frostfs-node/pkg/local_object_storage/pilorama/batch.go
Evgenii Stratonikov f2e5dead7e [#398] pilorama: Disallow applying same operations
1. In redo() we save the old state.
2. If we do redo() for the same operation twice, the old state will be
   overritten with the new one.
3. This in turn affects undo() and subsequent isAncestor() check.

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
2023-05-26 12:14:29 +00:00

72 lines
1.5 KiB
Go

package pilorama
import (
"sort"
"sync"
"time"
cidSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
"go.etcd.io/bbolt"
)
type batch struct {
forest *boltForest
timer *time.Timer
// mtx protects timer and operations fields.
// Because mtx can be taken inside a transaction,
// transactions MUST NOT be executed with the mutex taken to avoid a deadlock.
mtx sync.Mutex
start sync.Once
cid cidSDK.ID
treeID string
results []chan<- error
operations []*Move
}
func (b *batch) trigger() {
b.mtx.Lock()
if b.timer != nil {
b.timer.Stop()
}
b.mtx.Unlock()
b.start.Do(b.run)
}
func (b *batch) run() {
fullID := bucketName(b.cid, b.treeID)
err := b.forest.db.Update(func(tx *bbolt.Tx) error {
bLog, bTree, err := b.forest.getTreeBuckets(tx, fullID)
if err != nil {
return err
}
b.mtx.Lock()
b.timer = nil
b.mtx.Unlock()
// Sorting without a mutex is ok, because we append to this slice only if timer is non-nil.
// See (*boltForest).addBatch for details.
sort.Slice(b.operations, func(i, j int) bool {
return b.operations[i].Time < b.operations[j].Time
})
b.operations = removeDuplicatesInPlace(b.operations)
var lm Move
return b.forest.applyOperation(bLog, bTree, b.operations, &lm)
})
for i := range b.results {
b.results[i] <- err
}
}
func removeDuplicatesInPlace(a []*Move) []*Move {
equalCount := 0
for i := 1; i < len(a); i++ {
if a[i].Time == a[i-1].Time {
equalCount++
} else {
a[i-equalCount] = a[i]
}
}
return a[:len(a)-equalCount]
}