chore: move the go code into a subfolder

apps/api/internal/eventstore/handler/crdb/lock.go

@@ -0,0 +1,107 @@
+package crdb
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/zitadel/logging"
+
+	"github.com/zitadel/zitadel/internal/database"
+	"github.com/zitadel/zitadel/internal/id"
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+const (
+	lockStmtFormat = "INSERT INTO %[1]s" +
+		" (locker_id, locked_until, projection_name, instance_id) VALUES %[2]s" +
+		" ON CONFLICT (projection_name, instance_id)" +
+		" DO UPDATE SET locker_id = $1, locked_until = now()+$2::INTERVAL" +
+		" WHERE %[1]s.projection_name = $3 AND %[1]s.instance_id = ANY ($%[3]d) AND (%[1]s.locker_id = $1 OR %[1]s.locked_until < now())"
+)
+
+type Locker interface {
+	Lock(ctx context.Context, lockDuration time.Duration, instanceIDs ...string) <-chan error
+	Unlock(instanceIDs ...string) error
+}
+
+type locker struct {
+	client         *sql.DB
+	lockStmt       func(values string, instances int) string
+	workerName     string
+	projectionName string
+}
+
+func NewLocker(client *sql.DB, lockTable, projectionName string) Locker {
+	workerName, err := id.SonyFlakeGenerator().Next()
+	logging.OnError(err).Panic("unable to generate lockID")
+	return &locker{
+		client: client,
+		lockStmt: func(values string, instances int) string {
+			return fmt.Sprintf(lockStmtFormat, lockTable, values, instances)
+		},
+		workerName:     workerName,
+		projectionName: projectionName,
+	}
+}
+
+func (h *locker) Lock(ctx context.Context, lockDuration time.Duration, instanceIDs ...string) <-chan error {
+	errs := make(chan error)
+	go h.handleLock(ctx, errs, lockDuration, instanceIDs...)
+	return errs
+}
+
+func (h *locker) handleLock(ctx context.Context, errs chan error, lockDuration time.Duration, instanceIDs ...string) {
+	renewLock := time.NewTimer(0)
+	for {
+		select {
+		case <-renewLock.C:
+			errs <- h.renewLock(ctx, lockDuration, instanceIDs...)
+			//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, instanceIDs ...string) error {
+	lockStmt, values := h.lockStatement(lockDuration, instanceIDs)
+	res, err := h.client.ExecContext(ctx, lockStmt, values...)
+	if err != nil {
+		return zerrors.ThrowInternal(err, "CRDB-uaDoR", "unable to execute lock")
+	}
+	if rows, _ := res.RowsAffected(); rows == 0 {
+		return zerrors.ThrowAlreadyExists(nil, "CRDB-mmi4J", "projection already locked")
+	}
+	return nil
+}
+
+func (h *locker) Unlock(instanceIDs ...string) error {
+	lockStmt, values := h.lockStatement(0, instanceIDs)
+	_, err := h.client.Exec(lockStmt, values...)
+	if err != nil {
+		return zerrors.ThrowUnknown(err, "CRDB-JjfwO", "unlock failed")
+	}
+	return nil
+}
+
+func (h *locker) lockStatement(lockDuration time.Duration, instanceIDs database.TextArray[string]) (string, []interface{}) {
+	valueQueries := make([]string, len(instanceIDs))
+	values := make([]interface{}, len(instanceIDs)+4)
+	values[0] = h.workerName
+	//the unit of crdb interval is seconds (https://www.cockroachlabs.com/docs/stable/interval.html).
+	values[1] = lockDuration
+	values[2] = h.projectionName
+	for i, instanceID := range instanceIDs {
+		valueQueries[i] = "($1, now()+$2::INTERVAL, $3, $" + strconv.Itoa(i+4) + ")"
+		values[i+3] = instanceID
+	}
+	values[len(values)-1] = instanceIDs
+	return h.lockStmt(strings.Join(valueQueries, ", "), len(values)), values
+}