response.go

/*
Copyright (c) 2014 Ashley Jeffs

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

package types

import "fmt"

//--------------------------------------------------------------------------------------------------

// Response - A response from an output, agent or broker that confirms the input of successful
// message receipt.
type Response interface {
	Error() error
	ErrorMap() map[int]error
}

//--------------------------------------------------------------------------------------------------

// MappedResponse - Returned by a broker to provide a map of errors representing agent errors.
type MappedResponse struct {
	Errors map[int]error
}

// Error - Returns nil if no errors are present, otherwise a concatenated blob of errors.
func (b MappedResponse) Error() error {
	if len(b.Errors) > 0 {
		return fmt.Errorf("%v", b.Errors)
	}
	return nil
}

// ErrorMap - Returns a map of errors returned by agents, represented by index.
func (b MappedResponse) ErrorMap() map[int]error {
	if len(b.Errors) > 0 {
		return b.Errors
	}
	return nil
}

// NewMappedResponse - Returns a response tailored for a broker (with n agents).
func NewMappedResponse() MappedResponse {
	return MappedResponse{
		Errors: make(map[int]error),
	}
}

//--------------------------------------------------------------------------------------------------

// SimpleResponse - Returned by an output or agent to provide a single return message.
type SimpleResponse struct {
	err error
}

// Error - Returns the underlying error.
func (o SimpleResponse) Error() error {
	return o.err
}

// ErrorMap - Returns nil.
func (o SimpleResponse) ErrorMap() map[int]error {
	return nil
}

// NewSimpleResponse - Returns a response with an error (nil error signals successful receipt).
func NewSimpleResponse(err error) SimpleResponse {
	return SimpleResponse{
		err: err,
	}
}

//--------------------------------------------------------------------------------------------------