oracular (3) memcached_memory_allocators.3.gz

NAME

       memcached_memory_allocators - libmemcached Documentation

       Manage memory allocator functions

SYNOPSIS

       #include <libmemcached/memcached.h>
              Compile and link with -lmemcached

       memcached_return_t  memcached_set_memory_allocators(memcached_st  *ptr,  memcached_malloc_fn  mem_malloc,
       memcached_free_fn  mem_free,  memcached_realloc_fn  mem_realloc,  memcached_calloc_fn  mem_calloc,   void
       *context)

              Parameters

                     • ptr -- pointer to an initialized memcached_st struct

                     • mem_malloc -- pointer to a memcached_malloc_fn callback

                     • mem_free -- pointer to a memcached_free_fn callback

                     • mem_realloc -- pointer to a memcached_realloc_fn callback

                     • mem_calloc -- pointer to a memcached_calloc_fn callback

                     • context -- pointer to a user supplied context

              Returns
                     memcached_return_t indicating success

       void      memcached_get_memory_allocators(memcached_st     *ptr,     memcached_malloc_fn     *mem_malloc,
       memcached_free_fn *mem_free, memcached_realloc_fn *mem_realloc, memcached_calloc_fn *mem_calloc)

              Parameters

                     • ptr -- pointer to an initialized memcached_st struct

                     • mem_malloc -- pointer to store the address of the memcached_malloc_fn callback

                     • mem_free -- pointer to store the address of the memcached_free_fn callback

                     • mem_realloc -- pointer to store the address of the memcached_realloc_fn callback

                     • mem_calloc -- pointer to store the address of the memcached_calloc_fn callback

       void *memcached_get_memory_allocators_context(const memcached_st *ptr)

              Parameters
                     ptr -- pointer to an initialized memcached_st struct

              Returns
                     pointer to the user supplied context

       typedef void *(*memcached_malloc_fn)(memcached_st *ptr, const size_t size, void *context)

              Param ptr
                     pointer to an initialized memcached_st struct

              Param size
                     the number of bytes to allocate

              Param context
                     pointer to the user supplied context

              Returns
                     pointer to at least size bytes of allocated memory

       typedef void *(*memcached_realloc_fn)(memcached_st *ptr, void *mem, const size_t size, void *context)

              Param ptr
                     pointer to an initialized memcached_st struct

              Param mem
                     pointer to previously allocated memory

              Param size
                     the number of bytes to allocate

              Param context
                     pointer to the user supplied context

              Returns
                     pointer to at least size bytes of allocated memory

       typedef void (*memcached_free_fn)(memcached_st *ptr, void *mem, void *context)

              Param ptr
                     pointer to an initialized memcached_st struct

              Param mem
                     pointer to previously allocated memory

              Param context
                     pointer to the user supplied context

       typedef void *(*memcached_calloc_fn)(memcached_st *ptr, size_t nelem, const size_t elsize, void *context)

              Param ptr
                     pointer to an initialized memcached_st struct

              Param nelem
                     number of elements to allocate

              Param elsize
                     the number of bytes to allocate per element

              Param context
                     pointer to the user supplied context

              Returns
                     pointer to at least elsize * nelem  bytes of allocated and zeroed memory

DESCRIPTION

       libmemcached allows you to specify your own memory  allocators,  optimized  for  your  application.  This
       enables libmemcached to be used inside of applications that have their own malloc implementation.

       memcached_set_memory_allocators()  is  used  to  set the memory allocators used by the memcached instance
       specified by ptr. Please note that you cannot override only one of the memory  allocators,  you  have  to
       specify  a  complete  new set if you want to override one of them. All of the memory allocation functions
       should behave as specified in the C99 standard. Specify NULL as  all  functions  to  reset  them  to  the
       default values.

       memcached_get_memory_allocators()  is  used  to  get  the currently used memory allocators by a memcached
       handle.

       memcached_get_memory_allocators_context() returns the void * that  was  passed  in  during  the  call  to
       memcached_set_memory_allocators().

       The first argument to the memory allocator functions is a pointer to a memcached structure, the is passed
       as const and you will need to clone it in order to make use of any operation which would modify it.

NOTES

       In version 0.38 all functions were modified to have a context void pointer passed to them.  This  was  so
       that custom allocators could have their own space for memory.

RETURN VALUE

       memcached_set_memory_allocators()  returns  MEMCACHED_SUCCESS  upon success, and MEMCACHED_FAILURE if you
       don't pass a complete set of function pointers.

SEE ALSO

       memcached(1) libmemcached(3) memcached_strerror(3)