runtimes/google/vsync/kvdb_test.go - release.go.x.ref - Git at Google

 package vsync

 // Tests for the Veyron Sync K/V DB component.

 import (
 	"fmt"
 	"os"
 	"reflect"
 	"testing"
 	"time"
 )

 // A user structure stores info in the "users" table.
 type user struct {
 	Username string
 	Drinks   []string
 }

 // A drink structure stores info in the "drinks" table.
 type drink struct {
 	Name    string
 	Alcohol bool
 }

 var (
 	users = []user{
 		{Username: "lancelot", Drinks: []string{"beer", "coffee"}},
 		{Username: "arthur", Drinks: []string{"coke", "beer", "coffee"}},
 		{Username: "robin", Drinks: []string{"pepsi"}},
 		{Username: "galahad"},
 	}
 	drinks = []drink{
 		{Name: "coke", Alcohol: false},
 		{Name: "pepsi", Alcohol: false},
 		{Name: "beer", Alcohol: true},
 		{Name: "coffee", Alcohol: false},
 	}
 )

 // createTestDB creates a K/V DB with 2 tables.
 func createTestDB(t *testing.T) (fname string, db *kvdb, usersTbl, drinksTbl *kvtable) {
 	fname = fmt.Sprintf("%s/sync_kvdb_test_%d_%d", os.TempDir(), os.Getpid(), time.Now().UnixNano())
 	db, tbls, err := kvdbOpen(fname, []string{"users", "drinks"})
 	if err != nil {
 		os.Remove(fname)
 		t.Fatalf("cannot create new K/V DB file %s: %v", fname, err)
 	}

 	if _, err = os.Stat(fname); err != nil {
 		os.Remove(fname)
 		t.Fatalf("newly created K/V DB file %s not found: %v", fname, err)
 	}

 	usersTbl, drinksTbl = tbls[0], tbls[1]
 	return
 }

 // initTestTables initializes the K/V tables used by the tests.
 func initTestTables(t *testing.T, usersTbl, drinksTbl *kvtable, useCreate bool) {
 	userPut, drinkPut, funcName := usersTbl.set, drinksTbl.set, "set()"
 	if useCreate {
 		userPut, drinkPut, funcName = usersTbl.create, drinksTbl.create, "create()"
 	}

 	for _, uu := range users {
 		if err := userPut(uu.Username, &uu); err != nil {
 			t.Fatalf("%s failed for user %s", funcName, uu.Username)
 		}
 	}

 	for _, dd := range drinks {
 		if err := drinkPut(dd.Name, &dd); err != nil {
 			t.Fatalf("%s failed for drink %s", funcName, dd.Name)
 		}
 	}

 	return
 }

 // checkTestTables verifies the contents of the K/V tables.
 func checkTestTables(t *testing.T, usersTbl, drinksTbl *kvtable) {
 	for _, uu := range users {
 		var u2 user
 		if err := usersTbl.get(uu.Username, &u2); err != nil {
 			t.Fatalf("get() failed for user %s", uu.Username)
 		}
 		if !reflect.DeepEqual(u2, uu) {
 			t.Fatalf("got wrong data for user %s: %#v instead of %#v", uu.Username, u2, uu)
 		}
 		if !usersTbl.hasKey(uu.Username) {
 			t.Fatalf("hasKey() did not find user %s", uu.Username)
 		}
 	}
 	for _, dd := range drinks {
 		var d2 drink
 		if err := drinksTbl.get(dd.Name, &d2); err != nil {
 			t.Fatalf("get() failed for drink %s", dd.Name)
 		}
 		if !reflect.DeepEqual(d2, dd) {
 			t.Fatalf("got wrong data for drink %s: %#v instead of %#v", dd.Name, d2, dd)
 		}
 		if !drinksTbl.hasKey(dd.Name) {
 			t.Fatalf("hasKey() did not find drink %s", dd.Name)
 		}
 	}
 }

