Adding upstream version 0.28.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

core/db_retry.go

@@ -0,0 +1,70 @@
+package core
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/pocketbase/dbx"
+)
+
+// default retries intervals (in ms)
+var defaultRetryIntervals = []int{50, 100, 150, 200, 300, 400, 500, 700, 1000}
+
+// default max retry attempts
+const defaultMaxLockRetries = 12
+
+func execLockRetry(timeout time.Duration, maxRetries int) dbx.ExecHookFunc {
+	return func(q *dbx.Query, op func() error) error {
+		if q.Context() == nil {
+			cancelCtx, cancel := context.WithTimeout(context.Background(), timeout)
+			defer func() {
+				cancel()
+				//nolint:staticcheck
+				q.WithContext(nil) // reset
+			}()
+			q.WithContext(cancelCtx)
+		}
+
+		execErr := baseLockRetry(func(attempt int) error {
+			return op()
+		}, maxRetries)
+		if execErr != nil && !errors.Is(execErr, sql.ErrNoRows) {
+			execErr = fmt.Errorf("%w; failed query: %s", execErr, q.SQL())
+		}
+
+		return execErr
+	}
+}
+
+func baseLockRetry(op func(attempt int) error, maxRetries int) error {
+	attempt := 1
+
+Retry:
+	err := op(attempt)
+
+	if err != nil && attempt <= maxRetries {
+		errStr := err.Error()
+		// we are checking the error against the plain error texts since the codes could vary between drivers
+		if strings.Contains(errStr, "database is locked") ||
+			strings.Contains(errStr, "table is locked") {
+			// wait and retry
+			time.Sleep(getDefaultRetryInterval(attempt))
+			attempt++
+			goto Retry
+		}
+	}
+
+	return err
+}
+
+func getDefaultRetryInterval(attempt int) time.Duration {
+	if attempt < 0 || attempt > len(defaultRetryIntervals)-1 {
+		return time.Duration(defaultRetryIntervals[len(defaultRetryIntervals)-1]) * time.Millisecond
+	}
+
+	return time.Duration(defaultRetryIntervals[attempt]) * time.Millisecond
+}