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.Dd March 29, 2012
.Dt CK_HT_GET_SPMC 3
.Sh NAME
.Nm ck_ht_get_spmc
.Nd load a key-value pair from a hash table
.Sh LIBRARY
Concurrency Kit (libck, \-lck)
.Sh SYNOPSIS
.In ck_ht.h
.Ft bool
.Fn ck_ht_get_spmc "ck_ht_t *ht" "ck_ht_hash_t h" "ck_ht_entry_t *entry"
.Sh DESCRIPTION
The
.Fn ck_ht_get_spmc
function will return the value associated with the key specified in the
.Fa entry
argument in the hash table pointed to by the
.Fa ht
argument. The key specified in
.Fa entry
is expected to have the hash value specified by the
.Fa h
argument.
.Pp
If
.Fa ht
was created with CK_HT_MODE_BYTESTRING then
.Fa entry
must have been initialized with the
.Xr ck_ht_entry_set_key 3
or
.Xr ck_ht_entry_set 3
functions. If
.Fa ht
was created with CK_HT_MODE_DIRECT then
.Fa entry
must have been initialized with the
.Xr ck_ht_entry_key_set_direct 3
or
.Xr ck_ht_entry_set_direct 3
functions.
.Pp
It is expected that
.Fa h
was initialized with
.Xr ck_ht_hash 3
if
.Fa ht
was created with CK_HT_MODE_BYTESTRING. If
.Fa ht
was initialized with CK_HT_MODE_DIRECT then it is
expected that
.Fa h
was initialized with the
.Xr ck_ht_hash_direct 3
function.
.Pp
If the call to
.Fn ck_ht_get_spmc
was successful then the key-value pair in
.Fa entry
was successfully found in the hash table pointed
to by
.Fa h
and will fail if the key specified in
.Fa entry
does not exist in the hash table. If successful
.Fa entry
will contain the key-value pair found in the hash table
pointed to by the
.Fa ht
argument.
.Pp
If
.Fa ht
was initialized with CK_HT_MODE_BYTESTRING then
the key/value pair in
.Fa entry
may be extracted using the
.Xr ck_ht_entry_key 3
and
.Xr ck_ht_entry_value 3
functions. The length of the key may be extracted
using the
.Xr ck_ht_entry_key_length 3
function.
.Pp
If
.Fa ht
was initialized with CK_HT_MODE_DIRECT then the
key/value pair in
.Fa entry
may be extracted using the
.Xr ck_ht_entry_key_direct 3
and
.Xr ck_ht_entry_value_direct 3
functions.
.Pp
This function is safe to call in the presence of a concurrent writer.
.Sh RETURN VALUES
Upon successful completion
.Fn ck_ht_get_spmc
returns
.Dv true.
If successful,
.Fa entry
will contain the key/value pair as found
in the hash table.
Otherwise the function returns
.Dv false
on failure.
.Sh ERRORS
.Bl -tag -width Er
Behavior is undefined if
.Fa entry
or
.Fa ht
are uninitialized. The function will return
.Dv false
if the key as specified in
.Fa entry
was not found in the hash table.
.El
.Sh SEE ALSO
.Xr ck_ht_stat 3 ,
.Xr ck_ht_init 3 ,
.Xr ck_ht_destroy 3 ,
.Xr ck_ht_hash 3 ,
.Xr ck_ht_hash_direct 3 ,
.Xr ck_ht_set_spmc 3 ,
.Xr ck_ht_put_spmc 3 ,
.Xr ck_ht_grow_spmc 3 ,
.Xr ck_ht_remove_spmc 3 ,
.Xr ck_ht_reset_spmc 3 ,
.Xr ck_ht_reset_size_spmc 3 ,
.Xr ck_ht_count 3 ,
.Xr ck_ht_entry_empty 3 ,
.Xr ck_ht_entry_key_set 3 ,
.Xr ck_ht_entry_key_set_direct 3 ,
.Xr ck_ht_entry_key 3 ,
.Xr ck_ht_entry_key_length 3 ,
.Xr ck_ht_entry_value 3 ,
.Xr ck_ht_entry_set 3 ,
.Xr ck_ht_entry_set_direct 3 ,
.Xr ck_ht_entry_key_direct 3 ,
.Xr ck_ht_entry_value_direct 3 ,
.Xr ck_ht_iterator_init 3 ,
.Xr ck_ht_next 3
.Pp
Additional information available at http://concurrencykit.org/