lnd/graph/errors.go

package graph

import (
	"fmt"
)

// ErrorCode is used to represent the various errors that can occur within this
// package.
type ErrorCode uint8

const (
	// ErrOutdated is returned when the routing update already have
	// been applied, or a newer update is already known.
	ErrOutdated ErrorCode = iota

	// ErrIgnored is returned when the update have been ignored because
	// this update can't bring us something new, or because a node
	// announcement was given for node not found in any channel.
	ErrIgnored
)

// Error is a structure that represent the error inside the graph package,
// this structure carries additional information about error code in order to
// be able distinguish errors outside of the current package.
type Error struct {
	err  error
	code ErrorCode
}

// Error represents errors as the string
// NOTE: Part of the error interface.
func (e *Error) Error() string {
	return e.err.Error()
}

// A compile time check to ensure Error implements the error interface.
var _ error = (*Error)(nil)

// NewErrf creates a Error by the given error formatted description and
// its corresponding error code.
func NewErrf(code ErrorCode, format string, a ...interface{}) *Error {
	return &Error{
		code: code,
		err:  fmt.Errorf(format, a...),
	}
}

// IsError is a helper function which is needed to have ability to check that
// returned error has specific error code.
func IsError(e interface{}, codes ...ErrorCode) bool {
	err, ok := e.(*Error)
	if !ok {
		return false
	}

	for _, code := range codes {
		if err.code == code {
			return true
		}
	}

	return false
}