1// Copyright (c) 2005, Google Inc.
2// All rights reserved.
3//
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5// modification, are permitted provided that the following conditions are
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7//
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17//
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19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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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,
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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 @pcre_have_type_traits@
46#define HAVE_TYPE_TRAITS
47#include <type_traits.h>
48#elif @pcre_have_bits_type_traits@
49#define HAVE_TYPE_TRAITS
50#include <bits/type_traits.h>
51#endif
52
53#include <pcre.h>
54
55using std::memcmp;
56using std::strlen;
57using std::string;
58
59namespace pcrecpp {
60
61class 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
167template<> 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
177std::ostream& operator<<(std::ostream& o, const pcrecpp::StringPiece& piece);
178
179#endif /* _PCRE_STRINGPIECE_H */
180