a little http server (and hello world app) in io

webserver.io

HttpServer := Object clone do(
  at := method(address,
    server := self clone

    address = address splitN(":", 1)
    ip := address at(0)
    port := if(address size > 1, address at(1) asNumber, 80);

    if (ip at(0) > 57 or ip at(0) < 48,
      ip = DNSResolver ipForHostName(ip)
    )

    server socket := Socket clone
    server socket setIpAddress(IPAddress clone setIp(ip) setPort(port))
    server socket setReadTimeout(60 * 60 * 24 * 365)

    server
  )

  run := method(
    socket serverOpen returnIfError

    while(true,
      client_sock := socket serverWaitForConnection
      if (client_sock isError, continue)
      HttpConnection with(self, client_sock) @handleRequests
    )
  )

  handle := method(request,
    Exception raise("override me")
  )
)


HttpConnection := Object clone do(
  with := method(server, sock,
    conn := self clone
    conn socket := sock
    conn server := server
    conn
  )

  handleRequests := method(
    while (self socket isOpen and handleOneRequest, true)
  )

  readRequestLine := method(
    request := Object clone

    line := readLine
    if (line asMutable strip size == 0,
      line = readLine
    )

    data := line splitNoEmpties(" ")
    if (data size != 3, return nil)
    if (data at(2) beginsWithSeq("HTTP/") not, return nil)

    request method := data at(0)

    path_qs := data at(1) splitN("?", 1)
    request path := path_qs at(0)
    request queryString := path_qs at(1)

    request httpVersion := data at(2) exSlice(5) asNumber

    request
  )

  readHeaders := method(
    headers := Map clone
    while (true,
      chunk := readLine
      if (chunk size == 0, break)

      chunk = chunk splitN(":", 1)
      headers atPut(chunk at(0) asLowercase, chunk)
    )
    headers
  )

  readBody := method(bytes,
    self socket readBytes(bytes)
  )

  handleOneRequest := method(
    request := readRequestLine

    if (request isNil,
      return false
    )

    request headers := readHeaders

    if (request headers hasKey("content-length") \
        and list("POST", "PUT") contains(request method),
      request body := readBody(
        request headers at("content-length") at(1) asNumber)
    )

    response := self server handle(request)

    if (response headers detect(k, k asLowercase == "content-length") not,
      response headers atPut("Content-Length", response body size asString)
    )

    response headers = response headers map(k, v, "#{k}: #{v}" interpolate) join("\n")
    self socket write("""HTTP/1.1 #{code} #{status}
#{headers}

#{body}""" interpolate(response) asMutable replaceSeq("\n", "\r\n"))
    true
  )

  readLine := method(
    text := socket readUntilSeq("\n")
    if (text endsWithSeq("\r"),
      text exSlice(0, -1)
    ,
      text
    )
  )
)


if (Sequence hasSlot("splitN") not,
  Sequence splitN := method(sep, n,
    size := sep size
    data := clone
    result := list()
    for (i, 1, n,
      index := data findSeq(sep)
      if (index isNil not,
        result append(data exSlice(0, index))
        data = data exSlice(index + size)
      )
    )
    result append(data)
  )
)


// example hello world application
HttpServer at("127.0.0.1:8010") do(
  handle := method(request,
    Object clone do(
      code := 200
      status := "OK"
      headers := Map clone atPut("Content-Type", "text/plain")
      body := "hello, world"
    )
  )
) run