73 lines
1.3 KiB
Go
73 lines
1.3 KiB
Go
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package dht
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import (
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"sync"
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"time"
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"github.com/anacrolix/dht/krpc"
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)
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// Transaction keeps track of a message exchange between nodes, such as a
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// query message and a response message.
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type Transaction struct {
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remoteAddr Addr
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t string
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onResponse func(krpc.Msg)
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onTimeout func()
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onSendError func(error)
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querySender func() error
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queryResendDelay func() time.Duration
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mu sync.Mutex
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gotResponse bool
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timer *time.Timer
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retries int
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lastSend time.Time
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}
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func (t *Transaction) handleResponse(m krpc.Msg) {
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t.mu.Lock()
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t.gotResponse = true
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t.mu.Unlock()
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t.onResponse(m)
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}
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func (t *Transaction) key() transactionKey {
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return transactionKey{
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t.remoteAddr.String(),
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t.t,
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}
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}
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func (t *Transaction) startResendTimer() {
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t.timer = time.AfterFunc(t.queryResendDelay(), t.resendCallback)
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}
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func (t *Transaction) resendCallback() {
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t.mu.Lock()
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defer t.mu.Unlock()
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if t.gotResponse {
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return
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}
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if t.retries == 2 {
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go t.onTimeout()
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return
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}
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t.retries++
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if err := t.sendQuery(); err != nil {
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go t.onSendError(err)
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return
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}
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if t.timer.Reset(t.queryResendDelay()) {
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panic("timer should have fired to get here")
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}
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}
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func (t *Transaction) sendQuery() error {
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if err := t.querySender(); err != nil {
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return err
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}
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t.lastSend = time.Now()
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return nil
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}
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