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Diffstat (limited to 'extern/ceres/include/ceres/internal/fixed_array.h')
| -rw-r--r-- | extern/ceres/include/ceres/internal/fixed_array.h | 573 |
1 files changed, 425 insertions, 148 deletions
diff --git a/extern/ceres/include/ceres/internal/fixed_array.h b/extern/ceres/include/ceres/internal/fixed_array.h index 387298c58d0..f8ef02d40e8 100644 --- a/extern/ceres/include/ceres/internal/fixed_array.h +++ b/extern/ceres/include/ceres/internal/fixed_array.h @@ -1,189 +1,466 @@ -// Ceres Solver - A fast non-linear least squares minimizer -// Copyright 2015 Google Inc. All rights reserved. -// http://ceres-solver.org/ +// Copyright 2018 The Abseil Authors. // -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are met: +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at // -// * 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. +// https://www.apache.org/licenses/LICENSE-2.0 // -// 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. +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. // -// Author: rennie@google.com (Jeffrey Rennie) -// Author: sanjay@google.com (Sanjay Ghemawat) -- renamed to FixedArray +// ----------------------------------------------------------------------------- +// File: fixed_array.h +// ----------------------------------------------------------------------------- +// +// A `FixedArray<T>` represents a non-resizable array of `T` where the length of +// the array can be determined at run-time. It is a good replacement for +// non-standard and deprecated uses of `alloca()` and variable length arrays +// within the GCC extension. (See +// https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html). +// +// `FixedArray` allocates small arrays inline, keeping performance fast by +// avoiding heap operations. It also helps reduce the chances of +// accidentally overflowing your stack if large input is passed to +// your function. #ifndef CERES_PUBLIC_INTERNAL_FIXED_ARRAY_H_ #define CERES_PUBLIC_INTERNAL_FIXED_ARRAY_H_ +#include <algorithm> +#include <array> #include <cstddef> -#include "Eigen/Core" -#include "ceres/internal/macros.h" -#include "ceres/internal/manual_constructor.h" +#include <memory> +#include <tuple> +#include <type_traits> + +#include <Eigen/Core> // For Eigen::aligned_allocator + +#include "ceres/internal/memory.h" #include "glog/logging.h" namespace ceres { namespace internal { -// A FixedArray<T> represents a non-resizable array of T where the -// length of the array does not need to be a compile time constant. -// -// FixedArray allocates small arrays inline, and large arrays on -// the heap. It is a good replacement for non-standard and deprecated -// uses of alloca() and variable length arrays (a GCC extension). -// -// FixedArray keeps performance fast for small arrays, because it -// avoids heap operations. It also helps reduce the chances of -// accidentally overflowing your stack if large input is passed to -// your function. +constexpr static auto kFixedArrayUseDefault = static_cast<size_t>(-1); + +// The default fixed array allocator. // -// Also, FixedArray is useful for writing portable code. Not all -// compilers support arrays of dynamic size. +// As one can not easily detect if a struct contains or inherits from a fixed +// size Eigen type, to be safe the Eigen::aligned_allocator is used by default. +// But trivial types can never contain Eigen types, so std::allocator is used to +// safe some heap memory. +template <typename T> +using FixedArrayDefaultAllocator = + typename std::conditional<std::is_trivial<T>::value, + std::allocator<T>, + Eigen::aligned_allocator<T>>::type; -// Most users should not specify an inline_elements argument and let -// FixedArray<> automatically determine the number of elements -// to store inline based on sizeof(T). +// ----------------------------------------------------------------------------- +// FixedArray +// ----------------------------------------------------------------------------- +// +// A `FixedArray` provides a run-time fixed-size array, allocating a small array +// inline for efficiency. // -// If inline_elements is specified, the FixedArray<> implementation -// will store arrays of length <= inline_elements inline. +// Most users should not specify an `inline_elements` argument and let +// `FixedArray` automatically determine the number of elements +// to store