Commit 170b8b4b authored by Damien Neil's avatar Damien Neil

all: add Unwrap and Is methods to various error types

Add Unwrap methods to types which wrap an underlying error:

  "encodinc/csv".ParseError
  "encoding/json".MarshalerError
  "net/http".transportReadFromServerError
  "net".OpError
  "net".DNSConfigError
  "net/url".Error
  "os/exec".Error
  "signal/internal/pty".PtyError
  "text/template".ExecError

Add os.ErrTemporary. A case could be made for putting this error
value in package net, since no exported error types in package os
include a Temporary method. However, syscall errors returned from
the os package do include this method.

Add Is methods to error types with a Timeout or Temporary method,
making errors.Is(err, os.Err{Timeout,Temporary}) equivalent to
testing the corresponding method:

  "context".DeadlineExceeded
  "internal/poll".TimeoutError
  "net".adrinfoErrno
  "net".OpError
  "net".DNSError
  "net/http".httpError
  "net/http".tlsHandshakeTimeoutError
  "net/pipe".timeoutError
  "net/url".Error

Updates #30322
Updates #29934

Change-Id: I409fb20c072ea39116ebfb8c7534d493483870dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/170037
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarMarcel van Lohuizen <mpvl@golang.org>
parent 59ea685c
...@@ -49,6 +49,7 @@ package context ...@@ -49,6 +49,7 @@ package context
import ( import (
"errors" "errors"
"internal/oserror"
"internal/reflectlite" "internal/reflectlite"
"sync" "sync"
"time" "time"
...@@ -162,6 +163,9 @@ type deadlineExceededError struct{} ...@@ -162,6 +163,9 @@ type deadlineExceededError struct{}
func (deadlineExceededError) Error() string { return "context deadline exceeded" } func (deadlineExceededError) Error() string { return "context deadline exceeded" }
func (deadlineExceededError) Timeout() bool { return true } func (deadlineExceededError) Timeout() bool { return true }
func (deadlineExceededError) Temporary() bool { return true } func (deadlineExceededError) Temporary() bool { return true }
func (deadlineExceededError) Is(target error) bool {
return target == oserror.ErrTimeout || target == oserror.ErrTemporary
}
// An emptyCtx is never canceled, has no values, and has no deadline. It is not // An emptyCtx is never canceled, has no values, and has no deadline. It is not
// struct{}, since vars of this type must have distinct addresses. // struct{}, since vars of this type must have distinct addresses.
......
...@@ -5,8 +5,10 @@ ...@@ -5,8 +5,10 @@
package context package context
import ( import (
"errors"
"fmt" "fmt"
"math/rand" "math/rand"
"os"
"runtime" "runtime"
"strings" "strings"
"sync" "sync"
...@@ -647,4 +649,7 @@ func XTestDeadlineExceededSupportsTimeout(t testingT) { ...@@ -647,4 +649,7 @@ func XTestDeadlineExceededSupportsTimeout(t testingT) {
if !i.Timeout() { if !i.Timeout() {
t.Fatal("wrong value for timeout") t.Fatal("wrong value for timeout")
} }
if !errors.Is(DeadlineExceeded, os.ErrTimeout) {
t.Fatal("errors.Is(DeadlineExceeded, os.ErrTimeout) = false, want true")
}
} }
...@@ -80,6 +80,8 @@ func (e *ParseError) Error() string { ...@@ -80,6 +80,8 @@ func (e *ParseError) Error() string {
return fmt.Sprintf("parse error on line %d, column %d: %v", e.Line, e.Column, e.Err) return fmt.Sprintf("parse error on line %d, column %d: %v", e.Line, e.Column, e.Err)
} }
func (e *ParseError) Unwrap() error { return e.Err }
// These are the errors that can be returned in ParseError.Err. // These are the errors that can be returned in ParseError.Err.
var ( var (
ErrTrailingComma = errors.New("extra delimiter at end of line") // Deprecated: No longer used. ErrTrailingComma = errors.New("extra delimiter at end of line") // Deprecated: No longer used.
