1 // Copyright 2004 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 "re2/stringpiece.h"
6 #include "util/util.h"
7
8 using re2::StringPiece;
9
operator <<(std::ostream & o,const StringPiece & piece)10 std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
11 o.write(piece.data(), piece.size());
12 return o;
13 }
14
_equal(const StringPiece & x,const StringPiece & y)15 bool StringPiece::_equal(const StringPiece& x, const StringPiece& y) {
16 int len = x.size();
17 if (len != y.size()) {
18 return false;
19 }
20 const char* p = x.data();
21 const char* p2 = y.data();
22 // Test last byte in case strings share large common prefix
23 if ((len > 0) && (p[len-1] != p2[len-1])) return false;
24 const char* p_limit = p + len;
25 for (; p < p_limit; p++, p2++) {
26 if (*p != *p2)
27 return false;
28 }
29 return true;
30 }
31
CopyToString(string * target) const32 void StringPiece::CopyToString(string* target) const {
33 target->assign(ptr_, length_);
34 }
35
copy(char * buf,size_type n,size_type pos) const36 int StringPiece::copy(char* buf, size_type n, size_type pos) const {
37 int ret = min(length_ - pos, n);
38 memcpy(buf, ptr_ + pos, ret);
39 return ret;
40 }
41
find(const StringPiece & s,size_type pos) const42 int StringPiece::find(const StringPiece& s, size_type pos) const {
43 if (length_ < 0 || pos > static_cast<size_type>(length_))
44 return npos;
45
46 const char* result = std::search(ptr_ + pos, ptr_ + length_,
47 s.ptr_, s.ptr_ + s.length_);
48 const size_type xpos = result - ptr_;
49 return xpos + s.length_ <= length_ ? xpos : npos;
50 }
51
find(char c,size_type pos) const52 int StringPiece::find(char c, size_type pos) const {
53 if (length_ <= 0 || pos >= static_cast<size_type>(length_)) {
54 return npos;
55 }
56 const char* result = std::find(ptr_ + pos, ptr_ + length_, c);
57 return result != ptr_ + length_ ? result - ptr_ : npos;
58 }
59
rfind(const StringPiece & s,size_type pos) const60 int StringPiece::rfind(const StringPiece& s, size_type pos) const {
61 if (length_ < s.length_) return npos;
62 const size_t ulen = length_;
63 if (s.length_ == 0) return min(ulen, pos);
64
65 const char* last = ptr_ + min(ulen - s.length_, pos) + s.length_;
66 const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);
67 return result != last ? result - ptr_ : npos;
68 }
69
rfind(char c,size_type pos) const70 int StringPiece::rfind(char c, size_type pos) const {
71 if (length_ <= 0) return npos;
72 for (int i = min(pos, static_cast<size_type>(length_ - 1));
73 i >= 0; --i) {
74 if (ptr_[i] == c) {
75 return i;
76 }
77 }
78 return npos;
79 }
80
substr(size_type pos,size_type n) const81 StringPiece StringPiece::substr(size_type pos, size_type n) const {
82 if (pos > length_) pos = length_;
83 if (n > length_ - pos) n = length_ - pos;
84 return StringPiece(ptr_ + pos, n);
85 }
86
87 const StringPiece::size_type StringPiece::npos = size_type(-1);
88