 func TestKVDBSet(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)

 	db.flush()
 }

 func TestKVDBCreate(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, true)

 	db.flush()
 }

 func TestKVDBBadGet(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	// The DB is empty, all gets must fail.
 	for _, uu := range users {
 		var u2 user
 		if err := usersTbl.get(uu.Username, &u2); err == nil {
 			t.Fatalf("get() found non-existent user %s in file %s: %v", uu.Username, kvdbfile, u2)
 		}
 	}
 	for _, dd := range drinks {
 		var d2 drink
 		if err := drinksTbl.get(dd.Name, &d2); err == nil {
 			t.Fatalf("get() found non-existent drink %s in file %s: %v", dd.Name, kvdbfile, d2)
 		}
 	}
 }

 func TestKVDBBadUpdate(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	// The DB is empty, all updates must fail.
 	for _, uu := range users {
 		u2 := user{Username: uu.Username}
 		if err := usersTbl.update(uu.Username, &u2); err == nil {
 			t.Fatalf("update() worked for a non-existent user %s in file %s", uu.Username, kvdbfile)
 		}
 	}
 	for _, dd := range drinks {
 		d2 := drink{Name: dd.Name}
 		if err := drinksTbl.update(dd.Name, &d2); err == nil {
 			t.Fatalf("update() worked for a non-existent drink %s in file %s", dd.Name, kvdbfile)
 		}
 	}
 }

 func TestKVDBBadHasKey(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	// The DB is empty, all key-checks must fail.
 	for _, uu := range users {
 		if usersTbl.hasKey(uu.Username) {
 			t.Fatalf("hasKey() found non-existent user %s in file %s", uu.Username, kvdbfile)
 		}
 	}
 	for _, dd := range drinks {
 		if drinksTbl.hasKey(dd.Name) {
 			t.Fatalf("hasKey() found non-existent drink %s in file %s", dd.Name, kvdbfile)
 		}
 	}
 }

 func TestKVDBGet(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)
 	checkTestTables(t, usersTbl, drinksTbl)

 	db.flush()
 	checkTestTables(t, usersTbl, drinksTbl)
 }

 func TestKVDBBadCreate(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)

 	// Must not be able to re-create the same entries.
 	for _, uu := range users {
 		u2 := user{Username: uu.Username}
 		if err := usersTbl.create(uu.Username, &u2); err == nil {
 			t.Fatalf("create() worked for an existing user %s in file %s", uu.Username, kvdbfile)
 		}
 	}
 	for _, dd := range drinks {
 		d2 := drink{Name: dd.Name}
 		if err := drinksTbl.create(dd.Name, &d2); err == nil {
 			t.Fatalf("create() worked for an existing drink %s in file %s", dd.Name, kvdbfile)
 		}
 	}

 	db.flush()
 }

 func TestKVDBReopen(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)

 	initTestTables(t, usersTbl, drinksTbl, true)

 	// Close the re-open the file.
 	db.flush()
 	db.close()

 	db, tbls, err := kvdbOpen(kvdbfile, []string{"users", "drinks"})
 	if err != nil {
 		t.Fatalf("Cannot re-open existing K/V DB file %s", kvdbfile)
 	}
 	defer db.close()

 	usersTbl, drinksTbl = tbls[0], tbls[1]
 	checkTestTables(t, usersTbl, drinksTbl)
 }

 func TestKVDBKeyIter(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)

