1/*
2 * Copyright (c) 2015-2017, Intel Corporation
3 *
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5 * modification, are permitted provided that the following conditions are met:
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9 * * Redistributions in binary form must reproduce the above copyright
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27 */
28
29/** \file
30 * \brief Utility functions related to SOM ("Start of Match").
31 */
32
33#ifndef NG_SOM_UTIL_H
34#define NG_SOM_UTIL_H
35
36#include "ng_util.h"
37#include "util/depth.h"
38
39#include <map>
40#include <unordered_map>
41#include <vector>
42
43namespace ue2 {
44
45class NGHolder;
46
47/**
48 * Returns min/max distance from start of match, index by vertex_id.
49 */
50std::vector<DepthMinMax> getDistancesFromSOM(const NGHolder &g);
51
52/**
53 * Returns true if the first match by end-offset must always be the first match
54 * by start-offset.
55 */
56bool firstMatchIsFirst(const NGHolder &p);
57
58struct smgb_cache : public mbsb_cache {
59 explicit smgb_cache(const NGHolder &gg) : mbsb_cache(gg) {}
60 std::map<NFAVertex, bool> smgb;
61};
62
63bool somMayGoBackwards(NFAVertex u, const NGHolder &g,
64 const std::unordered_map<NFAVertex, u32> &region_map,
65 smgb_cache &cache);
66
67/**
68 * Returns true if matching 'sent' causes all tail states in the main graph \a
69 * g to go dead. A tail state is any state with a region greater than
70 * \a last_head_region.
71 *
72 * - The graph \a sent must be a "kinda-DAG", where the only back-edges present
73 * are self-loops.
74 * - If the result is false, \a bad_region will be updated with the smallest
75 * region ID associated with a tail state that is still on.
76 */
77bool sentClearsTail(const NGHolder &g,
78 const std::unordered_map<NFAVertex, u32> &region_map,
79 const NGHolder &sent, u32 last_head_region,
80 u32 *bad_region);
81
82} // namespace ue2
83
84#endif // NG_SOM_UTIL_H
85