lua-buffet

Socket-like buffer objects for Lua

lua-buffet

[!Luarocks](https://luarocks.org/modules/undef/lua-buffet) [!OPM](https://opm.openresty.org/package/un-def/lua-buffet/) [!Build Status](https://travis-ci.org/un-def/lua-buffet) [!License][license]

Socket-like buffer objects for Lua

Name

The word “buffet” is a portmanteau of “buffer” and “socket”.

Description

A buffet is an object that has the same interface as socket objects in the popular Lua libraries LuaSocket and Lua Nginx Module but doesn't do any real network communication. Instead the network stack the buffet receives data from an arbitrary source. The data source can be a string, a table of strings or an iterator function producing strings.

The buffet works in a streaming fashion. That is, the buffet doesn't try to read and store internally the whole source data at once but reads as little as possible and only when necessary. That means that the buffet can be efficiently used as a proxy for sources of unlimited amounts of data such as real sockets or file I/O readers.

Another possible use is unit testing where the buffet can be used as a mock object instead of the real socket object.

Basic usage

    local buffet = require('buffet')
    local buffet_resty = require('buffet.resty')
    
    -- Input data is a string.
    -- Read data in chunks of 3 bytes.
    do
        local bf = buffet_resty.new('data string')
        print(buffet.is_closed(bf))   -- false
        repeat
            local data, err, partial = bf:receive(3)
            print(data, err, partial)
        until err
        print(buffet.is_closed(bf))   -- true
    end
    
    -- Input data is a table containing data chunks.
    -- Read data line by line.
    do
        local bf = buffet_resty.new({'line 1\nline', ' 2\nli', 'ne 3\n'})
        repeat
            local data, err, partial = bf:receive('*l')
            print(data, err, partial)
        until err
    end
    
    -- Input data is a function producing data chunks.
    -- Read data splitted by the specified pattern, up to 4 bytes at once.
    do
        local iterator = coroutine.wrap(function()
            coroutine.yield('first-==-se')
            coroutine.yield('cond-==')
            coroutine.yield('-thi')
            coroutine.yield('rd')
            coroutine.yield(nil, 'some error')
            coroutine.yield('unreachable')
        end)
        local bf = buffet_resty.new(iterator)
        local reader = bf:receiveuntil('-==-')
        print(buffet.get_iterator_error(bf))   -- nil
        repeat
            local data, err, partial = reader(4)
            print(data, err, partial)
        until err
        print(buffet.get_iterator_error(bf))   -- some error
    end
    
    -- Send data.
    do
        local bf = buffet_resty.new()
        for i = 1, 5 do
            local char = string.char(0x40 + i)
            bf:send(string.rep(char, i))
        end
        local send_buffer = buffet.get_send_buffer(bf)
        print(#send_buffer)   -- 5
        for _, chunk in ipairs(send_buffer) do
            print(chunk)
        end
        print(buffet.get_sent_data(bf))   -- ABBCCCDDDDEEEEE
    end

For more advanded usage see the examples directory.

Documentation

Documentation is available at https://undef.im/lua-buffet/.

Changelog

For detailed changelog see CHANGELOG.md.

TODO

OpenResty

ngx.socket.tcp

  • [x] constructor (ngx.socket.tcp ~ buffet.resty.new)

  • [x] :connect (noop)

  • [x] :sslhandshake (noop)

  • [x] :send

  • [x] :receive

    • [x] :receive()

    • [x] :receive('*l')

    • [x] :receive('*a')

    • [x] :receive(size)

  • [x] :receiveany

  • [x] :receiveuntil

    • [x] iterator()

    • [x] iterator(size)

    • [x] inclusive option

  • [x] :close

  • [x] :settimeout (noop)

  • [x] :settimeouts (noop)

  • [x] :setoption (noop)

  • [x] :setkeepalive (equivalent to :close)

  • [x] :getreusedtimes (noop)

ngx.socket.udp

...

LuaSocket

...

License

The [MIT License][license].

[license]: https://github.com/un-def/lua-buffet/blob/master/LICENSE

Authors

un.def

License

mit

Versions