/*
 * Copyright (c) 2015, Intel Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of Intel Corporation nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 */

/** \file
 * \brief Functions for pruning unreachable vertices or reports from the graph.
 */

#ifndef NG_PRUNE_H
#define NG_PRUNE_H

#include "ue2common.h"

namespace ue2 {

class NGHolder;
class ReportManager;

/** Remove any vertices that can't be reached by traversing the graph in
 * reverse from acceptEod. */
void pruneUnreachable(NGHolder &g);

/** Remove any vertices which can't be reached by traversing the graph forward
 * from start or in reverse from acceptEod. If \p renumber is false, no
 * vertex/edge renumbering is done. */
void pruneUseless(NGHolder &g, bool renumber = true);

/** Remove any vertices with empty reachability. */
void pruneEmptyVertices(NGHolder &g);

/** Remove any edges from vertices that generate accepts (for Highlander
 * graphs). */
void pruneHighlanderAccepts(NGHolder &g, const ReportManager &rm);

/**
 * Prune highlander reports that are dominated by earlier ones in the graph.
 */
void pruneHighlanderDominated(NGHolder &g, const ReportManager &rm);

/** Removes the given Report ID from vertices connected to accept, and then
 * prunes useless vertices that have had their report sets reduced to empty. */
void pruneReport(NGHolder &g, ReportID report);

/** Removes all Report IDs bar the given one from vertices connected to accept,
 * and then prunes useless vertices that have had their report sets reduced to
 * empty. */
void pruneAllOtherReports(NGHolder &g, ReportID report);

} // namespace ue2

#endif // NG_PRUNE_H