Initial commit of Hyperscan

src/parser/ComponentAlternation.cpp

@@ -0,0 +1,190 @@
+/*
+ * 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 Alternations (foo|bar|baz).
+ */
+
+
+#include "ComponentAlternation.h"
+
+#include "buildstate.h"
+#include "position.h"
+#include "position_info.h"
+#include "nfagraph/ng_builder.h"
+#include "ue2common.h"
+
+#include <algorithm>
+
+using namespace std;
+
+namespace ue2 {
+
+ComponentAlternation::ComponentAlternation() {
+    // empty
+}
+
+ComponentAlternation::~ComponentAlternation() {
+    // empty
+}
+
+ComponentAlternation::ComponentAlternation(const ComponentAlternation &other)
+    : Component(other) {
+    for (const auto &c : other.children) {
+        assert(c);
+        children.push_back(unique_ptr<Component>(c->clone()));
+    }
+}
+
+ComponentAlternation * ComponentAlternation::clone() const {
+    return new ComponentAlternation(*this);
+}
+
+Component *ComponentAlternation::accept(ComponentVisitor &v) {
+    Component *c = v.visit(this);
+    if (c != this) {
+        v.post(this);
+        return c;
+    }
+
+    for (auto i = children.begin(), e = children.end(); i != e; ++i) {
+        Component *child = i->get();
+        c = (*i)->accept(v);
+        if (c != child) {
+            // Child has been replaced (new Component pointer) or we've been
+            // instructed to delete it (null).
+            i->reset(c);
+        }
+    }
+
+    // Remove deleted children.
+    children.erase(remove(children.begin(), children.end(), nullptr),
+                   children.end());
+
+    v.post(this);
+    return this;
+}
+
+void ComponentAlternation::accept(ConstComponentVisitor &v) const {
+    v.pre(*this);
+    for (auto i = children.begin(), e = children.end(); i != e; ++i) {
+        (*i)->accept(v);
+        if (i + 1 != e) {
+            v.during(*this);
+        }
+    }
+
+    v.post(*this);
+}
+
+void ComponentAlternation::append(unique_ptr<Component> component) {
+    children.push_back(move(component));
+}
+
+vector<PositionInfo> ComponentAlternation::first() const {
+    // firsts come from all our subcomponents in position order. This will
+    // maintain left-to-right priority order.
+    vector<PositionInfo> firsts, subfirsts;
+
+    for (const auto &c : children) {
+        subfirsts = c->first();
+        firsts.insert(firsts.end(), subfirsts.begin(), subfirsts.end());
+    }
+    return firsts;
+}
+
+vector<PositionInfo> ComponentAlternation::last() const {
+    vector<PositionInfo> lasts, sublasts;
+
+    for (const auto &c : children) {
+        sublasts = c->last();
+        lasts.insert(lasts.end(), sublasts.begin(), sublasts.end());
+    }
+    return lasts;
+}
+
+bool ComponentAlternation::empty(void) const {
+    // an alternation can be empty if any of its components are empty
+    for (const auto &c : children) {
+        if (c->empty()) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+void ComponentAlternation::notePositions(GlushkovBuildState &bs) {
+    u32 pb = bs.getBuilder().numVertices();
+    for (auto &c : children) {
+        c->notePositions(bs);
+    }
+    recordPosBounds(pb, bs.getBuilder().numVertices());
+}
+
+void ComponentAlternation::buildFollowSet(GlushkovBuildState &bs,
+                                          const vector<PositionInfo> &lastPos) {
+    for (auto &c : children) {
+        c->buildFollowSet(bs, lastPos);
+    }
+}
+
+bool ComponentAlternation::checkEmbeddedStartAnchor(bool at_start) const {
+    bool rv = at_start;
+    for (const auto &c : children) {
+        rv &= c->checkEmbeddedStartAnchor(at_start);
+    }
+
+    return rv;
+}
+
+bool ComponentAlternation::checkEmbeddedEndAnchor(bool at_end) const {
+    bool rv = at_end;
+    for (const auto &c : children) {
+        rv &= c->checkEmbeddedEndAnchor(at_end);
+    }
+
+    return rv;
+}
+
+bool ComponentAlternation::vacuous_everywhere(void) const {
+    for (const auto &c : children) {
+        if (c->vacuous_everywhere()) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void ComponentAlternation::optimise(bool connected_to_sds) {
+    for (auto &c : children) {
+        c->optimise(connected_to_sds);
+    }
+}
+
+} // namespace ue2