bionic (3) ck_rhs_init.3.gz

NAME

     ck_rhs_init — initialize a hash set

LIBRARY

     Concurrency Kit (libck, -lck)

SYNOPSIS

     #include <ck_rhs.h>

     typedef unsigned long
     ck_rhs_hash_cb_t(const void *key, unsigned long seed);

     typedef bool
     ck_rhs_compare_cb_t(const void *c1, const void *c2);

     bool
     ck_rhs_init(ck_rhs_t *hs, unsigned int mode, ck_rhs_hash_cb_t *hash_function, ck_rhs_compare_cb_t *compare,
         struct ck_malloc *allocator, unsigned long capacity, unsigned long seed);

DESCRIPTION

     The ck_rhs_init() function initializes the hash set pointed to by the hs pointer.

     The argument mode specifies the type of key-value pairs to be stored in the hash set as well as the
     expected concurrent access model.  The value of mode consists of a bitfield of one of the following:

     CK_RHS_MODE_OBJECT
             The hash set is meant to store pointers to objects. This provides a hint that only CK_MD_VMA_BITS
             are necessary to encode the key argument. Any unused pointer bits are leveraged for internal
             optimizations.

     CK_RHS_MODE_DIRECT
             The hash set is meant to directly store key values and that all bits of the key are used to encode
             values.

     CK_RHS_MODE_READ_MOSTLY
             Optimize read operations over put/delete.

     The concurrent access model is specified by:

     CK_RHS_MODE_SPMC
             The hash set should allow for concurrent readers in the presence of a single writer.

     CK_RHS_MODE_MPMC
             The hash set should allow for concurrent readers in the presence of concurrent writers. This is
             currently unsupported.

     The developer is free to specify additional workload hints.  These hints are one of:

The argument hash_function is a mandatory pointer to a user-specified hash function.  A user-specified hash
function takes two arguments. The key argument is a pointer to a key. The seed argument is the initial seed
The compare argument is an optional pointer to a user-specified key comparison function. If NULL is specified in
The allocator argument is a pointer to a structure containing malloc and free function pointers which
initialized.

The argument capacity represents the initial number of keys the hash set is expected to contain. This argument
contain the number of entries capacity specifies.

The argument seed specifies the initial seed used by the underlying hash function.  The user is free to choose a

RETURN VALUES

     Upon successful completion ck_rhs_init() returns a value of true and otherwise returns a value of false to
     indicate an error.

ERRORS

     The behavior of ck_rhs_init() is undefined if hs is not a pointer to a ck_rhs_t object.

SEE ALSO

     ck_rhs_move(3), ck_rhs_destroy(3), CK_RHS_HASH(3), ck_rhs_iterator_init(3), ck_rhs_next(3), ck_rhs_get(3),
     ck_rhs_put(3), ck_rhs_put_unique(3), ck_rhs_set(3), ck_rhs_fas(3), ck_rhs_remove(3), ck_rhs_grow(3),
     ck_rhs_rebuild(3), ck_rhs_gc(3), ck_rhs_count(3), ck_rhs_reset(3), ck_rhs_reset_size(3), ck_rhs_stat(3)

     Additional information available at http://concurrencykit.org/

                                               September 17, 2012