MemoryPoolAllocator
Engine/source/persistence/rapidjson/allocators.h
Default memory allocator used by the parser and DOM.
Classes:
Chunk header for perpending to each chunk.
Public Static Attributes
Private Static Attributes
const int
Default chunk capacity.
Private Attributes
BaseAllocator *
base allocator for allocating memory chunks.
size_t
The minimum capacity of chunk when they are allocated.
ChunkHeader *
Head of the chunk linked-list. Only the head chunk serves allocation.
BaseAllocator *
base allocator created by this object.
void *
User supplied buffer.
Public Functions
MemoryPoolAllocator(size_t chunkSize, BaseAllocator * baseAllocator)
Constructor with chunkSize.
MemoryPoolAllocator(void * buffer, size_t size, size_t chunkSize, BaseAllocator * baseAllocator)
Constructor with user-supplied buffer.
Destructor.
size_t
Capacity()
Computes the total capacity of allocated memory chunks.
void *
size_t
Size()
Computes the memory blocks allocated.
Private Functions
Copy constructor is not permitted.
bool
AddChunk(size_t capacity)
Creates a new chunk.
operator=(const MemoryPoolAllocator & rhs)
Copy assignment operator is not permitted.
Detailed Description
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.
Parameters:
| BaseAllocator | the allocator type for allocating memory chunks. Default is CrtAllocator. |
note:implements Allocator concept
Public Static Attributes
const bool kNeedFree
Tell users that no need to call Free() with this allocator. (concept Allocator)
Private Static Attributes
const int kDefaultChunkCapacity
Default chunk capacity.
Private Attributes
BaseAllocator * baseAllocator_
base allocator for allocating memory chunks.
size_t chunk_capacity_
The minimum capacity of chunk when they are allocated.
ChunkHeader * chunkHead_
Head of the chunk linked-list. Only the head chunk serves allocation.
BaseAllocator * ownBaseAllocator_
base allocator created by this object.
void * userBuffer_
User supplied buffer.
Public Functions
MemoryPoolAllocator(size_t chunkSize, BaseAllocator * baseAllocator)
Constructor with chunkSize.
Parameters:
| chunkSize | The size of memory chunk. The default is kDefaultChunkSize. |
| baseAllocator | The allocator for allocating memory chunks. |
MemoryPoolAllocator(void * buffer, size_t size, size_t chunkSize, BaseAllocator * baseAllocator)
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.
Parameters:
| buffer | User supplied buffer. |
| size | Size of the buffer in bytes. It must at least larger than sizeof(ChunkHeader). |
| chunkSize | The size of memory chunk. The default is kDefaultChunkSize. |
| baseAllocator | The allocator for allocating memory chunks. |
~MemoryPoolAllocator()
Destructor.
This deallocates all memory chunks, excluding the user-supplied buffer.
Capacity()
Computes the total capacity of allocated memory chunks.
total capacity in bytes.
Clear()
Deallocates all memory chunks, excluding the user-supplied buffer.
Malloc(size_t size)
Allocates a memory block. (concept Allocator)
Realloc(void * originalPtr, size_t originalSize, size_t newSize)
Resizes a memory block (concept Allocator)
Size()
Computes the memory blocks allocated.
total used bytes.
Public Static Functions
Free(void * ptr)
Frees a memory block (concept Allocator)
Private Functions
MemoryPoolAllocator(const MemoryPoolAllocator & rhs)
Copy constructor is not permitted.
AddChunk(size_t capacity)
Creates a new chunk.
Parameters:
| capacity | Capacity of the chunk in bytes. |
true if success.
operator=(const MemoryPoolAllocator & rhs)
Copy assignment operator is not permitted.