Merge pull request #228 from carolynvs/managed-store

Extract ManagedStore interface from BackingStore

claim/claimstore.go

@@ -38,14 +38,14 @@ var (
 
 // Store is a persistent store for claims.
 type Store struct {
-	backingStore *crud.BackingStore
+	backingStore crud.ManagedStore
 	encrypt      EncryptionHandler
 	decrypt      EncryptionHandler
 }
 
 // NewClaimStore creates a persistent store for claims using the specified
-// backing key-blob store.
-func NewClaimStore(store *crud.BackingStore, encrypt EncryptionHandler, decrypt EncryptionHandler) Store {
+// backing datastore.
+func NewClaimStore(store crud.ManagedStore, encrypt EncryptionHandler, decrypt EncryptionHandler) Store {
 	if encrypt == nil {
 		encrypt = noOpEncryptionHandler
 	}
@@ -81,7 +81,7 @@ var noOpEncryptionHandler = func(data []byte) ([]byte, error) {
 }
 
 // GetBackingStore returns the data store behind this claim store.
-func (s Store) GetBackingStore() *crud.BackingStore {
+func (s Store) GetBackingStore() crud.ManagedStore {
 	return s.backingStore
 }
 

credentials/credstore.go

@@ -17,19 +17,19 @@ var ErrNotFound = errors.New("Credential set does not exist")
 
 // Store is a persistent store for credential sets.
 type Store struct {
-	backingStore *crud.BackingStore
+	backingStore crud.ManagedStore
 }
 
 // NewCredentialStore creates a persistent store for credential sets using the specified
 // backing key-blob store.
-func NewCredentialStore(store *crud.BackingStore) Store {
+func NewCredentialStore(store crud.ManagedStore) Store {
 	return Store{
 		backingStore: store,
 	}
 }
 
 // GetBackingStore returns the data store behind this credentials store.
-func (s Store) GetBackingStore() *crud.BackingStore {
+func (s Store) GetBackingStore() crud.ManagedStore {
 	return s.backingStore
 }
 

utils/crud/backingstore.go

@@ -1,13 +1,12 @@
 package crud
 
-var _ Store = &BackingStore{}
+var _ ManagedStore = &BackingStore{}
 
 // BackingStore wraps another store that may have Connect/Close methods that
 // need to be called.
 // - Connect is called before a method when the connection is closed.
 // - Close is called after each method when AutoClose is true (default).
 type BackingStore struct {
-
 	// AutoClose specifies if the connection should be automatically
 	// closed when done accessing the backing store.
 	AutoClose bool
@@ -75,6 +74,16 @@ func (s *BackingStore) autoClose() error {
 	return nil
 }
 
+func (s *BackingStore) Count(itemType string, group string) (int, error) {
+	handleClose, err := s.HandleConnect()
+	defer handleClose()
+	if err != nil {
+		return 0, err
+	}
+
+	return s.datastore.Count(itemType, group)
+}
+
 func (s *BackingStore) List(itemType string, group string) ([]string, error) {
 	handleClose, err := s.HandleConnect()
 	defer handleClose()

utils/crud/backingstore_test.go

@@ -209,3 +209,25 @@ func TestBackingStore_ReadAll(t *testing.T) {
 		})
 	}
 }
+
+func TestBackingStore_Count(t *testing.T) {
+	s := NewMockStore()
+
+	count, err := s.Count(testItemType, testGroup)
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 0, count, "Count should be 0 for an empty datastore")
+
+	err = s.Save(testItemType, testGroup, "key1", []byte("value1"))
+	require.NoError(t, err, "Save failed")
+
+	count, err = s.Count(testItemType, testGroup)
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 1, count, "Count should be 1 after adding an item")
+
+	err = s.Delete(testItemType, "key1")
+	require.NoError(t, err, "Delete failed")
+
+	count, err = s.Count(testItemType, testGroup)
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 0, count, "Count should be 0 after deleting the item")
+}

utils/crud/filesystem.go

@@ -31,6 +31,11 @@ type FileSystemStore struct {
 	fileExtensions map[string]string
 }
 
