forked from go-kratos/kratos
/
utils.go
159 lines (135 loc) · 3.21 KB
/
utils.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
149
150
151
152
153
154
155
156
157
158
159
package blademaster
import (
"os"
"path"
)
func lastChar(str string) uint8 {
if str == "" {
panic("The length of the string can't be 0")
}
return str[len(str)-1]
}
func joinPaths(absolutePath, relativePath string) string {
if relativePath == "" {
return absolutePath
}
finalPath := path.Join(absolutePath, relativePath)
appendSlash := lastChar(relativePath) == '/' && lastChar(finalPath) != '/'
if appendSlash {
return finalPath + "/"
}
return finalPath
}
func resolveAddress(addr []string) string {
switch len(addr) {
case 0:
if port := os.Getenv("PORT"); port != "" {
//debugPrint("Environment variable PORT=\"%s\"", port)
return ":" + port
}
//debugPrint("Environment variable PORT is undefined. Using port :8080 by default")
return ":8080"
case 1:
return addr[0]
default:
panic("too much parameters")
}
}
// cleanPath is the URL version of path.Clean, it returns a canonical URL path
// for p, eliminating . and .. elements.
//
// The following rules are applied iteratively until no further processing can
// be done:
// 1. Replace multiple slashes with a single slash.
// 2. Eliminate each . path name element (the current directory).
// 3. Eliminate each inner .. path name element (the parent directory)
// along with the non-.. element that precedes it.
// 4. Eliminate .. elements that begin a rooted path:
// that is, replace "/.." by "/" at the beginning of a path.
//
// If the result of this process is an empty string, "/" is returned.
func cleanPath(p string) string {
// Turn empty string into "/"
if p == "" {
return "/"
}
n := len(p)
var buf []byte
// Invariants:
// reading from path; r is index of next byte to process.
// writing to buf; w is index of next byte to write.
// path must start with '/'
r := 1
w := 1
if p[0] != '/' {
r = 0
buf = make([]byte, n+1)
buf[0] = '/'
}
trailing := n > 1 && p[n-1] == '/'
// A bit more clunky without a 'lazybuf' like the path package, but the loop
// gets completely inlined (bufApp). So in contrast to the path package this
// loop has no expensive function calls (except 1x make)
for r < n {
switch {
case p[r] == '/':
// empty path element, trailing slash is added after the end
r++
case p[r] == '.' && r+1 == n:
trailing = true
r++
case p[r] == '.' && p[r+1] == '/':
// . element
r += 2
case p[r] == '.' && p[r+1] == '.' && (r+2 == n || p[r+2] == '/'):
// .. element: remove to last /
r += 3
if w > 1 {
// can backtrack
w--
if buf == nil {
for w > 1 && p[w] != '/' {
w--
}
} else {
for w > 1 && buf[w] != '/' {
w--
}
}
}
default:
// real path element.
// add slash if needed
if w > 1 {
bufApp(&buf, p, w, '/')
w++
}
// copy element
for r < n && p[r] != '/' {
bufApp(&buf, p, w, p[r])
w++
r++
}
}
}
// re-append trailing slash
if trailing && w > 1 {
bufApp(&buf, p, w, '/')
w++
}
if buf == nil {
return p[:w]
}
return string(buf[:w])
}
// internal helper to lazily create a buffer if necessary.
func bufApp(buf *[]byte, s string, w int, c byte) {
if *buf == nil {
if s[w] == c {
return
}
*buf = make([]byte, len(s))
copy(*buf, s[:w])
}
(*buf)[w] = c
}