added select auto fail/retry

daos/base.go

@@ -4,19 +4,12 @@
 package daos
 
 import (
-	"context"
 	"errors"
-	"strings"
-	"sync"
-	"time"
 
 	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase/models"
-	"golang.org/x/sync/semaphore"
 )
 
-const DefaultMaxFailRetries = 5
-
 // New creates a new Dao instance with the provided db builder
 // (for both async and sync db operations).
 func New(db dbx.Builder) *Dao {
@@ -39,10 +32,6 @@ type Dao struct {
 	concurrentDB    dbx.Builder
 	nonconcurrentDB dbx.Builder
 
-	// @todo delete after removing Block and Continue
-	sem *semaphore.Weighted
-	mux sync.RWMutex
-
 	BeforeCreateFunc func(eventDao *Dao, m models.Model) error
 	AfterCreateFunc  func(eventDao *Dao, m models.Model)
 	BeforeUpdateFunc func(eventDao *Dao, m models.Model) error
@@ -74,55 +63,15 @@ func (dao *Dao) NonconcurrentDB() dbx.Builder {
 	return dao.nonconcurrentDB
 }
 
-// Deprecated: Will be removed in the next releases. Use [Dao.NonconcurrentDB()] instead.
-//
-// Block acquires a lock and blocks all other go routines that uses
-// the Dao instance until dao.Continue() is called, effectively making
-// the concurrent requests to perform synchronous db operations.
-//
-// This method should be used only as a last resort and as a workaround
-// for the SQLITE_BUSY error when mixing read&write in a transaction.
-//
-// Example:
-//
-// 	func someLongRunningTransaction() error {
-// 		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-// 		defer cancel()
-// 		if err := app.Dao().Block(ctx); err != nil {
-// 			return err
-// 		}
-// 		defer app.Dao().Continue()
-//
-// 		return app.Dao().RunInTransaction(func (txDao *daos.Dao) error {
-// 			// some long running read&write transaction...
-// 		})
-// 	}
-func (dao *Dao) Block(ctx context.Context) error {
-	if dao.sem == nil {
-		dao.mux.Lock()
-		dao.sem = semaphore.NewWeighted(1)
-		dao.mux.Unlock()
-	}
-
-	return dao.sem.Acquire(ctx, 1)
-}
-
-// Deprecated: Will be removed in the next releases. Use [Dao.NonconcurrentDB()] instead.
-//
-// Continue releases the previously acquired Block() lock.
-func (dao *Dao) Continue() {
-	if dao.sem == nil {
-		return
-	}
-
-	dao.sem.Release(1)
-}
-
 // ModelQuery creates a new query with preset Select and From fields
 // based on the provided model argument.
 func (dao *Dao) ModelQuery(m models.Model) *dbx.SelectQuery {
 	tableName := m.TableName()
-	return dao.DB().Select("{{" + tableName + "}}.*").From(tableName)
+
+	return dao.DB().
+		Select("{{" + tableName + "}}.*").
+		From(tableName).
+		WithExecHook(onLockErrorRetry)
 }
 
 // FindById finds a single db record with the specified id and
@@ -224,7 +173,7 @@ func (dao *Dao) Delete(m models.Model) error {
 		return errors.New("ID is not set")
 	}
 
-	return dao.failRetry(func(retryDao *Dao) error {
+	return dao.lockRetry(func(retryDao *Dao) error {
 		if retryDao.BeforeDeleteFunc != nil {
 			if err := retryDao.BeforeDeleteFunc(retryDao, m); err != nil {
 				return err
@@ -240,20 +189,20 @@ func (dao *Dao) Delete(m models.Model) error {
 		}
 
 		return nil
-	}, DefaultMaxFailRetries)
+	}, defaultMaxRetries)
 }
 
 // Save upserts (update or create if primary key is not set) the provided model.
 func (dao *Dao) Save(m models.Model) error {
 	if m.IsNew() {
-		return dao.failRetry(func(retryDao *Dao) error {
+		return dao.lockRetry(func(retryDao *Dao) error {
 			return retryDao.create(m)
-		}, DefaultMaxFailRetries)
+		}, defaultMaxRetries)
 	}
 
-	return dao.failRetry(func(retryDao *Dao) error {
+	return dao.lockRetry(func(retryDao *Dao) error {
 		return retryDao.update(m)
-	}, DefaultMaxFailRetries)
+	}, defaultMaxRetries)
 }
 
 func (dao *Dao) update(m models.Model) error {
@@ -347,32 +296,19 @@ func (dao *Dao) create(m models.Model) error {
 	return nil
 }
 
-func (dao *Dao) failRetry(op func(retryDao *Dao) error, maxRetries int) error {
+func (dao *Dao) lockRetry(op func(retryDao *Dao) error, maxRetries int) error {
 	retryDao := dao
-	attempts := 1
 
-Retry:
-	if attempts == 2 {
-		// assign new Dao without the before hooks to avoid triggering
-		// the already fired before callbacks multiple times
-		retryDao = NewMultiDB(dao.concurrentDB, dao.nonconcurrentDB)
-		retryDao.AfterCreateFunc = dao.AfterCreateFunc
-		retryDao.AfterUpdateFunc = dao.AfterUpdateFunc
-		retryDao.AfterDeleteFunc = dao.AfterDeleteFunc
-	}
+	return baseLockRetry(func(attempt int) error {
+		if attempt == 2 {
+			// assign new Dao without the before hooks to avoid triggering
+			// the already fired before callbacks multiple times
+			retryDao = NewMultiDB(dao.concurrentDB, dao.nonconcurrentDB)
+			retryDao.AfterCreateFunc = dao.AfterCreateFunc
+			retryDao.AfterUpdateFunc = dao.AfterUpdateFunc
+			retryDao.AfterDeleteFunc = dao.AfterDeleteFunc
+		}
 
-	// execute
-	err := op(retryDao)
-
-	if err != nil &&
-		attempts < maxRetries &&
-		// note: we are checking the err message so that we can handle both the cgo and noncgo errors
-		strings.Contains(err.Error(), "database is locked") {
-		// wait and retry
-		time.Sleep(time.Duration(200*attempts) * time.Millisecond)
-		attempts++
-		goto Retry
-	}
-
-	return err
+		return op(retryDao)
+	}, maxRetries)
 }