Files
2022-05-21 01:38:58 +03:00

157 lines
4.6 KiB
Go

// Copyright 2019 The Cockroach Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied. See the License for the specific language governing
// permissions and limitations under the License.
package domains
import (
"errors"
"fmt"
"path/filepath"
"runtime"
"github.com/cockroachdb/errors/barriers"
"github.com/cockroachdb/errors/errbase"
)
// Domain is the type of a domain annotation.
type Domain string
// NoDomain is the domain of errors that don't originate
// from a barrier.
const NoDomain Domain = "error domain: <none>"
// GetDomain extracts the domain of the given error, or NoDomain if
// the error's cause does not have a domain annotation.
func GetDomain(err error) Domain {
for {
if b, ok := err.(*withDomain); ok {
return b.domain
}
// Recurse to the cause.
if c := errbase.UnwrapOnce(err); c != nil {
err = c
continue
}
break
}
return NoDomain
}
// WithDomain wraps an error so that it appears to come from the given domain.
//
// Domain is shown:
// - via `errors.GetSafeDetails()`.
// - when formatting with `%+v`.
// - in Sentry reports.
func WithDomain(err error, domain Domain) error {
if err == nil {
return nil
}
return &withDomain{cause: err, domain: domain}
}
// New creates an error in the implicit domain (see PackageDomain() below)
// of its caller.
//
// Domain is shown:
// - via `errors.GetSafeDetails()`.
// - when formatting with `%+v`.
// - in Sentry reports.
func New(msg string) error {
return WithDomain(errors.New(msg), PackageDomainAtDepth(1))
}
// Newf/Errorf with format and args can be implemented similarly.
// HandledInDomain creates an error in the given domain and retains
// the details of the given original error as context for
// debugging. The original error is hidden and does not become a
// "cause" for the new error. The original's error _message_
// is preserved.
//
// See the documentation of `WithDomain()` and `errors.Handled()` for details.
func HandledInDomain(err error, domain Domain) error {
return WithDomain(barriers.Handled(err), domain)
}
// HandledInDomainWithMessage is like HandledWithMessage but with a domain.
func HandledInDomainWithMessage(err error, domain Domain, msg string) error {
return WithDomain(barriers.HandledWithMessage(err, msg), domain)
}
// Handled creates a handled error in the implicit domain (see
// PackageDomain() below) of its caller.
//
// See the documentation of `barriers.Handled()` for details.
func Handled(err error) error {
return HandledInDomain(err, PackageDomainAtDepth(1))
}
// Handledf with format and args can be implemented similarly.
// NotInDomain returns true if and only if the error's
// domain is not one of the specified domains.
func NotInDomain(err error, domains ...Domain) bool {
return notInDomainInternal(GetDomain(err), domains...)
}
func notInDomainInternal(d Domain, domains ...Domain) bool {
for _, given := range domains {
if d == given {
return false
}
}
return true
}
// EnsureNotInDomain checks whether the error is in the given domain(s).
// If it is, the given constructor if provided is called to construct
// an alternate error. If no error constructor is provided,
// a new barrier is constructed automatically using the first
// provided domain as new domain. The original error message
// is preserved.
func EnsureNotInDomain(
err error, constructor func(originalDomain Domain, err error) error, forbiddenDomains ...Domain,
) error {
if err == nil {
return nil
}
// Is the error already in the wanted domains?
errDomain := GetDomain(err)
if notInDomainInternal(errDomain, forbiddenDomains...) {
// No: no-op.
return err
}
return constructor(errDomain, err)
}
// PackageDomain returns an error domain that represents the
// package of its caller.
func PackageDomain() Domain {
return PackageDomainAtDepth(1)
}
// PackageDomainAtDepth returns an error domain that describes the
// package at the given call depth.
func PackageDomainAtDepth(depth int) Domain {
_, f, _, _ := runtime.Caller(1 + depth)
return Domain("error domain: pkg " + filepath.Dir(f))
}
// NamedDomain returns an error domain identified by the given string.
func NamedDomain(domainName string) Domain {
return Domain(fmt.Sprintf("error domain: %q", domainName))
}