......
...@@ -270,6 +270,8 @@ func (e *MarshalerError) Error() string { ...@@ -270,6 +270,8 @@ func (e *MarshalerError) Error() string {
return "json: error calling MarshalJSON for type " + e.Type.String() + ": " + e.Err.Error() return "json: error calling MarshalJSON for type " + e.Type.String() + ": " + e.Err.Error()
} }
func (e *MarshalerError) Unwrap() error { return e.Err }
var hex = "0123456789abcdef" var hex = "0123456789abcdef"
// An encodeState encodes JSON into a bytes.Buffer. // An encodeState encodes JSON into a bytes.Buffer.
......
...@@ -140,6 +140,7 @@ var pkgDeps = map[string][]string{ ...@@ -140,6 +140,7 @@ var pkgDeps = map[string][]string{
"image/color", "image/color",
"image/color/palette", "image/color/palette",
"internal/fmtsort", "internal/fmtsort",
"internal/oserror",
"reflect", "reflect",
}, },
...@@ -166,7 +167,7 @@ var pkgDeps = map[string][]string{ ...@@ -166,7 +167,7 @@ var pkgDeps = map[string][]string{
"syscall/js", "syscall/js",
}, },
"internal/poll": {"L0", "internal/race", "syscall", "time", "unicode/utf16", "unicode/utf8", "internal/syscall/windows"}, "internal/poll": {"L0", "internal/oserror", "internal/race", "syscall", "time", "unicode/utf16", "unicode/utf8", "internal/syscall/windows"},
"internal/testlog": {"L0"}, "internal/testlog": {"L0"},
"os": {"L1", "os", "syscall", "time", "internal/oserror", "internal/poll", "internal/syscall/windows", "internal/syscall/unix", "internal/testlog"}, "os": {"L1", "os", "syscall", "time", "internal/oserror", "internal/poll", "internal/syscall/windows", "internal/syscall/unix", "internal/testlog"},
"path/filepath": {"L2", "os", "syscall", "internal/syscall/windows"}, "path/filepath": {"L2", "os", "syscall", "internal/syscall/windows"},
...@@ -249,7 +250,7 @@ var pkgDeps = map[string][]string{ ...@@ -249,7 +250,7 @@ var pkgDeps = map[string][]string{
"compress/gzip": {"L4", "compress/flate"}, "compress/gzip": {"L4", "compress/flate"},
"compress/lzw": {"L4"}, "compress/lzw": {"L4"},
"compress/zlib": {"L4", "compress/flate"}, "compress/zlib": {"L4", "compress/flate"},
"context": {"errors", "internal/reflectlite", "sync", "time"}, "context": {"errors", "internal/oserror", "internal/reflectlite", "sync", "time"},
"database/sql": {"L4", "container/list", "context", "database/sql/driver", "database/sql/internal"}, "database/sql": {"L4", "container/list", "context", "database/sql/driver", "database/sql/internal"},
"database/sql/driver": {"L4", "context", "time", "database/sql/internal"}, "database/sql/driver": {"L4", "context", "time", "database/sql/internal"},
"debug/dwarf": {"L4"}, "debug/dwarf": {"L4"},
......
...@@ -15,6 +15,50 @@ var ( ...@@ -15,6 +15,50 @@ var (
ErrExist = errors.New("file already exists") ErrExist = errors.New("file already exists")
ErrNotExist = errors.New("file does not exist") ErrNotExist = errors.New("file does not exist")
ErrClosed = errors.New("file already closed") ErrClosed = errors.New("file already closed")
ErrTemporary = errors.New("temporary error") ErrTemporary = temporaryError{}
ErrTimeout = errors.New("deadline exceeded") ErrTimeout = timeoutError{}
) )
type timeoutError struct{}
func (timeoutError) Error() string { return "deadline exceeded" }
func (timeoutError) Timeout() bool { return true }
type temporaryError struct{}
func (temporaryError) Error() string { return "temporary error" }
func (temporaryError) Temporary() bool { return true }
// IsTimeout reports whether err indicates a timeout.