+func (s FileSystemStore) Count(itemType string, group string) (int, error) {
+	names, err := s.List(itemType, group)
+	return len(names), err
+}
+
 func (s FileSystemStore) List(itemType string, group string) ([]string, error) {
 	if err := s.ensure(itemType); err != nil {
 		return nil, err

utils/crud/filesystem_test.go

@@ -6,13 +6,14 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 var _ Store = FileSystemStore{}
 
 func TestFilesystemStore(t *testing.T) {
 	is := assert.New(t)
-	tmdir, err := ioutil.TempDir("", "duffle-test-")
+	tmdir, err := ioutil.TempDir("", "cnab-test-")
 	is.NoError(err)
 	defer os.RemoveAll(tmdir)
 	s := NewFileSystemStore(tmdir, map[string]string{testItemType: ".json"})
@@ -30,3 +31,28 @@ func TestFilesystemStore(t *testing.T) {
 	is.NoError(err)
 	is.Len(list, 0)
 }
+
+func TestFileSystemStore_Count(t *testing.T) {
+	tmdir, err := ioutil.TempDir("", "cnab-test-")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmdir)
+	s := NewFileSystemStore(tmdir, map[string]string{testItemType: ".json"})
+
+	count, err := s.Count(testItemType, "")
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 0, count, "Count should be 0 for an empty datastore")
+
+	err = s.Save(testItemType, "", "key1", []byte("value1"))
+	require.NoError(t, err, "Save failed")
+
+	count, err = s.Count(testItemType, "")
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 1, count, "Count should be 1 after adding an item")
+
+	err = s.Delete(testItemType, "key1")
+	require.NoError(t, err, "Delete failed")
+
+	count, err = s.Count(testItemType, "")
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 0, count, "Count should be 0 after deleting the item")
+}

utils/crud/mock_store.go

@@ -89,6 +89,11 @@ func (s MockStore) key(itemType string, id string) string {
 	return path.Join(itemType, id)
 }
 
+func (s MockStore) Count(itemType string, group string) (int, error) {
+	names, err := s.List(itemType, group)
+	return len(names), err
+}
+
 func (s MockStore) List(itemType string, group string) ([]string, error) {
 	if s.ListMock != nil {
 		return s.ListMock(itemType, group)

utils/crud/mock_store_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestMockStoreWithGroups(t *testing.T) {
@@ -49,3 +50,25 @@ func TestMockStoreWithoutGroups(t *testing.T) {
 	is.NoError(err)
 	is.Equal(groups, []string{"test"})
 }
+
+func TestMockStore_Count(t *testing.T) {
+	s := NewMockStore()
+
+	count, err := s.Count(testItemType, "")
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 0, count, "Count should be 0 for an empty datastore")
+
+	err = s.Save(testItemType, "", "key1", []byte("value1"))
+	require.NoError(t, err, "Save failed")
+
+	count, err = s.Count(testItemType, "")
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 1, count, "Count should be 1 after adding an item")
+
+	err = s.Delete(testItemType, "key1")
+	require.NoError(t, err, "Delete failed")
+
+	count, err = s.Count(testItemType, "")
+	require.NoError(t, err, "Count failed")
+	assert.Equal(t, 0, count, "Count should be 0 after deleting the item")
+}

utils/crud/mongodb.go

@@ -69,6 +69,19 @@ func (s *mongoDBStore) getCollection(itemType string) *mgo.Collection {
 	return c
 }
 
+func (s *mongoDBStore) Count(itemType string, group string) (int, error) {
+	collection := s.getCollection(itemType)
+
+	var query map[string]string
+	if group != "" {
+		query = map[string]string{
+			"group": group,
+		}
+	}
+	n, err := collection.Find(query).Count()
+	return n, wrapErr(err)
+}
+
 func (s *mongoDBStore) List(itemType string, group string) ([]string, error) {
 	collection := s.getCollection(itemType)
 

utils/crud/store.go

@@ -2,12 +2,41 @@ package crud
 
 // Store is a simplified interface to a key-blob store supporting CRUD operations.
 type Store interface {
+	// Count the number of items of the optional type and group.
+	Count(itemType string, group string) (int, error)
+
+	// List the names of the items of the optional type and group.
 	List(itemType string, group string) ([]string, error)
+
+	// Save an item's data using the specified name with optional metadata
+	// identifying it with an item type and group.
 	Save(itemType string, group string, name string, data []byte) error
+
+	// Read the data for a named item of the optional type.
 	Read(itemType string, name string) ([]byte, error)
+
+	// Delete a named item of the optional type.
 	Delete(itemType string, name string) error
 }
 
+// ManagedStore is a wrapped crud.Store with a managed connection lifecycle.
+type ManagedStore interface {
+	// Store is the underlying datastore.
+	Store
+
+	// ReadAll retrieves all the items with the optional item type.
+	ReadAll(itemType string, group string) ([][]byte, error)
+
+	// GetDataStore returns the datastore managed by this instance.
+	GetDataStore() Store
+
+	// HandleConnect connects if necessary, returning a function to close the
+	// connection. This close function may be a no-op when connection was
+	// already established and this call to Connect isn't managing the
+	// connection.
+	HandleConnect() (func() error, error)
+}
+
 // HasConnect indicates that a struct must be initialized using the Connect
 // method before the interface's methods are called.
 type HasConnect interface {