// Copyright (c) 2005, Google Inc.

// All rights reserved.

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

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// contributors may be used to endorse or promote products derived from

// this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

// Author: Sanjay Ghemawat

//

// A string like object that points into another piece of memory.

// Useful for providing an interface that allows clients to easily

// pass in either a "const char*" or a "string".

//

// Arghh!  I wish C++ literals were automatically of type "string".

#ifndef _PCRE_STRINGPIECE_H

#define _PCRE_STRINGPIECE_H

#include <cstring>

#include <string>

#include <iosfwd>    // for ostream forward-declaration

#if @pcre_have_type_traits@

#define HAVE_TYPE_TRAITS

#include <type_traits.h>

#elif @pcre_have_bits_type_traits@

#define HAVE_TYPE_TRAITS

#include <bits/type_traits.h>

#endif

#include <pcre.h>

using std::memcmp;

using std::strlen;

using std::string;

namespace pcrecpp {

class PCRECPP_EXP_DEFN StringPiece {

 private:

  const char*   ptr_;

  int           length_;

 public:

  // We provide non-explicit singleton constructors so users can pass

  // in a "const char*" or a "string" wherever a "StringPiece" is

  // expected.

  StringPiece()

    : ptr_(NULL), length_(0) { }

  StringPiece(const char* str)

    : ptr_(str), length_(static_cast<int>(strlen(ptr_))) { }

  StringPiece(const unsigned char* str)

    : ptr_(reinterpret_cast<const char*>(str)),

      length_(static_cast<int>(strlen(ptr_))) { }

  StringPiece(const string& str)

    : ptr_(str.data()), length_(static_cast<int>(str.size())) { }

  StringPiece(const char* offset, int len)

    : ptr_(offset), length_(len) { }

  // data() may return a pointer to a buffer with embedded NULs, and the

  // returned buffer may or may not be null terminated.  Therefore it is

  // typically a mistake to pass data() to a routine that expects a NUL

  // terminated string.  Use "as_string().c_str()" if you really need to do

  // this.  Or better yet, change your routine so it does not rely on NUL

  // termination.

  const char* data() const { return ptr_; }

  int size() const { return length_; }

  bool empty() const { return length_ == 0; }

  void clear() { ptr_ = NULL; length_ = 0; }

  void set(const char* buffer, int len) { ptr_ = buffer; length_ = len; }

  void set(const char* str) {

    ptr_ = str;

    length_ = static_cast<int>(strlen(str));

  }

  void set(const void* buffer, int len) {

    ptr_ = reinterpret_cast<const char*>(buffer);

    length_ = len;

  }

  char operator[](int i) const { return ptr_[i]; }

  void remove_prefix(int n) {

    ptr_ += n;

    length_ -= n;

  }

  void remove_suffix(int n) {

    length_ -= n;

  }

  bool operator==(const StringPiece& x) const {

    return ((length_ == x.length_) &&

            (memcmp(ptr_, x.ptr_, length_) == 0));

  }

  bool operator!=(const StringPiece& x) const {

    return !(*this == x);

  }

#define STRINGPIECE_BINARY_PREDICATE(cmp,auxcmp)                             \

  bool operator cmp (const StringPiece& x) const {                           \

    int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_); \

    return ((r auxcmp 0) || ((r == 0) && (length_ cmp x.length_)));          \

  }

  STRINGPIECE_BINARY_PREDICATE(<,  <);

  STRINGPIECE_BINARY_PREDICATE(<=, <);

  STRINGPIECE_BINARY_PREDICATE(>=, >);

  STRINGPIECE_BINARY_PREDICATE(>,  >);

#undef STRINGPIECE_BINARY_PREDICATE

  int compare(const StringPiece& x) const {

    int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_);

    if (r == 0) {

      if (length_ < x.length_) r = -1;

      else if (length_ > x.length_) r = +1;

    }

    return r;

  }

  string as_string() const {

    return string(data(), size());

  }

  void CopyToString(string* target) const {

    target->assign(ptr_, length_);

  }

  // Does "this" start with "x"

  bool starts_with(const StringPiece& x) const {

    return ((length_ >= x.length_) && (memcmp(ptr_, x.ptr_, x.length_) == 0));

  }

};

}   // namespace pcrecpp

// ------------------------------------------------------------------

// Functions used to create STL containers that use StringPiece

//  Remember that a StringPiece's lifetime had better be less than

//  that of the underlying string or char*.  If it is not, then you

//  cannot safely store a StringPiece into an STL container

// ------------------------------------------------------------------

#ifdef HAVE_TYPE_TRAITS

// This makes vector<StringPiece> really fast for some STL implementations

template<> struct __type_traits<pcrecpp::StringPiece> {

  typedef __true_type    has_trivial_default_constructor;

  typedef __true_type    has_trivial_copy_constructor;

  typedef __true_type    has_trivial_assignment_operator;

  typedef __true_type    has_trivial_destructor;

  typedef __true_type    is_POD_type;

};

#endif

// allow StringPiece to be logged

PCRECPP_EXP_DECL std::ostream& operator<<(std::ostream& o,

                                          const pcrecpp::StringPiece& piece);

#endif /* _PCRE_STRINGPIECE_H */