lib/src/main/java/io/v/syncbase/v23/services/syncbase/nosql/ScanStream.java

// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package io.v.syncbase.v23.services.syncbase.nosql;

import io.v.v23.verror.VException;

/**
 * An interface for iterating through a collection of key/value pairs (obtained via
 * {@link Table#scan Table.scan()}).
 */
public interface ScanStream extends Stream {
    /**
     * Returns the key of the element that was staged by {@link #advance}.
     * <p>
     * This method does not block.
     *
     * @throws VException  if {@link #advance} returned {@code false} or was not called at all
     */
    String key() throws VException;

    /**
     * Returns the value of the element that was staged by {@link #advance}.
     * <p>
     * This method does not block.
     *
     * @throws VException if the value could not be decoded or if {@link #advance} returned
     *                    {@code false} or was not called at all
     */
    Object value() throws VException;
}