大端协议通信--lua简易客户端

为了配合服务器测试大端通信协议，自己结合网上资料写了个简易的供自己测试使用，特此记录。
socket 需要安装luasocket后才能使用。
今天发现在skynet中有相关案例，可以直接用，比自己瞎折腾的东西好多了。
不过这么折腾一回对自己掌握这一块内容是有帮助的。

local socket = require("socket")
local DataType = {
    CHAR = 1,
    SHORT = 2,
    INT = 3,
    INT64 = 4,
    FLOAT = 5,
    OTHER = 6,
    ARRAY = 16,
}

local DataSize = {
    SIZE_SHORT = 3,
    SIZE_INT = 5,
    SIZE_INT64 = 9,
    SIZE_FLOAT = 5,
}

function readChar(buf,pos)
    if pos+2 > string.len(buf)+1 then
        return nil,pos
    end
    local t = string.unpack(">b",buf,pos)
    pos = pos + 1
    if t == DataType.CHAR then
        local v = string.unpack(">b",buf,pos)
        pos = pos + 1
        return v,pos
    end
    return nil,pos
end

function readShort(buf,pos)
    if pos+3 > string.len(buf)+1 then
        return nil,pos
    end
    local t = string.unpack(">b",buf,pos)
    pos = pos + 1
    if t == DataType.SHORT then
        local v = string.unpack(">h",buf,pos)
        pos = pos + 2
        return v,pos
    end
    return nil,pos
end

function readInt(buf,pos)
    print(pos,"len = ",string.len(buf));
    if pos+5 > string.len(buf)+1 then
        return nil,pos
    end
    local t = string.unpack(">b",buf,pos)
    pos = pos + 1
    if t == DataType.INT then
        local v = string.unpack(">i4",buf,pos)
        pos = pos + 4
        return v,pos
    end
    return nil,pos
end

function readInt64(buf,pos)
    if pos+9 > string.len(buf)+1 then
        return nil,pos
    end
    local t = string.unpack(">b",buf,pos)
    pos = pos + 1
    if t == DataType.INT64 then
        local v = string.unpack(">l",buf,pos)
        pos = pos + 8
        return v,pos
    end
    return nil,pos
end

function readFloat(buf,pos)
    if pos+5 > string.len(buf)+1 then
        return nil,pos
    end
    local t = string.unpack(">b",buf,pos)
    pos = pos + 1
    if t == DataType.FLOAT then
        local v = string.unpack(">f",buf,pos)
        pos = pos + 4
        return v,pos
    end
    return nil,pos
end

function readString(buf,pos)
    if pos+3 > string.len(buf)+1 then
        return nil,pos
    end
    local t = string.unpack(">b",buf,pos)
    pos = pos + 1
    if t == (DataType.ARRAY + DataType.CHAR) then
        local v = string.unpack(">s2",buf,pos)
        pos = pos + 2 + string.len(v)
        return v,pos
    end
    return nil,pos
end

function readHead(buf,pos)
    local head = {}
    if string.len(buf) >= 6 then
        head.cmd,head.seq,head.ret = string.unpack(">hhh",buf,pos)
        pos = pos + 6
        return head,pos
    end
    return nil,pos
end

function writeObjectArrayHeader(pkg,f,array_len)
    local ret = string.pack(">bh",f,array_len)
    pkg = pkg..ret
    return pkg
end

function writeChar(pkg,c)
    local ret = string.pack(">bb",DataType.CHAR,c)
    pkg = pkg..ret
    return pkg
end

function writeShort(pkg,i16)
    local ret = string.pack(">bh",DataType.SHORT,i16)
    pkg = pkg..ret
    return pkg
end

function writeInt(pkg,i)
    local ret = string.pack(">bi4",DataType.INT,i)
    pkg = pkg..ret
    return pkg
end

function writeInt64(pkg,i64)
    local ret = string.pack(">bl",DataType.INT64,i64)
    pkg = pkg..ret
    return pkg
end

function writeFloat(pkg,f)
    local ret = string.pack(">bi4",DataType.FLOAT,f)
    pkg = pkg..ret
    return pkg
end

function writeString(pkg,s)
    local ret = string.pack(">bs2",(DataType.ARRAY + DataType.CHAR),s)
    pkg = pkg..ret
    return pkg
end

function writeHead(cmd,seq,ret)
    local ret = string.pack(">hhh",cmd,seq,ret)
    return ret
end

function unpack(buf_src)
    local pos = 1
    local head
    local body = {}
    local buf = crypt.xor_str(buf_src, "aCD390&6")

    head,pos = readHead(buf,pos)
    return head,body
end


local host = "127.0.0.1"
local port = 5000
local sock = assert(socket.connect(host, port))
sock:settimeout(0)

print("Press enter after input something:")

local input, recvt, sendt, status

while true do
   local whtsend = io.read()
    print("屏幕输入的内容:",whtsend)
    local pkg = writeHead(whtsend,2,0)
    pkg = writeString(pkg,"330374657362523456")
    pkg = writeString(pkg,"张三")
--    pkg = writeString(pkg,"EFGH")
--    pkg = writeString(pkg,"9CBF8A4DCB8E30682B927F352D6559A0")  --密码123456a
--    pkg = writeString(pkg,"E10ADC3949BA59ABBE56E057F20F883E")    --密码:123456

    local enc_pkg = crypt.xor_str(pkg,PKG_PWD)
    local input = string.pack(">s2",enc_pkg)

    print("需要发送的数据值:",input)
    print("传送的数据的长度",string.len(input))
    if #input > 0 then
        assert(sock:send(input .. "\n"))
    end

    recvt, sendt, status = socket.select({sock}, nil, 1)
    while #recvt > 0 do
        local response, receive_status = sock:receive()

        if receive_status ~= "closed" then
            if response then
                print(response)
                recvt, sendt, status = socket.select({sock}, nil, 1)
            end
        else
            break
        end
    end
end