MagickCore, C API: Memory Allocation @ ImageMagick

AcquireAlignedMemory • AcquireMagickMemory • AcquireQuantumMemory • AcquireVirtualMemory • CopyMagickMemory • GetMagickMemoryMethods • GetVirtualMemoryBlob • RelinquishAlignedMemory • RelinquishMagickMemory • RelinquishVirtualMemory • ResetMagickMemory • ResizeMagickMemory • ResizeQuantumMemory • SetMagickMemoryMethods

AcquireAlignedMemory

AcquireAlignedMemory() returns a pointer to a block of memory at least size bytes whose address is aligned on a cache line or page boundary.

The format of the AcquireAlignedMemory method is:

void *AcquireAlignedMemory(const size_t count,const size_t quantum)

A description of each parameter follows:

count: the number of quantum elements to allocate.
quantum: the number of bytes in each quantum.

AcquireMagickMemory

AcquireMagickMemory() returns a pointer to a block of memory at least size bytes suitably aligned for any use.

The format of the AcquireMagickMemory method is:

void *AcquireMagickMemory(const size_t size)

A description of each parameter follows:

size: the size of the memory in bytes to allocate.

AcquireQuantumMemory

AcquireQuantumMemory() returns a pointer to a block of memory at least count * quantum bytes suitably aligned for any use.

The format of the AcquireQuantumMemory method is:

void *AcquireQuantumMemory(const size_t count,const size_t quantum)

A description of each parameter follows:

count: the number of quantum elements to allocate.
quantum: the number of bytes in each quantum.

AcquireVirtualMemory() allocates a pointer to a block of memory at least size bytes suitably aligned for any use. In addition to heap, it also supports memory-mapped and file-based memory-mapped memory requests.

The format of the AcquireVirtualMemory method is:

MemoryInfo *AcquireVirtualMemory(const size_t count,const size_t quantum)

A description of each parameter follows:

count: the number of quantum elements to allocate.
quantum: the number of bytes in each quantum.

CopyMagickMemory

CopyMagickMemory() copies size bytes from memory area source to the destination. Copying between objects that overlap will take place correctly. It returns destination.

The format of the CopyMagickMemory method is:

void *CopyMagickMemory(void *destination,const void *source,
  const size_t size)

A description of each parameter follows:

destination: the destination.
source: the source.
size: the size of the memory in bytes to allocate.

GetMagickMemoryMethods

GetMagickMemoryMethods() gets the methods to acquire, resize, and destroy memory.

The format of the GetMagickMemoryMethods() method is:

void GetMagickMemoryMethods(AcquireMemoryHandler *acquire_memory_handler,
  ResizeMemoryHandler *resize_memory_handler,
  DestroyMemoryHandler *destroy_memory_handler)

A description of each parameter follows:

acquire_memory_handler: method to acquire memory (e.g. malloc).
resize_memory_handler: method to resize memory (e.g. realloc).
destroy_memory_handler: method to destroy memory (e.g. free).

GetVirtualMemoryBlob

GetVirtualMemoryBlob() returns the virtual memory blob associated with the specified MemoryInfo structure.

The format of the GetVirtualMemoryBlob method is:

void *GetVirtualMemoryBlob(const MemoryInfo *memory_info)

A description of each parameter follows:

memory_info: The MemoryInfo structure.

RelinquishAlignedMemory

RelinquishAlignedMemory() frees memory acquired with AcquireAlignedMemory() or reuse.

The format of the RelinquishAlignedMemory method is:

void *RelinquishAlignedMemory(void *memory)

A description of each parameter follows:

memory: A pointer to a block of memory to free for reuse.

RelinquishMagickMemory

RelinquishMagickMemory() frees memory acquired with AcquireMagickMemory() or AcquireQuantumMemory() for reuse.

The format of the RelinquishMagickMemory method is:

void *RelinquishMagickMemory(void *memory)

A description of each parameter follows:

memory: A pointer to a block of memory to free for reuse.

RelinquishVirtualMemory

RelinquishVirtualMemory() frees memory acquired with AcquireVirtualMemory().

The format of the RelinquishVirtualMemory method is:

MemoryInfo *RelinquishVirtualMemory(MemoryInfo *memory_info)

A description of each parameter follows:

memory_info: A pointer to a block of memory to free for reuse.

ResetMagickMemory

ResetMagickMemory() fills the first size bytes of the memory area pointed to by memory with the constant byte c.

The format of the ResetMagickMemory method is:

void *ResetMagickMemory(void *memory,int byte,const size_t size)

A description of each parameter follows:

memory: a pointer to a memory allocation.
byte: set the memory to this value.
size: size of the memory to reset.

ResizeMagickMemory

ResizeMagickMemory() changes the size of the memory and returns a pointer to the (possibly moved) block. The contents will be unchanged up to the lesser of the new and old sizes.

The format of the ResizeMagickMemory method is:

void *ResizeMagickMemory(void *memory,const size_t size)

A description of each parameter follows:

memory: A pointer to a memory allocation.
size: the new size of the allocated memory.

ResizeQuantumMemory

ResizeQuantumMemory() changes the size of the memory and returns a pointer to the (possibly moved) block. The contents will be unchanged up to the lesser of the new and old sizes.

The format of the ResizeQuantumMemory method is:

void *ResizeQuantumMemory(void *memory,const size_t count,
  const size_t quantum)

A description of each parameter follows:

memory: A pointer to a memory allocation.
count: the number of quantum elements to allocate.
quantum: the number of bytes in each quantum.

SetMagickMemoryMethods

SetMagickMemoryMethods() sets the methods to acquire, resize, and destroy memory. Your custom memory methods must be set prior to the MagickCoreGenesis() method.

The format of the SetMagickMemoryMethods() method is:

SetMagickMemoryMethods(AcquireMemoryHandler acquire_memory_handler,
  ResizeMemoryHandler resize_memory_handler,
  DestroyMemoryHandler destroy_memory_handler)

A description of each parameter follows:

acquire_memory_handler: method to acquire memory (e.g. malloc).
resize_memory_handler: method to resize memory (e.g. realloc).
destroy_memory_handler: method to destroy memory (e.g. free).