[wip] gets destination backup working for KVStore

persistence/blockstore/block_store.go

@@ -93,6 +93,10 @@ func (bs *blockStore) Stop() error {
 	return bs.kv.Stop()
 }
 
+func (bs *blockStore) Backup(path string) error {
+	return bs.kv.Backup(path)
+}
+
 func (bs *blockStore) Delete(key []byte) error         { return bs.kv.Delete(key) }
 func (bs *blockStore) Exists(key []byte) (bool, error) { return bs.kv.Exists(key) }
 func (bs *blockStore) GetAll(prefixKey []byte, descending bool) (keys, values [][]byte, err error) {

persistence/kvstore/kvstore.go

@@ -4,7 +4,10 @@ package kvstore
 
 import (
 	"errors"
+	"fmt"
 	"log"
+	"os"
+	"path/filepath"
 
 	badger "github.com/dgraph-io/badger/v3"
 	"github.com/pokt-network/smt"
@@ -22,6 +25,8 @@ type KVStore interface {
 	GetAll(prefixKey []byte, descending bool) (keys, values [][]byte, err error)
 	Exists(key []byte) (bool, error)
 	ClearAll() error
+
+	Backup(filepath string) error
 }
 
 const (
@@ -141,6 +146,31 @@ func (store *badgerKVStore) Stop() error {
 	return store.db.Close()
 }
 
+// Backup creates a backup for the badgerDB at the provided path.
+// It creates a file
+func (store *badgerKVStore) Backup(backupPath string) error {
+	// create backup directory if it doesn't exist
+	if err := os.MkdirAll(filepath.Dir(backupPath), os.ModePerm); err != nil {
+		return fmt.Errorf("failed to create backup directory: %v", err)
+	}
+
+	// create the backup file itself
+	backupFile, err := os.Create(backupPath)
+	if err != nil {
+		return fmt.Errorf("failed to create backup file: %v", err)
+	}
+	defer backupFile.Close()
+
+	// dump the database to the backup file
+	// CONSIDER: ??? err := store.db.NewStream().Backup(backupFile, 0) // What's the difference here?
+	_, err = store.db.Backup(backupFile, 0)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // PrefixEndBytes returns the end byteslice for a noninclusive range
 // that would include all byte slices for which the input is the prefix
 func prefixEndBytes(prefix []byte) []byte {

persistence/kvstore/kvstore_test.go

@@ -2,6 +2,10 @@ package kvstore
 
 import (
 	"encoding/hex"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -330,10 +334,65 @@ func TestKVStore_ClearAll(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestKVStore_Backup(t *testing.T) {
+	t.Run("should backup an in-memory database", func(t *testing.T) {
+		store := NewMemKVStore()
+		require.NotNil(t, store)
+
+		tmpdir := t.TempDir()
+		path := filepath.Join(tmpdir, "TestKVStore_Backup_InMemory.bak")
+		require.NoError(t, store.Backup(path))
+
+		empty, err := isEmpty(t, tmpdir)
+		require.NoError(t, err)
+		require.False(t, empty)
+
+		// assert on individual files
+		files, err := ioutil.ReadDir(tmpdir)
+		require.NoError(t, err)
+		require.Equal(t, len(files), 1)
+	})
+	t.Run("should backup an on-disk store database", func(t *testing.T) {
+		tmpdir := t.TempDir()
+		kvpath := filepath.Join(tmpdir, "TestKVStore_Backup_OnDisk_Source.bak")
+		store, err := NewKVStore(kvpath)
+		require.NoError(t, err)
+		require.NotNil(t, store)
+
+		backupDir := t.TempDir()
+		path := filepath.Join(backupDir, "TestKVStore_Backup_OnDisk_Destination.bak")
+		require.NoError(t, store.Backup(path))
+
+		empty, err := isEmpty(t, backupDir)
+		require.NoError(t, err)
+		require.False(t, empty)
+
+		// assert on individual files
+		files, err := ioutil.ReadDir(backupDir)
+		require.NoError(t, err)
+		require.Equal(t, len(files), 1)
+	})
+}
+
 func setupStore(t *testing.T, store KVStore) {
 	t.Helper()
 	err := store.Set([]byte("foo"), []byte("bar"))
 	require.NoError(t, err)
 	err = store.Set([]byte("baz"), []byte("bin"))
 	require.NoError(t, err)
 }
+
+func isEmpty(t *testing.T, dir string) (bool, error) {
+	t.Helper()
+	f, err := os.Open(dir)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	_, err = f.Readdirnames(1)
+	if err == io.EOF {
+		return true, nil
+	}
+	return false, err
+}

