/
collection_dura.go
174 lines (148 loc) · 3.68 KB
/
collection_dura.go
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package gocb
import (
"time"
gocbcore "github.com/couchbase/gocbcore/v9"
)
func (c *Collection) observeOnceSeqNo(
tracectx requestSpanContext,
docID string,
mt gocbcore.MutationToken,
replicaIdx int,
cancelCh chan struct{},
timeout time.Duration,
) (didReplicate, didPersist bool, errOut error) {
opm := c.newKvOpManager("observeOnceSeqNo", tracectx)
defer opm.Finish()
opm.SetDocumentID(docID)
opm.SetCancelCh(cancelCh)
opm.SetTimeout(timeout)
agent, err := c.getKvProvider()
if err != nil {
return false, false, err
}
err = opm.Wait(agent.ObserveVb(gocbcore.ObserveVbOptions{
VbID: mt.VbID,
VbUUID: mt.VbUUID,
ReplicaIdx: replicaIdx,
TraceContext: opm.TraceSpan(),
Deadline: opm.Deadline(),
}, func(res *gocbcore.ObserveVbResult, err error) {
if err != nil || res == nil {
errOut = opm.EnhanceErr(err)
opm.Reject()
return
}
didReplicate = res.CurrentSeqNo >= mt.SeqNo
didPersist = res.PersistSeqNo >= mt.SeqNo
opm.Resolve(nil)
}))
if err != nil {
errOut = err
}
return
}
func (c *Collection) observeOne(
tracectx requestSpanContext,
docID string,
mt gocbcore.MutationToken,
replicaIdx int,
replicaCh, persistCh chan struct{},
cancelCh chan struct{},
timeout time.Duration,
) {
sentReplicated := false
sentPersisted := false
calc := gocbcore.ExponentialBackoff(10*time.Microsecond, 100*time.Millisecond, 0)
retries := uint32(0)
ObserveLoop:
for {
select {
case <-cancelCh:
break ObserveLoop
default:
// not cancelled yet
}
didReplicate, didPersist, err := c.observeOnceSeqNo(tracectx, docID, mt, replicaIdx, cancelCh, timeout)
if err != nil {
logDebugf("ObserveOnce failed unexpected: %s", err)
return
}
if didReplicate && !sentReplicated {
replicaCh <- struct{}{}
sentReplicated = true
}
if didPersist && !sentPersisted {
persistCh <- struct{}{}
sentPersisted = true
}
// If we've got persisted and replicated, we can just stop
if sentPersisted && sentReplicated {
break ObserveLoop
}
waitTmr := gocbcore.AcquireTimer(calc(retries))
retries++
select {
case <-waitTmr.C:
gocbcore.ReleaseTimer(waitTmr, true)
case <-cancelCh:
gocbcore.ReleaseTimer(waitTmr, false)
}
}
}
func (c *Collection) waitForDurability(
tracectx requestSpanContext,
docID string,
mt gocbcore.MutationToken,
replicateTo uint,
persistTo uint,
deadline time.Time,
cancelCh chan struct{},
) error {
opm := c.newKvOpManager("waitForDurability", tracectx)
defer opm.Finish()
opm.SetDocumentID(docID)
agent, err := c.getKvProvider()
if err != nil {
return err
}
snapshot, err := agent.ConfigSnapshot()
if err != nil {
return err
}
numReplicas, err := snapshot.NumReplicas()
if err != nil {
return err
}
numServers := numReplicas + 1
if replicateTo > uint(numServers-1) || persistTo > uint(numServers) {
return opm.EnhanceErr(ErrDurabilityImpossible)
}
subOpCancelCh := make(chan struct{}, 1)
replicaCh := make(chan struct{}, numServers)
persistCh := make(chan struct{}, numServers)
for replicaIdx := 0; replicaIdx < numServers; replicaIdx++ {
go c.observeOne(opm.TraceSpan(), docID, mt, replicaIdx, replicaCh, persistCh, subOpCancelCh, time.Until(deadline))
}
numReplicated := uint(0)
numPersisted := uint(0)
for {
select {
case <-replicaCh:
numReplicated++
case <-persistCh:
numPersisted++
case <-time.After(time.Until(deadline)):
// deadline exceeded
close(subOpCancelCh)
return opm.EnhanceErr(ErrAmbiguousTimeout)
case <-cancelCh:
// parent asked for cancellation
close(subOpCancelCh)
return opm.EnhanceErr(ErrRequestCanceled)
}
if numReplicated >= replicateTo && numPersisted >= persistTo {
close(subOpCancelCh)
return nil
}
}
}