intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 607 insertions, 0 deletions

diff --git a/contrib/libs/hyperscan/src/nfa/accel_dfa_build_strat.cpp b/contrib/libs/hyperscan/src/nfa/accel_dfa_build_strat.cpp
new file mode 100644
index 0000000000..ae71e141a2
--- /dev/null
+++ b/contrib/libs/hyperscan/src/nfa/accel_dfa_build_strat.cpp
@@ -0,0 +1,607 @@
+/*
+ * Copyright (c) 2015-2017, 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.
+ */
+
+#include "accel_dfa_build_strat.h"
+
+#include "accel.h"
+#include "grey.h"
+#include "nfagraph/ng_limex_accel.h"
+#include "shufticompile.h"
+#include "trufflecompile.h"
+#include "util/accel_scheme.h"
+#include "util/charreach.h"
+#include "util/container.h"
+#include "util/dump_charclass.h"
+#include "util/small_vector.h"
+#include "util/verify_types.h"
+
+#include <sstream>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#define PATHS_LIMIT 500
+
+using namespace std;
+
+namespace ue2 {
+
+namespace {
+struct path {
+    small_vector<CharReach, MAX_ACCEL_DEPTH + 1> reach;
+    dstate_id_t dest = DEAD_STATE;
+    explicit path(dstate_id_t base) : dest(base) {}
+};
+};
+
+template<typename Container>
+void dump_paths(const Container &paths) {
+    for (UNUSED const path &p : paths) {
+        DEBUG_PRINTF("[%s] -> %u\n", describeClasses(p.reach).c_str(), p.dest);
+    }
+    DEBUG_PRINTF("%zu paths\n", paths.size());
+}
+
+static
+vector<CharReach> reverse_alpha_remapping(const raw_dfa &rdfa) {
+    vector<CharReach> rv(rdfa.alpha_size - 1); /* TOP not required */
+
+    for (u32 i = 0; i < N_CHARS; i++) {
+        rv.at(rdfa.alpha_remap[i]).set(i);
+    }
+
+    return rv;
+}
+
+static
+bool is_useful_path(const vector<path> &good, const path &p) {
+    for (const auto &g : good) {
+        assert(g.dest == p.dest);
+        assert(g.reach.size() <= p.reach.size());
+        auto git = g.reach.rbegin();
+        auto pit = p.reach.rbegin();
+
+        for (; git != g.reach.rend(); ++git, ++pit) {
+            if (!pit->isSubsetOf(*git)) {
+                goto next;
+            }
+        }
+        DEBUG_PRINTF("better: [%s] -> %u\n", describeClasses(g.reach).c_str(),
+                     g.dest);
+
+        return false;
+    next:;
+    }
+
+    return true;
+}
+
+static
+path append(const path &orig, const CharReach &cr, u32 new_dest) {
+    path p(new_dest);
+    p.reach = orig.reach;
+    p.reach.push_back(cr);
+
+    return p;
+}
+
+static
+void extend(const raw_dfa &rdfa, const vector<CharReach> &rev_map,
+            const path &p, unordered_map<u32, vector<path>> &all,
+            vector<path> &out) {
+    const dstate &s = rdfa.states[p.dest];
+
+    if (!p.reach.empty() && p.reach.back().none()) {
+        out.push_back(p);
+        return;
+    }
+
+    if (!s.reports.empty()) {
+        if (generates_callbacks(rdfa.kind)) {
+            out.push_back(p);
+            return;
+        } else {
+            path pp = append(p, CharReach(), p.dest);
+            all[p.dest].push_back(pp);
+            out.push_back(move(pp));
+        }
+    }
+
+    if (!s.reports_eod.empty()) {
+        path pp = append(p, CharReach(), p.dest);
+        all[p.dest].push_back(pp);
+        out.push_back(move(pp));
+    }
+
+    flat_map<u32, CharReach> dest;
+    for (u32 i = 0; i < rev_map.size(); i++) {
+        u32 succ = s.next[i];
+        dest[succ] |= rev_map[i];
+    }
+
+    for (const auto &e : dest) {
+        path pp = append(p, e.second, e.first);
+        if (!is_useful_path(all[e.first], pp)) {
+            DEBUG_PRINTF("not useful: [%s] -> %u\n",
+                         describeClasses(pp.reach).c_str(), pp.dest);
+            continue;
+        }
+
+        DEBUG_PRINTF("----good: [%s] -> %u\n",
