/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* * This file is part of the LibreOffice project. * * 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/. * * This file incorporates work covered by the following license notice: * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed * with this work for additional information regarding copyright * ownership. The ASF licenses this file to you 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 http://www.apache.org/licenses/LICENSE-2.0 . */ #ifndef INCLUDED_O3TL_VECTOR_POOL_HXX #define INCLUDED_O3TL_VECTOR_POOL_HXX #include #include namespace o3tl { namespace detail { template class simple_pool_impl : public Container { typedef typename Container::value_type value_type; std::ptrdiff_t mnFirstFreeIndex; public: simple_pool_impl() : mnFirstFreeIndex(-1) {} std::ptrdiff_t alloc() { return store(ValueType()); } std::ptrdiff_t store(const ValueType& rCopy) { if( mnFirstFreeIndex != -1 ) { std::ptrdiff_t nIdx=mnFirstFreeIndex; mnFirstFreeIndex = this->at(mnFirstFreeIndex).nextFree; this->at(nIdx).value = rCopy; this->at(nIdx).nextFree = -1; return nIdx; } else { this->push_back(value_type(rCopy)); return this->size()-1; } } void free( std::ptrdiff_t nIdx ) { this->at(nIdx).nextFree = mnFirstFreeIndex; mnFirstFreeIndex = nIdx; } const ValueType& get( std::ptrdiff_t nIdx ) const { return this->operator[](nIdx).value; } ValueType& get( std::ptrdiff_t nIdx ) { return this->operator[](nIdx).value; } }; template< typename ValueType > struct struct_from_value { struct type { type() : value(), nextFree(-1) {} explicit type( ValueType val ) : value(std::move(val)), nextFree(-1) {} ValueType value; std::ptrdiff_t nextFree; }; }; } /** Simple vector-based memory pool allocator This template can be used to provide simple pooled memory allocation from a container class that adheres to the stl random access container concept. Note that alloc/free works with _indices_ into the container! @example
vector_pool myPool;
int nIdx=myPool.alloc();
myPool[nIdx] = myVal;
 ... do stuff ...
myPool.free(nIdx);
        
*/ template struct vector_pool : public detail::simple_pool_impl::type > > {}; } #endif /* INCLUDED_O3TL_VECTOR_POOL_HXX */ /* vim:set shiftwidth=4 softtabstop=4 expandtab: */