giedomak/Telepath

/**
 * Copyright (C) 2016-2017 - All rights reserved.
 * This file is part of the telepath project which is released under the GPLv3 license.
 * See file LICENSE.txt or go to http://www.gnu.org/licenses/gpl.txt for full license details.
 * You may use, distribute and modify this code under the terms of the GPLv3 license.
 */

package com.github.giedomak.telepath.kpathindex

import com.github.giedomak.telepath.datamodels.graph.Path
import com.github.giedomak.telepath.datamodels.graph.PathPrefix
import java.io.IOException
import java.util.stream.Stream

/**
 * KPathIndex interface defining the public methods of a path index.
 *
 * @property k K indicates the paths with up to this K number of edges are indexed in the kPathIndex.
 * For example: if K=2, the index contains all paths which have 1 or 2 edges along the path.
 * @property insertCallback Callback which will be called after insertion of a path into the index.
 */
interface KPathIndex {

    var k: Int
    var insertCallback: ((Path) -> Unit)?

    /**
     * Search method to lookup paths in the KPathIndex.
     *
     * @param pathPrefix The prefix of a path which we need to search.
     * @return An Iterable with Paths which satisfy the pathPrefix.
     * @throws IOException I/O error.
     */
    fun search(pathPrefix: PathPrefix): Stream<Path>

    /**
     * Insert method to insert a Path into the KPathIndex.
     *
     * @param path The path we will insert into the KPathIndex.
     */
    fun insert(path: Path, dryRun: Boolean = false)

}