func IsTimeout(err error) bool {
for err != nil {
if err == ErrTimeout {
return true
}
if x, ok := err.(interface{ Timeout() bool }); ok {
return x.Timeout()
}
if x, ok := err.(interface{ Is(error) bool }); ok && x.Is(ErrTimeout) {
return true
}
err = errors.Unwrap(err)
}
return false
}
// IsTemporary reports whether err indicates a temporary condition.
func IsTemporary(err error) bool {
for err != nil {
if err == ErrTemporary {
return true
}
if x, ok := err.(interface{ Temporary() bool }); ok {
return x.Temporary()
}
if x, ok := err.(interface{ Is(error) bool }); ok && x.Is(ErrTemporary) {
return true
}
err = errors.Unwrap(err)
}
return false
}
package oserror_test
import (
"errors"
"fmt"
"internal/oserror"
"os"
"testing"
)
type ttError struct {
timeout bool
temporary bool
}
func (e ttError) Error() string {
return fmt.Sprintf("ttError{timeout:%v temporary:%v}", e.timeout, e.temporary)
}
func (e ttError) Timeout() bool { return e.timeout }
func (e ttError) Temporary() bool { return e.temporary }
type isError struct {
err error
}
func (e isError) Error() string { return fmt.Sprintf("isError(%v)", e.err) }
func (e isError) Is(target error) bool { return e.err == target }
func TestIsTimeout(t *testing.T) {
for _, test := range []struct {
want bool
err error
}{
{true, ttError{timeout: true}},
{true, isError{os.ErrTimeout}},
{true, os.ErrTimeout},
{true, fmt.Errorf("wrap: %w", os.ErrTimeout)},
{false, ttError{timeout: false}},
{false, errors.New("error")},
} {
if got, want := oserror.IsTimeout(test.err), test.want; got != want {
t.Errorf("IsTimeout(err) = %v, want %v\n%+v", got, want, test.err)
}
}
}
func TestIsTemporary(t *testing.T) {
for _, test := range []struct {
want bool
err error
}{
{true, ttError{temporary: true}},
{true, isError{os.ErrTemporary}},
{true, os.ErrTemporary},
{true, fmt.Errorf("wrap: %w", os.ErrTemporary)},
{false, ttError{temporary: false}},
{false, errors.New("error")},
} {
if got, want := oserror.IsTemporary(test.err), test.want; got != want {
t.Errorf("IsTemporary(err) = %v, want %v\n%+v", got, want, test.err)
}
}
}
...@@ -9,7 +9,10 @@ ...@@ -9,7 +9,10 @@
// runtime scheduler. // runtime scheduler.
package poll package poll
import "errors" import (
"errors"
"internal/oserror"
)
// ErrNetClosing is returned when a network descriptor is used after // ErrNetClosing is returned when a network descriptor is used after
// it has been closed. Keep this string consistent because of issue // it has been closed. Keep this string consistent because of issue
...@@ -44,6 +47,10 @@ func (e *TimeoutError) Error() string { return "i/o timeout" } ...@@ -44,6 +47,10 @@ func (e *TimeoutError) Error() string { return "i/o timeout" }
func (e *TimeoutError) Timeout() bool { return true } func (e *TimeoutError) Timeout() bool { return true }
func (e *TimeoutError) Temporary() bool { return true } func (e *TimeoutError) Temporary() bool { return true }
func (e *TimeoutError) Is(target error) bool {
return target == oserror.ErrTimeout || target == oserror.ErrTemporary
}
// ErrNotPollable is returned when the file or socket is not suitable // ErrNotPollable is returned when the file or socket is not suitable
// for event notification. // for event notification.
var ErrNotPollable = errors.New("not pollable") var ErrNotPollable = errors.New("not pollable")
......