 	// Get the list of all entry keys in each table.
 	keylist := ""
 	err := usersTbl.keyIter(func(key string) {
 		keylist += key + ","
 	})
 	if err != nil || keylist != "arthur,galahad,lancelot,robin," {
 		t.Fatalf("keyIter() failed in file %s: err %v, user names: %v", kvdbfile, err, keylist)
 	}
 	keylist = ""
 	err = drinksTbl.keyIter(func(key string) {
 		keylist += key + ","
 	})
 	if err != nil || keylist != "beer,coffee,coke,pepsi," {
 		t.Fatalf("keyIter() failed in file %s: err %v, drink names: %v", kvdbfile, err, keylist)
 	}

 	db.flush()
 }

 func TestKVDBUpdate(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)

 	initTestTables(t, usersTbl, drinksTbl, false)
 	db.flush()
 	db.close()

 	db, tbls, err := kvdbOpen(kvdbfile, []string{"users", "drinks"})
 	if err != nil {
 		t.Fatalf("Cannot re-open existing K/V DB file %s", kvdbfile)
 	}
 	defer db.close()

 	usersTbl, drinksTbl = tbls[0], tbls[1]

 	for _, uu := range users {
 		key := uu.Username
 		u2 := uu
 		u2.Username += "-New"

 		if err = usersTbl.update(key, &u2); err != nil {
 			t.Fatalf("update() failed for user %s in file %s", key, kvdbfile)
 		}

 		var u3 user
 		if err = usersTbl.get(key, &u3); err != nil {
 			t.Fatalf("get() failed for user %s in file %s", key, kvdbfile)
 		}
 		if !reflect.DeepEqual(u3, u2) {
 			t.Fatalf("got wrong new data for user %s in file %s: %#v instead of %#v", key, kvdbfile, u3, u2)
 		}
 	}

 	for _, dd := range drinks {
 		key := dd.Name
 		d2 := dd
 		d2.Alcohol = !d2.Alcohol

 		if err = drinksTbl.update(key, &d2); err != nil {
 			t.Fatalf("update() failed for drink %s in file %s", key, kvdbfile)
 		}

 		var d3 drink
 		if err = drinksTbl.get(key, &d3); err != nil {
 			t.Fatalf("get() failed for drink %s in file %s", key, kvdbfile)
 		}
 		if !reflect.DeepEqual(d3, d2) {
 			t.Fatalf("got wrong new data for drink %s in file %s: %#v instead of %#v", key, kvdbfile, d3, d2)
 		}
 	}

 	db.flush()
 }

 func TestKVDBSetAgain(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)

 	for _, uu := range users {
 		key := uu.Username
 		u2 := uu
 		u2.Username += "-New"

 		if err := usersTbl.set(key, &u2); err != nil {
 			t.Fatalf("set() again failed for user %s in file %s", key, kvdbfile)
 		}

 		var u3 user
 		if err := usersTbl.get(key, &u3); err != nil {
 			t.Fatalf("get() failed for user %s in file %s", key, kvdbfile)
 		}
 		if !reflect.DeepEqual(u3, u2) {
 			t.Fatalf("got wrong new data for user %s in file %s: %#v instead of %#v", key, kvdbfile, u3, u2)
 		}
 	}

 	for _, dd := range drinks {
 		key := dd.Name
 		d2 := dd
 		d2.Alcohol = !d2.Alcohol

 		if err := drinksTbl.update(key, &d2); err != nil {
 			t.Fatalf("set() again failed for drink %s in file %s", key, kvdbfile)
 		}

 		var d3 drink
 		if err := drinksTbl.get(key, &d3); err != nil {
 			t.Fatalf("get() failed for drink %s in file %s", key, kvdbfile)
 		}
 		if !reflect.DeepEqual(d3, d2) {
 			t.Fatalf("got wrong new data for drink %s in file %s: %#v instead of %#v", key, kvdbfile, d3, d2)
 		}
 	}

 	db.flush()
 }

 func TestKVDBCompact(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)

 	db.flush()

 	// Make some NOP changes and flush the DB after each change to grow the file.
 	for _, uu := range users {
 		key := uu.Username
 		if err := usersTbl.set(key, &uu); err != nil {
 			t.Fatalf("set() NOP failed for user %s in file %s", key, kvdbfile)
 		}
 		db.flush()
 	}

 	for _, dd := range drinks {
 		key := dd.Name
 		if err := drinksTbl.update(key, &dd); err != nil {
 			t.Fatalf("set() NOP failed for drink %s in file %s", key, kvdbfile)
 		}
 		db.flush()
 	}

