/*
 * 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
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 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 */

/** \file
 * \brief Reverse acceleration analysis.
 */

#ifndef NG_REVACC_H
#define NG_REVACC_H

#include "util/charreach.h"

#include <vector>

struct NFA;

namespace ue2 {

class NGHolder;

#define MAX_RACCEL_OFFSET 16

struct RevAccInfo {
    RevAccInfo(void);
    bool valid;
    std::vector<CharReach> acceptReach;  /**< bytes which can appear n
                                          *  bytes before a match */
    std::vector<CharReach> acceptEodReach; /**< bytes which can appear n
                                            *  bytes before eod match */
};

void buildReverseAcceleration(struct NFA *nfa, const RevAccInfo &rev_info,
                              u32 min_width, bool eod_only = false);

void populateReverseAccelerationInfo(RevAccInfo &rai, const NGHolder &g);
void mergeReverseAccelerationInfo(RevAccInfo &dest, const RevAccInfo &vic);

} // namespace ue2

#endif
