NAME

cache_callbacks — Pre-defined cache callbacks used to configure a cache

SYNOPSIS

#include <cache.h>
#include <cache_callbacks.h>

uintptr_t
cache_key_hash_cb_cstring(void *key, void *unused);

uintptr_t
cache_key_hash_cb_integer(void *key, void *unused);

bool
cache_key_is_equal_cb_cstring(void *key1, void *key2, void *unused);

bool
cache_key_is_equal_cb_integer(void *key1, void *key2, void *unused);

void
cache_release_cb_free(void *key_or_value, void *unused);

void
cache_value_make_purgeable_cb(void *value, void *unused);

bool
cache_value_make_nonpurgeable_cb(void *value, void *unused);

uintptr_t
cache_hash_byte_string(const char *data, size_t bytes);

DESCRIPTION

These functions are intended to be used as callbacks to configure how a cache functions. They should be set in the cache_attributes_t passed into cache_create. They support common key types and offer support for using purgeable memory to allocate cache values.

cache_key_hash_cb_cstring() A key_hash_cb() function for NULL-terminated cstring keys.

cache_key_hash_cb_integer() A key_hash_cb() function for integer keys.

cache_key_is_equal_cb_cstring() A key_is_equal_cb() function for cstring keys.

cache_key_is_equal_cb_integer() A key_is_equal_cb() function for integer keys.

cache_release_cb_free() Can be used for key_release_cb() or value_release_cb() for keys/values allocated from malloc and family.

cache_value_make_purgeable_cb() Can be used for value_make_purgeable_cb() with values allocated from the purgeable malloc zone (see malloc/malloc.h). Calls malloc_make_purgeable() on value when it is unreferenced in order to reduce paging under memory pressure.

cache_value_make_nonpurgeable_cb() Can be used for value_make_nonpurgeable_cb() with values allocated from the purgeable malloc zone (see malloc/malloc.h). Calls malloc_make_nonpurgeable() on value when it is referenced in order to make a value nonpurgeable.

cache_hash_byte_string() Calculates a hash from a bytes string data of length bytes.

SEE ALSO

libcache(3) cache_create(3)