feat(interal/client): scan

internal/client/client.go

@@ -27,6 +27,7 @@ type Client interface {
 	Get(ctx context.Context, key []byte) ([]byte, error)
 	Delete(ctx context.Context, key []byte) error
 	TTL(ctx context.Context, key []byte) (uint64, error)
+	Scan(ctx context.Context, start []byte, limit int) ([]Entry, error)
 	Close(ctx context.Context) error
 }
 

internal/client/entry.go

@@ -0,0 +1,13 @@
+package client
+
+type Entry struct {
+	K, V []byte
+}
+
+func (e Entry) Key() string {
+	return string(e.K)
+}
+
+func (e Entry) Value() string {
+	return string(e.V)
+}

internal/client/raw.go

@@ -48,6 +48,23 @@ func (c *rawClient) TTL(ctx context.Context, key []byte) (uint64, error) {
 	return 0, nil
 }
 
+func (c *rawClient) Scan(ctx context.Context, start []byte, limit int) ([]Entry, error) {
+	keys, values, err := c.client.Scan(ctx, start, nil, limit)
+	if err != nil {
+		return nil, err
+	}
+
+	entries := make([]Entry, 0, len(keys))
+	for i, key := range keys {
+		entries[i] = Entry{
+			K: key,
+			V: values[i],
+		}
+	}
+
+	return entries, nil
+}
+
 func (c *rawClient) Close(ctx context.Context) error {
 	return c.client.Close()
 }

internal/client/txn.go

@@ -64,6 +64,32 @@ func (c *txnClient) TTL(ctx context.Context, key []byte) (uint64, error) {
 	return 0, errors.New("TTL is not supported in txn mode")
 }
 
+func (c *txnClient) Scan(ctx context.Context, start []byte, limit int) ([]Entry, error) {
+	tx, err := c.client.Begin()
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Commit(ctx)
+
+	it, err := tx.Iter(start, nil)
+	if err != nil {
+		return nil, err
+	}
+	defer it.Close()
+
+	var entries []Entry
+	for it.Valid() && limit > 0 {
+		entries = append(entries, Entry{
+			K: it.Key()[:],
+			V: it.Value()[:],
+		})
+		limit--
+		it.Next()
+	}
+
+	return entries, nil
+}
+
 func (c *txnClient) Close(ctx context.Context) error {
 	return c.client.Close()
 }