class Excon::Connection

def request(params, &block)
  begin
    # connection has defaults, merge in new params to override
    params = @connection.merge(params)
    params[:headers] = @connection[:headers].merge(params[:headers] || {})
    # if path is empty or doesn't start with '/', insert one
    unless params[:path][0..0] == '/'
      params[:path].insert(0, '/')
    end
    # start with "METHOD /path"
    request = params[:method].to_s.upcase << ' ' << params[:path]
    # add query to path, if there is one
    case params[:query]
    when String
      request << '?' << params[:query]
    when Hash
      request << '?'
      for key, values in params[:query]
        for value in [*values]
          value_string = value && ('=' << CGI.escape(value.to_s))
          request << key.to_s << value_string.to_s << '&'
        end
      end
      request.chop! # remove trailing '&'
    end
    # finish first line with "HTTP/1.1\r\n"
    request << HTTP_1_1
    # calculate content length and set to handle non-ascii
    params[:headers]['Content-Length'] = case params[:body]
    when File
      params[:body].binmode
      File.size(params[:body].path)
    when String
      if params[:body].respond_to?(:force_encoding)
        params[:body].force_encoding('BINARY')
      end
      params[:body].length
    else
      0
    end
    # add headers to request
    for key, value in params[:headers]
      request << key.to_s << ': ' << value.to_s << CR_NL
    end
    # add additional "\r\n" to indicate end of headers
    request << CR_NL
    # write out the request, sans body
    socket.write(request)
    # write out the body
    if params[:body]
      if params[:body].is_a?(String)
        socket.write(params[:body])
      else
        while chunk = params[:body].read(CHUNK_SIZE)
          socket.write(chunk)
        end
      end
    end
    # read the response
    response = Excon::Response.parse(socket, params, &block)
    if response.headers['Connection'] == 'close'
      reset
    end
    response
  rescue => socket_error
    reset
    raise(Excon::Errors::SocketError.new(socket_error))
  end
  if params[:expects] && ![*params[:expects]].include?(response.status)
    reset
    raise(Excon::Errors.status_error(params, response))
  else
    response
  end
rescue => request_error
  if params[:idempotent] &&
      (request_error.is_a?(Excon::Errors::SocketError) ||
      (request_error.is_a?(Excon::Errors::HTTPStatusError) && response.status != 404))
    retries_remaining ||= 4
    retries_remaining -= 1
    if retries_remaining > 0
      retry
    else
      raise(request_error)
    end
  else
    raise(request_error)
  end
end