Initial commit of Hyperscan

src/nfa/castlecompile.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 Castle: multi-tenant repeat engine, compiler code.
+ */
+
+#ifndef NFA_CASTLECOMPILE_H
+#define NFA_CASTLECOMPILE_H
+
+#include "nfa_kind.h"
+#include "ue2common.h"
+#include "nfagraph/ng_repeat.h"
+#include "util/alloc.h"
+#include "util/depth.h"
+
+#include <map>
+#include <memory>
+#include <set>
+#include <vector>
+
+struct NFA;
+
+namespace ue2 {
+
+class CharReach;
+class NGHolder;
+struct CompileContext;
+
+/**
+ * \brief Prototype for a Castle engine: contains at least one CastleRepeat.
+ *
+ * Currently, all repeats in a Castle must have the same character
+ * reachability.
+ *
+ * A CastleProto is converted into a single NFA, with each top triggering a
+ * unique repeat. A CastleProto can contain at most CastleProto::max_occupancy
+ * elements.
+ */
+struct CastleProto {
+    static constexpr size_t max_occupancy = 65536; // arbitrary limit
+    explicit CastleProto(const PureRepeat &pr);
+    const CharReach &reach() const;
+
+    u32 add(const PureRepeat &pr);
+
+    /**
+     * \brief Merge in the given repeat, returning the top used.
+     *
+     * If the repeat already exists in this castle, we will re-use (and return)
+     * the old top. If it doesn't, it will be added and assigned a new top.
+     * Returns \ref max_occupancy if capacity would be exceeded.
+     */
+    u32 merge(const PureRepeat &pr);
+
+    /** \brief Mapping from unique top id to repeat. */
+    std::map<u32, PureRepeat> repeats;
+};
+
+std::set<ReportID> all_reports(const CastleProto &proto);
+depth findMinWidth(const CastleProto &proto);
+depth findMaxWidth(const CastleProto &proto);
+
+/**
+ * \brief Remap tops to be contiguous.
+ *
+ * Remap the tops in the given CastleProto so that they're contiguous in the
+ * range [0 .. N-1].
+ */
+void remapCastleTops(CastleProto &proto, std::map<u32, u32> &top_map);
+
+/**
+ * \brief Construct an NFA from a CastleProto.
+ *
+ * NOTE: Tops must be contiguous, i.e. \ref remapCastleTops must have been run
+ * first.
+ */
+ue2::aligned_unique_ptr<NFA>
+buildCastle(const CastleProto &proto,
+            const std::map<u32, std::vector<std::vector<CharReach>>> &triggers,
+            const CompileContext &cc);
+
+/**
+ * \brief Merge two CastleProto prototypes together, if possible.
+ *
+ * Returns true if merge of all repeats in c2 into c1 succeeds, and fills
+ * mapping with the repeat indices.
+ */
+bool mergeCastle(CastleProto &c1, const CastleProto &c2,
+                 std::map<u32, u32> &top_map);
+
+/**
+ * \brief True if the two castles are identical with respect to the reports
+ * given; i.e. the same tops lead to the same repeats, just with report1 in c1
+ * and report2 in c2.
+ *
+ * Repeats leading to other reports are ignored.
+ */
+bool is_equal(const CastleProto &c1, ReportID report1, const CastleProto &c2,
+              ReportID report2);
+
+/**
+ * \brief True if the two castles given are identical.
+ */
+bool is_equal(const CastleProto &c1, const CastleProto &c2);
+
+/**
+ * \brief True if the given castle contains more than a single instance of any
+ * of the reports in the given set.
+ */
+bool requiresDedupe(const CastleProto &proto, const std::set<ReportID> &reports);
+
+/**
+ * \brief Build an NGHolder from a CastleProto.
+ */
+std::unique_ptr<NGHolder> makeHolder(const CastleProto &castle, nfa_kind kind,
+                                     const CompileContext &cc);
+
+} // namespace ue2
+
+#endif // NFA_CASTLECOMPILE_H