transactor

README

Let's imagine we have MyService where transactional behavior is required and 2 repositories OrderRepository and PaymentRepository which must create order and payment consistently within single transaction, so if either first or second fail - no data is created at all and transaction is rolled back.
Firstly, for object which requires transactional behavior you can define property with transactor interface, so now trx can accept any transactor no matter if it is postgres or mongo or anything else. Please, see original example from mongo-driver for running transactions, in short, mongo-driver package injects session data to context, so context is source of truth - are we running within transaction or not.
Add code to your repositories totally ignoring any transactional behavior. You can use repositories in combination with transactor in MyService like shown below:

type MyService struct {
	trx transactor // in this example will be maintained via mongo_transactor.NewMongoDriverTransactor
	orderRps OrderRepository // order repository added
	paymentRps PaymentRepository // payment repository added
}

// new method CreateOrderWithItems is added
func (s *MyService) CreateOrderAndPayment(ctx context.Context, order *Order, payment *Payment) error {
	// WithinTransaction injects pgx.Tx into ctx, so txCtx is already with injected transaction
	err := s.trx.WithinTransaction(ctx, func (txCtx context.Context) error {
		var inTxErr error

		// txCtx has pgx.Tx injected - Runner in repository will return pgx.Tx
		inTxErr = s.orderRps.CreateOrder(txCtx, order)
		if inTxErr != nil {
			// if error - transaction is rolled back
			return inTxErr
		}
		
		// txCtx has pgx.Tx injected - Runner in repository will return pgx.Tx
		inTxErr = s.paymentRps.CreatePayment(txCtx, payment)
		if inTxErr != nil {
			// if error - transaction is rolled back 
			return inTxErr
		}
		
		// transaction is committed if returned error is nil
		return nil
	})
}

As you can see from example above, transaction is shared between 2 repositories through context where it is injected

Documentation

Overview

Package transactor contains logic for mongo-driver transactional behavior

Index

• type MongoDriverTransactor
  • func NewMongoDriverTransactor(client *mongo.Client) MongoDriverTransactor

Types

type MongoDriverTransactor

type MongoDriverTransactor interface {
	WithinTransaction(ctx context.Context, txFn func(context.Context) error) error
	WithinTransactionWithOptions(ctx context.Context, txFn func(context.Context) error, opts ...*options.TransactionOptions) error
}

MongoDriverTransactor represents mongodb transactor behavior

func NewMongoDriverTransactor

func NewMongoDriverTransactor(client *mongo.Client) MongoDriverTransactor

NewMongoDriverTransactor builds new MongoDriverTransactor