inline based on `sizeof(T)`. If `inline_elements` is specified, the +// `FixedArray` implementation will use inline storage for arrays with a +// length <= `inline_elements`. // -// Finally note that unlike vector<T> FixedArray<T> will not zero-initialize -// simple types like int, double, bool, etc. +// Note that a `FixedArray` constructed with a `size_type` argument will +// default-initialize its values by leaving trivially constructible types +// uninitialized (e.g. int, int[4], double), and others default-constructed. +// This matches the behavior of c-style arrays and `std::array`, but not +// `std::vector`. // -// Non-POD types will be default-initialized just like regular vectors or -// arrays. +// Note that `FixedArray` does not provide a public allocator; if it requires a +// heap allocation, it will do so with global `::operator new[]()` and +// `::operator delete[]()`, even if T provides class-scope overrides for these +// operators. +template <typename T, + size_t N = kFixedArrayUseDefault, + typename A = FixedArrayDefaultAllocator<T>> +class FixedArray { + static_assert(!std::is_array<T>::value || std::extent<T>::value > 0, + "Arrays with unknown bounds cannot be used with FixedArray."); -#if defined(_WIN64) - typedef __int64 ssize_t; -#elif defined(_WIN32) - typedef __int32 ssize_t; -#endif + static constexpr size_t kInlineBytesDefault = 256; + + using AllocatorTraits = std::allocator_traits<A>; + // std::iterator_traits isn't guaranteed to be SFINAE-friendly until C++17, + // but this seems to be mostly pedantic. + template <typename Iterator> + using EnableIfForwardIterator = typename std::enable_if<std::is_convertible< + typename std::iterator_traits<Iterator>::iterator_category, + std::forward_iterator_tag>::value>::type; + static constexpr bool DefaultConstructorIsNonTrivial() { + return !std::is_trivially_default_constructible<StorageElement>::value; + } -template <typename T, ssize_t inline_elements = -1> -class FixedArray { public: - // For playing nicely with stl: - typedef T value_type; - typedef T* iterator; - typedef T const* const_iterator; - typedef T& reference; - typedef T const& const_reference; - typedef T* pointer; - typedef std::ptrdiff_t difference_type; - typedef size_t size_type; - - // REQUIRES: n >= 0 - // Creates an array object that can store "n" elements. - // - // FixedArray<T> will not zero-initialiaze POD (simple) types like int, - // double, bool, etc. - // Non-POD types will be default-initialized just like regular vectors or - // arrays. - explicit FixedArray(size_type n); - - // Releases any resources. - ~FixedArray(); - - // Returns the length of the array. - inline size_type size() const { return size_; } - - // Returns the memory size of the array in bytes. - inline size_t memsize() const { return size_ * sizeof(T); } - - // Returns a pointer to the underlying element array. - inline const T* get() const { return &array_[0].element; } - inline T* get() { return &array_[0].element; } + using allocator_type = typename AllocatorTraits::allocator_type; + using value_type = typename AllocatorTraits::value_type; + using pointer = typename AllocatorTraits::pointer; + using const_pointer = typename AllocatorTraits::const_pointer; + using reference = value_type&; + using const_reference = const value_type&; + using size_type = typename AllocatorTraits::size_type; + using difference_type = typename AllocatorTraits::difference_type; + using iterator = pointer; + using const_iterator = const_pointer; + using reverse_iterator = std::reverse_iterator<iterator>; + using const_reverse_iterator = std::reverse_iterator<const_iterator>; + + static constexpr size_type inline_elements = + (N == kFixedArrayUseDefault ? kInlineBytesDefault / sizeof(value_type) + : static_cast<size_type>(N)); + + FixedArray(const FixedArray& other, + const allocator_type& a = allocator_type()) + : FixedArray(other.begin(), other.end(), a) {} + + FixedArray(FixedArray&& other, const allocator_type& a = allocator_type()) + : FixedArray(std::make_move_iterator(other.begin()), + std::make_move_iterator(other.end()), + a) {} + + // Creates an array object that can store `n` elements. + // Note that trivially constructible elements will be uninitialized. + explicit FixedArray(size_type n, const allocator_type& a = allocator_type()) + : storage_(n, a) { + if (DefaultConstructorIsNonTrivial()) { + ConstructRange(storage_.alloc(), storage_.begin(), storage_.end()); + } + } + // Creates