Initial commit of Hyperscan

src/nfagraph/ng_limex_accel.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 NFA acceleration analysis code.
+ */
+
+#ifndef NG_LIMEX_ACCEL_H
+#define NG_LIMEX_ACCEL_H
+
+#include "ng_holder.h"
+#include "ng_misc_opt.h"
+#include "ue2common.h"
+#include "util/charreach.h"
+#include "util/order_check.h"
+#include "util/ue2_containers.h"
+
+#include <map>
+#include <vector>
+
+namespace ue2 {
+
+/* compile time accel defs */
+#define MAX_ACCEL_DEPTH 4
+#define MAX_MERGED_ACCEL_STOPS 200
+#define ACCEL_MAX_STOP_CHAR 24
+#define ACCEL_MAX_FLOATING_STOP_CHAR 192 /* accelerating sds is important */
+
+void findAccelFriends(const NGHolder &g, NFAVertex v,
+                  const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic,
+                      u32 offset,
+                      ue2::flat_set<NFAVertex> *friends);
+
+struct DoubleAccelInfo {
+    DoubleAccelInfo() : offset(0) {}
+    u32 offset;                         //!< offset correction to apply
+    CharReach stop1;                    //!< single-byte accel stop literals
+    flat_set<std::pair<u8, u8>> stop2;  //!< double-byte accel stop literals
+};
+
+DoubleAccelInfo findBestDoubleAccelInfo(const NGHolder &g, NFAVertex v);
+
+struct AccelScheme {
+    AccelScheme(const CharReach &cr_in, u32 offset_in)
+        : cr(cr_in), offset(offset_in) {
+        assert(offset <= MAX_ACCEL_DEPTH);
+    }
+    AccelScheme() : cr(CharReach::dot()), offset(MAX_ACCEL_DEPTH + 1) {}
+
+    bool operator<(const AccelScheme &b) const {
+        const AccelScheme &a = *this;
+
+        // Don't use ORDER_CHECK as it will (stupidly) eval count() too many
+        // times.
+        const size_t a_count = cr.count(), b_count = b.cr.count();
+        if (a_count != b_count) {
+            return a_count < b_count;
+        }
+
+        /* TODO: give bonus if one is a 'caseless' character */
+        ORDER_CHECK(offset);
+        ORDER_CHECK(cr);
+        return false;
+    }
+
+    bool operator>(const AccelScheme &b) const {
+        return b < *this;
+    }
+
+    CharReach cr;
+    u32 offset;
+};
+
+NFAVertex get_sds_or_proxy(const NGHolder &g);
+
+AccelScheme nfaFindAccel(const NGHolder &g, const std::vector<NFAVertex> &verts,
+                    const std::vector<CharReach> &refined_cr,
+                    const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic,
+                    bool allow_wide);
+
+/** \brief Check if vertex \a v is an accelerable state (for a limex NFA). */
+bool nfaCheckAccel(const NGHolder &g, NFAVertex v,
+                   const std::vector<CharReach> &refined_cr,
+                   const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic,
+                   AccelScheme *as, bool allow_wide);
+
+} // namespace ue2
+
+#endif