1 files changed, 46 insertions, 30 deletions

diff --git a/src/dedo.go b/src/dedo.go
index d8655bb..af29fdd 100644
--- a/src/dedo.go
+++ b/src/dedo.go
@@ -63,28 +63,44 @@ import (
 
 type CursorI interface{
 	First() ([]byte, []byte)
+	Last()  ([]byte, []byte)
 	Next()  ([]byte, []byte)
+	Prev()  ([]byte, []byte)
+	Seek([]byte) ([]byte, []byte)
+	Delete() error
+}
+
+type BucketI interface{
+	Get([]byte) []byte
+	Put([]byte, []byte) error
+	Delete([]byte) error
+	ForEach(func([]byte, []byte) error) error
+	CreateBucket([]byte) (BucketI, error)
+	DeleteBucket([]byte) error
+	Bucket([]byte) BucketI
+	NextSequence() (uint64, error)
+	Cursor() CursorI
 }
 
 type SnapshotI interface{
-	Bucket([]byte) *bucketT
+	Bucket([]byte) BucketI
 	Cursor() CursorI
-	ForEach(func([]byte, *bucketT) error) error
+	ForEach(func([]byte, BucketI) error) error
 
 	WriteTo(io.Writer) (int64, error)
 	Check() <-chan error
 }
 
 type TransactionI interface{
-	Bucket([]byte) *bucketT
+	Bucket([]byte) BucketI
 	Cursor() CursorI
-	ForEach(func([]byte, *bucketT) error) error
+	ForEach(func([]byte, BucketI) error) error
 
 	WriteTo(io.Writer) (int64, error)
 	Check() <-chan error
 
-	CreateBucket           ([]byte) (*bucketT, error)
-	CreateBucketIfNotExists([]byte) (*bucketT, error)
+	CreateBucket           ([]byte) (BucketI, error)
+	CreateBucketIfNotExists([]byte) (BucketI, error)
 	DeleteBucket([]byte) error
 	OnCommit(func())
 }
@@ -597,7 +613,7 @@ func bucketCursor(b *bucketT) *cursorT {
 	}
 }
 
-func (b *bucketT) Cursor() *cursorT {
+func (b *bucketT) Cursor() CursorI {
 	return bucketCursor(b)
 }
 
@@ -613,7 +629,7 @@ func bucketGetNested(b *bucketT, name []byte) *bucketT {
 	}
 
 	// Move cursor to key.
-	c := b.Cursor()
+	c := bucketCursor(b)
 	k, v, flags := c.seek(name)
 
 	// Return nil if the key doesn't exist or it is not a bucket.
@@ -630,7 +646,7 @@ func bucketGetNested(b *bucketT, name []byte) *bucketT {
 	return child
 }
 
-func (b *bucketT) Bucket(name []byte) *bucketT {
+func (b *bucketT) Bucket(name []byte) BucketI {
 	return bucketGetNested(b, name)
 }
 
@@ -670,7 +686,7 @@ func bucketCreateBucket(b *bucketT, key []byte) (*bucketT, error) {
 	}
 
 	// Move cursor to correct position.
-	c := b.Cursor()
+	c := bucketCursor(b)
 	k, _, flags := c.seek(key)
 
 	// Return an error if there is an existing key.
@@ -698,10 +714,10 @@ func bucketCreateBucket(b *bucketT, key []byte) (*bucketT, error) {
 	// the tx.
 	b.page = nil
 
-	return b.Bucket(key), nil
+	return bucketGetNested(b, key), nil
 }
 
-func (b *bucketT) CreateBucket(key []byte) (*bucketT, error) {
+func (b *bucketT) CreateBucket(key []byte) (BucketI, error) {
 	return bucketCreateBucket(b, key)
 }
 
@@ -710,9 +726,9 @@ func (b *bucketT) CreateBucket(key []byte) (*bucketT, error) {
 /// blank, or if the bucket name is too long.  The bucket instance is only valid
 /// for the lifetime of the transaction.
 func bucketCreateBucketIfNotExists(b *bucketT, key []byte) (*bucketT, error) {
-	child, err := b.CreateBucket(key)
+	child, err := bucketCreateBucket(b, key)
 	if err == ErrBucketExists {
-		return b.Bucket(key), nil
+		return bucketGetNested(b, key), nil
 	} else if err != nil {
 		return nil, err
 	}
@@ -733,7 +749,7 @@ func bucketDeleteBucket(b *bucketT, key []byte) error {
 	}
 
 	// Move cursor to correct position.
-	c := b.Cursor()
+	c := bucketCursor(b)
 	k, _, flags := c.seek(key)
 
 	// Return an error if bucket doesn't exist or is not a bucket.
@@ -744,7 +760,7 @@ func bucketDeleteBucket(b *bucketT, key []byte) error {
 	}
 
 	// Recursively delete all child buckets.
-	child := b.Bucket(key)
+	child := bucketGetNested(b, key)
 	err := child.ForEach(func(k, v []byte) error {
 		if v == nil {
 			err := child.DeleteBucket(k)
@@ -780,7 +796,7 @@ func (b *bucketT) DeleteBucket(key []byte) error {
 /// value if the key does not exist or if the key is a nested bucket.  The
 /// returned value is only valid for the life of the transaction.
 func bucketGet(b *bucketT, key []byte) []byte {
-	k, v, flags := b.Cursor().seek(key)
+	k, v, flags := bucketCursor(b).seek(key)
 
