Replace RE2 import with a dependency

third_party/re2/re2/prefilter.h

-// Copyright 2009 The RE2 Authors.  All Rights Reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Prefilter is the class used to extract string guards from regexps.
-// Rather than using Prefilter class directly, use FilteredRE2.
-// See filtered_re2.h
-
-#ifndef RE2_PREFILTER_H_
-#define RE2_PREFILTER_H_
-
-#include "util/util.h"
-
-namespace re2 {
-
-class RE2;
-
-class Regexp;
-
-class Prefilter {
-  // Instead of using Prefilter directly, use FilteredRE2; see filtered_re2.h
- public:
-  enum Op {
-    ALL = 0,  // Everything matches
-    NONE,  // Nothing matches
-    ATOM,  // The string atom() must match
-    AND,   // All in subs() must match
-    OR,   // One of subs() must match
-  };
-
-  explicit Prefilter(Op op);
-  ~Prefilter();
-
-  Op op() { return op_; }
-  const string& atom() const { return atom_; }
-  void set_unique_id(int id) { unique_id_ = id; }
-  int unique_id() const { return unique_id_; }
-
-  // The children of the Prefilter node.
-  vector<Prefilter*>* subs() {
-    CHECK(op_ == AND || op_ == OR);
-    return subs_;
-  }
-
-  // Set the children vector. Prefilter takes ownership of subs and
-  // subs_ will be deleted when Prefilter is deleted.
-  void set_subs(vector<Prefilter*>* subs) { subs_ = subs; }
-
-  // Given a RE2, return a Prefilter. The caller takes ownership of
-  // the Prefilter and should deallocate it. Returns NULL if Prefilter
-  // cannot be formed.
-  static Prefilter* FromRE2(const RE2* re2);
-
-  // Returns a readable debug string of the prefilter.
-  string DebugString() const;
-
- private:
-  class Info;
-
-  // Combines two prefilters together to create an AND. The passed
-  // Prefilters will be part of the returned Prefilter or deleted.
-  static Prefilter* And(Prefilter* a, Prefilter* b);
-
-  // Combines two prefilters together to create an OR. The passed
-  // Prefilters will be part of the returned Prefilter or deleted.
-  static Prefilter* Or(Prefilter* a, Prefilter* b);
-
-  // Generalized And/Or
-  static Prefilter* AndOr(Op op, Prefilter* a, Prefilter* b);
-
-  static Prefilter* FromRegexp(Regexp* a);
-
-  static Prefilter* FromString(const string& str);
-
-  static Prefilter* OrStrings(set<string>* ss);
-
-  static Info* BuildInfo(Regexp* re);
-
-  Prefilter* Simplify();
-
-  // Kind of Prefilter.
-  Op op_;
-
-  // Sub-matches for AND or OR Prefilter.
-  vector<Prefilter*>* subs_;
-
-  // Actual string to match in leaf node.
-  string atom_;
-
-  // If different prefilters have the same string atom, or if they are
-  // structurally the same (e.g., OR of same atom strings) they are
-  // considered the same unique nodes. This is the id for each unique
-  // node. This field is populated with a unique id for every node,
-  // and -1 for duplicate nodes.
-  int unique_id_;
-
-  // Used for debugging, helps in tracking memory leaks.
-  int alloc_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(Prefilter);
-};
-
-}  // namespace re2
-
-#endif  // RE2_PREFILTER_H_