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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */
#ifndef AlignedTArray_h__
#define AlignedTArray_h__
#include "mozilla/Alignment.h"
#include "nsTArray.h"
/**
* E: element type, must be a POD type.
* N: N bytes alignment for the first element, defaults to 32
* S: S bytes of inline storage
*/
template <typename E, int S, int N = 32>
class AlignedAutoTArray : private AutoTArray<E, S + N> {
static_assert((N & (N - 1)) == 0, "N must be power of 2");
typedef AutoTArray<E, S + N> base_type;
public:
typedef E elem_type;
typedef typename base_type::size_type size_type;
typedef typename base_type::index_type index_type;
AlignedAutoTArray() = default;
explicit AlignedAutoTArray(size_type capacity)
: base_type(capacity + sExtra) {}
elem_type* Elements() { return getAligned(base_type::Elements()); }
const elem_type* Elements() const {
return getAligned(base_type::Elements());
}
elem_type& operator[](index_type i) { return Elements()[i]; }
const elem_type& operator[](index_type i) const { return Elements()[i]; }
void SetLength(size_type newLen) { base_type::SetLength(newLen + sExtra); }
[[nodiscard]] bool SetLength(size_type newLen, const mozilla::fallible_t&) {
return base_type::SetLength(newLen + sExtra, mozilla::fallible);
}
size_type Length() const {
return base_type::Length() <= sExtra ? 0 : base_type::Length() - sExtra;
}
using base_type::ShallowSizeOfExcludingThis;
using base_type::ShallowSizeOfIncludingThis;
private:
AlignedAutoTArray(const AlignedAutoTArray& other) = delete;
void operator=(const AlignedAutoTArray& other) = delete;
static const size_type sPadding =
N <= MOZ_ALIGNOF(E) ? 0 : N - MOZ_ALIGNOF(E);
static const size_type sExtra = (sPadding + sizeof(E) - 1) / sizeof(E);
template <typename U>
static U* getAligned(U* p) {
return reinterpret_cast<U*>(((uintptr_t)p + N - 1) & ~(N - 1));
}
};
/**
* E: element type, must be a POD type.
* N: N bytes alignment for the first element, defaults to 32
*/
template <typename E, int N = 32>
class AlignedTArray : private nsTArray_Impl<E, nsTArrayInfallibleAllocator> {
static_assert((N & (N - 1)) == 0, "N must be power of 2");
typedef nsTArray_Impl<E, nsTArrayInfallibleAllocator> base_type;
public:
typedef E elem_type;
typedef typename base_type::size_type size_type;
typedef typename base_type::index_type index_type;
AlignedTArray() = default;
explicit AlignedTArray(size_type capacity) : base_type(capacity + sExtra) {}
elem_type* Elements() { return getAligned(base_type::Elements()); }
const elem_type* Elements() const {
return getAligned(base_type::Elements());
}
elem_type& operator[](index_type i) { return Elements()[i]; }
const elem_type& operator[](index_type i) const { return Elements()[i]; }
void SetLength(size_type newLen) { base_type::SetLength(newLen + sExtra); }
[[nodiscard]] bool SetLength(size_type newLen, const mozilla::fallible_t&) {
return base_type::SetLength(newLen + sExtra, mozilla::fallible);
}
size_type Length() const {
return base_type::Length() <= sExtra ? 0 : base_type::Length() - sExtra;
}
using base_type::ShallowSizeOfExcludingThis;
using base_type::ShallowSizeOfIncludingThis;
private:
AlignedTArray(const AlignedTArray& other) = delete;
void operator=(const AlignedTArray& other) = delete;
static const size_type sPadding =
N <= MOZ_ALIGNOF(E) ? 0 : N - MOZ_ALIGNOF(E);
static const size_type sExtra = (sPadding + sizeof(E) - 1) / sizeof(E);
template <typename U>
static U* getAligned(U* p) {
return reinterpret_cast<U*>(((uintptr_t)p + N - 1) & ~(N - 1));
}
};
#endif // AlignedTArray_h__