zitadel/internal/eventstore/handler/crdb/lock.go
Livio Amstutz 9ab566fdeb
fix(query): keys (#2755)
* fix: add keys to projections

* change to multiple tables

* query keys

* query keys

* fix race condition

* fix timer reset

* begin tests

* tests

* remove migration

* only send to keyChannel if not nil
2022-01-12 13:22:04 +01:00

93 lines
2.5 KiB
Go

package crdb
import (
"context"
"database/sql"
"fmt"
"os"
"time"
"github.com/caos/logging"
"github.com/caos/zitadel/internal/errors"
"github.com/caos/zitadel/internal/id"
)
const (
lockStmtFormat = "INSERT INTO %[1]s" +
" (locker_id, locked_until, projection_name) VALUES ($1, now()+$2::INTERVAL, $3)" +
" ON CONFLICT (projection_name)" +
" DO UPDATE SET locker_id = $1, locked_until = now()+$2::INTERVAL" +
" WHERE %[1]s.projection_name = $3 AND (%[1]s.locker_id = $1 OR %[1]s.locked_until < now())"
)
type Locker interface {
Lock(ctx context.Context, lockDuration time.Duration) <-chan error
Unlock() error
}
type locker struct {
client *sql.DB
lockStmt string
workerName string
projectionName string
}
func NewLocker(client *sql.DB, lockTable, projectionName string) Locker {
workerName, err := os.Hostname()
if err != nil || workerName == "" {
workerName, err = id.SonyFlakeGenerator.Next()
logging.Log("CRDB-bdO56").OnError(err).Panic("unable to generate lockID")
}
return &locker{
client: client,
lockStmt: fmt.Sprintf(lockStmtFormat, lockTable),
workerName: workerName,
projectionName: projectionName,
}
}
func (h *locker) Lock(ctx context.Context, lockDuration time.Duration) <-chan error {
errs := make(chan error)
go h.handleLock(ctx, errs, lockDuration)
return errs
}
func (h *locker) handleLock(ctx context.Context, errs chan error, lockDuration time.Duration) {
renewLock := time.NewTimer(0)
for {
select {
case <-renewLock.C:
errs <- h.renewLock(ctx, lockDuration)
//refresh the lock 500ms before it times out. 500ms should be enough for one transaction
renewLock.Reset(lockDuration - (500 * time.Millisecond))
case <-ctx.Done():
close(errs)
renewLock.Stop()
return
}
}
}
func (h *locker) renewLock(ctx context.Context, lockDuration time.Duration) error {
//the unit of crdb interval is seconds (https://www.cockroachlabs.com/docs/stable/interval.html).
res, err := h.client.Exec(h.lockStmt, h.workerName, lockDuration.Seconds(), h.projectionName)
if err != nil {
return errors.ThrowInternal(err, "CRDB-uaDoR", "unable to execute lock")
}
if rows, _ := res.RowsAffected(); rows == 0 {
return errors.ThrowAlreadyExists(nil, "CRDB-mmi4J", "projection already locked")
}
return nil
}
func (h *locker) Unlock() error {
_, err := h.client.Exec(h.lockStmt, h.workerName, float64(0), h.projectionName)
if err != nil {
return errors.ThrowUnknown(err, "CRDB-JjfwO", "unlock failed")
}
return nil
}