Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(155)

Side by Side Diff: base/string_piece.h

Issue 12982018: Move string_piece.h to base/strings. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Created 7 years, 9 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch
« no previous file with comments | « base/base.gypi ('k') | base/string_piece.cc » ('j') | no next file with comments »
Toggle Intra-line Diffs ('i') | Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
OLDNEW
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be 2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. 3 // found in the LICENSE file.
4 // Copied from strings/stringpiece.h with modifications
5 //
6 // A string-like object that points to a sized piece of memory.
7 //
8 // Functions or methods may use const StringPiece& parameters to accept either
9 // a "const char*" or a "string" value that will be implicitly converted to
10 // a StringPiece. The implicit conversion means that it is often appropriate
11 // to include this .h file in other files rather than forward-declaring
12 // StringPiece as would be appropriate for most other Google classes.
13 //
14 // Systematic usage of StringPiece is encouraged as it will reduce unnecessary
15 // conversions from "const char*" to "string" and back again.
16 //
17 // StringPiece16 is similar to StringPiece but for base::string16 instead of
18 // std::string. We do not define as large of a subset of the STL functions
19 // from basic_string as in StringPiece, but this can be changed if these
20 // functions (find, find_first_of, etc.) are found to be useful in this context.
21 //
22 4
23 #ifndef BASE_STRING_PIECE_H_ 5 // TODO(brettw) move callers to using the new location
24 #define BASE_STRING_PIECE_H_ 6 #include "base/strings/string_piece.h"
25
26 #include <stddef.h>
27
28 #include <iosfwd>
29 #include <string>
30
31 #include "base/base_export.h"
32 #include "base/basictypes.h"
33 #include "base/hash_tables.h"
34 #include "base/string16.h"
35
36 namespace base {
37
38 template <typename STRING_TYPE> class BasicStringPiece;
39 typedef BasicStringPiece<std::string> StringPiece;
40 typedef BasicStringPiece<string16> StringPiece16;
41
42 namespace internal {
43
44 // Defines the types, methods, operators, and data members common to both
45 // StringPiece and StringPiece16. Do not refer to this class directly, but
46 // rather to BasicStringPiece, StringPiece, or StringPiece16.
47 template <typename STRING_TYPE> class StringPieceDetail {
48 public:
49 // standard STL container boilerplate
50 typedef size_t size_type;
51 typedef typename STRING_TYPE::value_type value_type;
52 typedef const value_type* pointer;
53 typedef const value_type& reference;
54 typedef const value_type& const_reference;
55 typedef ptrdiff_t difference_type;
56 typedef const value_type* const_iterator;
57 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
58
59 static const size_type npos;
60
61 public:
62 // We provide non-explicit singleton constructors so users can pass
63 // in a "const char*" or a "string" wherever a "StringPiece" is
64 // expected (likewise for char16, string16, StringPiece16).
65 StringPieceDetail() : ptr_(NULL), length_(0) {}
66 StringPieceDetail(const value_type* str)
67 : ptr_(str),
68 length_((str == NULL) ? 0 : STRING_TYPE::traits_type::length(str)) {}
69 StringPieceDetail(const STRING_TYPE& str)
70 : ptr_(str.data()), length_(str.size()) {}
71 StringPieceDetail(const value_type* offset, size_type len)
72 : ptr_(offset), length_(len) {}
73 StringPieceDetail(const typename STRING_TYPE::const_iterator& begin,
74 const typename STRING_TYPE::const_iterator& end)
75 : ptr_((end > begin) ? &(*begin) : NULL),
76 length_((end > begin) ? (size_type)(end - begin) : 0) {}
77
78 // data() may return a pointer to a buffer with embedded NULs, and the
79 // returned buffer may or may not be null terminated. Therefore it is
80 // typically a mistake to pass data() to a routine that expects a NUL
81 // terminated string.
82 const value_type* data() const { return ptr_; }
83 size_type size() const { return length_; }
84 size_type length() const { return length_; }
85 bool empty() const { return length_ == 0; }
86
87 void clear() {
88 ptr_ = NULL;
89 length_ = 0;
90 }
91 void set(const value_type* data, size_type len) {
92 ptr_ = data;
93 length_ = len;
94 }
95 void set(const value_type* str) {
96 ptr_ = str;
97 length_ = str ? STRING_TYPE::traits_type::length(str) : 0;
98 }
99
100 value_type operator[](size_type i) const { return ptr_[i]; }
101
102 void remove_prefix(size_type n) {
103 ptr_ += n;
104 length_ -= n;
105 }
106
107 void remove_suffix(size_type n) {
108 length_ -= n;
109 }
110
111 int compare(const BasicStringPiece<STRING_TYPE>& x) const {
112 int r = wordmemcmp(
113 ptr_, x.ptr_, (length_ < x.length_ ? length_ : x.length_));
114 if (r == 0) {
115 if (length_ < x.length_) r = -1;
116 else if (length_ > x.length_) r = +1;
117 }
118 return r;
119 }
120
121 STRING_TYPE as_string() const {
122 // std::string doesn't like to take a NULL pointer even with a 0 size.
