// 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.
// * Neither the name of Google Inc. nor the names of its
// 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 0
#define HAVE_TYPE_TRAITS
#include <type_traits.h>
#elif 0
#define HAVE_TYPE_TRAITS
#include <bits/type_traits.h>
#endif

#include <pcre.h>

namespace pcrecpp {

using std::memcmp;
using std::strlen;
using std::string;

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 */