Add global refs to use for default keyword args for connect_timeout a…

…nd a new closeimmediately keyword arg that controls whether a connection should be immediately closed after a client request is finished. This is an internal-only kw for now as I test out some precompile things

src/Connections.jl

@@ -433,6 +433,8 @@ end
 @noinline connection_limit_warning(cl) = cl === nothing ||
  @warn "connection_limit no longer supported as a keyword argument; use `HTTP.set_default_connection_limit!($cl)` before any requests are made or construct a shared pool via `POOL = HTTP.Pool($cl)` and pass to each request like `pool=POOL` instead."
 
+const DEFAULT_CONNECT_TIMEOUT = Ref{Int}(30)
+
 """
  newconnection(type, host, port) -> Connection
 
@@ -446,7 +448,7 @@ function newconnection(::Type{T},
  connection_limit=nothing,
  forcenew::Bool=false,
  idle_timeout=typemax(Int),
- connect_timeout::Int=30,
+ connect_timeout::Int=DEFAULT_CONNECT_TIMEOUT[],
  require_ssl_verification::Bool=NetworkOptions.verify_host(host, "SSL"),
  keepalive::Bool=true,
  kw...) where {T <: IO}

src/clientlayers/ConnectionRequest.jl

@@ -46,6 +46,8 @@ end
 
 export connectionlayer
 
+const CLOSE_IMMEDIATELY = Ref{Bool}(false)
+
 """
  connectionlayer(handler) -> handler
 
@@ -55,7 +57,7 @@ Close the connection if the request throws an exception.
 Otherwise leave it open so that it can be reused.
 """
 function connectionlayer(handler)
- return function connections(req; proxy=getproxy(req.url.scheme, req.url.host), socket_type::Type=TCPSocket, socket_type_tls::Union{Nothing, Type}=nothing, readtimeout::Int=0, connect_timeout::Int=30, logerrors::Bool=false, logtag=nothing, kw...)
+ return function connections(req; proxy=getproxy(req.url.scheme, req.url.host), socket_type::Type=TCPSocket, socket_type_tls::Union{Nothing, Type}=nothing, readtimeout::Int=0, connect_timeout::Int=30, logerrors::Bool=false, logtag=nothing, closeimmediately::Bool=CLOSE_IMMEDIATELY[], kw...)
  local io, stream
  if proxy !== nothing
  target_url = req.url
@@ -88,7 +90,7 @@ function connectionlayer(handler)
  req.context[:connect_duration_ms] = get(req.context, :connect_duration_ms, 0.0) + (time() - start_time) * 1000
  end
 
- shouldreuse = !(target_url.scheme in ("ws", "wss"))
+ shouldreuse = !(target_url.scheme in ("ws", "wss")) && !closeimmediately
  try
  if proxy !== nothing && target_url.scheme in ("https", "wss", "ws")
  shouldreuse = false