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

internal/eventstore/handler/crdb/lock.go

@@ -0,0 +1,92 @@
+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
+}