persistence/module.go

@@ -104,7 +104,7 @@ func (*persistenceModule) Create(bus modules.Bus, options ...modules.ModuleOptio
 		trees.WithTreeStoreDirectory(persistenceCfg.TreesStoreDir),
 		trees.WithLogger(m.logger))
 	if err != nil {
-		return nil, fmt.Errorf("failed to create TreeStoreModule: %w", err)
+		return nil, fmt.Errorf("failed to create %s: %w", modules.TreeStoreSubmoduleName, err)
 	}
 
 	m.config = persistenceCfg

persistence/trees/atomic_test.go

@@ -3,6 +3,8 @@ package trees
 import (
 	"encoding/hex"
 	"fmt"
+	"io"
+	"os"
 	"testing"
 
 	"github.com/pokt-network/pocket/logger"
@@ -146,8 +148,6 @@ func TestTreeStore_SaveAndLoad(t *testing.T) {
 		logger:       logger.Global.CreateLoggerForModule(modules.TreeStoreSubmoduleName),
 		treeStoreDir: tmpDir,
 	}
-	// TODO IN THIS COMMIT do we need to start this treestore?
-	// require.NoError(t, ts2.Start())
 
 	// Load sets a tree store to the provided worldstate
 	err = ts2.Load(w)
@@ -158,3 +158,68 @@ func TestTreeStore_SaveAndLoad(t *testing.T) {
 	// Assert that hash is unchanged from save and load
 	require.Equal(t, hash1, hash2)
 }
+
+func TestTreeStore_SaveBackup(t *testing.T) {
+	ts := newTestTreeStore(t)
+	tmpdir := t.TempDir()
+	// assert that the directory is empty before backup
+	ok, err := isEmpty(tmpdir)
+	require.NoError(t, err)
+	require.True(t, ok)
+
+	// Trigger a backup
+	require.NoError(t, ts.Backup(tmpdir))
+
+	// assert that the directory is not empty after Backup has returned
+	ok, err = isEmpty(tmpdir)
+	require.NoError(t, err)
+	require.False(t, ok)
+}
+
+// creates a new tree store with a tmp directory for nodestore persistence
+// and then starts the tree store and returns its pointer.
+func newTestTreeStore(t *testing.T) *treeStore {
+	ctrl := gomock.NewController(t)
+	tmpDir := t.TempDir()
+
+	mockTxIndexer := mock_types.NewMockTxIndexer(ctrl)
+	mockBus := mockModules.NewMockBus(ctrl)
+	mockPersistenceMod := mockModules.NewMockPersistenceModule(ctrl)
+
+	mockBus.EXPECT().GetPersistenceModule().AnyTimes().Return(mockPersistenceMod)
+	mockPersistenceMod.EXPECT().GetTxIndexer().AnyTimes().Return(mockTxIndexer)
+
+	ts := &treeStore{
+		logger:       &zerolog.Logger{},
+		treeStoreDir: tmpDir,
+	}
+	require.NoError(t, ts.Start())
+	require.NotNil(t, ts.rootTree.tree)
+
+	for _, treeName := range stateTreeNames {
+		err := ts.merkleTrees[treeName].tree.Update([]byte("foo"), []byte("bar"))
+		require.NoError(t, err)
+	}
+
+	err := ts.Commit()
+	require.NoError(t, err)
+
+	hash1 := ts.getStateHash()
+	require.NotEmpty(t, hash1)
+
+	return ts
+}
+
+func isEmpty(dir string) (bool, error) {
+	f, err := os.Open(dir)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	_, err = f.Readdirnames(1) // Or f.Readdir(1)
+	if err == io.EOF {
+		return true, nil
+	}
+	return false, err // Either not empty or error, suits both cases
+}

persistence/trees/module.go

@@ -12,13 +12,19 @@ import (
 
 var _ modules.TreeStoreModule = &treeStore{}
 
+// Create returns a TreeStoreSubmodule that has been setup with the provided TreeStoreOptions, started,
+// and then registered to the bus.
 func (*treeStore) Create(bus modules.Bus, options ...modules.TreeStoreOption) (modules.TreeStoreModule, error) {
 	m := &treeStore{}
 
 	for _, option := range options {
 		option(m)
 	}
 
+	if err := m.Start(); err != nil {
+		return nil, fmt.Errorf("failed to start %s: %w", modules.TreeStoreSubmoduleName, err)
+	}
+
 	bus.RegisterModule(m)
 
 	return m, nil
@@ -71,6 +77,7 @@ func (t *treeStore) Stop() error {
 
 func (t *treeStore) GetModuleName() string { return modules.TreeStoreSubmoduleName }
 
