1// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4// Copied from strings/stringpiece.cc with modifications
5
6#include <algorithm>
7#include <ostream>
8
9#include "phonenumbers/base/strings/string_piece.h"
10
11namespace i18n {
12namespace phonenumbers {
13
14typedef StringPiece::size_type size_type;
15
16std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
17  o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
18  return o;
19}
20
21bool operator==(const StringPiece& x, const StringPiece& y) {
22  if (x.size() != y.size())
23    return false;
24
25  return StringPiece::wordmemcmp(x.data(), y.data(), x.size()) == 0;
26}
27
28void StringPiece::CopyToString(std::string* target) const {
29  target->assign(!empty() ? data() : "", size());
30}
31
32void StringPiece::AppendToString(std::string* target) const {
33  if (!empty())
34    target->append(data(), size());
35}
36
37size_type StringPiece::copy(char* buf, size_type n, size_type pos) const {
38  size_type ret = std::min(length_ - pos, n);
39  memcpy(buf, ptr_ + pos, ret);
40  return ret;
41}
42
43size_type StringPiece::find(const StringPiece& s, size_type pos) const {
44  if (pos > length_)
45    return npos;
46
47  const char* result = std::search(ptr_ + pos, ptr_ + length_,
48                                   s.ptr_, s.ptr_ + s.length_);
49  const size_type xpos = result - ptr_;
50  return xpos + s.length_ <= length_ ? xpos : npos;
51}
52
53size_type StringPiece::find(char c, size_type pos) const {
54  if (pos >= length_)
55    return npos;
56
57  const char* result = std::find(ptr_ + pos, ptr_ + length_, c);
58  return result != ptr_ + length_ ? static_cast<size_t>(result - ptr_) : npos;
59}
60
61size_type StringPiece::rfind(const StringPiece& s, size_type pos) const {
62  if (length_ < s.length_)
63    return npos;
64
65  if (s.empty())
66    return std::min(length_, pos);
67
68  const char* last = ptr_ + std::min(length_ - s.length_, pos) + s.length_;
69  const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);
70  return result != last ? static_cast<size_t>(result - ptr_) : npos;
71}
72
73size_type StringPiece::rfind(char c, size_type pos) const {
74  if (length_ == 0)
75    return npos;
76
77  for (size_type i = std::min(pos, length_ - 1); ; --i) {
78    if (ptr_[i] == c)
79      return i;
80    if (i == 0)
81      break;
82  }
83  return npos;
84}
85
86// For each character in characters_wanted, sets the index corresponding
87// to the ASCII code of that character to 1 in table.  This is used by
88// the find_.*_of methods below to tell whether or not a character is in
89// the lookup table in constant time.
90// The argument `table' must be an array that is large enough to hold all
91// the possible values of an unsigned char.  Thus it should be be declared
92// as follows:
93//   bool table[UCHAR_MAX + 1]
94static inline void BuildLookupTable(const StringPiece& characters_wanted,
95                                    bool* table) {
96  const size_type length = characters_wanted.length();
97  const char* const data = characters_wanted.data();
98  for (size_type i = 0; i < length; ++i) {
99    table[static_cast<unsigned char>(data[i])] = true;
100  }
101}
102
103size_type StringPiece::find_first_of(const StringPiece& s,
104                                     size_type pos) const {
105  if (length_ == 0 || s.length_ == 0)
106    return npos;
107
108  // Avoid the cost of BuildLookupTable() for a single-character search.
109  if (s.length_ == 1)
110    return find_first_of(s.ptr_[0], pos);
111
112  bool lookup[UCHAR_MAX + 1] = { false };
113  BuildLookupTable(s, lookup);
114  for (size_type i = pos; i < length_; ++i) {
115    if (lookup[static_cast<unsigned char>(ptr_[i])]) {
116      return i;
117    }
118  }
119  return npos;
120}
121
122size_type StringPiece::find_first_not_of(const StringPiece& s,
123                                         size_type pos) const {
124  if (length_ == 0)
125    return npos;
126
127  if (s.length_ == 0)
128    return 0;
129
130  // Avoid the cost of BuildLookupTable() for a single-character search.
131  if (s.length_ == 1)
132    return find_first_not_of(s.ptr_[0], pos);
133
134  bool lookup[UCHAR_MAX + 1] = { false };
135  BuildLookupTable(s, lookup);
136  for (size_type i = pos; i < length_; ++i) {
137    if (!lookup[static_cast<unsigned char>(ptr_[i])]) {
138      return i;
139    }
140  }
141  return npos;
142}
143
144size_type StringPiece::find_first_not_of(char c, size_type pos) const {
145  if (length_ == 0)
146    return npos;
147
148  for (; pos < length_; ++pos) {
149    if (ptr_[pos] != c) {
150      return pos;
151    }
152  }
153  return npos;
154}
155
156size_type StringPiece::find_last_of(const StringPiece& s, size_type pos) const {
157  if (length_ == 0 || s.length_ == 0)
158    return npos;
159
160  // Avoid the cost of BuildLookupTable() for a single-character search.
161  if (s.length_ == 1)
162    return find_last_of(s.ptr_[0], pos);
163
164  bool lookup[UCHAR_MAX + 1] = { false };
165  BuildLookupTable(s, lookup);
166  for (size_type i = std::min(pos, length_ - 1); ; --i) {
167    if (lookup[static_cast<unsigned char>(ptr_[i])])
168      return i;
169    if (i == 0)
170      break;
171  }
172  return npos;
173}
174
175size_type StringPiece::find_last_not_of(const StringPiece& s,
176                                        size_type pos) const {
177  if (length_ == 0)
178    return npos;
179
180  size_type i = std::min(pos, length_ - 1);
181  if (s.length_ == 0)
182    return i;
183
184  // Avoid the cost of BuildLookupTable() for a single-character search.
185  if (s.length_ == 1)
186    return find_last_not_of(s.ptr_[0], pos);
187
188  bool lookup[UCHAR_MAX + 1] = { false };
189  BuildLookupTable(s, lookup);
190  for (; ; --i) {
191    if (!lookup[static_cast<unsigned char>(ptr_[i])])
192      return i;
193    if (i == 0)
194      break;
195  }
196  return npos;
197}
198
199size_type StringPiece::find_last_not_of(char c, size_type pos) const {
200  if (length_ == 0)
201    return npos;
202
203  for (size_type i = std::min(pos, length_ - 1); ; --i) {
204    if (ptr_[i] != c)
205      return i;
206    if (i == 0)
207      break;
208  }
209  return npos;
210}
211
212StringPiece StringPiece::substr(size_type pos, size_type n) const {
213  if (pos > length_) pos = length_;
214  if (n > length_ - pos) n = length_ - pos;
215  return StringPiece(ptr_ + pos, n);
216}
217
218const StringPiece::size_type StringPiece::npos = size_type(-1);
219
220}  // namespace phonenumbers
221}  // namespace i18n
222