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Diffstat (limited to 'include/rapidjson/allocators.h')
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diff --git a/include/rapidjson/allocators.h b/include/rapidjson/allocators.h deleted file mode 100644 index 98affe03..00000000 --- a/include/rapidjson/allocators.h +++ /dev/null @@ -1,271 +0,0 @@ -// Tencent is pleased to support the open source community by making RapidJSON available. -// -// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved. -// -// Licensed under the MIT License (the "License"); you may not use this file except -// in compliance with the License. You may obtain a copy of the License at -// -// http://opensource.org/licenses/MIT -// -// 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. - -#ifndef RAPIDJSON_ALLOCATORS_H_ -#define RAPIDJSON_ALLOCATORS_H_ - -#include "rapidjson.h" - -RAPIDJSON_NAMESPACE_BEGIN - -/////////////////////////////////////////////////////////////////////////////// -// Allocator - -/*! \class rapidjson::Allocator - \brief Concept for allocating, resizing and freeing memory block. - - Note that Malloc() and Realloc() are non-static but Free() is static. - - So if an allocator need to support Free(), it needs to put its pointer in - the header of memory block. - -\code -concept Allocator { - static const bool kNeedFree; //!< Whether this allocator needs to call Free(). - - // Allocate a memory block. - // \param size of the memory block in bytes. - // \returns pointer to the memory block. - void* Malloc(size_t size); - - // Resize a memory block. - // \param originalPtr The pointer to current memory block. Null pointer is permitted. - // \param originalSize The current size in bytes. (Design issue: since some allocator may not book-keep this, explicitly pass to it can save memory.) - // \param newSize the new size in bytes. - void* Realloc(void* originalPtr, size_t originalSize, size_t newSize); - - // Free a memory block. - // \param pointer to the memory block. Null pointer is permitted. - static void Free(void *ptr); -}; -\endcode -*/ - -/////////////////////////////////////////////////////////////////////////////// -// CrtAllocator - -//! C-runtime library allocator. -/*! This class is just wrapper for standard C library memory routines. - \note implements Allocator concept -*/ -class CrtAllocator { -public: - static const bool kNeedFree = true; - void* Malloc(size_t size) { - if (size) // behavior of malloc(0) is implementation defined. - return std::malloc(size); - else - return NULL; // standardize to returning NULL. - } - void* Realloc(void* originalPtr, size_t originalSize, size_t newSize) { - (void)originalSize; - if (newSize == 0) { - std::free(originalPtr); - return NULL; - } - return std::realloc(originalPtr, newSize); - } - static void Free(void *ptr) { std::free(ptr); } -}; - -/////////////////////////////////////////////////////////////////////////////// -// MemoryPoolAllocator - -//! Default memory allocator used by the parser and DOM. -/*! This allocator allocate memory blocks from pre-allocated memory chunks. - - It does not free memory blocks. And Realloc() only allocate new memory. - - The memory chunks are allocated by BaseAllocator, which is CrtAllocator by default. - - User may also supply a buffer as the first chunk. - - If the user-buffer is full then additional chunks are allocated by BaseAllocator. - - The user-buffer is not deallocated by this allocator. - - \tparam BaseAllocator the allocator type for allocating memory chunks. Default is CrtAllocator. - \note implements Allocator concept -*/ -template <typename BaseAllocator = CrtAllocator> -class MemoryPoolAllocator { -public: - static const bool kNeedFree = false; //!< Tell users that no need to call Free() with this allocator. (concept Allocator) - - //! Constructor with chunkSize. - /*! \param chunkSize The size of memory chunk. The default is kDefaultChunkSize. - \param baseAllocator The allocator for allocating memory chunks. - */ - MemoryPoolAllocator(size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) : - chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(0), baseAllocator_(baseAllocator), ownBaseAllocator_(0) - { - } - - //! Constructor with user-supplied buffer. - /*! The user buffer will be used firstly. When it is full, memory pool allocates new chunk with chunk size. - - The user buffer will not be deallocated when this allocator is destructed. - - \param buffer User supplied buffer. - \param size Size of the buffer in bytes. It must at least larger than sizeof(ChunkHeader). - \param chunkSize The size of memory chunk. The default is kDefaultChunkSize. - \param baseAllocator The allocator for allocating memory chunks. - */ - MemoryPoolAllocator(void *buffer, size_t size, size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) : - chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(buffer), baseAllocator_(baseAllocator), ownBaseAllocator_(0) - { - RAPIDJSON_ASSERT(buffer != 0); - RAPIDJSON_ASSERT(size > sizeof(ChunkHeader)); - chunkHead_ = reinterpret_cast<ChunkHeader*>(buffer); - chunkHead_->capacity = size - sizeof(ChunkHeader); - chunkHead_->size = 0; - chunkHead_->next = 0; - } - - //! Destructor. - /*! This deallocates all memory chunks, excluding the user-supplied buffer. - */ - ~MemoryPoolAllocator() { - Clear(); - RAPIDJSON_DELETE(ownBaseAllocator_); - } - - //! Deallocates all memory chunks, excluding the user-supplied buffer. - void Clear() { - while (chunkHead_ && chunkHead_ != userBuffer_) { - ChunkHeader* next = chunkHead_->next; - baseAllocator_->Free(chunkHead_); - chunkHead_ = next; - } - if (chunkHead_ && chunkHead_ == userBuffer_) - chunkHead_->size = 0; // Clear user buffer - } - - //! Computes the total capacity of allocated memory chunks. - /*! \return total capacity in bytes. - */ - size_t Capacity() const { - size_t capacity = 0; - for (ChunkHeader* c = chunkHead_; c != 0; c = c->next) - capacity += c->capacity; - return capacity; - } - - //! Computes the memory blocks allocated. - /*! \return total used bytes. - */ - size_t Size() const { - size_t size = 0; - for (ChunkHeader* c = chunkHead_; c != 0; c = c->next) - size += c->size; - return size; - } - - //! Allocates a memory block. (concept Allocator) - void* Malloc(size_t size) { - if (!size) - return NULL; - - size = RAPIDJSON_ALIGN(size); - if (chunkHead_ == 0 || chunkHead_->size + size > chunkHead_->capacity) - if (!AddChunk(chunk_capacity_ > size ? chunk_capacity_ : size)) - return NULL; - - void *buffer = reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size; - chunkHead_->size += size; - return buffer; - } - - //! Resizes a memory block (concept Allocator) - void* Realloc(void* originalPtr, size_t originalSize, size_t newSize) { - if (originalPtr == 0) - return Malloc(newSize); - - if (newSize == 0) - return NULL; - - originalSize = RAPIDJSON_ALIGN(originalSize); - newSize = RAPIDJSON_ALIGN(newSize); - - // Do not shrink if new size is smaller than original - if (originalSize >= newSize) - return originalPtr; - - // Simply expand it if it is the last allocation and there is sufficient space - if (originalPtr == reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size - originalSize) { - size_t increment = static_cast<size_t>(newSize - originalSize); - if (chunkHead_->size + increment <= chunkHead_->capacity) { - chunkHead_->size += increment; - return originalPtr; - } - } - - // Realloc process: allocate and copy memory, do not free original buffer. - if (void* newBuffer = Malloc(newSize)) { - if (originalSize) - std::memcpy(newBuffer, originalPtr, originalSize); - return newBuffer; - } - else - return NULL; - } - - //! Frees a memory block (concept Allocator) - static void Free(void *ptr) { (void)ptr; } // Do nothing - -private: - //! Copy constructor is not permitted. - MemoryPoolAllocator(const MemoryPoolAllocator& rhs) /* = delete */; - //! Copy assignment operator is not permitted. - MemoryPoolAllocator& operator=(const MemoryPoolAllocator& rhs) /* = delete */; - - //! Creates a new chunk. - /*! \param capacity Capacity of the chunk in bytes. - \return true if success. - */ - bool AddChunk(size_t capacity) { - if (!baseAllocator_) - ownBaseAllocator_ = baseAllocator_ = RAPIDJSON_NEW(BaseAllocator()); - if (ChunkHeader* chunk = reinterpret_cast<ChunkHeader*>(baseAllocator_->Malloc(RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + capacity))) { - chunk->capacity = capacity; - chunk->size = 0; - chunk->next = chunkHead_; - chunkHead_ = chunk; - return true; - } - else - return false; - } - - static const int kDefaultChunkCapacity = 64 * 1024; //!< Default chunk capacity. - - //! Chunk header for perpending to each chunk. - /*! Chunks are stored as a singly linked list. - */ - struct ChunkHeader { - size_t capacity; //!< Capacity of the chunk in bytes (excluding the header itself). - size_t size; //!< Current size of allocated memory in bytes. - ChunkHeader *next; //!< Next chunk in the linked list. - }; - - ChunkHeader *chunkHead_; //!< Head of the chunk linked-list. Only the head chunk serves allocation. - size_t chunk_capacity_; //!< The minimum capacity of chunk when they are allocated. - void *userBuffer_; //!< User supplied buffer. - BaseAllocator* baseAllocator_; //!< base allocator for allocating memory chunks. - BaseAllocator* ownBaseAllocator_; //!< base allocator created by this object. -}; - -RAPIDJSON_NAMESPACE_END - -#endif // RAPIDJSON_ENCODINGS_H_ |