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codec.go
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codec.go
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package multiaddr
import (
"bytes"
"fmt"
"strings"
)
func stringToBytes(s string) ([]byte, error) {
// consume trailing slashes
s = strings.TrimRight(s, "/")
b := new(bytes.Buffer)
sp := strings.Split(s, "/")
if sp[0] != "" {
return nil, fmt.Errorf("invalid multiaddr, must begin with /")
}
// consume first empty elem
sp = sp[1:]
for len(sp) > 0 {
p := ProtocolWithName(sp[0])
if p.Code == 0 {
return nil, fmt.Errorf("no protocol with name %s", sp[0])
}
_, _ = b.Write(CodeToVarint(p.Code))
sp = sp[1:]
if p.Size == 0 { // no length.
continue
}
if len(sp) < 1 {
return nil, fmt.Errorf("protocol requires address, none given: %s", p.Name)
}
if p.Path {
// it's a path protocol (terminal).
// consume the rest of the address as the next component.
sp = []string{"/" + strings.Join(sp, "/")}
}
if p.Transcoder == nil {
return nil, fmt.Errorf("no transcoder for %s protocol", p.Name)
}
a, err := p.Transcoder.StringToBytes(sp[0])
if err != nil {
return nil, fmt.Errorf("failed to parse %s: %s %s", p.Name, sp[0], err)
}
if p.Size < 0 { // varint size.
_, _ = b.Write(CodeToVarint(len(a)))
}
b.Write(a)
sp = sp[1:]
}
return b.Bytes(), nil
}
func validateBytes(b []byte) (err error) {
for len(b) > 0 {
code, n, err := ReadVarintCode(b)
if err != nil {
return err
}
b = b[n:]
p := ProtocolWithCode(code)
if p.Code == 0 {
return fmt.Errorf("no protocol with code %d", code)
}
if p.Size == 0 {
continue
}
n, size, err := sizeForAddr(p, b)
if err != nil {
return err
}
b = b[n:]
if len(b) < size || size < 0 {
return fmt.Errorf("invalid value for size")
}
err = p.Transcoder.ValidateBytes(b[:size])
if err != nil {
return err
}
b = b[size:]
}
return nil
}
func bytesToString(b []byte) (ret string, err error) {
s := ""
for len(b) > 0 {
code, n, err := ReadVarintCode(b)
if err != nil {
return "", err
}
b = b[n:]
p := ProtocolWithCode(code)
if p.Code == 0 {
return "", fmt.Errorf("no protocol with code %d", code)
}
s += "/" + p.Name
if p.Size == 0 {
continue
}
n, size, err := sizeForAddr(p, b)
if err != nil {
return "", err
}
b = b[n:]
if len(b) < size || size < 0 {
return "", fmt.Errorf("invalid value for size")
}
if p.Transcoder == nil {
return "", fmt.Errorf("no transcoder for %s protocol", p.Name)
}
a, err := p.Transcoder.BytesToString(b[:size])
if err != nil {
return "", err
}
if p.Path && len(a) > 0 && a[0] == '/' {
a = a[1:]
}
if len(a) > 0 {
s += "/" + a
}
b = b[size:]
}
return s, nil
}
func sizeForAddr(p Protocol, b []byte) (skip, size int, err error) {
switch {
case p.Size > 0:
return 0, (p.Size / 8), nil
case p.Size == 0:
return 0, 0, nil
case p.Path:
size, n, err := ReadVarintCode(b)
if err != nil {
return 0, 0, err
}
return n, size, nil
default:
size, n, err := ReadVarintCode(b)
if err != nil {
return 0, 0, err
}
return n, size, nil
}
}
func bytesSplit(b []byte) ([][]byte, error) {
var ret [][]byte
for len(b) > 0 {
code, n, err := ReadVarintCode(b)
if err != nil {
return nil, err
}
p := ProtocolWithCode(code)
if p.Code == 0 {
return nil, fmt.Errorf("no protocol with code %d", b[0])
}
n2, size, err := sizeForAddr(p, b[n:])
if err != nil {
return nil, err
}
length := n + n2 + size
ret = append(ret, b[:length])
b = b[length:]
}
return ret, nil
}