 	// Compact the DB file and verify that it contains the same data and has a smaller size.
 	oldSize := fileSize(kvdbfile)

 	db, tbls, err := db.compact(kvdbfile, []string{"users", "drinks"})
 	if err != nil {
 		t.Fatalf("compact() failed to create a smaller version of K/V DB file %s: %v", kvdbfile, err)
 	}
 	defer db.close()

 	usersTbl, drinksTbl = tbls[0], tbls[1]

 	newSize := fileSize(kvdbfile)
 	if newSize >= oldSize {
 		t.Errorf("compact() failed to shrink file %s: old size %d, new size %d", kvdbfile, oldSize, newSize)
 	}

 	checkTestTables(t, usersTbl, drinksTbl)

 	// Verify that compact() rejects a filename without a basename.
 	for _, badfile := range []string{"/", ".", ".."} {
 		_, _, err := db.compact(badfile, []string{"users", "drinks"})
 		if err == nil {
 			t.Errorf("compact() did not fail when given the invalid filename: %s", badfile)
 		}
 	}
 }

 func TestKVDBDelete(t *testing.T) {
 	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
 	defer os.Remove(kvdbfile)
 	defer db.close()

 	initTestTables(t, usersTbl, drinksTbl, false)

 	db.flush()

 	// Delete entries and verify that they no longer exist.

 	for _, uu := range users {
 		key := uu.Username
 		if err := usersTbl.del(key); err != nil {
 			t.Errorf("del() failed for user %s in file %s", key, kvdbfile)
 		}
 		if usersTbl.hasKey(key) {
 			t.Errorf("hasKey() still finds deleted user %s in file %s", key, kvdbfile)
 		}
 	}

 	for _, dd := range drinks {
 		key := dd.Name
 		if err := drinksTbl.del(key); err != nil {
 			t.Errorf("del() failed for drink %s in file %s", key, kvdbfile)
 		}
 		if drinksTbl.hasKey(key) {
 			t.Errorf("hasKey() still finds deleted drink %s in file %s", key, kvdbfile)
 		}
 	}

 	db.flush()
 }
	package vsync

	// Tests for the Veyron Sync K/V DB component.

	import (
	"fmt"
	"os"
	"reflect"
	"testing"
	"time"
	)

	// A user structure stores info in the "users" table.
	type user struct {
	Username string
	Drinks []string
	}

	// A drink structure stores info in the "drinks" table.
	type drink struct {
	Name string
	Alcohol bool
	}

	var (
	users = []user{
	{Username: "lancelot", Drinks: []string{"beer", "coffee"}},
	{Username: "arthur", Drinks: []string{"coke", "beer", "coffee"}},
	{Username: "robin", Drinks: []string{"pepsi"}},
	{Username: "galahad"},
	}
	drinks = []drink{
	{Name: "coke", Alcohol: false},
	{Name: "pepsi", Alcohol: false},
	{Name: "beer", Alcohol: true},
	{Name: "coffee", Alcohol: false},
	}
	)

	// createTestDB creates a K/V DB with 2 tables.
	func createTestDB(t testing.T) (fname string, db kvdb, usersTbl, drinksTbl *kvtable) {
	fname = fmt.Sprintf("%s/sync_kvdb_test_%d_%d", os.TempDir(), os.Getpid(), time.Now().UnixNano())
	db, tbls, err := kvdbOpen(fname, []string{"users", "drinks"})
	if err != nil {
	os.Remove(fname)
	t.Fatalf("cannot create new K/V DB file %s: %v", fname, err)
	}

	if _, err = os.Stat(fname); err != nil {
	os.Remove(fname)
	t.Fatalf("newly created K/V DB file %s not found: %v", fname, err)
	}