 	// Return nil if this is a bucket.
 	if (flags & bucketLeafFlag) != 0 {
@@ -818,7 +834,7 @@ func bucketPut(b *bucketT, key []byte, value []byte) error {
 	}
 
 	// Move cursor to correct position.
-	c := b.Cursor()
+	c := bucketCursor(b)
 	k, _, flags := c.seek(key)
 
 	// Return an error if there is an existing key with a bucket value.
@@ -848,7 +864,7 @@ func bucketDelete(b *bucketT, key []byte) error {
 	}
 
 	// Move cursor to correct position.
-	c := b.Cursor()
+	c := bucketCursor(b)
 	_, _, flags := c.seek(key)
 
 	// Return an error if there is already existing bucket value.
@@ -998,7 +1014,7 @@ func (b *bucketT) spill() error {
 		}
 
 		// Update parent node.
-		c := b.Cursor()
+		c := bucketCursor(b)
 		k, _, flags := c.seek([]byte(name))
 		if !bytes.Equal([]byte(name), k) {
 			panic(fmt.Sprintf(
@@ -3554,7 +3570,7 @@ func (tx *transactionT) Size() int64 {
 /// buckets.  The cursor is only valid as long as the transaction is open.  Do
 /// not use a cursor after the transaction is closed.
 func txCursor(tx *transactionT) *cursorT {
-	return tx.root.Cursor()
+	return bucketCursor(&tx.root)
 }
 
 func (tx *transactionT) Cursor() CursorI {
@@ -3565,10 +3581,10 @@ func (tx *transactionT) Cursor() CursorI {
 /// exist.  The bucket instance is only valid for the lifetime of the
 /// transaction.
 func txBucket(tx *transactionT, name []byte) *bucketT {
-	return tx.root.Bucket(name)
+	return bucketGetNested(&tx.root, name)
 }
 
-func (tx *transactionT) Bucket(name []byte) *bucketT {
+func (tx *transactionT) Bucket(name []byte) BucketI {
 	return txBucket(tx, name)
 }
 
@@ -3577,10 +3593,10 @@ func (tx *transactionT) Bucket(name []byte) *bucketT {
 /// long.  The bucket instance is only valid for the lifetime of the
 /// transaction.
 func txCreateBucket(tx *transactionT, name []byte) (*bucketT, error) {
-	return tx.root.CreateBucket(name)
+	return bucketCreateBucket(&tx.root, name)
 }
 
-func (tx *transactionT) CreateBucket(name []byte) (*bucketT, error) {
+func (tx *transactionT) CreateBucket(name []byte) (BucketI, error) {
 	return txCreateBucket(tx, name)
 }
 
@@ -3592,7 +3608,7 @@ func txCreateBucketIfNotExists(tx *transactionT, name []byte) (*bucketT, error)
 	return tx.root.CreateBucketIfNotExists(name)
 }
 
-func (tx *transactionT) CreateBucketIfNotExists(name []byte) (*bucketT, error) {
+func (tx *transactionT) CreateBucketIfNotExists(name []byte) (BucketI, error) {
 	return txCreateBucketIfNotExists(tx, name)
 }
 
@@ -3609,7 +3625,7 @@ func (tx *transactionT) DeleteBucket(name []byte) error {
 /// transactionT.ForEach() executes a function for each bucket in the root.  If the
 /// provided function returns an error then the iteration is stopped and the
 /// error is returned to the caller.
-func txForEach(tx *transactionT, fn func([]byte, *bucketT) error) error {
+func txForEach(tx *transactionT, fn func([]byte, BucketI) error) error {
 	return tx.root.ForEach(func(k []byte, v []byte) error {
 		err := fn(k, tx.root.Bucket(k))
 		if err != nil {
@@ -3619,7 +3635,7 @@ func txForEach(tx *transactionT, fn func([]byte, *bucketT) error) error {
 	})
 }
 
-func (tx *transactionT) ForEach(fn func([]byte, *bucketT) error) error {
+func (tx *transactionT) ForEach(fn func([]byte, BucketI) error) error {
 	return txForEach(tx, fn)
 }
 
@@ -3907,7 +3923,7 @@ func (tx *transactionT) checkBucket(
 
 	// Check each bucket within this bucket.
 	_ = b.ForEach(func(k, v []byte) error {
-		child := b.Bucket(k)
+		child := bucketGetNested(b, k)
 		if child != nil {
 			tx.checkBucket(child, reachable, freed, ch)
 		}
@@ -4133,7 +4149,7 @@ func listExec(args argsT, db DatabaseI, r io.Reader, w io.Writer) error {
 		if len(args.bucket) == 0 {
 			return snapshot.ForEach(func(
 				name []byte,
-				bucket *bucketT,
+				bucket BucketI,
 			) error {
 				fmt.Fprintf(w, "%s\n", string(name))
 				return nil