+                     describeClasses(pp.reach).c_str(), pp.dest);
+        all[e.first].push_back(pp);
+        out.push_back(move(pp));
+    }
+}
+
+static
+vector<vector<CharReach>> generate_paths(const raw_dfa &rdfa,
+                                         dstate_id_t base, u32 len) {
+    const vector<CharReach> rev_map = reverse_alpha_remapping(rdfa);
+    vector<path> paths{path(base)};
+    unordered_map<u32, vector<path>> all;
+    all[base].push_back(path(base));
+    for (u32 i = 0; i < len && paths.size() < PATHS_LIMIT; i++) {
+        vector<path> next_gen;
+        for (const auto &p : paths) {
+            extend(rdfa, rev_map, p, all, next_gen);
+        }
+
+        paths = move(next_gen);
+    }
+
+    dump_paths(paths);
+
+    vector<vector<CharReach>> rv;
+    rv.reserve(paths.size());
+    for (auto &p : paths) {
+        rv.push_back(vector<CharReach>(std::make_move_iterator(p.reach.begin()),
+                                       std::make_move_iterator(p.reach.end())));
+    }
+    return rv;
+}
+
+static
+AccelScheme look_for_offset_accel(const raw_dfa &rdfa, dstate_id_t base,
+                                  u32 max_allowed_accel_offset) {
+    DEBUG_PRINTF("looking for accel for %hu\n", base);
+    vector<vector<CharReach>> paths =
+        generate_paths(rdfa, base, max_allowed_accel_offset + 1);
+    AccelScheme as = findBestAccelScheme(paths, CharReach(), true);
+    DEBUG_PRINTF("found %s + %u\n", describeClass(as.cr).c_str(), as.offset);
+    return as;
+}
+
+static UNUSED
+bool better(const AccelScheme &a, const AccelScheme &b) {
+    if (!a.double_byte.empty() && b.double_byte.empty()) {
+        return true;
+    }
+
+    if (!b.double_byte.empty()) {
+        return false;
+    }
+
+    return a.cr.count() < b.cr.count();
+}
+
+static
+bool double_byte_ok(const AccelScheme &info) {
+    return !info.double_byte.empty() &&
+           info.double_cr.count() < info.double_byte.size() &&
+           info.double_cr.count() <= 2;
+}
+
+static
+bool has_self_loop(dstate_id_t s, const raw_dfa &raw) {
+    u16 top_remap = raw.alpha_remap[TOP];
+    for (u32 i = 0; i < raw.states[s].next.size(); i++) {
+        if (i != top_remap && raw.states[s].next[i] == s) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static
+flat_set<u16> find_nonexit_symbols(const raw_dfa &rdfa,
+                                   const CharReach &escape) {
+    flat_set<u16> rv;
+    CharReach nonexit = ~escape;
+    for (auto i = nonexit.find_first(); i != nonexit.npos;
+         i = nonexit.find_next(i)) {
+        rv.insert(rdfa.alpha_remap[i]);
+    }
+
+    return rv;
+}
+
+static
+dstate_id_t get_sds_or_proxy(const raw_dfa &raw) {
+    if (raw.start_floating != DEAD_STATE) {
+        DEBUG_PRINTF("has floating start\n");
+        return raw.start_floating;
+    }
+
+    DEBUG_PRINTF("looking for SDS proxy\n");
+
+    dstate_id_t s = raw.start_anchored;
+
+    if (has_self_loop(s, raw)) {
+        return s;
+    }
+
+    u16 top_remap = raw.alpha_remap[TOP];
+
+    std::unordered_set<dstate_id_t> seen;
+    while (true) {
+        seen.insert(s);
+        DEBUG_PRINTF("basis %hu\n", s);
+
+        /* check if we are connected to a state with a self loop */
+        for (u32 i = 0; i < raw.states[s].next.size(); i++) {
+            dstate_id_t t = raw.states[s].next[i];
+            if (i != top_remap && t != DEAD_STATE && has_self_loop(t, raw)) {
+                return t;
+            }
+        }
+
+        /* find a neighbour to use as a basis for looking for the sds proxy */
+        dstate_id_t t = DEAD_STATE;
+        for (u32 i = 0; i < raw.states[s].next.size(); i++) {
+            dstate_id_t tt = raw.states[s].next[i];
+            if (i != top_remap && tt != DEAD_STATE && !contains(seen, tt)) {