an array initialized with `n` copies of `val`. + FixedArray(size_type n, + const value_type& val, + const allocator_type& a = allocator_type()) + : storage_(n, a) { + ConstructRange(storage_.alloc(), storage_.begin(), storage_.end(), val); + } + + // Creates an array initialized with the size and contents of `init_list`. + FixedArray(std::initializer_list<value_type> init_list, + const allocator_type& a = allocator_type()) + : FixedArray(init_list.begin(), init_list.end(), a) {} + + // Creates an array initialized with the elements from the input + // range. The array's size will always be `std::distance(first, last)`. + // REQUIRES: Iterator must be a forward_iterator or better. + template <typename Iterator, EnableIfForwardIterator<Iterator>* = nullptr> + FixedArray(Iterator first, + Iterator last, + const allocator_type& a = allocator_type()) + : storage_(std::distance(first, last), a) { + CopyRange(storage_.alloc(), storage_.begin(), first, last); + } + + ~FixedArray() noexcept { + for (auto* cur = storage_.begin(); cur != storage_.end(); ++cur) { + AllocatorTraits::destroy(storage_.alloc(), cur); + } + } + + // Assignments are deleted because they break the invariant that the size of a + // `FixedArray` never changes. + void operator=(FixedArray&&) = delete; + void operator=(const FixedArray&) = delete; + + // FixedArray::size() + // + // Returns the length of the fixed array. + size_type size() const { return storage_.size(); } + + // FixedArray::max_size() + // + // Returns the largest possible value of `std::distance(begin(), end())` for a + // `FixedArray<T>`. This is equivalent to the most possible addressable bytes + // over the number of bytes taken by T. + constexpr size_type max_size() const { + return (std::numeric_limits<difference_type>::max)() / sizeof(value_type); + } + + // FixedArray::empty() + // + // Returns whether or not the fixed array is empty. + bool empty() const { return size() == 0; } + + // FixedArray::memsize() + // + // Returns the memory size of the fixed array in bytes. + size_t memsize() const { return size() * sizeof(value_type); } + + // FixedArray::data() + // + // Returns a const T* pointer to elements of the `FixedArray`. This pointer + // can be used to access (but not modify) the contained elements. + const_pointer data() const { return AsValueType(storage_.begin()); } + + // Overload of FixedArray::data() to return a T* pointer to elements of the + // fixed array. This pointer can be used to access and modify the contained + // elements. + pointer data() { return AsValueType(storage_.begin()); } + + // FixedArray::operator[] + // + // Returns a reference the ith element of the fixed array. // REQUIRES: 0 <= i < size() - // Returns a reference to the "i"th element. - inline T& operator[](size_type i) { - DCHECK_LT(i, size_); - return array_[i].element; + reference operator[](size_type i) { + DCHECK_LT(i, size()); + return data()[i]; } + // Overload of FixedArray::operator()[] to return a const reference to the + // ith element of the fixed array. // REQUIRES: 0 <= i < size() - // Returns a reference to the "i"th element. - inline const T& operator[](size_type i) const { - DCHECK_LT(i, size_); - return array_[i].element; + const_reference operator[](size_type i) const { + DCHECK_LT(i, size()); + return data()[i]; + } + + // FixedArray::front() + // + // Returns a reference to the first element of the fixed array. + reference front() { return *begin(); } + + // Overload of FixedArray::front() to return a reference to the first element + // of a fixed array of const values. + const_reference front() const { return *begin(); } + + // FixedArray::back() + // + // Returns a reference to the last element of the fixed array. + reference back() { return *(end() - 1); } + + // Overload of FixedArray::back() to return a reference to the last element + // of a fixed array of const values. + const_reference back() const { return *(end() - 1); } + + // FixedArray::begin() + // + // Returns an iterator to the beginning of the fixed array. + iterator begin() { return data(); } + + // Overload of FixedArray::begin() to return a const iterator to the + // beginning of the fixed array. + const_iterator begin() const { return data(); } + + // FixedArray::cbegin() + // + // Returns a const iterator to the beginning of the fixed array. + const_iterator