dyutils=require("dyutils")
bit=require("bit")
lpack=require("lua_pack")
cjson=require("cjson")
base64=require("base64")
syslog=require("syslog")
sqlite3=require("lsqlite3")
function protocol_decode(input_str, len)
    local err_code=0
    --取出入参--
    local obj={}
    local input_obj=cjson.decode(input_str)
    local bin_str=input_obj.raw_data
    local id='post'
    --入参中的raw_data的二进制转换--
    local t_str=''
    for i=1,#bin_str,2 do
       t_str=t_str .. string.char(tonumber(string.sub(bin_str, i, i+1),16))
    end
    bin_str=t_str
    --分割位域--
    local format=">C3>S1"
    _,_,_,_,buf_len=bunpack(bin_str,format)
    --calc--
    format=string.format(">C3>S1>C2>A%u>C1",buf_len-1)
    _,_,_,_,buf_len,_,addr,data_str_a,crc=bunpack(bin_str,format)
    calc_crc=0
    for i=1,buf_len+6,1 do
        by_a=string.byte(bin_str,i)
        calc_crc = bit.bxor(calc_crc,by_a)
    end
    if calc_crc ~= crc then
        return -1,"",0
    end
    --出参格式化--
    obj.result=data_str_a
    obj.result8=data_str_a
    if string.len(obj.result8) == 10 then
        local num = tonumber(obj.result8,10)
        obj.result8 = string.format("%03d%05d",bit.band(bit.rshift(num,16),0xff),bit.band(num,0xffff))
    end
    obj.term_addr=string.format("%02X", addr)
    obj.identifier=id
    local json_str=cjson.encode(obj)
    return err_code,json_str,#json_str
end
-- test_str='{"raw_data":"55AA30000B000130343739373531363334CD","identifier":""}'
-- protocol_decode(test_str,#test_str)--