+                t = tt;
+                break;
+            }
+        }
+
+        if (t == DEAD_STATE) {
+            /* we were unable to find a state to use as a SDS proxy */
+            return DEAD_STATE;
+        }
+
+        s = t;
+    }
+}
+
+static
+set<dstate_id_t> find_region(const raw_dfa &rdfa, dstate_id_t base,
+                             const AccelScheme &ei) {
+    DEBUG_PRINTF("looking for region around %hu\n", base);
+
+    set<dstate_id_t> region = {base};
+
+    if (!ei.double_byte.empty()) {
+        return region;
+    }
+
+    DEBUG_PRINTF("accel %s+%u\n", describeClass(ei.cr).c_str(), ei.offset);
+
+    const CharReach &escape = ei.cr;
+    auto nonexit_symbols = find_nonexit_symbols(rdfa, escape);
+
+    vector<dstate_id_t> pending = {base};
+    while (!pending.empty()) {
+        dstate_id_t curr = pending.back();
+        pending.pop_back();
+        for (auto s : nonexit_symbols) {
+            dstate_id_t t = rdfa.states[curr].next[s];
+            if (contains(region, t)) {
+                continue;
+            }
+
+            DEBUG_PRINTF("    %hu is in region\n", t);
+            region.insert(t);
+            pending.push_back(t);
+        }
+    }
+
+    return region;
+}
+
+AccelScheme
+accel_dfa_build_strat::find_escape_strings(dstate_id_t this_idx) const {
+    AccelScheme rv;
+    const raw_dfa &rdfa = get_raw();
+    rv.cr.clear();
+    rv.offset = 0;
+    const dstate &raw = rdfa.states[this_idx];
+    const vector<CharReach> rev_map = reverse_alpha_remapping(rdfa);
+    bool outs2_broken = false;
+    flat_map<dstate_id_t, CharReach> succs;
+
+    for (u32 i = 0; i < rev_map.size(); i++) {
+        if (raw.next[i] == this_idx) {
+            continue;
+        }
+
+        const CharReach &cr_i = rev_map.at(i);
+
+        rv.cr |= cr_i;
+        dstate_id_t next_id = raw.next[i];
+
+        DEBUG_PRINTF("next is %hu\n", next_id);
+        const dstate &raw_next = rdfa.states[next_id];
+
+        if (outs2_broken) {
+            continue;
+        }
+
+        if (!raw_next.reports.empty() && generates_callbacks(rdfa.kind)) {
+            DEBUG_PRINTF("leads to report\n");
+            outs2_broken = true; /* cannot accelerate over reports */
+            continue;
+        }
+        succs[next_id] |= cr_i;
+    }
+
+    if (!outs2_broken) {
+        for (const auto &e : succs) {
+            const CharReach &cr_i = e.second;
+            const dstate &raw_next = rdfa.states[e.first];
+
+            CharReach cr_all_j;
+            for (u32 j = 0; j < rev_map.size(); j++) {
+                if (raw_next.next[j] == raw.next[j]) {
+                    continue;
+                }
+
+                DEBUG_PRINTF("state %hu: adding sym %u -> %hu to 2 \n", e.first,
+                             j, raw_next.next[j]);
+                cr_all_j |= rev_map.at(j);
+            }
+
+            if (cr_i.count() * cr_all_j.count() > 8) {
+                DEBUG_PRINTF("adding %zu to double_cr\n", cr_i.count());
+                rv.double_cr |= cr_i;
+            } else {
+                for (auto ii = cr_i.find_first(); ii != CharReach::npos;
+                     ii = cr_i.find_next(ii)) {
+                    for (auto jj = cr_all_j.find_first(); jj != CharReach::npos;
+                         jj = cr_all_j.find_next(jj)) {
+                        rv.double_byte.emplace((u8)ii, (u8)jj);
+                        if (rv.double_byte.size() > 8) {
+                            DEBUG_PRINTF("outs2 too big\n");
+                            outs2_broken = true;
+                            goto done;
+                        }
+                    }
+                }
+            }
+        }
+
+    done:
+        assert(outs2_broken || rv.double_byte.size() <= 8);
+        if (outs2_broken) {
+            rv.double_byte.clear();
+        }
+    }
+
+    DEBUG_PRINTF("this %u, sds proxy %hu\n", this_idx, get_sds_or_proxy(rdfa));
+    DEBUG_PRINTF("broken %d\n", outs2_broken);
+    if (!double_byte_ok(rv) && !is_triggered(rdfa.kind) &&
+        this_idx == rdfa.start_floating && this_idx != DEAD_STATE) {
+        DEBUG_PRINTF("looking for offset accel at %u\n", this_idx);
+        auto offset =
+            look_for_offset_accel(rdfa, this_idx, max_allowed_offset_accel());
+        DEBUG_PRINTF("width %zu vs %zu\n", offset.cr.count(), rv.cr.count());
+        if (double_byte_ok(offset) || offset.cr.count() < rv.cr.count()) {
+            DEBUG_PRINTF("using offset accel\n");
+            rv = offset;
+        }
+    }
+
+    return rv;
+}
+
+void
+accel_dfa_build_strat::buildAccel(UNUSED dstate_id_t this_idx,
+                                  const AccelScheme &info,
+                                  void *accel_out) {
+    AccelAux *accel = (AccelAux *)accel_out;
+
+    DEBUG_PRINTF("accelerations scheme has offset s%u/d%u\n", info.offset,
+                 info.double_offset);
+    accel->generic.offset = verify_u8(info.offset);
+
+    if (double_byte_ok(info) && info.double_cr.none() &&
+        info.double_byte.size() == 1) {
+        accel->accel_type = ACCEL_DVERM;
+        accel->dverm.c1 = info.double_byte.begin()->first;
+        accel->dverm.c2 = info.double_byte.begin()->second;
+        accel->dverm.offset = verify_u8(info.double_offset);
+        DEBUG_PRINTF("state %hu is double vermicelli\n", this_idx);
+        return;
+    }
+
+    if (double_byte_ok(info) && info.double_cr.none() &&
+        (info.double_byte.size() == 2 || info.double_byte.size() == 4)) {
+        bool ok = true;
+
+        assert(!info.double_byte.empty());
+        u8 firstC = info.double_byte.begin()->first & CASE_CLEAR;
+        u8 secondC = info.double_byte.begin()->second & CASE_CLEAR;
+
+        for (const pair<u8, u8> &p : info.double_byte) {
+            if ((p.first & CASE_CLEAR) != firstC ||
+                (p.second & CASE_CLEAR) != secondC) {
+                ok = false;
+                break;
+            }
+        }
+
+        if (ok) {
+            accel->accel_type = ACCEL_DVERM_NOCASE;
+            accel->dverm.c1 = firstC;
+            accel->dverm.c2 = secondC;
+            accel->dverm.offset = verify_u8(info.double_offset);
+            DEBUG_PRINTF("state %hu is nc double vermicelli\n", this_idx);
+            return;
+        }
+
+        u8 m1;
+        u8 m2;
+        if (buildDvermMask(info.double_byte, &m1, &m2)) {
+            accel->accel_type = ACCEL_DVERM_MASKED;
+            accel->dverm.offset = verify_u8(info.double_offset);
+            accel->dverm.c1 = info.double_byte.begin()->first & m1;
+            accel->dverm.c2 = info.double_byte.begin()->second & m2;
+            accel->dverm.m1 = m1;
+            accel->dverm.m2 = m2;
+            DEBUG_PRINTF(
+                "building maskeddouble-vermicelli for 0x%02hhx%02hhx\n",
+                accel->dverm.c1, accel->dverm.c2);
+            return;
+        }
+    }
+
+    if (double_byte_ok(info) &&
+        shuftiBuildDoubleMasks(
+            info.double_cr, info.double_byte, (u8 *)&accel->dshufti.lo1,
+            (u8 *)&accel->dshufti.hi1, (u8 *)&accel->dshufti.lo2,
+            (u8 *)&accel->dshufti.hi2)) {
+        accel->accel_type = ACCEL_DSHUFTI;
+        accel->dshufti.offset = verify_u8(info.double_offset);
+        DEBUG_PRINTF("state %hu is double shufti\n", this_idx);
+        return;
+    }
+
+    if (info.cr.none()) {
+        accel->accel_type = ACCEL_RED_TAPE;
+        DEBUG_PRINTF("state %hu is a dead end full of bureaucratic red tape"
