gecko-dev/xpcom/string/nsTSubstringTuple.h
Eric Rahm 030b39d813 Bug 1393230 - Part 3: Convert the xpcom string classes to be templated on char type. r=njn, r=fitzgen, r=sfink
This removes the double-include macro hackery that we use to define two
separate string types (nsAString and nsACString) in favor of a templated
solution.

Annotations for Valgrind and the JS hazard analysis are updated as well as
the rust binding generations for string code.

--HG--
extra : rebase_source : 63ab2c4620cfcd4b764d42d654c82f30f984d016
extra : source : 9115364cd4aa078c49bba7911069f8178e55166f
2017-08-14 14:22:50 -07:00

94 lines
2.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// IWYU pragma: private, include "nsString.h"
#ifndef nsTSubstringTuple_h
#define nsTSubstringTuple_h
#include "nsTStringRepr.h"
/**
* nsTSubstringTuple
*
* Represents a tuple of string fragments. Built as a recursive binary tree.
* It is used to implement the concatenation of two or more string objects.
*
* NOTE: This class is a private implementation detail and should never be
* referenced outside the string code.
*/
template <typename T>
class nsTSubstringTuple
{
public:
typedef T char_type;
typedef nsCharTraits<char_type> char_traits;
typedef nsTSubstringTuple<T> self_type;
typedef mozilla::detail::nsTStringRepr<char_type> base_string_type;
typedef uint32_t size_type;
public:
nsTSubstringTuple(const base_string_type* aStrA,
const base_string_type* aStrB)
: mHead(nullptr)
, mFragA(aStrA)
, mFragB(aStrB)
{
}
nsTSubstringTuple(const self_type& aHead,
const base_string_type* aStrB)
: mHead(&aHead)
, mFragA(nullptr) // this fragment is ignored when aHead != nullptr
, mFragB(aStrB)
{
}
/**
* computes the aggregate string length
*/
size_type Length() const;
/**
* writes the aggregate string to the given buffer. bufLen is assumed
* to be equal to or greater than the value returned by the Length()
* method. the string written to |buf| is not null-terminated.
*/
void WriteTo(char_type* aBuf, uint32_t aBufLen) const;
/**
* returns true if this tuple is dependent on (i.e., overlapping with)
* the given char sequence.
*/
bool IsDependentOn(const char_type* aStart, const char_type* aEnd) const;
private:
const self_type* const mHead;
const base_string_type* const mFragA;
const base_string_type* const mFragB;
};
template <typename T>
inline const nsTSubstringTuple<T>
operator+(const mozilla::detail::nsTStringRepr<T>& aStrA,
const mozilla::detail::nsTStringRepr<T>& aStrB)
{
return nsTSubstringTuple<T>(&aStrA, &aStrB);
}
template <typename T>
inline const nsTSubstringTuple<T>
operator+(const nsTSubstringTuple<T>& aHead,
const mozilla::detail::nsTStringRepr<T>& aStrB)
{
return nsTSubstringTuple<T>(aHead, &aStrB);
}
#endif