forked from golang/tools
/
uri.go
148 lines (136 loc) · 3.44 KB
/
uri.go
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
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package span
import (
"fmt"
"net/url"
"os"
"path"
"path/filepath"
"runtime"
"strings"
"unicode"
)
const fileScheme = "file"
// URI represents the full URI for a file.
type URI string
// Filename returns the file path for the given URI.
// It is an error to call this on a URI that is not a valid filename.
func (uri URI) Filename() string {
filename, err := filename(uri)
if err != nil {
panic(err)
}
return filepath.FromSlash(filename)
}
func filename(uri URI) (string, error) {
if uri == "" {
return "", nil
}
u, err := url.ParseRequestURI(string(uri))
if err != nil {
return "", err
}
if u.Scheme != fileScheme {
return "", fmt.Errorf("only file URIs are supported, got %q from %q", u.Scheme, uri)
}
if isWindowsDriveURI(u.Path) {
u.Path = u.Path[1:]
}
return u.Path, nil
}
// NewURI returns a span URI for the string.
// It will attempt to detect if the string is a file path or uri.
func NewURI(s string) URI {
if u, err := url.PathUnescape(s); err == nil {
s = u
}
if strings.HasPrefix(s, fileScheme+"://") {
return URI(s)
}
return FileURI(s)
}
func CompareURI(a, b URI) int {
if equalURI(a, b) {
return 0
}
if a < b {
return -1
}
return 1
}
func equalURI(a, b URI) bool {
if a == b {
return true
}
// If we have the same URI basename, we may still have the same file URIs.
if !strings.EqualFold(path.Base(string(a)), path.Base(string(b))) {
return false
}
fa, err := filename(a)
if err != nil {
return false
}
fb, err := filename(b)
if err != nil {
return false
}
// Stat the files to check if they are equal.
infoa, err := os.Stat(filepath.FromSlash(fa))
if err != nil {
return false
}
infob, err := os.Stat(filepath.FromSlash(fb))
if err != nil {
return false
}
return os.SameFile(infoa, infob)
}
// FileURI returns a span URI for the supplied file path.
// It will always have the file scheme.
func FileURI(path string) URI {
if path == "" {
return ""
}
// Handle standard library paths that contain the literal "$GOROOT".
// TODO(rstambler): The go/packages API should allow one to determine a user's $GOROOT.
const prefix = "$GOROOT"
if len(path) >= len(prefix) && strings.EqualFold(prefix, path[:len(prefix)]) {
suffix := path[len(prefix):]
path = runtime.GOROOT() + suffix
}
if !isWindowsDrivePath(path) {
if abs, err := filepath.Abs(path); err == nil {
path = abs
}
}
// Check the file path again, in case it became absolute.
if isWindowsDrivePath(path) {
path = "/" + path
}
path = filepath.ToSlash(path)
u := url.URL{
Scheme: fileScheme,
Path: path,
}
return URI(u.String())
}
// isWindowsDrivePath returns true if the file path is of the form used by
// Windows. We check if the path begins with a drive letter, followed by a ":".
func isWindowsDrivePath(path string) bool {
if len(path) < 4 {
return false
}
return unicode.IsLetter(rune(path[0])) && path[1] == ':'
}
// isWindowsDriveURI returns true if the file URI is of the format used by
// Windows URIs. The url.Parse package does not specially handle Windows paths
// (see https://golang.org/issue/6027). We check if the URI path has
// a drive prefix (e.g. "/C:"). If so, we trim the leading "/".
func isWindowsDriveURI(uri string) bool {
if len(uri) < 4 {
return false
}
return uri[0] == '/' && unicode.IsLetter(rune(uri[1])) && uri[2] == ':'
}