+                     " from which there is no escape\n",
+                     this_idx);
+        return;
+    }
+
+    if (info.cr.count() == 1) {
+        accel->accel_type = ACCEL_VERM;
+        accel->verm.c = info.cr.find_first();
+        DEBUG_PRINTF("state %hu is vermicelli\n", this_idx);
+        return;
+    }
+
+    if (info.cr.count() == 2 && info.cr.isCaselessChar()) {
+        accel->accel_type = ACCEL_VERM_NOCASE;
+        accel->verm.c = info.cr.find_first() & CASE_CLEAR;
+        DEBUG_PRINTF("state %hu is caseless vermicelli\n", this_idx);
+        return;
+    }
+
+    if (info.cr.count() > max_floating_stop_char()) {
+        accel->accel_type = ACCEL_NONE;
+        DEBUG_PRINTF("state %hu is too broad\n", this_idx);
+        return;
+    }
+
+    accel->accel_type = ACCEL_SHUFTI;
+    if (-1 != shuftiBuildMasks(info.cr, (u8 *)&accel->shufti.lo,
+                               (u8 *)&accel->shufti.hi)) {
+        DEBUG_PRINTF("state %hu is shufti\n", this_idx);
+        return;
+    }
+
+    assert(!info.cr.none());
+    accel->accel_type = ACCEL_TRUFFLE;
+    truffleBuildMasks(info.cr, (u8 *)&accel->truffle.mask1,
+                      (u8 *)&accel->truffle.mask2);
+    DEBUG_PRINTF("state %hu is truffle\n", this_idx);
+}
+
+map<dstate_id_t, AccelScheme>
+accel_dfa_build_strat::getAccelInfo(const Grey &grey) {
+    map<dstate_id_t, AccelScheme> rv;
+    raw_dfa &rdfa = get_raw();
+    if (!grey.accelerateDFA) {
+        return rv;
+    }
+
+    dstate_id_t sds_proxy = get_sds_or_proxy(rdfa);
+    DEBUG_PRINTF("sds %hu\n", sds_proxy);
+
+    /* Find accel info for a single state. */
+    auto do_state = [&](size_t i) {
+        if (i == DEAD_STATE) {
+            return;
+        }
+
+        /* Note on report acceleration states: While we can't accelerate while
+         * we are spamming out callbacks, the QR code paths don't raise reports
+         * during scanning so they can accelerate report states. */
+        if (generates_callbacks(rdfa.kind) && !rdfa.states[i].reports.empty()) {
+            return;
+        }
+
+        size_t single_limit =
+            i == sds_proxy ? max_floating_stop_char() : max_stop_char();
+        DEBUG_PRINTF("inspecting %zu/%hu: %zu\n", i, sds_proxy, single_limit);
+
+        AccelScheme ei = find_escape_strings(i);
+        if (ei.cr.count() > single_limit) {
+            DEBUG_PRINTF("state %zu is not accelerable has %zu\n", i,
+                         ei.cr.count());
+            return;
+        }
+
+        DEBUG_PRINTF("state %zu should be accelerable %zu\n", i, ei.cr.count());
+
+        rv[i] = ei;
+    };
+
+    if (only_accel_init) {
+        DEBUG_PRINTF("only computing accel for init states\n");
+        do_state(rdfa.start_anchored);
+        if (rdfa.start_floating != rdfa.start_anchored) {
+            do_state(rdfa.start_floating);
+        }
+    } else {
+        DEBUG_PRINTF("computing accel for all states\n");
+        for (size_t i = 0; i < rdfa.states.size(); i++) {
+            do_state(i);
+        }
+    }
+
+    /* provide acceleration states to states in the region of sds */
+    if (contains(rv, sds_proxy)) {
+        AccelScheme sds_ei = rv[sds_proxy];
+        sds_ei.double_byte.clear(); /* region based on single byte scheme
+                                     * may differ from double byte */
+        DEBUG_PRINTF("looking to expand offset accel to nearby states, %zu\n",
+                     sds_ei.cr.count());
+        auto sds_region = find_region(rdfa, sds_proxy, sds_ei);
+        for (auto s : sds_region) {
+            if (!contains(rv, s) || better(sds_ei, rv[s])) {
+                rv[s] = sds_ei;
+            }
+        }
+    }
+
+    return rv;
+}
+};