status-go/vendor/github.com/multiformats/go-multiaddr/multiaddr.go

203 lines
4.4 KiB
Go

package multiaddr
import (
"bytes"
"encoding/json"
"fmt"
"log"
"strings"
)
// multiaddr is the data structure representing a Multiaddr
type multiaddr struct {
bytes []byte
}
// NewMultiaddr parses and validates an input string, returning a *Multiaddr
func NewMultiaddr(s string) (a Multiaddr, err error) {
defer func() {
if e := recover(); e != nil {
log.Printf("Panic in NewMultiaddr on input %q: %s", s, e)
err = fmt.Errorf("%v", e)
}
}()
b, err := stringToBytes(s)
if err != nil {
return nil, err
}
return &multiaddr{bytes: b}, nil
}
// NewMultiaddrBytes initializes a Multiaddr from a byte representation.
// It validates it as an input string.
func NewMultiaddrBytes(b []byte) (a Multiaddr, err error) {
defer func() {
if e := recover(); e != nil {
log.Printf("Panic in NewMultiaddrBytes on input %q: %s", b, e)
err = fmt.Errorf("%v", e)
}
}()
if err := validateBytes(b); err != nil {
return nil, err
}
return &multiaddr{bytes: b}, nil
}
// Equal tests whether two multiaddrs are equal
func (m *multiaddr) Equal(m2 Multiaddr) bool {
return bytes.Equal(m.bytes, m2.Bytes())
}
// Bytes returns the []byte representation of this Multiaddr
//
// Do not modify the returned buffer, it may be shared.
func (m *multiaddr) Bytes() []byte {
return m.bytes
}
// String returns the string representation of a Multiaddr
func (m *multiaddr) String() string {
s, err := bytesToString(m.bytes)
if err != nil {
panic(fmt.Errorf("multiaddr failed to convert back to string. corrupted? %s", err))
}
return s
}
func (m *multiaddr) MarshalBinary() ([]byte, error) {
return m.Bytes(), nil
}
func (m *multiaddr) UnmarshalBinary(data []byte) error {
new, err := NewMultiaddrBytes(data)
if err != nil {
return err
}
*m = *(new.(*multiaddr))
return nil
}
func (m *multiaddr) MarshalText() ([]byte, error) {
return []byte(m.String()), nil
}
func (m *multiaddr) UnmarshalText(data []byte) error {
new, err := NewMultiaddr(string(data))
if err != nil {
return err
}
*m = *(new.(*multiaddr))
return nil
}
func (m *multiaddr) MarshalJSON() ([]byte, error) {
return json.Marshal(m.String())
}
func (m *multiaddr) UnmarshalJSON(data []byte) error {
var v string
if err := json.Unmarshal(data, &v); err != nil {
return err
}
new, err := NewMultiaddr(v)
*m = *(new.(*multiaddr))
return err
}
// Protocols returns the list of protocols this Multiaddr has.
// will panic in case we access bytes incorrectly.
func (m *multiaddr) Protocols() []Protocol {
ps := make([]Protocol, 0, 8)
b := m.bytes
for len(b) > 0 {
code, n, err := ReadVarintCode(b)
if err != nil {
panic(err)
}
p := ProtocolWithCode(code)
if p.Code == 0 {
// this is a panic (and not returning err) because this should've been
// caught on constructing the Multiaddr
panic(fmt.Errorf("no protocol with code %d", b[0]))
}
ps = append(ps, p)
b = b[n:]
n, size, err := sizeForAddr(p, b)
if err != nil {
panic(err)
}
b = b[n+size:]
}
return ps
}
// Encapsulate wraps a given Multiaddr, returning the resulting joined Multiaddr
func (m *multiaddr) Encapsulate(o Multiaddr) Multiaddr {
mb := m.bytes
ob := o.Bytes()
b := make([]byte, len(mb)+len(ob))
copy(b, mb)
copy(b[len(mb):], ob)
return &multiaddr{bytes: b}
}
// Decapsulate unwraps Multiaddr up until the given Multiaddr is found.
func (m *multiaddr) Decapsulate(o Multiaddr) Multiaddr {
s1 := m.String()
s2 := o.String()
i := strings.LastIndex(s1, s2)
if i < 0 {
// if multiaddr not contained, returns a copy.
cpy := make([]byte, len(m.bytes))
copy(cpy, m.bytes)
return &multiaddr{bytes: cpy}
}
if i == 0 {
return nil
}
ma, err := NewMultiaddr(s1[:i])
if err != nil {
panic("Multiaddr.Decapsulate incorrect byte boundaries.")
}
return ma
}
var ErrProtocolNotFound = fmt.Errorf("protocol not found in multiaddr")
func (m *multiaddr) ValueForProtocol(code int) (value string, err error) {
err = ErrProtocolNotFound
ForEach(m, func(c Component) bool {
if c.Protocol().Code == code {
value = c.Value()
err = nil
return false
}
return true
})
return
}
// FilterAddrs is a filter that removes certain addresses, according to the given filters.
// If all filters return true, the address is kept.
func FilterAddrs(a []Multiaddr, filters ...func(Multiaddr) bool) []Multiaddr {
b := make([]Multiaddr, 0, len(a))
addrloop:
for _, addr := range a {
for _, filter := range filters {
if !filter(addr) {
continue addrloop
}
}
b = append(b, addr)
}
return b
}