third_party/re2/util/stringpiece.cc

   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
  10 std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
  11   o.write(piece.data(), piece.size());
  12   return o;
  13 }
  14
  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
  32 void StringPiece::CopyToString(string* target) const {
  33   target->assign(ptr_, length_);
  34 }
  35
  36 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
  42 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
  52 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
  60 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
  70 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
  81 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);