	usersTbl, drinksTbl = tbls[0], tbls[1]
	return
	}

	// initTestTables initializes the K/V tables used by the tests.
	func initTestTables(t testing.T, usersTbl, drinksTbl kvtable, useCreate bool) {
	userPut, drinkPut, funcName := usersTbl.set, drinksTbl.set, "set()"
	if useCreate {
	userPut, drinkPut, funcName = usersTbl.create, drinksTbl.create, "create()"
	}

	for _, uu := range users {
	if err := userPut(uu.Username, &uu); err != nil {
	t.Fatalf("%s failed for user %s", funcName, uu.Username)
	}
	}

	for _, dd := range drinks {
	if err := drinkPut(dd.Name, &dd); err != nil {
	t.Fatalf("%s failed for drink %s", funcName, dd.Name)
	}
	}

	return
	}

	// checkTestTables verifies the contents of the K/V tables.
	func checkTestTables(t testing.T, usersTbl, drinksTbl kvtable) {
	for _, uu := range users {
	var u2 user
	if err := usersTbl.get(uu.Username, &u2); err != nil {
	t.Fatalf("get() failed for user %s", uu.Username)
	}
	if !reflect.DeepEqual(u2, uu) {
	t.Fatalf("got wrong data for user %s: %#v instead of %#v", uu.Username, u2, uu)
	}
	if !usersTbl.hasKey(uu.Username) {
	t.Fatalf("hasKey() did not find user %s", uu.Username)
	}
	}
	for _, dd := range drinks {
	var d2 drink
	if err := drinksTbl.get(dd.Name, &d2); err != nil {
	t.Fatalf("get() failed for drink %s", dd.Name)
	}
	if !reflect.DeepEqual(d2, dd) {
	t.Fatalf("got wrong data for drink %s: %#v instead of %#v", dd.Name, d2, dd)
	}
	if !drinksTbl.hasKey(dd.Name) {
	t.Fatalf("hasKey() did not find drink %s", dd.Name)
	}
	}
	}

	func TestKVDBSet(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)

	db.flush()
	}

	func TestKVDBCreate(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, true)

	db.flush()
	}

	func TestKVDBBadGet(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	// The DB is empty, all gets must fail.
	for _, uu := range users {
	var u2 user
	if err := usersTbl.get(uu.Username, &u2); err == nil {
	t.Fatalf("get() found non-existent user %s in file %s: %v", uu.Username, kvdbfile, u2)
	}
	}
	for _, dd := range drinks {
	var d2 drink
	if err := drinksTbl.get(dd.Name, &d2); err == nil {
	t.Fatalf("get() found non-existent drink %s in file %s: %v", dd.Name, kvdbfile, d2)
	}
	}
	}

	func TestKVDBBadUpdate(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	// The DB is empty, all updates must fail.
	for _, uu := range users {
	u2 := user{Username: uu.Username}
	if err := usersTbl.update(uu.Username, &u2); err == nil {
	t.Fatalf("update() worked for a non-existent user %s in file %s", uu.Username, kvdbfile)
	}
	}
	for _, dd := range drinks {
	d2 := drink{Name: dd.Name}
	if err := drinksTbl.update(dd.Name, &d2); err == nil {
	t.Fatalf("update() worked for a non-existent drink %s in file %s", dd.Name, kvdbfile)
	}
	}
	}

	func TestKVDBBadHasKey(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	// The DB is empty, all key-checks must fail.
	for _, uu := range users {
	if usersTbl.hasKey(uu.Username) {
	t.Fatalf("hasKey() found non-existent user %s in file %s", uu.Username, kvdbfile)
	}
	}
	for _, dd := range drinks {
	if drinksTbl.hasKey(dd.Name) {
	t.Fatalf("hasKey() found non-existent drink %s in file %s", dd.Name, kvdbfile)
	}
	}
	}

	func TestKVDBGet(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)
	checkTestTables(t, usersTbl, drinksTbl)

	db.flush()
	checkTestTables(t, usersTbl, drinksTbl)
	}

	func TestKVDBBadCreate(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)

