Initial commit of Hyperscan

src/nfagraph/ng_mcclellan_internal.h

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+/*
+ * 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
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** \file
+ * \brief Shared build code for DFAs (McClellan, Haig).
+ */
+
+#ifndef NG_MCCLELLAN_INTERNAL_H
+#define NG_MCCLELLAN_INTERNAL_H
+
+#include "ue2common.h"
+#include "nfa/mcclellancompile.h"
+#include "nfagraph/ng_holder.h"
+#include "nfagraph/ng_restructuring.h" // for NO_STATE
+#include "util/charreach.h"
+#include "util/graph_range.h"
+#include "util/ue2_containers.h"
+
+#include <boost/dynamic_bitset.hpp>
+
+#include <map>
+#include <vector>
+
+namespace ue2 {
+
+struct raw_dfa;
+
+/** Fills alpha, unalpha and returns alphabet size. */
+u16 buildAlphabetFromEquivSets(const std::vector<CharReach> &esets,
+                               std::array<u16, ALPHABET_SIZE> &alpha,
+                               std::array<u16, ALPHABET_SIZE> &unalpha);
+
+/** \brief Calculates an alphabet remapping based on the symbols which the
+ * graph discriminates on. Throws in some special DFA symbols as well. */
+void calculateAlphabet(const NGHolder &g, std::array<u16, ALPHABET_SIZE> &alpha,
+                       std::array<u16, ALPHABET_SIZE> &unalpha, u16 *alphasize);
+
+void getFullTransitionFromState(const raw_dfa &n, u16 state,
+                                u16 *out_table);
+
+/** produce a map of states on which it is valid to receive tops */
+void markToppableStarts(const NGHolder &g,
+                        const ue2::unordered_map<NFAVertex, u32> &state_ids,
+                        bool single_trigger,
+                        const std::vector<std::vector<CharReach>> &triggers,
+                        boost::dynamic_bitset<> *out);
+
+template<typename autom>
+void transition_graph(autom &nfa, const std::vector<NFAVertex> &vByStateId,
+                      const typename autom::StateSet &in,
+                      typename autom::StateSet *next) {
+    typedef typename autom::StateSet StateSet;
+    const NGHolder &graph = nfa.graph;
+    const auto &state_ids = nfa.state_ids;
+    const auto &alpha = nfa.alpha;
+    const StateSet &squash = nfa.squash;
+    const std::map<u32, StateSet> &squash_mask = nfa.squash_mask;
+    const std::vector<CharReach> &cr_by_index = nfa.cr_by_index;
+
+    for (symbol_t s = 0; s < nfa.alphasize; s++) {
+        next[s].reset();
+    }
+
+    /* generate top transitions, false -> top = selfloop */
+    bool top_allowed = is_triggered(graph);
+
+    StateSet succ = nfa.dead;
+    for (size_t i = in.find_first(); i != in.npos; i = in.find_next(i)) {
+        NFAVertex u = vByStateId[i];
+
+        for (const auto &v : adjacent_vertices_range(u, graph)) {
+            if (state_ids.at(v) == NO_STATE) {
+                continue;
+            }
+            succ.set(graph[v].index);
+        }
+
+        if (top_allowed && !nfa.toppable.test(i)) {
+            /* we don't need to generate a top at this location as we are in
+             * an nfa state which cannot be on when a trigger arrives. */
+            top_allowed = false;
+        }
+    }
+
+    StateSet active_squash = succ & squash;
+    if (active_squash.any()) {
+        for (size_t j = active_squash.find_first(); j != active_squash.npos;
+             j = active_squash.find_next(j)) {
+            succ &= squash_mask.find(j)->second;
+        }
+    }
+
+    for (size_t j = succ.find_first(); j != succ.npos; j = succ.find_next(j)) {
+        const CharReach &cr = cr_by_index[j];
+        for (size_t s = cr.find_first(); s != cr.npos; s = cr.find_next(s)) {
+            next[s].set(j); /* already alpha'ed */
+        }
+    }
+
+    next[alpha[TOP]] = in;
+
+    if (top_allowed) {
+        /* we don't add in the anchored starts as the only case as the only
+         * time it is appropriate is if no characters have been consumed.*/
+        next[alpha[TOP]] |= nfa.initDS;
+
+        active_squash = next[alpha[TOP]] & squash;
+        if (active_squash.any()) {
+            for (size_t j = active_squash.find_first(); j != active_squash.npos;
+                 j = active_squash.find_next(j)) {
+                next[alpha[TOP]] &= squash_mask.find(j)->second;
+            }
+        }
+    }
+}
+
+} // namespace ue2
+
+#endif