boltdb_test.go

package db

import (
	"os"
	"testing"

	"github.com/boltdb/bolt"
)

func TestBoltTransactions(t *testing.T) {
	os.Remove("testdata/test.db")
	defer os.Remove("testdata/test.db")

	db, err := bolt.Open("testdata/test.db", 0644, nil)
	if err != nil {
		t.Fatal(err)
	}
	defer db.Close()

	// Set an initial value in a bucket

	err = db.Update(func(tx *bolt.Tx) error {
		bkt, err := tx.CreateBucket([]byte("test"))
		if err != nil {
			return err
		}

		return bkt.Put([]byte("key"), []byte("avalue"))
	})
	if err != nil {
		t.Fatal(err)
	}

	// Start a routine that can perform an update in the background when
	// requested to

	start := make(chan struct{})
	done := make(chan struct{})
	go func() {
		<-start
		err := db.Update(func(tx *bolt.Tx) error {
			bkt := tx.Bucket([]byte("test"))
			return bkt.Put([]byte("key"), []byte("differentvalue"))
		})
		if err != nil {
			t.Fatal(err)
		}
		done <- struct{}{}
	}()

	// Start a read transaction, read back the value we set before, allow the
	// other write transaction to happen in the meantime, and verify we do not
	// see that write in our transaction.

	err = db.View(func(tx *bolt.Tx) error {
		// Read back the value

		bkt := tx.Bucket([]byte("test"))
		val := bkt.Get([]byte("key"))
		if string(val) != "avalue" {
			t.Fatal("%q %= %q", val, "avalue")
		}

		// Run an update on a different goroutine

		start <- struct{}{}
		<-done

		// We should not see the change

		val = bkt.Get([]byte("key"))
		if string(val) != "avalue" {
			t.Fatal("%q %= %q", val, "avalue")
		}

		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
}