72 lines
1.3 KiB
Go
72 lines
1.3 KiB
Go
package udp
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"net"
|
|
"sync"
|
|
)
|
|
|
|
// Maintains a mapping of transaction IDs to handlers.
|
|
type Dispatcher struct {
|
|
mu sync.RWMutex
|
|
transactions map[TransactionId]Transaction
|
|
}
|
|
|
|
// The caller owns b.
|
|
func (me *Dispatcher) Dispatch(b []byte, addr net.Addr) error {
|
|
buf := bytes.NewBuffer(b)
|
|
var rh ResponseHeader
|
|
err := Read(buf, &rh)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
me.mu.RLock()
|
|
defer me.mu.RUnlock()
|
|
if t, ok := me.transactions[rh.TransactionId]; ok {
|
|
t.h(DispatchedResponse{
|
|
Header: rh,
|
|
Body: append([]byte(nil), buf.Bytes()...),
|
|
Addr: addr,
|
|
})
|
|
return nil
|
|
} else {
|
|
return fmt.Errorf("unknown transaction id %v", rh.TransactionId)
|
|
}
|
|
}
|
|
|
|
func (me *Dispatcher) forgetTransaction(id TransactionId) {
|
|
me.mu.Lock()
|
|
defer me.mu.Unlock()
|
|
delete(me.transactions, id)
|
|
}
|
|
|
|
func (me *Dispatcher) NewTransaction(h TransactionResponseHandler) Transaction {
|
|
me.mu.Lock()
|
|
defer me.mu.Unlock()
|
|
for {
|
|
id := RandomTransactionId()
|
|
if _, ok := me.transactions[id]; ok {
|
|
continue
|
|
}
|
|
t := Transaction{
|
|
d: me,
|
|
h: h,
|
|
id: id,
|
|
}
|
|
if me.transactions == nil {
|
|
me.transactions = make(map[TransactionId]Transaction)
|
|
}
|
|
me.transactions[id] = t
|
|
return t
|
|
}
|
|
}
|
|
|
|
type DispatchedResponse struct {
|
|
Header ResponseHeader
|
|
// Response payload, after the header.
|
|
Body []byte
|
|
// Response source address
|
|
Addr net.Addr
|
|
}
|