109 lines
2.3 KiB
Go
109 lines
2.3 KiB
Go
package httpbinding
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
)
|
|
|
|
const (
|
|
uriTokenStart = '{'
|
|
uriTokenStop = '}'
|
|
uriTokenSkip = '+'
|
|
)
|
|
|
|
func bufCap(b []byte, n int) []byte {
|
|
if cap(b) < n {
|
|
return make([]byte, 0, n)
|
|
}
|
|
|
|
return b[0:0]
|
|
}
|
|
|
|
// replacePathElement replaces a single element in the path []byte.
|
|
// Escape is used to control whether the value will be escaped using Amazon path escape style.
|
|
func replacePathElement(path, fieldBuf []byte, key, val string, escape bool) ([]byte, []byte, error) {
|
|
fieldBuf = bufCap(fieldBuf, len(key)+3) // { <key> [+] }
|
|
fieldBuf = append(fieldBuf, uriTokenStart)
|
|
fieldBuf = append(fieldBuf, key...)
|
|
|
|
start := bytes.Index(path, fieldBuf)
|
|
end := start + len(fieldBuf)
|
|
if start < 0 || len(path[end:]) == 0 {
|
|
// TODO what to do about error?
|
|
return path, fieldBuf, fmt.Errorf("invalid path index, start=%d,end=%d. %s", start, end, path)
|
|
}
|
|
|
|
encodeSep := true
|
|
if path[end] == uriTokenSkip {
|
|
// '+' token means do not escape slashes
|
|
encodeSep = false
|
|
end++
|
|
}
|
|
|
|
if escape {
|
|
val = EscapePath(val, encodeSep)
|
|
}
|
|
|
|
if path[end] != uriTokenStop {
|
|
return path, fieldBuf, fmt.Errorf("invalid path element, does not contain token stop, %s", path)
|
|
}
|
|
end++
|
|
|
|
fieldBuf = bufCap(fieldBuf, len(val))
|
|
fieldBuf = append(fieldBuf, val...)
|
|
|
|
keyLen := end - start
|
|
valLen := len(fieldBuf)
|
|
|
|
if keyLen == valLen {
|
|
copy(path[start:], fieldBuf)
|
|
return path, fieldBuf, nil
|
|
}
|
|
|
|
newLen := len(path) + (valLen - keyLen)
|
|
if len(path) < newLen {
|
|
path = path[:cap(path)]
|
|
}
|
|
if cap(path) < newLen {
|
|
newURI := make([]byte, newLen)
|
|
copy(newURI, path)
|
|
path = newURI
|
|
}
|
|
|
|
// shift
|
|
copy(path[start+valLen:], path[end:])
|
|
path = path[:newLen]
|
|
copy(path[start:], fieldBuf)
|
|
|
|
return path, fieldBuf, nil
|
|
}
|
|
|
|
// EscapePath escapes part of a URL path in Amazon style.
|
|
func EscapePath(path string, encodeSep bool) string {
|
|
var buf bytes.Buffer
|
|
for i := 0; i < len(path); i++ {
|
|
c := path[i]
|
|
if noEscape[c] || (c == '/' && !encodeSep) {
|
|
buf.WriteByte(c)
|
|
} else {
|
|
fmt.Fprintf(&buf, "%%%02X", c)
|
|
}
|
|
}
|
|
return buf.String()
|
|
}
|
|
|
|
var noEscape [256]bool
|
|
|
|
func init() {
|
|
for i := 0; i < len(noEscape); i++ {
|
|
// AWS expects every character except these to be escaped
|
|
noEscape[i] = (i >= 'A' && i <= 'Z') ||
|
|
(i >= 'a' && i <= 'z') ||
|
|
(i >= '0' && i <= '9') ||
|
|
i == '-' ||
|
|
i == '.' ||
|
|
i == '_' ||
|
|
i == '~'
|
|
}
|
|
}
|