123 return empty() ? STRING_TYPE() : STRING_TYPE(data(), size());
124 }
125
126 const_iterator begin() const { return ptr_; }
127 const_iterator end() const { return ptr_ + length_; }
128 const_reverse_iterator rbegin() const {
129 return const_reverse_iterator(ptr_ + length_);
130 }
131 const_reverse_iterator rend() const {
132 return const_reverse_iterator(ptr_);
133 }
134
135 size_type max_size() const { return length_; }
136 size_type capacity() const { return length_; }
137
138 static int wordmemcmp(const value_type* p,
139 const value_type* p2,
140 size_type N) {
141 return STRING_TYPE::traits_type::compare(p, p2, N);
142 }
143
144 protected:
145 const value_type* ptr_;
146 size_type length_;
147 };
148
149 template <typename STRING_TYPE>
150 const typename StringPieceDetail<STRING_TYPE>::size_type
151 StringPieceDetail<STRING_TYPE>::npos =
152 typename StringPieceDetail<STRING_TYPE>::size_type(-1);
153
154 // MSVC doesn't like complex extern templates and DLLs.
155 #if !defined(COMPILER_MSVC)
156 extern template class BASE_EXPORT StringPieceDetail<std::string>;
157 extern template class BASE_EXPORT StringPieceDetail<string16>;
158 #endif
159
160 BASE_EXPORT void CopyToString(const StringPiece& self, std::string* target);
161 BASE_EXPORT void AppendToString(const StringPiece& self, std::string* target);
162 BASE_EXPORT StringPieceDetail<std::string>::size_type copy(
163 const StringPiece& self,
164 char* buf,
165 StringPieceDetail<std::string>::size_type n,
166 StringPieceDetail<std::string>::size_type pos);
167 BASE_EXPORT StringPieceDetail<std::string>::size_type find(
168 const StringPiece& self,
169 const StringPiece& s,
170 StringPieceDetail<std::string>::size_type pos);
171 BASE_EXPORT StringPieceDetail<std::string>::size_type find(
172 const StringPiece& self,
173 char c,
174 StringPieceDetail<std::string>::size_type pos);
175 BASE_EXPORT StringPieceDetail<std::string>::size_type rfind(
176 const StringPiece& self,
177 const StringPiece& s,
178 StringPieceDetail<std::string>::size_type pos);
179 BASE_EXPORT StringPieceDetail<std::string>::size_type rfind(
180 const StringPiece& self,
181 char c,
182 StringPieceDetail<std::string>::size_type pos);
183 BASE_EXPORT StringPieceDetail<std::string>::size_type find_first_of(
184 const StringPiece& self,
185 const StringPiece& s,
186 StringPieceDetail<std::string>::size_type pos);
187 BASE_EXPORT StringPieceDetail<std::string>::size_type find_first_not_of(
188 const StringPiece& self,
189 const StringPiece& s,
190 StringPieceDetail<std::string>::size_type pos);
191 BASE_EXPORT StringPieceDetail<std::string>::size_type find_first_not_of(
192 const StringPiece& self,
193 char c,
194 StringPieceDetail<std::string>::size_type pos);
195 BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_of(
196 const StringPiece& self,
197 const StringPiece& s,
198 StringPieceDetail<std::string>::size_type pos);
199 BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_of(
200 const StringPiece& self,
201 char c,
202 StringPieceDetail<std::string>::size_type pos);
203 BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_not_of(
204 const StringPiece& self,
205 const StringPiece& s,
206 StringPieceDetail<std::string>::size_type pos);
207 BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_not_of(
208 const StringPiece& self,
209 char c,
210 StringPieceDetail<std::string>::size_type pos);
211 BASE_EXPORT StringPiece substr(const StringPiece& self,
212 StringPieceDetail<std::string>::size_type pos,
213 StringPieceDetail<std::string>::size_type n);
214 } // namespace internal
215
216 // Defines the template type that is instantiated as either StringPiece or
217 // StringPiece16.
