106 lines
2.8 KiB
C++
106 lines
2.8 KiB
C++
/*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Copyright 2015 Danny Robson <danny@nerdcruft.net>
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*/
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#ifndef CRUFT_UTIL_ALLOC_RAW_LINEAR_HPP
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#define CRUFT_UTIL_ALLOC_RAW_LINEAR_HPP
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#include "../../view.hpp"
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#include "../../pointer.hpp"
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#include <cstddef>
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#include <iterator>
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namespace util::alloc::raw {
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// allocate progressively across a buffer without concern for deallocation.
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// deallocation is a noop; the only way to free allocations is via reset.
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class linear {
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public:
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linear (const linear&) = delete;
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linear (linear&&) = delete;
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linear& operator= (const linear&) = delete;
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linear& operator= (linear&&) = delete;
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linear (util::view<std::byte*> _data);
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template <typename T>
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util::view<T*>
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allocate (size_t count)
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{
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auto const bytes = count * sizeof (T);
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if (m_cursor + bytes > m_end)
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throw std::bad_alloc ();
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auto ptr = m_cursor;
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m_cursor += bytes;
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return { util::cast::alignment<T*> (ptr), count };
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}
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template <typename T>
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util::view<T*>
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allocate (size_t count, size_t alignment)
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{
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auto const bytes = count * sizeof (T);
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auto ptr = util::align (m_cursor, alignment);
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if (ptr + bytes > m_end)
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throw std::bad_alloc ();
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m_cursor = ptr + bytes;
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return { util::cast::alignment<T*> (ptr), count };
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}
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template <typename T>
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void deallocate (util::view<T*> ptr)
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{
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(void)ptr;
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}
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std::byte* data (void);
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std::byte* begin (void);
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std::byte* end (void);
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std::byte* cursor (void);
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const std::byte* data (void) const;
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const std::byte* begin (void) const;
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const std::byte* end (void) const;
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const std::byte* cursor (void) const;
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size_t offset (const void*) const;
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template <typename T>
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size_t
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offset (util::view<T*> ptr) const
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{
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return offset (ptr.data ());
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}
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void reset (void);
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size_t capacity (void) const;
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size_t used (void) const;
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size_t remain (void) const;
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protected:
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std::byte *const m_begin;
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std::byte *const m_end;
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std::byte *m_cursor;
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};
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}
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#endif
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