cbegin() const { return begin(); } + + // FixedArray::end() + // + // Returns an iterator to the end of the fixed array. + iterator end() { return data() + size(); } + + // Overload of FixedArray::end() to return a const iterator to the end of the + // fixed array. + const_iterator end() const { return data() + size(); } + + // FixedArray::cend() + // + // Returns a const iterator to the end of the fixed array. + const_iterator cend() const { return end(); } + + // FixedArray::rbegin() + // + // Returns a reverse iterator from the end of the fixed array. + reverse_iterator rbegin() { return reverse_iterator(end()); } + + // Overload of FixedArray::rbegin() to return a const reverse iterator from + // the end of the fixed array. + const_reverse_iterator rbegin() const { + return const_reverse_iterator(end()); } - inline iterator begin() { return &array_[0].element; } - inline iterator end() { return &array_[size_].element; } + // FixedArray::crbegin() + // + // Returns a const reverse iterator from the end of the fixed array. + const_reverse_iterator crbegin() const { return rbegin(); } - inline const_iterator begin() const { return &array_[0].element; } - inline const_iterator end() const { return &array_[size_].element; } + // FixedArray::rend() + // + // Returns a reverse iterator from the beginning of the fixed array. + reverse_iterator rend() { return reverse_iterator(begin()); } + + // Overload of FixedArray::rend() for returning a const reverse iterator + // from the beginning of the fixed array. + const_reverse_iterator rend() const { + return const_reverse_iterator(begin()); + } + + // FixedArray::crend() + // + // Returns a reverse iterator from the beginning of the fixed array. + const_reverse_iterator crend() const { return rend(); } + + // FixedArray::fill() + // + // Assigns the given `value` to all elements in the fixed array. + void fill(const value_type& val) { std::fill(begin(), end(), val); } + + // Relational operators. Equality operators are elementwise using + // `operator==`, while order operators order FixedArrays lexicographically. + friend bool operator==(const FixedArray& lhs, const FixedArray& rhs) { + return std::equal(lhs.begin(), lhs.end(), rhs.begin(), rhs.end()); + } + + friend bool operator!=(const FixedArray& lhs, const FixedArray& rhs) { + return !(lhs == rhs); + } + + friend bool operator<(const FixedArray& lhs, const FixedArray& rhs) { + return std::lexicographical_compare( + lhs.begin(), lhs.end(), rhs.begin(), rhs.end()); + } + + friend bool operator>(const FixedArray& lhs, const FixedArray& rhs) { + return rhs < lhs; + } + + friend bool operator<=(const FixedArray& lhs, const FixedArray& rhs) { + return !(rhs < lhs); + } + + friend bool operator>=(const FixedArray& lhs, const FixedArray& rhs) { + return !(lhs < rhs); + } private: - // Container to hold elements of type T. This is necessary to handle - // the case where T is a a (C-style) array. The size of InnerContainer - // and T must be the same, otherwise callers' assumptions about use - // of this code will be broken. - struct InnerContainer { - T element; + // StorageElement + // + // For FixedArrays with a C-style-array value_type, StorageElement is a POD + // wrapper struct called StorageElementWrapper that holds the value_type + // instance inside. This is needed for construction and destruction of the + // entire array regardless of how many dimensions it has. For all other cases, + // StorageElement is just an alias of value_type. + // + // Maintainer's Note: The simpler solution would be to simply wrap value_type + // in a struct whether it's an array or not. That causes some paranoid + // diagnostics to misfire, believing that 'data()' returns a pointer to a + // single element, rather than the packed array that it really is. + // e.g.: + // + // FixedArray<char> buf(1); + // sprintf(buf.data(), "foo"); + // + // error: call to int __builtin___sprintf_chk(etc...) + // will always overflow destination buffer [-Werror] + // + template <typename OuterT, + typename InnerT = typename std::remove_extent<OuterT>::type, + size_t InnerN = std::extent<OuterT>::value> + struct StorageElementWrapper { + InnerT array[InnerN]; }; - // How many elements should we store inline? - // a. If not specified, use a default of 256 bytes (256 bytes - // seems small enough to not cause stack overflow or unnecessary - // stack pollution, while still allowing stack allocation for - // reasonably long character arrays. - // b. Never use 0 length arrays (not ISO C++) - static const size_type S1 = ((inline_elements < 0) - ? (256/sizeof(T)) : inline_elements); - static const size_type S2 = (S1 <= 0) ? 