frostfs-s3-gw/api/handler/s3encoder.go

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package handler
import (
"strings"
)
type encoding int
const (
encodePathSegment encoding = iota
encodeQueryComponent
)
const (
urlEncodingType = "url"
upperhex = "0123456789ABCDEF"
)
func shouldEscape(c byte) bool {
if 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' {
return false
}
switch c {
case '-', '_', '.', '/', '*':
return false
}
return true
}
// s3URLEncode is based on url.QueryEscape() code
// while considering some S3 exceptions.
func s3URLEncode(s string, mode encoding) string {
spaceCount, hexCount := 0, 0
for i := 0; i < len(s); i++ {
c := s[i]
if shouldEscape(c) {
if c == ' ' && mode == encodeQueryComponent {
spaceCount++
} else {
hexCount++
}
}
}
if spaceCount == 0 && hexCount == 0 {
return s
}
var buf [64]byte
var t []byte
required := len(s) + 2*hexCount
if required <= len(buf) {
t = buf[:required]
} else {
t = make([]byte, required)
}
if hexCount == 0 {
copy(t, s)
for i := 0; i < len(s); i++ {
if s[i] == ' ' {
t[i] = '+'
}
}
return string(t)
}
j := 0
for i := 0; i < len(s); i++ {
switch c := s[i]; {
case c == ' ' && mode == encodeQueryComponent:
t[j] = '+'
j++
case shouldEscape(c):
t[j] = '%'
t[j+1] = upperhex[c>>4]
t[j+2] = upperhex[c&15]
j += 3
default:
t[j] = s[i]
j++
}
}
return string(t)
}
func s3QueryEncode(name string, encodingType string) (result string) {
if encodingType == "" {
return name
}
encodingType = strings.ToLower(encodingType)
switch encodingType {
case urlEncodingType:
return s3URLEncode(name, encodeQueryComponent)
}
return name
}
func s3PathEncode(name string, encodingType string) (result string) {
if encodingType == "" {
return name
}
encodingType = strings.ToLower(encodingType)
switch encodingType {
case urlEncodingType:
return s3URLEncode(name, encodePathSegment)
}
return name
}