1 // Copyright (c) 2011 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
9 #include "base/string_piece.h"
13 typedef StringPiece::size_type size_type;
15 bool operator==(const StringPiece& x, const StringPiece& y) {
16 if (x.size() != y.size())
19 return StringPiece::wordmemcmp(x.data(), y.data(), x.size()) == 0;
22 void StringPiece::CopyToString(std::string* target) const {
23 target->assign(!empty() ? data() : "", size());
26 void StringPiece::AppendToString(std::string* target) const {
28 target->append(data(), size());
31 size_type StringPiece::copy(char* buf, size_type n, size_type pos) const {
32 size_type ret = std::min(length_ - pos, n);
33 memcpy(buf, ptr_ + pos, ret);
37 size_type StringPiece::find(const StringPiece& s, size_type pos) const {
41 const char* result = std::search(ptr_ + pos, ptr_ + length_,
42 s.ptr_, s.ptr_ + s.length_);
43 const size_type xpos = result - ptr_;
44 return xpos + s.length_ <= length_ ? xpos : npos;
47 size_type StringPiece::find(char c, size_type pos) const {
51 const char* result = std::find(ptr_ + pos, ptr_ + length_, c);
52 return result != ptr_ + length_ ? static_cast<size_t>(result - ptr_) : npos;
55 size_type StringPiece::rfind(const StringPiece& s, size_type pos) const {
56 if (length_ < s.length_)
60 return std::min(length_, pos);
62 const char* last = ptr_ + std::min(length_ - s.length_, pos) + s.length_;
63 const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);
64 return result != last ? static_cast<size_t>(result - ptr_) : npos;
67 size_type StringPiece::rfind(char c, size_type pos) const {
71 for (size_type i = std::min(pos, length_ - 1); ; --i) {
80 // For each character in characters_wanted, sets the index corresponding
81 // to the ASCII code of that character to 1 in table. This is used by
82 // the find_.*_of methods below to tell whether or not a character is in
83 // the lookup table in constant time.
84 // The argument `table' must be an array that is large enough to hold all
85 // the possible values of an unsigned char. Thus it should be be declared
87 // bool table[UCHAR_MAX + 1]
88 static inline void BuildLookupTable(const StringPiece& characters_wanted,
90 const size_type length = characters_wanted.length();
91 const char* const data = characters_wanted.data();
92 for (size_type i = 0; i < length; ++i) {
93 table[static_cast<unsigned char>(data[i])] = true;
97 size_type StringPiece::find_first_of(const StringPiece& s,
98 size_type pos) const {
99 if (length_ == 0 || s.length_ == 0)
102 // Avoid the cost of BuildLookupTable() for a single-character search.
104 return find_first_of(s.ptr_[0], pos);
106 bool lookup[UCHAR_MAX + 1] = { false };
107 BuildLookupTable(s, lookup);
108 for (size_type i = pos; i < length_; ++i) {
109 if (lookup[static_cast<unsigned char>(ptr_[i])]) {
116 size_type StringPiece::find_first_not_of(const StringPiece& s,
117 size_type pos) const {
124 // Avoid the cost of BuildLookupTable() for a single-character search.
126 return find_first_not_of(s.ptr_[0], pos);
128 bool lookup[UCHAR_MAX + 1] = { false };
129 BuildLookupTable(s, lookup);
130 for (size_type i = pos; i < length_; ++i) {
131 if (!lookup[static_cast<unsigned char>(ptr_[i])]) {
138 size_type StringPiece::find_first_not_of(char c, size_type pos) const {
142 for (; pos < length_; ++pos) {
143 if (ptr_[pos] != c) {
150 size_type StringPiece::find_last_of(const StringPiece& s, size_type pos) const {
151 if (length_ == 0 || s.length_ == 0)
154 // Avoid the cost of BuildLookupTable() for a single-character search.
156 return find_last_of(s.ptr_[0], pos);
158 bool lookup[UCHAR_MAX + 1] = { false };
159 BuildLookupTable(s, lookup);
160 for (size_type i = std::min(pos, length_ - 1); ; --i) {
161 if (lookup[static_cast<unsigned char>(ptr_[i])])
169 size_type StringPiece::find_last_not_of(const StringPiece& s,
170 size_type pos) const {
174 size_type i = std::min(pos, length_ - 1);
178 // Avoid the cost of BuildLookupTable() for a single-character search.
180 return find_last_not_of(s.ptr_[0], pos);
182 bool lookup[UCHAR_MAX + 1] = { false };
183 BuildLookupTable(s, lookup);
185 if (!lookup[static_cast<unsigned char>(ptr_[i])])
193 size_type StringPiece::find_last_not_of(char c, size_type pos) const {
197 for (size_type i = std::min(pos, length_ - 1); ; --i) {
206 StringPiece StringPiece::substr(size_type pos, size_type n) const {
207 if (pos > length_) pos = length_;
208 if (n > length_ - pos) n = length_ - pos;
209 return StringPiece(ptr_ + pos, n);
212 const StringPiece::size_type StringPiece::npos = size_type(-1);