218 template <typename STRING_TYPE> class BasicStringPiece :
219 public internal::StringPieceDetail<STRING_TYPE> {
220 public:
221 typedef typename internal::StringPieceDetail<STRING_TYPE>::value_type
222 value_type;
223 typedef typename internal::StringPieceDetail<STRING_TYPE>::size_type
224 size_type;
225
226 BasicStringPiece() {}
227 BasicStringPiece(const value_type*str)
228 : internal::StringPieceDetail<STRING_TYPE>(str) {}
229 BasicStringPiece(const STRING_TYPE& str)
230 : internal::StringPieceDetail<STRING_TYPE>(str) {}
231 BasicStringPiece(const value_type* offset, size_type len)
232 : internal::StringPieceDetail<STRING_TYPE>(offset, len) {}
233 BasicStringPiece(const typename STRING_TYPE::const_iterator& begin,
234 const typename STRING_TYPE::const_iterator& end)
235 : internal::StringPieceDetail<STRING_TYPE>(begin, end) {}
236 };
237
238 // Specializes BasicStringPiece for std::string to add a few operations that
239 // are not needed for string16.
240 template <> class BasicStringPiece<std::string> :
241 public internal::StringPieceDetail<std::string> {
242 public:
243 BasicStringPiece() {}
244 BasicStringPiece(const char* str)
245 : internal::StringPieceDetail<std::string>(str) {}
246 BasicStringPiece(const std::string& str)
247 : internal::StringPieceDetail<std::string>(str) {}
248 BasicStringPiece(const char* offset, size_type len)
249 : internal::StringPieceDetail<std::string>(offset, len) {}
250 BasicStringPiece(const std::string::const_iterator& begin,
251 const std::string::const_iterator& end)
252 : internal::StringPieceDetail<std::string>(begin, end) {}
253
254 // Prevent the following overload of set() from hiding the definitions in the
255 // base class.
256 using internal::StringPieceDetail<std::string>::set;
257
258 void set(const void* data, size_type len) {
259 ptr_ = reinterpret_cast<const value_type*>(data);
260 length_ = len;
261 }
262
263 void CopyToString(std::string* target) const {
264 internal::CopyToString(*this, target);
265 }
266
267 void AppendToString(std::string* target) const {
268 internal::AppendToString(*this, target);
269 }
270
271 // Does "this" start with "x"
272 bool starts_with(const BasicStringPiece& x) const {
273 return ((length_ >= x.length_) &&
274 (wordmemcmp(ptr_, x.ptr_, x.length_) == 0));
275 }
276
277 // Does "this" end with "x"
278 bool ends_with(const BasicStringPiece& x) const {
279 return ((length_ >= x.length_) &&
280 (wordmemcmp(ptr_ + (length_-x.length_), x.ptr_, x.length_) == 0));
281 }
282
283 size_type copy(char* buf, size_type n, size_type pos = 0) const {
284 return internal::copy(*this, buf, n, pos);
285 }
286
287 size_type find(const BasicStringPiece& s, size_type pos = 0) const {
288 return internal::find(*this, s, pos);
289 }
290
291 size_type find(char c, size_type pos = 0) const {
292 return internal::find(*this, c, pos);
293 }
294
295 size_type rfind(const BasicStringPiece& s, size_type pos = npos) const {
296 return internal::rfind(*this, s, pos);
297 }
298
299 size_type rfind(char c, size_type pos = npos) const {
300 return internal::rfind(*this, c, pos);
301 }
302
303 size_type find_first_of(const BasicStringPiece& s, size_type pos = 0) const {
304 return internal::find_first_of(*this, s, pos);
305 }
306
307 size_type find_first_of(char c, size_type pos = 0) const {
308 return find(c, pos);
309 }
310
311 size_type find_first_not_of(const BasicStringPiece& s,
312 size_type pos = 0) const {
313 return internal::find_first_not_of(*this, s, pos);
314 }
315
316 size_type find_first_not_of(char c, size_type pos = 0) const {
317 return internal::find_first_not_of(*this, c, pos);
318 }
319
320 size_type find_last_of(const BasicStringPiece& s,
321 size_type pos = npos) const {
322 return internal::find_last_of(*this, s, pos);
323 }
324
325 size_type find_last_of(char c, size_type pos = npos) const {
326 return rfind(c, pos);
327 }
328
329 size_type find_last_not_of(const BasicStringPiece& s,
330 size_type pos = npos) const {
331 return internal::find_last_not_of(*this, s, pos);
332 }
333
334 size_type find_last_not_of(char c, size_type pos = npos) const {
335 return internal::find_last_not_of(*this, c, pos);
336 }
337
338 BasicStringPiece substr(size_type pos, size_type n = npos) const {
339 return internal::substr(*this, pos, n);
340 }
341 };
342
343 // MSVC doesn't like complex extern templates and DLLs.
