errorcontext

Documentation

Overview

Package errorcontext implements a Context that can be canceled with a specific error instead of the usual context.Canceled.

Index

• type CancelFunc
  • func New(parent context.Context) (context.Context, CancelFunc)
• type ErrorContext
  • func (c *ErrorContext) Cancel(err error)
  • func (c *ErrorContext) Err() error

Examples

• ErrorContext

Types

type CancelFunc

type CancelFunc func(error)

CancelFunc extends the regular context.CancelFunc with an error argument

func New

func New(parent context.Context) (context.Context, CancelFunc)

New returns a new ErrorContext that extends the parent context

type ErrorContext

type ErrorContext struct {
	context.Context
	// contains filtered or unexported fields
}

ErrorContext can be used to attach errors to a context cancelation.

Example

package main

import (
	"go.thethings.network/lorawan-stack/v3/pkg/errorcontext"
	"go.thethings.network/lorawan-stack/v3/pkg/util/test"
)

var err error

func main() {
	ctx, cancel := errorcontext.New(test.Context())
	defer cancel(nil)

	go func() {
		for {
			// do work
			if err != nil {
				cancel(err)
			}
		}
	}()

	for {
		select {
		// case data := <-dataChan:
		case <-ctx.Done():
			return
		}
	}
}

func (*ErrorContext) Cancel

func (c *ErrorContext) Cancel(err error)

Cancel the ErrorContext with an error. The context can not be re-used or re-canceled after this function is called.

func (*ErrorContext) Err

func (c *ErrorContext) Err() error

Err returns the err of the ErrorContext if non-nil, or the error of the underlying Context.