	// Must not be able to re-create the same entries.
	for _, uu := range users {
	u2 := user{Username: uu.Username}
	if err := usersTbl.create(uu.Username, &u2); err == nil {
	t.Fatalf("create() worked for an existing user %s in file %s", uu.Username, kvdbfile)
	}
	}
	for _, dd := range drinks {
	d2 := drink{Name: dd.Name}
	if err := drinksTbl.create(dd.Name, &d2); err == nil {
	t.Fatalf("create() worked for an existing drink %s in file %s", dd.Name, kvdbfile)
	}
	}

	db.flush()
	}

	func TestKVDBReopen(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)

	initTestTables(t, usersTbl, drinksTbl, true)

	// Close the re-open the file.
	db.flush()
	db.close()

	db, tbls, err := kvdbOpen(kvdbfile, []string{"users", "drinks"})
	if err != nil {
	t.Fatalf("Cannot re-open existing K/V DB file %s", kvdbfile)
	}
	defer db.close()

	usersTbl, drinksTbl = tbls[0], tbls[1]
	checkTestTables(t, usersTbl, drinksTbl)
	}

	func TestKVDBKeyIter(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)

	// Get the list of all entry keys in each table.
	keylist := ""
	err := usersTbl.keyIter(func(key string) {
	keylist += key + ","
	})
	if err != nil \|\| keylist != "arthur,galahad,lancelot,robin," {
	t.Fatalf("keyIter() failed in file %s: err %v, user names: %v", kvdbfile, err, keylist)
	}
	keylist = ""
	err = drinksTbl.keyIter(func(key string) {
	keylist += key + ","
	})
	if err != nil \|\| keylist != "beer,coffee,coke,pepsi," {
	t.Fatalf("keyIter() failed in file %s: err %v, drink names: %v", kvdbfile, err, keylist)
	}

	db.flush()
	}

	func TestKVDBUpdate(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)

	initTestTables(t, usersTbl, drinksTbl, false)
	db.flush()
	db.close()

	db, tbls, err := kvdbOpen(kvdbfile, []string{"users", "drinks"})
	if err != nil {
	t.Fatalf("Cannot re-open existing K/V DB file %s", kvdbfile)
	}
	defer db.close()

	usersTbl, drinksTbl = tbls[0], tbls[1]

	for _, uu := range users {
	key := uu.Username
	u2 := uu
	u2.Username += "-New"

	if err = usersTbl.update(key, &u2); err != nil {
	t.Fatalf("update() failed for user %s in file %s", key, kvdbfile)
	}

	var u3 user
	if err = usersTbl.get(key, &u3); err != nil {
	t.Fatalf("get() failed for user %s in file %s", key, kvdbfile)
	}
	if !reflect.DeepEqual(u3, u2) {
	t.Fatalf("got wrong new data for user %s in file %s: %#v instead of %#v", key, kvdbfile, u3, u2)
	}
	}

	for _, dd := range drinks {
	key := dd.Name
	d2 := dd
	d2.Alcohol = !d2.Alcohol

	if err = drinksTbl.update(key, &d2); err != nil {
	t.Fatalf("update() failed for drink %s in file %s", key, kvdbfile)
	}

	var d3 drink
	if err = drinksTbl.get(key, &d3); err != nil {
	t.Fatalf("get() failed for drink %s in file %s", key, kvdbfile)
	}
	if !reflect.DeepEqual(d3, d2) {
	t.Fatalf("got wrong new data for drink %s in file %s: %#v instead of %#v", key, kvdbfile, d3, d2)
	}
	}

	db.flush()
	}

	func TestKVDBSetAgain(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)

