index = data_buffer })
+end
+
+-- Push functions
+
+function data_buffer:put_byte(byte)
+	if byte < 0 or byte > 255 then
+		error("invalid byte")
+	end
+
+	self.bytes[self.pos] = byte
+
+	self.pos = self.pos + 1
+end
+
+function data_buffer:put_bytes(bytes)
+	for i = 1, #bytes do
+		self:put_byte(bytes[i])
+	end
+end
+
+function data_buffer:put_single(single)
+	self:put_bytes(bit_converter.single_to_bytes(single))
+end
+
+function data_buffer:put_double(double)
+	self:put_bytes(bit_converter.double_to_bytes(double))
+end
+
+function data_buffer:put_string(str)
+	self:put_bytes(bit_converter.string_to_bytes(str))
+end
+
+function data_buffer:put_bool(bool)
+	self:put_byte(bit_converter.bool_to_byte(bool))
+end
+
+function data_buffer:put_uint16(uint16)
+	self:put_bytes(bit_converter.uint16_to_bytes(uint16))
+end
+
+function data_buffer:put_uint32(uint32)
+	self:put_bytes(bit_converter.uint32_to_bytes(uint32))
+end
+
+function data_buffer:put_int16(int16)
+	self:put_bytes(bit_converter.int16_to_bytes(int16))
+end
+
+function data_buffer:put_int32(int32)
+	self:put_bytes(bit_converter.int32_to_bytes(int32))
+end
+
+function data_buffer:put_int64(int64)
+	self:put_bytes(bit_converter.int64_to_bytes(int64))
+end
+
+-- Get functions
+
+function data_buffer:get_byte()
+	local byte = self.bytes[self.pos]
+	self.pos = self.pos + 1
+	return byte
+end
+
+function data_buffer:get_single()
+	return bit_converter.bytes_to_single(self:get_bytes(4))
+end
+
+function data_buffer:get_double()
+	return bit_converter.bytes_to_double(self:get_bytes(8))
+end
+
+function data_buffer:get_string()
+	local len = self:get_bytes(4)
+	local str = self:get_bytes(bit_converter.bytes_to_int32(len))
+	local bytes = { }
+
+	for i = 1, #len do
+		bytes[i] = len[i]
+	end
+
+	for i = 1, #str do
+		bytes[#bytes + 1] = str[i]
+	end
+
+	return bit_converter.bytes_to_string(bytes)
+end
+
+function data_buffer:get_bool()
+	return bit_converter.byte_to_bool(self:get_byte())
+end
+
+function data_buffer:get_int16()
+	return bit_converter.bytes_to_int16(self:get_bytes(2))
+end
+
+function data_buffer:get_int32()
+	return bit_converter.bytes_to_int32(self:get_bytes(4))
+end
+
+function data_buffer:get_int64()
+	return bit_converter.bytes_to_int64(self:get_bytes(8))
+end
+
+function data_buffer:size()
+	return #self.bytes
+end
+
+function data_buffer:get_bytes(len)
+	if len == nil then
+		return self.bytes
+	else
+		local bytes = { }
+
+		for i = 1, n do
+			bytes[i] = self:get_byte()
+		end
+
+		return bytes
+	end
+end
+
+function data_buffer:set_position(pos)
+	self.pos = pos
+end
+
+function data_buffer:set_bytes(bytes)
+	for i = 1, #bytes do
+		local byte = bytes[i]
+		if byte < 0 or byte > 255 then
+			error("invalid byte")
+		end
+	end
+
+	self.bytes = bytes
+end
+
+setmetatable(data_buffer, data_buffer)
+
+return data_buffer