vendor.github.com.pion.stun.helpers.go Maven / Gradle / Ivy
package stun
// Interfaces that are implemented by message attributes, shorthands for them,
// or helpers for message fields as type or transaction id.
type (
// Setter sets *Message attribute.
Setter interface {
AddTo(m *Message) error
}
// Getter parses attribute from *Message.
Getter interface {
GetFrom(m *Message) error
}
// Checker checks *Message attribute.
Checker interface {
Check(m *Message) error
}
)
// Build resets message and applies setters to it in batch, returning on
// first error. To prevent allocations, pass pointers to values.
//
// Example:
// var (
// t = BindingRequest
// username = NewUsername("username")
// nonce = NewNonce("nonce")
// realm = NewRealm("example.org")
// )
// m := new(Message)
// m.Build(t, username, nonce, realm) // 4 allocations
// m.Build(&t, &username, &nonce, &realm) // 0 allocations
//
// See BenchmarkBuildOverhead.
func (m *Message) Build(setters ...Setter) error {
m.Reset()
m.WriteHeader()
for _, s := range setters {
if err := s.AddTo(m); err != nil {
return err
}
}
return nil
}
// Check applies checkers to message in batch, returning on first error.
func (m *Message) Check(checkers ...Checker) error {
for _, c := range checkers {
if err := c.Check(m); err != nil {
return err
}
}
return nil
}
// Parse applies getters to message in batch, returning on first error.
func (m *Message) Parse(getters ...Getter) error {
for _, c := range getters {
if err := c.GetFrom(m); err != nil {
return err
}
}
return nil
}
// MustBuild wraps Build call and panics on error.
func MustBuild(setters ...Setter) *Message {
m, err := Build(setters...)
if err != nil {
panic(err) // nolint
}
return m
}
// Build wraps Message.Build method.
func Build(setters ...Setter) (*Message, error) {
m := new(Message)
if err := m.Build(setters...); err != nil {
return nil, err
}
return m, nil
}
// ForEach is helper that iterates over message attributes allowing to call
// Getter in f callback to get all attributes of type t and returning on first
// f error.
//
// The m.Get method inside f will be returning next attribute on each f call.
// Does not error if there are no results.
func (m *Message) ForEach(t AttrType, f func(m *Message) error) error {
attrs := m.Attributes
defer func() {
m.Attributes = attrs
}()
for i, a := range attrs {
if a.Type != t {
continue
}
m.Attributes = attrs[i:]
if err := f(m); err != nil {
return err
}
}
return nil
}