	for _, uu := range users {
	key := uu.Username
	u2 := uu
	u2.Username += "-New"

	if err := usersTbl.set(key, &u2); err != nil {
	t.Fatalf("set() again failed for user %s in file %s", key, kvdbfile)
	}

	var u3 user
	if err := usersTbl.get(key, &u3); err != nil {
	t.Fatalf("get() failed for user %s in file %s", key, kvdbfile)
	}
	if !reflect.DeepEqual(u3, u2) {
	t.Fatalf("got wrong new data for user %s in file %s: %#v instead of %#v", key, kvdbfile, u3, u2)
	}
	}

	for _, dd := range drinks {
	key := dd.Name
	d2 := dd
	d2.Alcohol = !d2.Alcohol

	if err := drinksTbl.update(key, &d2); err != nil {
	t.Fatalf("set() again failed for drink %s in file %s", key, kvdbfile)
	}

	var d3 drink
	if err := drinksTbl.get(key, &d3); err != nil {
	t.Fatalf("get() failed for drink %s in file %s", key, kvdbfile)
	}
	if !reflect.DeepEqual(d3, d2) {
	t.Fatalf("got wrong new data for drink %s in file %s: %#v instead of %#v", key, kvdbfile, d3, d2)
	}
	}

	db.flush()
	}

	func TestKVDBCompact(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)

	db.flush()

	// Make some NOP changes and flush the DB after each change to grow the file.
	for _, uu := range users {
	key := uu.Username
	if err := usersTbl.set(key, &uu); err != nil {
	t.Fatalf("set() NOP failed for user %s in file %s", key, kvdbfile)
	}
	db.flush()
	}

	for _, dd := range drinks {
	key := dd.Name
	if err := drinksTbl.update(key, &dd); err != nil {
	t.Fatalf("set() NOP failed for drink %s in file %s", key, kvdbfile)
	}
	db.flush()
	}

	// Compact the DB file and verify that it contains the same data and has a smaller size.
	oldSize := fileSize(kvdbfile)

	db, tbls, err := db.compact(kvdbfile, []string{"users", "drinks"})
	if err != nil {
	t.Fatalf("compact() failed to create a smaller version of K/V DB file %s: %v", kvdbfile, err)
	}
	defer db.close()

	usersTbl, drinksTbl = tbls[0], tbls[1]

	newSize := fileSize(kvdbfile)
	if newSize >= oldSize {
	t.Errorf("compact() failed to shrink file %s: old size %d, new size %d", kvdbfile, oldSize, newSize)
	}

	checkTestTables(t, usersTbl, drinksTbl)

	// Verify that compact() rejects a filename without a basename.
	for _, badfile := range []string{"/", ".", ".."} {
	_, _, err := db.compact(badfile, []string{"users", "drinks"})
	if err == nil {
	t.Errorf("compact() did not fail when given the invalid filename: %s", badfile)
	}
	}
	}

	func TestKVDBDelete(t *testing.T) {
	kvdbfile, db, usersTbl, drinksTbl := createTestDB(t)
	defer os.Remove(kvdbfile)
	defer db.close()

	initTestTables(t, usersTbl, drinksTbl, false)

	db.flush()

	// Delete entries and verify that they no longer exist.

	for _, uu := range users {
	key := uu.Username
	if err := usersTbl.del(key); err != nil {
	t.Errorf("del() failed for user %s in file %s", key, kvdbfile)
	}
	if usersTbl.hasKey(key) {
	t.Errorf("hasKey() still finds deleted user %s in file %s", key, kvdbfile)
	}
	}

	for _, dd := range drinks {
	key := dd.Name
	if err := drinksTbl.del(key); err != nil {
	t.Errorf("del() failed for drink %s in file %s", key, kvdbfile)
	}
	if drinksTbl.hasKey(key) {
	t.Errorf("hasKey() still finds deleted drink %s in file %s", key, kvdbfile)
	}
	}

	db.flush()
	}