344 #if !defined(COMPILER_MSVC)
345 // We can't explicitly declare the std::string instantiation here because it was
346 // already instantiated when specialized, above. Not only is it a no-op, but
347 // currently it also crashes Clang (see http://crbug.com/107412).
348 extern template class BASE_EXPORT BasicStringPiece<string16>;
349 #endif
350
351 BASE_EXPORT bool operator==(const StringPiece& x, const StringPiece& y);
352
353 inline bool operator!=(const StringPiece& x, const StringPiece& y) {
354 return !(x == y);
355 }
356
357 inline bool operator<(const StringPiece& x, const StringPiece& y) {
358 const int r = StringPiece::wordmemcmp(
359 x.data(), y.data(), (x.size() < y.size() ? x.size() : y.size()));
360 return ((r < 0) || ((r == 0) && (x.size() < y.size())));
361 }
362
363 inline bool operator>(const StringPiece& x, const StringPiece& y) {
364 return y < x;
365 }
366
367 inline bool operator<=(const StringPiece& x, const StringPiece& y) {
368 return !(x > y);
369 }
370
371 inline bool operator>=(const StringPiece& x, const StringPiece& y) {
372 return !(x < y);
373 }
374
375 inline bool operator==(const StringPiece16& x, const StringPiece16& y) {
376 if (x.size() != y.size())
377 return false;
378
379 return StringPiece16::wordmemcmp(x.data(), y.data(), x.size()) == 0;
380 }
381
382 inline bool operator!=(const StringPiece16& x, const StringPiece16& y) {
383 return !(x == y);
384 }
385
386 inline bool operator<(const StringPiece16& x, const StringPiece16& y) {
387 const int r = StringPiece16::wordmemcmp(
388 x.data(), y.data(), (x.size() < y.size() ? x.size() : y.size()));
389 return ((r < 0) || ((r == 0) && (x.size() < y.size())));
390 }
391
392 inline bool operator>(const StringPiece16& x, const StringPiece16& y) {
393 return y < x;
394 }
395
396 inline bool operator<=(const StringPiece16& x, const StringPiece16& y) {
397 return !(x > y);
398 }
399
400 inline bool operator>=(const StringPiece16& x, const StringPiece16& y) {
401 return !(x < y);
402 }
403
404 BASE_EXPORT std::ostream& operator<<(std::ostream& o,
405 const StringPiece& piece);
406
407 } // namespace base
408
409 // We provide appropriate hash functions so StringPiece and StringPiece16 can
410 // be used as keys in hash sets and maps.
411
412 // This hash function is copied from base/hash_tables.h. We don't use the
413 // ones already defined for string and string16 directly because it would
414 // require the string constructors to be called, which we don't want.
415 #define HASH_STRING_PIECE(StringPieceType, string_piece) \
416 std::size_t result = 0; \
417 for (StringPieceType::const_iterator i = string_piece.begin(); \
418 i != string_piece.end(); ++i) \
419 result = (result * 131) + *i; \
420 return result; \
421
422 namespace BASE_HASH_NAMESPACE {
423 #if defined(COMPILER_GCC)
424
425 template<>
426 struct hash<base::StringPiece> {
427 std::size_t operator()(const base::StringPiece& sp) const {
428 HASH_STRING_PIECE(base::StringPiece, sp);
429 }
430 };
431 template<>
432 struct hash<base::StringPiece16> {
433 std::size_t operator()(const base::StringPiece16& sp16) const {
434 HASH_STRING_PIECE(base::StringPiece16, sp16);
435 }
436 };
437
438 #elif defined(COMPILER_MSVC)
439
440 inline size_t hash_value(const base::StringPiece& sp) {
441 HASH_STRING_PIECE(base::StringPiece, sp);
442 }
443 inline size_t hash_value(const base::StringPiece16& sp16) {
444 HASH_STRING_PIECE(base::StringPiece16, sp16);
445 }
446
447 #endif // COMPILER
448
449 } // namespace BASE_HASH_NAMESPACE
450
451 #endif // BASE_STRING_PIECE_H_
OLDNEW
« no previous file with comments | « base/base.gypi ('k') | base/string_piece.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698