1 : S1; - static const size_type kInlineElements = S2; - - size_type const size_; - InnerContainer* const array_; - - // Allocate some space, not an array of elements of type T, so that we can - // skip calling the T constructors and destructors for space we never use. - ManualConstructor<InnerContainer> inline_space_[kInlineElements]; -}; + using StorageElement = + typename std::conditional<std::is_array<value_type>::value, + StorageElementWrapper<value_type>, + value_type>::type; -// Implementation details follow - -template <class T, ssize_t S> -inline FixedArray<T, S>::FixedArray(typename FixedArray<T, S>::size_type n) - : size_(n), - array_((n <= kInlineElements - ? reinterpret_cast<InnerContainer*>(inline_space_) - : new InnerContainer[n])) { - // Construct only the elements actually used. - if (array_ == reinterpret_cast<InnerContainer*>(inline_space_)) { - for (size_t i = 0; i != size_; ++i) { - inline_space_[i].Init(); - } + static pointer AsValueType(pointer ptr) { return ptr; } + static pointer AsValueType(StorageElementWrapper<value_type>* ptr) { + return std::addressof(ptr->array); } -} -template <class T, ssize_t S> -inline FixedArray<T, S>::~FixedArray() { - if (array_ != reinterpret_cast<InnerContainer*>(inline_space_)) { - delete[] array_; - } else { - for (size_t i = 0; i != size_; ++i) { - inline_space_[i].Destroy(); + static_assert(sizeof(StorageElement) == sizeof(value_type), ""); + static_assert(alignof(StorageElement) == alignof(value_type), ""); + + class NonEmptyInlinedStorage { + public: + StorageElement* data() { return reinterpret_cast<StorageElement*>(buff_); } + void AnnotateConstruct(size_type) {} + void AnnotateDestruct(size_type) {} + + // #ifdef ADDRESS_SANITIZER + // void* RedzoneBegin() { return &redzone_begin_; } + // void* RedzoneEnd() { return &redzone_end_ + 1; } + // #endif // ADDRESS_SANITIZER + + private: + // ADDRESS_SANITIZER_REDZONE(redzone_begin_); + alignas(StorageElement) char buff_[sizeof(StorageElement[inline_elements])]; + // ADDRESS_SANITIZER_REDZONE(redzone_end_); + }; + + class EmptyInlinedStorage { + public: + StorageElement* data() { return nullptr; } + void AnnotateConstruct(size_type) {} + void AnnotateDestruct(size_type) {} + }; + + using InlinedStorage = + typename std::conditional<inline_elements == 0, + EmptyInlinedStorage, + NonEmptyInlinedStorage>::type; + + // Storage + // + // An instance of Storage manages the inline and out-of-line memory for + // instances of FixedArray. This guarantees that even when construction of + // individual elements fails in the FixedArray constructor body, the + // destructor for Storage will still be called and out-of-line memory will be + // properly deallocated. + // + class Storage : public InlinedStorage { + public: + Storage(size_type n, const allocator_type& a) + : size_alloc_(n, a), data_(InitializeData()) {} + + ~Storage() noexcept { + if (UsingInlinedStorage(size())) { + InlinedStorage::AnnotateDestruct(size()); + } else { + AllocatorTraits::deallocate(alloc(), AsValueType(begin()), size()); + } } - } -} + + size_type size() const { return std::get<0>(size_alloc_); } + StorageElement* begin() const { return data_; } + StorageElement* end() const { return begin() + size(); } + allocator_type& alloc() { return std::get<1>(size_alloc_); } + + private: + static bool UsingInlinedStorage(size_type n) { + return n <= inline_elements; + } + + StorageElement* InitializeData() { + if (UsingInlinedStorage(size())) { + InlinedStorage::AnnotateConstruct(size()); + return InlinedStorage::data(); + } else { + return reinterpret_cast<StorageElement*>( + AllocatorTraits::allocate(alloc(), size())); + } + } + + // Using std::tuple and not absl::CompressedTuple, as it has a lot of + // dependencies to other absl headers. + std::tuple<size_type, allocator_type> size_alloc_; + StorageElement* data_; + }; + + Storage storage_; +}; + +template <typename T, size_t N, typename A> +constexpr size_t FixedArray<T, N, A>::kInlineBytesDefault; + +template <typename T, size_t N, typename A> +constexpr typename FixedArray<T, N, A>::size_type + FixedArray<T, N, A>::inline_elements; } // namespace internal } // namespace ceres |