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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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 <string.h>
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::string;
56
57namespace pcrecpp {
58
59class PCRECPP_EXP_DEFN StringPiece {
60 private:
61  const char*   ptr_;
62  int           length_;
63
64 public:
65  // We provide non-explicit singleton constructors so users can pass
66  // in a "const char*" or a "string" wherever a "StringPiece" is
67  // expected.
68  StringPiece()
69    : ptr_(NULL), length_(0) { }
70  StringPiece(const char* str)
71    : ptr_(str), length_(static_cast<int>(strlen(ptr_))) { }
72  StringPiece(const unsigned char* str)
73    : ptr_(reinterpret_cast<const char*>(str)),
74      length_(static_cast<int>(strlen(ptr_))) { }
75  StringPiece(const string& str)
76    : ptr_(str.data()), length_(static_cast<int>(str.size())) { }
77  StringPiece(const char* offset, int len)
78    : ptr_(offset), length_(len) { }
79
80  // data() may return a pointer to a buffer with embedded NULs, and the
81  // returned buffer may or may not be null terminated.  Therefore it is
82  // typically a mistake to pass data() to a routine that expects a NUL
83  // terminated string.  Use "as_string().c_str()" if you really need to do
84  // this.  Or better yet, change your routine so it does not rely on NUL
85  // termination.
86  const char* data() const { return ptr_; }
87  int size() const { return length_; }
88  bool empty() const { return length_ == 0; }
89
90  void clear() { ptr_ = NULL; length_ = 0; }
91  void set(const char* buffer, int len) { ptr_ = buffer; length_ = len; }
92  void set(const char* str) {
93    ptr_ = str;
94    length_ = static_cast<int>(strlen(str));
95  }
96  void set(const void* buffer, int len) {
97    ptr_ = reinterpret_cast<const char*>(buffer);
98    length_ = len;
99  }
100
101  char operator[](int i) const { return ptr_[i]; }
102
103  void remove_prefix(int n) {
104    ptr_ += n;
105    length_ -= n;
106  }
107
108  void remove_suffix(int n) {
109    length_ -= n;
110  }
111
112  bool operator==(const StringPiece& x) const {
113    return ((length_ == x.length_) &&
114            (memcmp(ptr_, x.ptr_, length_) == 0));
115  }
116  bool operator!=(const StringPiece& x) const {
117    return !(*this == x);
118  }
119
120#define STRINGPIECE_BINARY_PREDICATE(cmp,auxcmp)                             \
121  bool operator cmp (const StringPiece& x) const {                           \
122    int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_); \
123    return ((r auxcmp 0) || ((r == 0) && (length_ cmp x.length_)));          \
124  }
125  STRINGPIECE_BINARY_PREDICATE(<,  <);
126  STRINGPIECE_BINARY_PREDICATE(<=, <);
127  STRINGPIECE_BINARY_PREDICATE(>=, >);
128  STRINGPIECE_BINARY_PREDICATE(>,  >);
129#undef STRINGPIECE_BINARY_PREDICATE
130
131  int compare(const StringPiece& x) const {
132    int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_);
133    if (r == 0) {
134      if (length_ < x.length_) r = -1;
135      else if (length_ > x.length_) r = +1;
136    }
137    return r;
138  }
139
140  string as_string() const {
141    return string(data(), size());
142  }
143
144  void CopyToString(string* target) const {
145    target->assign(ptr_, length_);
146  }
147
148  // Does "this" start with "x"
149  bool starts_with(const StringPiece& x) const {
150    return ((length_ >= x.length_) && (memcmp(ptr_, x.ptr_, x.length_) == 0));
151  }
152};
153
154}   // namespace pcrecpp
155
156// ------------------------------------------------------------------
157// Functions used to create STL containers that use StringPiece
158//  Remember that a StringPiece's lifetime had better be less than
159//  that of the underlying string or char*.  If it is not, then you
160//  cannot safely store a StringPiece into an STL container
161// ------------------------------------------------------------------
162
163#ifdef HAVE_TYPE_TRAITS
164// This makes vector<StringPiece> really fast for some STL implementations
165template<> struct __type_traits<pcrecpp::StringPiece> {
166  typedef __true_type    has_trivial_default_constructor;
167  typedef __true_type    has_trivial_copy_constructor;
168  typedef __true_type    has_trivial_assignment_operator;
169  typedef __true_type    has_trivial_destructor;
170  typedef __true_type    is_POD_type;
171};
172#endif
173
174// allow StringPiece to be logged
175std::ostream& operator<<(std::ostream& o, const pcrecpp::StringPiece& piece);
176
177#endif /* _PCRE_STRINGPIECE_H */
178