...@@ -24,6 +24,7 @@ import "C" ...@@ -24,6 +24,7 @@ import "C"
import ( import (
"context" "context"
"os"
"syscall" "syscall"
"unsafe" "unsafe"
) )
...@@ -37,6 +38,16 @@ func (eai addrinfoErrno) Error() string { return C.GoString(C.gai_strerror(C.i ...@@ -37,6 +38,16 @@ func (eai addrinfoErrno) Error() string { return C.GoString(C.gai_strerror(C.i
func (eai addrinfoErrno) Temporary() bool { return eai == C.EAI_AGAIN } func (eai addrinfoErrno) Temporary() bool { return eai == C.EAI_AGAIN }
func (eai addrinfoErrno) Timeout() bool { return false } func (eai addrinfoErrno) Timeout() bool { return false }
func (eai addrinfoErrno) Is(target error) bool {
switch target {
case os.ErrTemporary:
return eai.Temporary()
case os.ErrTimeout:
return eai.Timeout()
}
return false
}
type portLookupResult struct { type portLookupResult struct {
port int port int
err error err error
......
...@@ -788,6 +788,8 @@ type transportReadFromServerError struct { ...@@ -788,6 +788,8 @@ type transportReadFromServerError struct {
err error err error
} }
func (e transportReadFromServerError) Unwrap() error { return e.err }
func (e transportReadFromServerError) Error() string { func (e transportReadFromServerError) Error() string {
return fmt.Sprintf("net/http: Transport failed to read from server: %v", e.err) return fmt.Sprintf("net/http: Transport failed to read from server: %v", e.err)
} }
...@@ -2155,6 +2157,16 @@ func (e *httpError) Error() string { return e.err } ...@@ -2155,6 +2157,16 @@ func (e *httpError) Error() string { return e.err }
func (e *httpError) Timeout() bool { return e.timeout } func (e *httpError) Timeout() bool { return e.timeout }
func (e *httpError) Temporary() bool { return true } func (e *httpError) Temporary() bool { return true }
func (e *httpError) Is(target error) bool {
switch target {
case os.ErrTimeout:
return e.timeout
case os.ErrTemporary:
return true
}
return false
}
var errTimeout error = &httpError{err: "net/http: timeout awaiting response headers", timeout: true} var errTimeout error = &httpError{err: "net/http: timeout awaiting response headers", timeout: true}
// errRequestCanceled is set to be identical to the one from h2 to facilitate // errRequestCanceled is set to be identical to the one from h2 to facilitate
...@@ -2489,6 +2501,10 @@ func (tlsHandshakeTimeoutError) Timeout() bool { return true } ...@@ -2489,6 +2501,10 @@ func (tlsHandshakeTimeoutError) Timeout() bool { return true }
func (tlsHandshakeTimeoutError) Temporary() bool { return true } func (tlsHandshakeTimeoutError) Temporary() bool { return true }
func (tlsHandshakeTimeoutError) Error() string { return "net/http: TLS handshake timeout" } func (tlsHandshakeTimeoutError) Error() string { return "net/http: TLS handshake timeout" }
func (tlsHandshakeTimeoutError) Is(target error) bool {
return target == os.ErrTimeout || target == os.ErrTemporary
}
// fakeLocker is a sync.Locker which does nothing. It's used to guard // fakeLocker is a sync.Locker which does nothing. It's used to guard
// test-only fields when not under test, to avoid runtime atomic // test-only fields when not under test, to avoid runtime atomic
// overhead. // overhead.
......
...@@ -448,6 +448,8 @@ type OpError struct { ...@@ -448,6 +448,8 @@ type OpError struct {
Err error Err error
} }
func (e *OpError) Unwrap() error { return e.Err }
func (e *OpError) Error() string { func (e *OpError) Error() string {
if e == nil { if e == nil {
return "<nil>" return "<nil>"
...@@ -514,6 +516,16 @@ func (e *OpError) Temporary() bool { ...@@ -514,6 +516,16 @@ func (e *OpError) Temporary() bool {
return ok && t.Temporary() return ok && t.Temporary()
} }
func (e *OpError) Is(target error) bool {
switch target {
case os.ErrTemporary:
return e.Temporary()
case os.ErrTimeout:
return e.Timeout()
}
return false
}
// A ParseError is the error type of literal network address parsers. // A ParseError is the error type of literal network address parsers.
