vendor/github.com/aws/aws-sdk-go/aws/awsutil/string_value.go

   1 package awsutil
   2
   3 import (
   4         "bytes"
   5         "fmt"
   6         "reflect"
   7         "strings"
   8 )
   9
  10 // StringValue returns the string representation of a value.
  11 func StringValue(i interface{}) string {
  12         var buf bytes.Buffer
  13         stringValue(reflect.ValueOf(i), 0, &buf)
  14         return buf.String()
  15 }
  16
  17 func stringValue(v reflect.Value, indent int, buf *bytes.Buffer) {
  18         for v.Kind() == reflect.Ptr {
  19                 v = v.Elem()
  20         }
  21
  22         switch v.Kind() {
  23         case reflect.Struct:
  24                 buf.WriteString("{\n")
  25
  26                 names := []string{}
  27                 for i := 0; i < v.Type().NumField(); i++ {
  28                         name := v.Type().Field(i).Name
  29                         f := v.Field(i)
  30                         if name[0:1] == strings.ToLower(name[0:1]) {
  31                                 continue // ignore unexported fields
  32                         }
  33                         if (f.Kind() == reflect.Ptr || f.Kind() == reflect.Slice) && f.IsNil() {
  34                                 continue // ignore unset fields
  35                         }
  36                         names = append(names, name)
  37                 }
  38
  39                 for i, n := range names {
  40                         val := v.FieldByName(n)
  41                         buf.WriteString(strings.Repeat(" ", indent+2))
  42                         buf.WriteString(n + ": ")
  43                         stringValue(val, indent+2, buf)
  44
  45                         if i < len(names)-1 {
  46                                 buf.WriteString(",\n")
  47                         }
  48                 }
  49
  50                 buf.WriteString("\n" + strings.Repeat(" ", indent) + "}")
  51         case reflect.Slice:
  52                 nl, id, id2 := "", "", ""
  53                 if v.Len() > 3 {
  54                         nl, id, id2 = "\n", strings.Repeat(" ", indent), strings.Repeat(" ", indent+2)
  55                 }
  56                 buf.WriteString("[" + nl)
  57                 for i := 0; i < v.Len(); i++ {
  58                         buf.WriteString(id2)
  59                         stringValue(v.Index(i), indent+2, buf)
  60
  61                         if i < v.Len()-1 {
  62                                 buf.WriteString("," + nl)
  63                         }
  64                 }
  65
  66                 buf.WriteString(nl + id + "]")
  67         case reflect.Map:
  68                 buf.WriteString("{\n")
  69
  70                 for i, k := range v.MapKeys() {
  71                         buf.WriteString(strings.Repeat(" ", indent+2))
  72                         buf.WriteString(k.String() + ": ")
  73                         stringValue(v.MapIndex(k), indent+2, buf)
  74
  75                         if i < v.Len()-1 {
  76                                 buf.WriteString(",\n")
  77                         }
  78                 }
  79
  80                 buf.WriteString("\n" + strings.Repeat(" ", indent) + "}")
  81         default:
  82                 format := "%v"
  83                 switch v.Interface().(type) {
  84                 case string:
  85                         format = "%q"
  86                 }
  87                 fmt.Fprintf(buf, format, v.Interface())
  88         }
  89 }