forked from aws/aws-sdk-go-v2
/
prettify.go
131 lines (113 loc) · 2.78 KB
/
prettify.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
package awsutil
import (
"bytes"
"fmt"
"io"
"reflect"
"strings"
)
// Prettify returns the string representation of a value.
func Prettify(i interface{}) string {
var buf bytes.Buffer
prettify(reflect.ValueOf(i), 0, &buf)
return buf.String()
}
// prettify will recursively walk value v to build a textual
// representation of the value.
func prettify(v reflect.Value, indent int, buf *bytes.Buffer) {
isPtr := false
for v.Kind() == reflect.Ptr {
isPtr = true
v = v.Elem()
}
switch v.Kind() {
case reflect.Struct:
strtype := v.Type().String()
if strtype == "time.Time" {
fmt.Fprintf(buf, "%s", v.Interface())
break
} else if strings.HasPrefix(strtype, "io.") {
buf.WriteString("<buffer>")
break
}
if isPtr {
buf.WriteRune('&')
}
buf.WriteString("{\n")
names := []string{}
for i := 0; i < v.Type().NumField(); i++ {
name := v.Type().Field(i).Name
f := v.Field(i)
if name[0:1] == strings.ToLower(name[0:1]) {
continue // ignore unexported fields
}
if (f.Kind() == reflect.Ptr || f.Kind() == reflect.Slice || f.Kind() == reflect.Map) && f.IsNil() {
continue // ignore unset fields
}
names = append(names, name)
}
for i, n := range names {
val := v.FieldByName(n)
buf.WriteString(strings.Repeat(" ", indent+2))
buf.WriteString(n + ": ")
prettify(val, indent+2, buf)
if i < len(names)-1 {
buf.WriteString(",\n")
}
}
buf.WriteString("\n" + strings.Repeat(" ", indent) + "}")
case reflect.Slice:
strtype := v.Type().String()
if strtype == "[]uint8" {
fmt.Fprintf(buf, "<binary> len %d", v.Len())
break
}
nl, id, id2 := "\n", strings.Repeat(" ", indent), strings.Repeat(" ", indent+2)
if isPtr {
buf.WriteRune('&')
}
buf.WriteString("[" + nl)
for i := 0; i < v.Len(); i++ {
buf.WriteString(id2)
prettify(v.Index(i), indent+2, buf)
if i < v.Len()-1 {
buf.WriteString("," + nl)
}
}
buf.WriteString(nl + id + "]")
case reflect.Map:
if isPtr {
buf.WriteRune('&')
}
buf.WriteString("{\n")
for i, k := range v.MapKeys() {
buf.WriteString(strings.Repeat(" ", indent+2))
buf.WriteString(k.String() + ": ")
prettify(v.MapIndex(k), indent+2, buf)
if i < v.Len()-1 {
buf.WriteString(",\n")
}
}
buf.WriteString("\n" + strings.Repeat(" ", indent) + "}")
default:
if !v.IsValid() {
fmt.Fprint(buf, "<invalid value>")
return
}
for v.Kind() == reflect.Interface && !v.IsNil() {
v = v.Elem()
}
if v.Kind() == reflect.Ptr || v.Kind() == reflect.Struct || v.Kind() == reflect.Map || v.Kind() == reflect.Slice {
prettify(v, indent, buf)
return
}
format := "%v"
switch v.Interface().(type) {
case string:
format = "%q"
case io.ReadSeeker, io.Reader:
format = "buffer(%p)"
}
fmt.Fprintf(buf, format, v.Interface())
}
}