type ParseError struct { type ParseError struct {
// Type is the type of string that was expected, such as // Type is the type of string that was expected, such as
...@@ -563,6 +575,7 @@ type DNSConfigError struct { ...@@ -563,6 +575,7 @@ type DNSConfigError struct {
Err error Err error
} }
func (e *DNSConfigError) Unwrap() error { return e.Err }
func (e *DNSConfigError) Error() string { return "error reading DNS config: " + e.Err.Error() } func (e *DNSConfigError) Error() string { return "error reading DNS config: " + e.Err.Error() }
func (e *DNSConfigError) Timeout() bool { return false } func (e *DNSConfigError) Timeout() bool { return false }
func (e *DNSConfigError) Temporary() bool { return false } func (e *DNSConfigError) Temporary() bool { return false }
...@@ -604,6 +617,16 @@ func (e *DNSError) Timeout() bool { return e.IsTimeout } ...@@ -604,6 +617,16 @@ func (e *DNSError) Timeout() bool { return e.IsTimeout }
// error and return a DNSError for which Temporary returns false. // error and return a DNSError for which Temporary returns false.
func (e *DNSError) Temporary() bool { return e.IsTimeout || e.IsTemporary } func (e *DNSError) Temporary() bool { return e.IsTimeout || e.IsTemporary }
func (e *DNSError) Is(target error) bool {
switch target {
case os.ErrTemporary:
return e.Temporary()
case os.ErrTimeout:
return e.Timeout()
}
return false
}
type writerOnly struct { type writerOnly struct {
io.Writer io.Writer
} }
......
...@@ -6,6 +6,7 @@ package net ...@@ -6,6 +6,7 @@ package net
import ( import (
"io" "io"
"os"
"sync" "sync"
"time" "time"
) )
...@@ -84,6 +85,10 @@ func (timeoutError) Error() string { return "deadline exceeded" } ...@@ -84,6 +85,10 @@ func (timeoutError) Error() string { return "deadline exceeded" }
func (timeoutError) Timeout() bool { return true } func (timeoutError) Timeout() bool { return true }
func (timeoutError) Temporary() bool { return true } func (timeoutError) Temporary() bool { return true }
func (timeoutError) Is(target error) bool {
return target == os.ErrTemporary || target == os.ErrTimeout
}
type pipeAddr struct{} type pipeAddr struct{}
func (pipeAddr) Network() string { return "pipe" } func (pipeAddr) Network() string { return "pipe" }
......
...@@ -7,7 +7,9 @@ ...@@ -7,7 +7,9 @@
package net package net
import ( import (
"errors"
"fmt" "fmt"
"internal/oserror"
"internal/poll" "internal/poll"
"internal/testenv" "internal/testenv"
"io" "io"
...@@ -88,6 +90,9 @@ func TestDialTimeout(t *testing.T) { ...@@ -88,6 +90,9 @@ func TestDialTimeout(t *testing.T) {
if nerr, ok := err.(Error); !ok || !nerr.Timeout() { if nerr, ok := err.(Error); !ok || !nerr.Timeout() {
t.Fatalf("#%d: %v", i, err) t.Fatalf("#%d: %v", i, err)
} }
if !errors.Is(err, oserror.ErrTimeout) {
t.Fatalf("#%d: Dial error is not os.ErrTimeout: %v", i, err)
}
} }
} }
} }
......
