1 // Copyright (c) 2005, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above 11 // copyright notice, this list of conditions and the following disclaimer 12 // in the documentation and/or other materials provided with the 13 // distribution. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 16 // this software without specific prior written permission. 17 // 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 // 30 // Author: Sanjay Ghemawat 31 // 32 // A string like object that points into another piece of memory. 33 // Useful for providing an interface that allows clients to easily 34 // pass in either a "const char*" or a "string". 35 // 36 // Arghh! I wish C++ literals were automatically of type "string". 37 38 #ifndef _PCRE_STRINGPIECE_H 39 #define _PCRE_STRINGPIECE_H 40 41 #include <cstring> 42 #include <string> 43 #include <iosfwd> // for ostream forward-declaration 44 45 #if 0 46 #define HAVE_TYPE_TRAITS 47 #include <type_traits.h> 48 #elif 0 49 #define HAVE_TYPE_TRAITS 50 #include <bits/type_traits.h> 51 #endif 52 53 #include <pcre.h> 54 55 using std::memcmp; 56 using std::strlen; 57 using std::string; 58 59 namespace pcrecpp { 60 61 class PCRECPP_EXP_DEFN StringPiece { 62 private: 63 const char* ptr_; 64 int length_; 65 66 public: 67 // We provide non-explicit singleton constructors so users can pass 68 // in a "const char*" or a "string" wherever a "StringPiece" is 69 // expected. 70 StringPiece() 71 : ptr_(NULL), length_(0) { } 72 StringPiece(const char* str) 73 : ptr_(str), length_(static_cast<int>(strlen(ptr_))) { } 74 StringPiece(const unsigned char* str) 75 : ptr_(reinterpret_cast<const char*>(str)), 76 length_(static_cast<int>(strlen(ptr_))) { } 77 StringPiece(const string& str) 78 : ptr_(str.data()), length_(static_cast<int>(str.size())) { } 79 StringPiece(const char* offset, int len) 80 : ptr_(offset), length_(len) { } 81 82 // data() may return a pointer to a buffer with embedded NULs, and the 83 // returned buffer may or may not be null terminated. Therefore it is 84 // typically a mistake to pass data() to a routine that expects a NUL 85 // terminated string. Use "as_string().c_str()" if you really need to do 86 // this. Or better yet, change your routine so it does not rely on NUL 87 // termination. 88 const char* data() const { return ptr_; } 89 int size() const { return length_; } 90 bool empty() const { return length_ == 0; } 91 92 void clear() { ptr_ = NULL; length_ = 0; } 93 void set(const char* buffer, int len) { ptr_ = buffer; length_ = len; } 94 void set(const char* str) { 95 ptr_ = str; 96 length_ = static_cast<int>(strlen(str)); 97 } 98 void set(const void* buffer, int len) { 99 ptr_ = reinterpret_cast<const char*>(buffer); 100 length_ = len; 101 } 102 103 char operator[](int i) const { return ptr_[i]; } 104 105 void remove_prefix(int n) { 106 ptr_ += n; 107 length_ -= n; 108 } 109 110 void remove_suffix(int n) { 111 length_ -= n; 112 } 113 114 bool operator==(const StringPiece& x) const { 115 return ((length_ == x.length_) && 116 (memcmp(ptr_, x.ptr_, length_) == 0)); 117 } 118 bool operator!=(const StringPiece& x) const { 119 return !(*this == x); 120 } 121 122 #define STRINGPIECE_BINARY_PREDICATE(cmp,auxcmp) \ 123 bool operator cmp (const StringPiece& x) const { \ 124 int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_); \ 125 return ((r auxcmp 0) || ((r == 0) && (length_ cmp x.length_))); \ 126 } 127 STRINGPIECE_BINARY_PREDICATE(<, <); 128 STRINGPIECE_BINARY_PREDICATE(<=, <); 129 STRINGPIECE_BINARY_PREDICATE(>=, >); 130 STRINGPIECE_BINARY_PREDICATE(>, >); 131 #undef STRINGPIECE_BINARY_PREDICATE 132 133 int compare(const StringPiece& x) const { 134 int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_); 135 if (r == 0) { 136 if (length_ < x.length_) r = -1; 137 else if (length_ > x.length_) r = +1; 138 } 139 return r; 140 } 141 142 string as_string() const { 143 return string(data(), size()); 144 } 145 146 void CopyToString(string* target) const { 147 target->assign(ptr_, length_); 148 } 149 150 // Does "this" start with "x" 151 bool starts_with(const StringPiece& x) const { 152 return ((length_ >= x.length_) && (memcmp(ptr_, x.ptr_, x.length_) == 0)); 153 } 154 }; 155 156 } // namespace pcrecpp 157 158 // ------------------------------------------------------------------ 159 // Functions used to create STL containers that use StringPiece 160 // Remember that a StringPiece's lifetime had better be less than 161 // that of the underlying string or char*. If it is not, then you 162 // cannot safely store a StringPiece into an STL container 163 // ------------------------------------------------------------------ 164 165 #ifdef HAVE_TYPE_TRAITS 166 // This makes vector<StringPiece> really fast for some STL implementations 167 template<> struct __type_traits<pcrecpp::StringPiece> { 168 typedef __true_type has_trivial_default_constructor; 169 typedef __true_type has_trivial_copy_constructor; 170 typedef __true_type has_trivial_assignment_operator; 171 typedef __true_type has_trivial_destructor; 172 typedef __true_type is_POD_type; 173 }; 174 #endif 175 176 // allow StringPiece to be logged 177 PCRECPP_EXP_DECL std::ostream& operator<<(std::ostream& o, 178 const pcrecpp::StringPiece& piece); 179 180 #endif /* _PCRE_STRINGPIECE_H */ 181
