commands.go

package main

//go:generate stringer -type=CommandID

// Mapping of command IDs to names is generated by stringer -- re run
// "go generate" if you change the ID list below.

// CommandID identifies one of the commands that libgozerian sends back via its
// C interface.
type CommandID int

const (
	// DONE indicates that no more commands will be delivered for this request or response
	DONE CommandID = iota
	// ERRR indicates that there was an error processing a request or response. No more
	// commands will be delivered.
	ERRR
	// RBOD indicates that the request or response requests that the message body
	// be delivered via one of the C functions for that purpose.
	RBOD
	// WHDR indicates that the request or response headers must be re-written to
	// match the new values.
	WHDR
	// WURI indicates that the request URI must change
	WURI
	// WSTA indicates that the HTTP status code on the response must change
	WSTA
	// SWCH indicates that the request or response path has changed so that
	// libgozerian will provide the complete response. If we are on the request path,
	// no target server should be invoked. If are are on the response path, then
	// the existing response should be discarded.
	SWCH
	// WBOD indicates that the request or response body is being rewritten and should
	// be replaced with the chunks identified by this command.
	WBOD
)

const (
	cmdDone = "DONE"
	cmdErrr = "ERRR"
	cmdRbod = "RBOD"
	cmdWhdr = "WHDR"
	cmdWURI = "WURI"
	cmdWsta = "WSTA"
	cmdSwch = "SWCH"
	cmdWbod = "WBOD"
)

type command struct {
	id  CommandID
	msg string
}

func createErrorCommand(err error) command {
	return command{
		id:  ERRR,
		msg: err.Error(),
	}
}

func (c command) String() string {
	pfx := c.id.String()
	return pfx + c.msg
}