...@@ -13,6 +13,7 @@ package url ...@@ -13,6 +13,7 @@ package url
import ( import (
"errors" "errors"
"fmt" "fmt"
"internal/oserror"
"sort" "sort"
"strconv" "strconv"
"strings" "strings"
...@@ -25,25 +26,10 @@ type Error struct { ...@@ -25,25 +26,10 @@ type Error struct {
Err error Err error
} }
func (e *Error) Error() string { return e.Op + " " + e.URL + ": " + e.Err.Error() } func (e *Error) Unwrap() error { return e.Err }
func (e *Error) Error() string { return e.Op + " " + e.URL + ": " + e.Err.Error() }
type timeout interface { func (e *Error) Timeout() bool { return oserror.IsTimeout(e.Err) }
Timeout() bool func (e *Error) Temporary() bool { return oserror.IsTemporary(e.Err) }
}
func (e *Error) Timeout() bool {
t, ok := e.Err.(timeout)
return ok && t.Timeout()
}
type temporary interface {
Temporary() bool
}
func (e *Error) Temporary() bool {
t, ok := e.Err.(temporary)
return ok && t.Temporary()
}
func ishex(c byte) bool { func ishex(c byte) bool {
switch { switch {
......
...@@ -23,6 +23,7 @@ var ( ...@@ -23,6 +23,7 @@ var (
ErrNotExist = errNotExist() // "file does not exist" ErrNotExist = errNotExist() // "file does not exist"
ErrClosed = errClosed() // "file already closed" ErrClosed = errClosed() // "file already closed"
ErrTimeout = errTimeout() // "deadline exceeded" ErrTimeout = errTimeout() // "deadline exceeded"
ErrTemporary = errTemporary() // "temporary error"
ErrNoDeadline = errNoDeadline() // "file type does not support deadline" ErrNoDeadline = errNoDeadline() // "file type does not support deadline"
) )
...@@ -32,6 +33,7 @@ func errExist() error { return oserror.ErrExist } ...@@ -32,6 +33,7 @@ func errExist() error { return oserror.ErrExist }
func errNotExist() error { return oserror.ErrNotExist } func errNotExist() error { return oserror.ErrNotExist }
func errClosed() error { return oserror.ErrClosed } func errClosed() error { return oserror.ErrClosed }
func errTimeout() error { return oserror.ErrTimeout } func errTimeout() error { return oserror.ErrTimeout }
func errTemporary() error { return oserror.ErrTemporary }
func errNoDeadline() error { return poll.ErrNoDeadline } func errNoDeadline() error { return poll.ErrNoDeadline }
type timeout interface { type timeout interface {
......
...@@ -47,6 +47,8 @@ func (e *Error) Error() string { ...@@ -47,6 +47,8 @@ func (e *Error) Error() string {
return "exec: " + strconv.Quote(e.Name) + ": " + e.Err.Error() return "exec: " + strconv.Quote(e.Name) + ": " + e.Err.Error()
} }
func (e *Error) Unwrap() error { return e.Err }
// Cmd represents an external command being prepared or run. // Cmd represents an external command being prepared or run.
// //
// A Cmd cannot be reused after calling its Run, Output or CombinedOutput // A Cmd cannot be reused after calling its Run, Output or CombinedOutput
......
...@@ -38,6 +38,8 @@ func (e *PtyError) Error() string { ...@@ -38,6 +38,8 @@ func (e *PtyError) Error() string {
return fmt.Sprintf("%s: %s", e.FuncName, e.ErrorString) return fmt.Sprintf("%s: %s", e.FuncName, e.ErrorString)
} }
func (e *PtyError) Unwrap() error { return e.Errno }
// Open returns a master pty and the name of the linked slave tty. // Open returns a master pty and the name of the linked slave tty.
func Open() (master *os.File, slave string, err error) { func Open() (master *os.File, slave string, err error) {
m, err := C.posix_openpt(C.O_RDWR) m, err := C.posix_openpt(C.O_RDWR)
......
...@@ -121,6 +121,10 @@ func (e ExecError) Error() string { ...@@ -121,6 +121,10 @@ func (e ExecError) Error() string {
return e.Err.Error() return e.Err.Error()
} }
func (e ExecError) Unwrap() error {
return e.Err
}
// errorf records an ExecError and terminates processing. // errorf records an ExecError and terminates processing.
func (s *state) errorf(format string, args ...interface{}) { func (s *state) errorf(format string, args ...interface{}) {
name := doublePercent(s.tmpl.Name()) name := doublePercent(s.tmpl.Name())
......
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