multiple tries

backend/v3/domain/command.go

@@ -0,0 +1,105 @@
+package domain
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+type Commander interface {
+	Execute(ctx context.Context, opts *CommandOpts) (err error)
+}
+
+type Invoker interface {
+	Invoke(ctx context.Context, command Commander, opts *CommandOpts) error
+}
+
+type CommandOpts struct {
+	DB      database.QueryExecutor
+	Invoker Invoker
+}
+
+type ensureTxOpts struct {
+	*database.TransactionOptions
+}
+
+type EnsureTransactionOpt func(*ensureTxOpts)
+
+// EnsureTx ensures that the DB is a transaction. If it is not, it will start a new transaction.
+// The returned close function will end the transaction. If the DB is already a transaction, the close function
+// will do nothing because another [Commander] is already responsible for ending the transaction.
+func (o *CommandOpts) EnsureTx(ctx context.Context, opts ...EnsureTransactionOpt) (close func(context.Context, error) error, err error) {
+	beginner, ok := o.DB.(database.Beginner)
+	if !ok {
+		// db is already a transaction
+		return func(_ context.Context, err error) error {
+			return err
+		}, nil
+	}
+
+	txOpts := &ensureTxOpts{
+		TransactionOptions: new(database.TransactionOptions),
+	}
+	for _, opt := range opts {
+		opt(txOpts)
+	}
+
+	tx, err := beginner.Begin(ctx, txOpts.TransactionOptions)
+	if err != nil {
+		return nil, err
+	}
+	o.DB = tx
+
+	return func(ctx context.Context, err error) error {
+		return tx.End(ctx, err)
+	}, nil
+}
+
+// EnsureClient ensures that the o.DB is a client. If it is not, it will get a new client from the [database.Pool].
+// The returned close function will release the client. If the o.DB is already a client or transaction, the close function
+// will do nothing because another [Commander] is already responsible for releasing the client.
+func (o *CommandOpts) EnsureClient(ctx context.Context) (close func(_ context.Context) error, err error) {
+	pool, ok := o.DB.(database.Pool)
+	if !ok {
+		// o.DB is already a client
+		return func(_ context.Context) error {
+			return nil
+		}, nil
+	}
+	client, err := pool.Acquire(ctx)
+	if err != nil {
+		return nil, err
+	}
+	o.DB = client
+	return func(ctx context.Context) error {
+		return client.Release(ctx)
+	}, nil
+}
+
+func (o *CommandOpts) Invoke(ctx context.Context, command Commander) error {
+	if o.Invoker == nil {
+		return command.Execute(ctx, o)
+	}
+	return o.Invoker.Invoke(ctx, command, o)
+}
+
+func DefaultOpts(invoker Invoker) *CommandOpts {
+	if invoker == nil {
+		invoker = &noopInvoker{}
+	}
+	return &CommandOpts{
+		DB:      pool,
+		Invoker: invoker,
+	}
+}
+
+type noopInvoker struct {
+	next Invoker
+}
+
+func (i *noopInvoker) Invoke(ctx context.Context, command Commander, opts *CommandOpts) error {
+	if i.next != nil {
+		return i.next.Invoke(ctx, command, opts)
+	}
+	return command.Execute(ctx, opts)
+}