![]() |
![]() |
![]() |
![]() |
<GHashTable>
The GHashTable struct is an opaque data structure to represent a [Hash Table][glib-Hash-Tables]. It should only be accessed via the following functions.
(define-values (%return) (hash-table:add? hash-table key))
This is a convenience function for using a GHashTable as a set. It
is equivalent to calling g_hash_table_replace()
with key
as both the
key and the value.
In particular, this means that if key
already exists in the hash table, then
the old copy of key
in the hash table is freed and key
replaces it in the
table.
When a hash table only ever contains keys that have themselves as the corresponding value it is able to be stored more efficiently. See the discussion in the section description.
Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.
(define-values (%return) (hash-table:contains? hash-table key))
Checks if key
is in hash_table
.
(define-values () (hash-table:destroy hash-table))
Destroys all keys and values in the GHashTable and decrements its
reference count by 1. If keys and/or values are dynamically allocated,
you should either free them first or create the GHashTable with destroy
notifiers using g_hash_table_new_full()
. In the latter case the destroy
functions you supplied will be called on all keys and values during the
destruction phase.
(define-values (%return) (hash-table:insert? hash-table key value))
Inserts a new key and value into a GHashTable.
If the key already exists in the GHashTable its current
value is replaced with the new value. If you supplied a
value_destroy_func
when creating the GHashTable, the old
value is freed using that function. If you supplied a
key_destroy_func
when creating the GHashTable, the passed
key is freed using that function.
Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.
(define-values (%return) (hash-table:lookup hash-table key))
Looks up a key in a GHashTable. Note that this function cannot
distinguish between a key that is not present and one which is present
and has the value NULL
. If you need this distinction, use
g_hash_table_lookup_extended()
.
(define-values (%return orig-key value) (hash-table:lookup-extended hash-table lookup-key))
Looks up a key in the GHashTable, returning the original key and the
associated value and a gboolean which is TRUE
if the key was found. This
is useful if you need to free the memory allocated for the original key,
for example before calling g_hash_table_remove()
.
You can actually pass NULL
for lookup_key
to test
whether the NULL
key exists, provided the hash and equal functions
of hash_table
are NULL
-safe.
(define-values (%return) (hash-table:remove? hash-table key))
Removes a key and its associated value from a GHashTable.
If the GHashTable was created using g_hash_table_new_full()
, the
key and value are freed using the supplied destroy functions, otherwise
you have to make sure that any dynamically allocated values are freed
yourself.
(define-values () (hash-table:remove-all hash-table))
Removes all keys and their associated values from a GHashTable.
If the GHashTable was created using g_hash_table_new_full()
,
the keys and values are freed using the supplied destroy functions,
otherwise you have to make sure that any dynamically allocated
values are freed yourself.
(define-values (%return) (hash-table:replace? hash-table key value))
Inserts a new key and value into a GHashTable similar to
g_hash_table_insert()
. The difference is that if the key
already exists in the GHashTable, it gets replaced by the
new key. If you supplied a value_destroy_func
when creating
the GHashTable, the old value is freed using that function.
If you supplied a key_destroy_func
when creating the
GHashTable, the old key is freed using that function.
Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.
(define-values (%return) (hash-table:size hash-table))
Returns the number of elements contained in the GHashTable.
(define-values (%return) (hash-table:steal? hash-table key))
Removes a key and its associated value from a GHashTable without calling the key and value destroy functions.
(define-values () (hash-table:steal-all hash-table))
Removes all keys and their associated values from a GHashTable without calling the key and value destroy functions.
(define-values (%return stolen-key stolen-value) (hash-table:steal-extended hash-table lookup-key))
Looks up a key in the GHashTable, stealing the original key and the
associated value and returning TRUE
if the key was found. If the key was
not found, FALSE
is returned.
If found, the stolen key and value are removed from the hash table without
calling the key and value destroy functions, and ownership is transferred to
the caller of this method; as with g_hash_table_steal()
.
You can pass NULL
for lookup_key
, provided the hash and equal functions
of hash_table
are NULL
-safe.
(define-values () (hash-table:unref hash-table))
Atomically decrements the reference count of hash_table
by one.
If the reference count drops to 0, all keys and values will be
destroyed, and all memory allocated by the hash table is released.
This function is MT-safe and may be called from any thread.