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30 // Author: Sanjay Ghemawat
31 
32 #ifdef HAVE_CONFIG_H
33 #include "config.h"
34 #endif
35 
36 #include <vector>
37 #include <assert.h>
38 
39 #include "pcrecpp_internal.h"
40 #include "pcre_scanner.h"
41 
42 using std::vector;
43 
44 namespace pcrecpp {
45 
Scanner()46 Scanner::Scanner()
47   : data_(),
48     input_(data_),
49     skip_(NULL),
50     should_skip_(false),
51     skip_repeat_(false),
52     save_comments_(false),
53     comments_(NULL),
54     comments_offset_(0) {
55 }
56 
Scanner(const string & in)57 Scanner::Scanner(const string& in)
58   : data_(in),
59     input_(data_),
60     skip_(NULL),
61     should_skip_(false),
62     skip_repeat_(false),
63     save_comments_(false),
64     comments_(NULL),
65     comments_offset_(0) {
66 }
67 
~Scanner()68 Scanner::~Scanner() {
69   delete skip_;
70   delete comments_;
71 }
72 
SetSkipExpression(const char * re)73 void Scanner::SetSkipExpression(const char* re) {
74   delete skip_;
75   if (re != NULL) {
76     skip_ = new RE(re);
77     should_skip_ = true;
78     skip_repeat_ = true;
79     ConsumeSkip();
80   } else {
81     skip_ = NULL;
82     should_skip_ = false;
83     skip_repeat_ = false;
84   }
85 }
86 
Skip(const char * re)87 void Scanner::Skip(const char* re) {
88   delete skip_;
89   if (re != NULL) {
90     skip_ = new RE(re);
91     should_skip_ = true;
92     skip_repeat_ = false;
93     ConsumeSkip();
94   } else {
95     skip_ = NULL;
96     should_skip_ = false;
97     skip_repeat_ = false;
98   }
99 }
100 
DisableSkip()101 void Scanner::DisableSkip() {
102   assert(skip_ != NULL);
103   should_skip_ = false;
104 }
105 
EnableSkip()106 void Scanner::EnableSkip() {
107   assert(skip_ != NULL);
108   should_skip_ = true;
109   ConsumeSkip();
110 }
111 
LineNumber() const112 int Scanner::LineNumber() const {
113   // TODO: Make it more efficient by keeping track of the last point
114   // where we computed line numbers and counting newlines since then.
115   // We could use std:count, but not all systems have it. :-(
116   int count = 1;
117   for (const char* p = data_.data(); p < input_.data(); ++p)
118     if (*p == '\n')
119       ++count;
120   return count;
121 }
122 
Offset() const123 int Scanner::Offset() const {
124   return (int)(input_.data() - data_.c_str());
125 }
126 
LookingAt(const RE & re) const127 bool Scanner::LookingAt(const RE& re) const {
128   int consumed;
129   return re.DoMatch(input_, RE::ANCHOR_START, &consumed, 0, 0);
130 }
131 
132 
Consume(const RE & re,const Arg & arg0,const Arg & arg1,const Arg & arg2)133 bool Scanner::Consume(const RE& re,
134                       const Arg& arg0,
135                       const Arg& arg1,
136                       const Arg& arg2) {
137   const bool result = re.Consume(&input_, arg0, arg1, arg2);
138   if (result && should_skip_) ConsumeSkip();
139   return result;
140 }
141 
142 // helper function to consume *skip_ and honour save_comments_
ConsumeSkip()143 void Scanner::ConsumeSkip() {
144   const char* start_data = input_.data();
145   while (skip_->Consume(&input_)) {
146     if (!skip_repeat_) {
147       // Only one skip allowed.
148       break;
149     }
150   }
151   if (save_comments_) {
152     if (comments_ == NULL) {
153       comments_ = new vector<StringPiece>;
154     }
155     // already pointing one past end, so no need to +1
156     int length = (int)(input_.data() - start_data);
157     if (length > 0) {
158       comments_->push_back(StringPiece(start_data, length));
159     }
160   }
161 }
162 
163 
GetComments(int start,int end,vector<StringPiece> * ranges)164 void Scanner::GetComments(int start, int end, vector<StringPiece> *ranges) {
165   // short circuit out if we've not yet initialized comments_
166   // (e.g., when save_comments is false)
167   if (!comments_) {
168     return;
169   }
170   // TODO: if we guarantee that comments_ will contain StringPieces
171   // that are ordered by their start, then we can do a binary search
172   // for the first StringPiece at or past start and then scan for the
173   // ones contained in the range, quit early (use equal_range or
174   // lower_bound)
175   for (vector<StringPiece>::const_iterator it = comments_->begin();
176        it != comments_->end(); ++it) {
177     if ((it->data() >= data_.c_str() + start &&
178          it->data() + it->size() <= data_.c_str() + end)) {
179       ranges->push_back(*it);
180     }
181   }
182 }
183 
184 
GetNextComments(vector<StringPiece> * ranges)185 void Scanner::GetNextComments(vector<StringPiece> *ranges) {
186   // short circuit out if we've not yet initialized comments_
187   // (e.g., when save_comments is false)
188   if (!comments_) {
189     return;
190   }
191   for (vector<StringPiece>::const_iterator it =
192          comments_->begin() + comments_offset_;
193        it != comments_->end(); ++it) {
194     ranges->push_back(*it);
195     ++comments_offset_;
196   }
197 }
198 
199 }   // namespace pcrecpp
200