moby/errdefs/is.go
Sebastiaan van Stijn 7d4b788381 errdefs: remove "ErrAlreadyExists" because it's not an error
The `ErrAlreadyExists` error is used for 304 statuses, which
is not an error-condition, so should probably not be defined
as part of the errdefs package.

This patch removes the `ErrAlreadyExists` interface, and related
helpers, as it was currently not used.

Note that a 304 status can fulfil certain use-cases, but (refering
to https://www.codetinkerer.com/2015/12/04/choosing-an-http-status-code.html)
could probably be handled by a 200 OK, unless we want to perform
caching in the client.

If we do want to use 304 statuses, perhaps we need a separate class
of "errors" for this (?).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2019-03-21 21:25:15 +00:00

107 lines
2.5 KiB
Go

package errdefs // import "github.com/docker/docker/errdefs"
type causer interface {
Cause() error
}
func getImplementer(err error) error {
switch e := err.(type) {
case
ErrNotFound,
ErrInvalidParameter,
ErrConflict,
ErrUnauthorized,
ErrUnavailable,
ErrForbidden,
ErrSystem,
ErrNotModified,
ErrNotImplemented,
ErrCancelled,
ErrDeadline,
ErrDataLoss,
ErrUnknown:
return err
case causer:
return getImplementer(e.Cause())
default:
return err
}
}
// IsNotFound returns if the passed in error is an ErrNotFound
func IsNotFound(err error) bool {
_, ok := getImplementer(err).(ErrNotFound)
return ok
}
// IsInvalidParameter returns if the passed in error is an ErrInvalidParameter
func IsInvalidParameter(err error) bool {
_, ok := getImplementer(err).(ErrInvalidParameter)
return ok
}
// IsConflict returns if the passed in error is an ErrConflict
func IsConflict(err error) bool {
_, ok := getImplementer(err).(ErrConflict)
return ok
}
// IsUnauthorized returns if the passed in error is an ErrUnauthorized
func IsUnauthorized(err error) bool {
_, ok := getImplementer(err).(ErrUnauthorized)
return ok
}
// IsUnavailable returns if the passed in error is an ErrUnavailable
func IsUnavailable(err error) bool {
_, ok := getImplementer(err).(ErrUnavailable)
return ok
}
// IsForbidden returns if the passed in error is an ErrForbidden
func IsForbidden(err error) bool {
_, ok := getImplementer(err).(ErrForbidden)
return ok
}
// IsSystem returns if the passed in error is an ErrSystem
func IsSystem(err error) bool {
_, ok := getImplementer(err).(ErrSystem)
return ok
}
// IsNotModified returns if the passed in error is a NotModified error
func IsNotModified(err error) bool {
_, ok := getImplementer(err).(ErrNotModified)
return ok
}
// IsNotImplemented returns if the passed in error is an ErrNotImplemented
func IsNotImplemented(err error) bool {
_, ok := getImplementer(err).(ErrNotImplemented)
return ok
}
// IsUnknown returns if the passed in error is an ErrUnknown
func IsUnknown(err error) bool {
_, ok := getImplementer(err).(ErrUnknown)
return ok
}
// IsCancelled returns if the passed in error is an ErrCancelled
func IsCancelled(err error) bool {
_, ok := getImplementer(err).(ErrCancelled)
return ok
}
// IsDeadline returns if the passed in error is an ErrDeadline
func IsDeadline(err error) bool {
_, ok := getImplementer(err).(ErrDeadline)
return ok
}
// IsDataLoss returns if the passed in error is an ErrDataLoss
func IsDataLoss(err error) bool {
_, ok := getImplementer(err).(ErrDataLoss)
return ok
}