summaryrefslogtreecommitdiffhomepage
path: root/pkg/syserror/syserror.go
blob: 4228707f4a9a074e2489f995f24eadd72d3ff21d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
// Copyright 2018 Google LLC
//
// 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 syserror contains syscall error codes exported as error interface
// instead of Errno. This allows for fast comparison and returns when the
// comparand or return value is of type error because there is no need to
// convert from Errno to an interface, i.e., runtime.convT2I isn't called.
package syserror

import (
	"errors"
	"syscall"
)

// The following variables have the same meaning as their syscall equivalent.
var (
	E2BIG        = error(syscall.E2BIG)
	EACCES       = error(syscall.EACCES)
	EAGAIN       = error(syscall.EAGAIN)
	EBADF        = error(syscall.EBADF)
	EBUSY        = error(syscall.EBUSY)
	ECHILD       = error(syscall.ECHILD)
	ECONNREFUSED = error(syscall.ECONNREFUSED)
	ECONNRESET   = error(syscall.ECONNRESET)
	EEXIST       = error(syscall.EEXIST)
	EFAULT       = error(syscall.EFAULT)
	EFBIG        = error(syscall.EFBIG)
	EIDRM        = error(syscall.EIDRM)
	EINTR        = error(syscall.EINTR)
	EINVAL       = error(syscall.EINVAL)
	EIO          = error(syscall.EIO)
	EISDIR       = error(syscall.EISDIR)
	ELIBBAD      = error(syscall.ELIBBAD)
	ELOOP        = error(syscall.ELOOP)
	EMFILE       = error(syscall.EMFILE)
	EMSGSIZE     = error(syscall.EMSGSIZE)
	ENAMETOOLONG = error(syscall.ENAMETOOLONG)
	ENOATTR      = ENODATA
	ENODATA      = error(syscall.ENODATA)
	ENODEV       = error(syscall.ENODEV)
	ENOENT       = error(syscall.ENOENT)
	ENOEXEC      = error(syscall.ENOEXEC)
	ENOLCK       = error(syscall.ENOLCK)
	ENOLINK      = error(syscall.ENOLINK)
	ENOMEM       = error(syscall.ENOMEM)
	ENOSPC       = error(syscall.ENOSPC)
	ENOSYS       = error(syscall.ENOSYS)
	ENOTDIR      = error(syscall.ENOTDIR)
	ENOTEMPTY    = error(syscall.ENOTEMPTY)
	ENOTSUP      = error(syscall.ENOTSUP)
	ENOTTY       = error(syscall.ENOTTY)
	ENXIO        = error(syscall.ENXIO)
	EOPNOTSUPP   = error(syscall.EOPNOTSUPP)
	EOVERFLOW    = error(syscall.EOVERFLOW)
	EPERM        = error(syscall.EPERM)
	EPIPE        = error(syscall.EPIPE)
	ERANGE       = error(syscall.ERANGE)
	EROFS        = error(syscall.EROFS)
	ESPIPE       = error(syscall.ESPIPE)
	ESRCH        = error(syscall.ESRCH)
	ETIMEDOUT    = error(syscall.ETIMEDOUT)
	EUSERS       = error(syscall.EUSERS)
	EWOULDBLOCK  = error(syscall.EWOULDBLOCK)
	EXDEV        = error(syscall.EXDEV)
)

var (
	// ErrWouldBlock is an internal error used to indicate that an operation
	// cannot be satisfied immediately, and should be retried at a later
	// time, possibly when the caller has received a notification that the
	// operation may be able to complete. It is used by implementations of
	// the kio.File interface.
	ErrWouldBlock = errors.New("request would block")

	// ErrInterrupted is returned if a request is interrupted before it can
	// complete.
	ErrInterrupted = errors.New("request was interrupted")

	// ErrExceedsFileSizeLimit is returned if a request would exceed the
	// file's size limit.
	ErrExceedsFileSizeLimit = errors.New("exceeds file size limit")
)

// errorMap is the map used to convert generic errors into errnos.
var errorMap = map[error]syscall.Errno{}

// errorUnwrappers is an array of unwrap functions to extract typed errors.
var errorUnwrappers = []func(error) (syscall.Errno, bool){}

// AddErrorTranslation allows modules to populate the error map by adding their
// own translations during initialization. Returns if the error translation is
// accepted or not. A pre-existing translation will not be overwritten by the
// new translation.
func AddErrorTranslation(from error, to syscall.Errno) bool {
	if _, ok := errorMap[from]; ok {
		return false
	}

	errorMap[from] = to
	return true
}

// AddErrorUnwrapper registers an unwrap method that can extract a concrete error
// from a typed, but not initialized, error.
func AddErrorUnwrapper(unwrap func(e error) (syscall.Errno, bool)) {
	errorUnwrappers = append(errorUnwrappers, unwrap)
}

// TranslateError translates errors to errnos, it will return false if
// the error was not registered.
func TranslateError(from error) (syscall.Errno, bool) {
	err, ok := errorMap[from]
	if ok {
		return err, ok
	}
	// Try to unwrap the error if we couldn't match an error
	// exactly.  This might mean that a package has its own
	// error type.
	for _, unwrap := range errorUnwrappers {
		err, ok := unwrap(from)
		if ok {
			return err, ok
		}
	}
	return 0, false
}

// ConvertIntr converts the provided error code (err) to another one (intr) if
// the first error corresponds to an interrupted operation.
func ConvertIntr(err, intr error) error {
	if err == ErrInterrupted {
		return intr
	}
	return err
}

func init() {
	AddErrorTranslation(ErrWouldBlock, syscall.EWOULDBLOCK)
	AddErrorTranslation(ErrInterrupted, syscall.EINTR)
	AddErrorTranslation(ErrExceedsFileSizeLimit, syscall.EFBIG)
}