status-go/discovery/muxer.go

135 lines
3.1 KiB
Go

package discovery
import (
"fmt"
"strings"
"sync"
"time"
"github.com/ethereum/go-ethereum/p2p/discv5"
"github.com/status-im/status-go/common"
)
// NewMultiplexer creates Multiplexer instance.
func NewMultiplexer(discoveries []Discovery) Multiplexer {
return Multiplexer{discoveries}
}
// Multiplexer allows to use multiple discoveries behind single Discovery interface.
type Multiplexer struct {
discoveries []Discovery
}
// Running should return true if at least one discovery is running
func (m Multiplexer) Running() (rst bool) {
for i := range m.discoveries {
rst = rst || m.discoveries[i].Running()
}
return rst
}
// Start every discovery and stop every started in case if at least one fails.
func (m Multiplexer) Start() (err error) {
started := []int{}
for i := range m.discoveries {
if err = m.discoveries[i].Start(); err != nil {
break
}
started = append(started, i)
}
if err != nil {
for _, i := range started {
_ = m.discoveries[i].Stop()
}
}
return err
}
// Stop every discovery.
func (m Multiplexer) Stop() (err error) {
messages := []string{}
for i := range m.discoveries {
if err = m.discoveries[i].Stop(); err != nil {
messages = append(messages, err.Error())
}
}
if len(messages) != 0 {
return fmt.Errorf("failed to stop discoveries: %s", strings.Join(messages, "; "))
}
return nil
}
// Register passed topic and stop channel to every discovery and waits till it will return.
func (m Multiplexer) Register(topic string, stop chan struct{}) error {
errors := make(chan error, len(m.discoveries))
for i := range m.discoveries {
i := i
go func() {
defer common.LogOnPanic()
errors <- m.discoveries[i].Register(topic, stop)
}()
}
total := 0
messages := []string{}
for err := range errors {
total++
if err != nil {
messages = append(messages, err.Error())
}
if total == len(m.discoveries) {
break
}
}
if len(messages) != 0 {
return fmt.Errorf("failed to register %s: %s", topic, strings.Join(messages, "; "))
}
return nil
}
// Discover shares topic and channles for receiving results. And multiplexer periods that are sent to period channel.
func (m Multiplexer) Discover(topic string, period <-chan time.Duration, found chan<- *discv5.Node, lookup chan<- bool) error {
var (
periods = make([]chan time.Duration, len(m.discoveries))
messages = []string{}
wg sync.WaitGroup
mu sync.Mutex
)
wg.Add(len(m.discoveries) + 1)
for i := range m.discoveries {
i := i
periods[i] = make(chan time.Duration, 2)
go func() {
defer common.LogOnPanic()
err := m.discoveries[i].Discover(topic, periods[i], found, lookup)
if err != nil {
mu.Lock()
messages = append(messages, err.Error())
mu.Unlock()
}
wg.Done()
}()
}
go func() {
defer common.LogOnPanic()
for {
newPeriod, ok := <-period
for i := range periods {
if !ok {
close(periods[i])
} else {
periods[i] <- newPeriod
}
}
if !ok {
wg.Done()
return
}
}
}()
wg.Wait()
if len(messages) != 0 {
return fmt.Errorf("failed to discover topic %s: %s", topic, strings.Join(messages, "; "))
}
return nil
}