1 // Copyright 2009 The RE2 Authors.  All Rights Reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 
5 #include <string>
6 #include "util/util.h"
7 #include "re2/filtered_re2.h"
8 #include "re2/prefilter.h"
9 #include "re2/prefilter_tree.h"
10 
11 namespace re2 {
12 
FilteredRE2()13 FilteredRE2::FilteredRE2()
14     : compiled_(false),
15       prefilter_tree_(new PrefilterTree()) {
16 }
17 
~FilteredRE2()18 FilteredRE2::~FilteredRE2() {
19   for (int i = 0; i < re2_vec_.size(); i++)
20     delete re2_vec_[i];
21   delete prefilter_tree_;
22 }
23 
Add(const StringPiece & pattern,const RE2::Options & options,int * id)24 RE2::ErrorCode FilteredRE2::Add(const StringPiece& pattern,
25                                 const RE2::Options& options, int* id) {
26   RE2* re = new RE2(pattern, options);
27   RE2::ErrorCode code = re->error_code();
28 
29   if (!re->ok()) {
30     if (options.log_errors()) {
31       LOG(ERROR) << "Couldn't compile regular expression, skipping: "
32                  << re << " due to error " << re->error();
33     }
34     delete re;
35   } else {
36     *id = re2_vec_.size();
37     re2_vec_.push_back(re);
38   }
39 
40   return code;
41 }
42 
Compile(vector<string> * atoms)43 void FilteredRE2::Compile(vector<string>* atoms) {
44   if (compiled_ || re2_vec_.size() == 0) {
45     LOG(INFO) << "C: " << compiled_ << " S:" << re2_vec_.size();
46     return;
47   }
48 
49   for (int i = 0; i < re2_vec_.size(); i++) {
50     Prefilter* prefilter = Prefilter::FromRE2(re2_vec_[i]);
51     prefilter_tree_->Add(prefilter);
52   }
53   atoms->clear();
54   prefilter_tree_->Compile(atoms);
55   compiled_ = true;
56 }
57 
SlowFirstMatch(const StringPiece & text) const58 int FilteredRE2::SlowFirstMatch(const StringPiece& text) const {
59   for (int i = 0; i < re2_vec_.size(); i++)
60     if (RE2::PartialMatch(text, *re2_vec_[i]))
61       return i;
62   return -1;
63 }
64 
FirstMatch(const StringPiece & text,const vector<int> & atoms) const65 int FilteredRE2::FirstMatch(const StringPiece& text,
66                             const vector<int>& atoms) const {
67   if (!compiled_) {
68     LOG(DFATAL) << "FirstMatch called before Compile";
69     return -1;
70   }
71   vector<int> regexps;
72   prefilter_tree_->RegexpsGivenStrings(atoms, &regexps);
73   for (int i = 0; i < regexps.size(); i++)
74     if (RE2::PartialMatch(text, *re2_vec_[regexps[i]]))
75       return regexps[i];
76   return -1;
77 }
78 
AllMatches(const StringPiece & text,const vector<int> & atoms,vector<int> * matching_regexps) const79 bool FilteredRE2::AllMatches(
80     const StringPiece& text,
81     const vector<int>& atoms,
82     vector<int>* matching_regexps) const {
83   matching_regexps->clear();
84   vector<int> regexps;
85   prefilter_tree_->RegexpsGivenStrings(atoms, &regexps);
86   for (int i = 0; i < regexps.size(); i++)
87     if (RE2::PartialMatch(text, *re2_vec_[regexps[i]]))
88       matching_regexps->push_back(regexps[i]);
89   return !matching_regexps->empty();
90 }
91 
RegexpsGivenStrings(const vector<int> & matched_atoms,vector<int> * passed_regexps)92 void FilteredRE2::RegexpsGivenStrings(const vector<int>& matched_atoms,
93                                       vector<int>* passed_regexps) {
94   prefilter_tree_->RegexpsGivenStrings(matched_atoms, passed_regexps);
95 }
96 
97 
PrintPrefilter(int regexpid)98 void FilteredRE2::PrintPrefilter(int regexpid) {
99   prefilter_tree_->PrintPrefilter(regexpid);
100 }
101 
102 }  // namespace re2
103