+// setupTrees is called by Start and it loads the treestore at the given directory
 func (t *treeStore) setupTrees() error {
 	if t.treeStoreDir == ":memory:" {
 		return t.setupInMemory()

persistence/trees/module_test.go

@@ -48,7 +48,12 @@ func TestTreeStore_Create(t *testing.T) {
 	treemod, err := trees.Create(mockBus, trees.WithTreeStoreDirectory(":memory:"))
 	assert.NoError(t, err)
 
-	require.NoError(t, treemod.Start())
+	// Create should setup a value for each tree
+	for _, v := range stateTreeNames {
+		root, ns := treemod.GetTree(v)
+		require.NotEmpty(t, root)
+		require.NotEmpty(t, ns)
+	}
 
 	got := treemod.GetBus()
 	assert.Equal(t, got, mockBus)
@@ -68,21 +73,13 @@ func TestTreeStore_StartAndStop(t *testing.T) {
 	mockRuntimeMgr := mockModules.NewMockRuntimeMgr(ctrl)
 	mockBus := createMockBus(t, mockRuntimeMgr)
 
+	// Create returns a started TreeStoreSubmodule
 	treemod, err := trees.Create(
 		mockBus,
 		trees.WithTreeStoreDirectory(":memory:"),
 		trees.WithLogger(&zerolog.Logger{}))
 	assert.NoError(t, err)
 
-	// GetTree should return nil for each tree if Start has not been called
-	for _, v := range stateTreeNames {
-		root, ns := treemod.GetTree(v)
-		require.Empty(t, root)
-		require.Empty(t, ns)
-	}
-	// Should start without error
-	require.NoError(t, treemod.Start())
-
 	// Should stop without error
 	require.NoError(t, treemod.Stop())
 

persistence/trees/trees.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"hash"
 	"log"
+	"path/filepath"
 
 	"github.com/jackc/pgx/v5"
 	"github.com/pokt-network/pocket/persistence/indexer"
@@ -29,6 +30,7 @@ import (
 	"github.com/pokt-network/pocket/shared/modules"
 	"github.com/pokt-network/pocket/shared/modules/base_modules"
 	"github.com/pokt-network/smt"
+	"go.uber.org/multierr"
 )
 
 // smtTreeHasher sets the hasher used by the tree SMT trees
@@ -379,7 +381,10 @@ func (t *treeStore) save() (*worldState, error) {
 
 	w := &worldState{
 		treeStoreDir: t.treeStoreDir,
-		merkleTrees:  map[string]*stateTree{},
+		merkleRoots:  make(map[string][]byte),
+		merkleTrees:  make(map[string]*stateTree),
+		rootHash:     t.rootTree.tree.Root(),
+		rootTree:     t.rootTree,
 	}
 
 	for treeName := range t.merkleTrees {
@@ -403,6 +408,20 @@ func (t *treeStore) save() (*worldState, error) {
 	return w, nil
 }
 
+// Backup creates a new backup of each tree in the tree store to the provided directory.
+// Each tree is backed up in an eponymous file in the provided backupDir.
+func (t *treeStore) Backup(backupDir string) error {
+	errs := []error{}
+	for _, st := range t.merkleTrees {
+		treePath := filepath.Join(backupDir, st.name)
+		if err := st.nodeStore.Backup(treePath); err != nil {
+			t.logger.Err(err).Msgf("failed to backup %s tree: %+v", st.name, err)
+			errs = append(errs, err)
+		}
+	}
+	return multierr.Combine(errs...)
+}
+
 ////////////////////////
 // Actor Tree Helpers //
 ////////////////////////

persistence/trees/trees_test.go

@@ -50,8 +50,6 @@ func TestTreeStore_Update(t *testing.T) {
 		pmod := newTestPersistenceModule(t, dbUrl)
 		context := newTestPostgresContext(t, 0, pmod)
 
-		require.NoError(t, context.SetSavePoint())
-
 		hash1, err := context.ComputeStateHash()
 		require.NoError(t, err)
 		require.NotEmpty(t, hash1)
@@ -60,8 +58,6 @@ func TestTreeStore_Update(t *testing.T) {
 		_, err = createAndInsertDefaultTestApp(t, context)
 		require.NoError(t, err)
 
-		require.NoError(t, context.SetSavePoint())
-
 		hash2, err := context.ComputeStateHash()
 		require.NoError(t, err)
 		require.NotEmpty(t, hash2)