|
|
|
GLib Reference Manual | |
|---|
Double-ended QueuesDouble-ended Queues — double-ended queue data structure. |
#include <glib.h>
GQueue;
GQueue* g_queue_new (void);
void g_queue_free (GQueue *queue);
gboolean g_queue_is_empty (GQueue *queue);
guint g_queue_get_length (GQueue *queue);
void g_queue_reverse (GQueue *queue);
GQueue* g_queue_copy (GQueue *queue);
void g_queue_foreach (GQueue *queue,
GFunc func,
gpointer user_data);
GList* g_queue_find (GQueue *queue,
gconstpointer data);
GList* g_queue_find_custom (GQueue *queue,
gconstpointer data,
GCompareFunc func);
void g_queue_sort (GQueue *queue,
GCompareDataFunc compare_func,
gpointer user_data);
void g_queue_push_head (GQueue *queue,
gpointer data);
void g_queue_push_tail (GQueue *queue,
gpointer data);
void g_queue_push_nth (GQueue *queue,
gpointer data,
gint n);
gpointer g_queue_pop_head (GQueue *queue);
gpointer g_queue_pop_tail (GQueue *queue);
gpointer g_queue_pop_nth (GQueue *queue,
guint n);
gpointer g_queue_peek_head (GQueue *queue);
gpointer g_queue_peek_tail (GQueue *queue);
gpointer g_queue_peek_nth (GQueue *queue,
guint n);
gint g_queue_index (GQueue *queue,
gconstpointer data);
void g_queue_remove (GQueue *queue,
gconstpointer data);
void g_queue_remove_all (GQueue *queue,
gconstpointer data);
void g_queue_insert_before (GQueue *queue,
GList *sibling,
gpointer data);
void g_queue_insert_after (GQueue *queue,
GList *sibling,
gpointer data);
void g_queue_insert_sorted (GQueue *queue,
gpointer data,
GCompareDataFunc func,
gpointer user_data);
void g_queue_push_head_link (GQueue *queue,
GList *link_);
void g_queue_push_tail_link (GQueue *queue,
GList *link_);
void g_queue_push_nth_link (GQueue *queue,
gint n,
GList *link_);
GList* g_queue_pop_head_link (GQueue *queue);
GList* g_queue_pop_tail_link (GQueue *queue);
GList* g_queue_pop_nth_link (GQueue *queue,
guint n);
GList* g_queue_peek_head_link (GQueue *queue);
GList* g_queue_peek_tail_link (GQueue *queue);
GList* g_queue_peek_nth_link (GQueue *queue,
guint n);
gint g_queue_link_index (GQueue *queue,
GList *link_);
void g_queue_unlink (GQueue *queue,
GList *link_);
void g_queue_delete_link (GQueue *queue,
GList *link_);
The GQueue structure and its associated functions provide a standard queue data structure. Internally, GQueue uses the same data structure as GList to store elements.
The data contained in each element can be either integer values, by using one of the Type Conversion Macros, or simply pointers to any type of data.
To create a new GQueue, use g_queue_new().
To add elements, use g_queue_push_head(), g_queue_push_head_link(),
g_queue_push_tail() and g_queue_push_tail_link().
To remove elements, use g_queue_pop_head() and g_queue_pop_tail().
To free the entire queue, use g_queue_free().
typedef struct {
GList *head;
GList *tail;
guint length;
} GQueue;
Contains the public fields of a Queue.
void g_queue_free (GQueue *queue);
Frees the memory allocated for the GQueue.
queue : |
a GQueue. |
gboolean g_queue_is_empty (GQueue *queue);
Returns TRUE if the queue is empty.
queue : |
a GQueue. |
| Returns : | TRUE if the queue is empty.
|
guint g_queue_get_length (GQueue *queue);
Returns the number of items in queue.
queue : |
a GQueue |
| Returns : | The number of items in queue.
|
Since 2.4
void g_queue_reverse (GQueue *queue);
Reverses the order of the items in queue.
queue : |
a GQueue |
Since 2.4
GQueue* g_queue_copy (GQueue *queue);
Copies a queue. Note that is a shallow copy. If the elements in the
queue consist of pointers to data, the pointers are copied, but the
actual data is not.
queue : |
a GQueue |
| Returns : | A copy of queue
|
Since 2.4
void g_queue_foreach (GQueue *queue, GFunc func, gpointer user_data);
Calls func for each element in the queue passing user_data to the
function.
queue : |
a GQueue |
func : |
the function to call for each element's data |
user_data : |
user data to pass to func
|
Since 2.4
GList* g_queue_find (GQueue *queue, gconstpointer data);
Finds the first link in queue which contains data.
queue : |
a GQueue |
data : |
data to find |
| Returns : | The first link in queue which contains data.
|
Since 2.4
GList* g_queue_find_custom (GQueue *queue, gconstpointer data, GCompareFunc func);
Finds an element in a GQueue, using a supplied function to find the desired element. It iterates over the queue, calling the given function which should return 0 when the desired element is found. The function takes two gconstpointer arguments, the GQueue element's data and the given user data.
queue : |
a GQueue |
data : |
user data passed to func
|
func : |
a GCompareFunc to call for each element. It should return 0 when the desired element is found |
| Returns : | The found link, or NULL if it wasn't found
|
Since 2.4
void g_queue_sort (GQueue *queue, GCompareDataFunc compare_func, gpointer user_data);
Sorts queue using compare_func.
queue : |
a GQueue |
compare_func : |
the GCompareDataFunc used to sort queue. This function
is passed two elements of the queue and should return 0 if they are
equal, a negative value if the first comes before the second, and
a positive value if the second comes before the first.
|
user_data : |
user data passed to compare_func
|
Since 2.4
void g_queue_push_head (GQueue *queue, gpointer data);
Adds a new element at the head of the queue.
queue : |
a GQueue. |
data : |
the data for the new element. |
void g_queue_push_tail (GQueue *queue, gpointer data);
Adds a new element at the tail of the queue.
queue : |
a GQueue. |
data : |
the data for the new element. |
void g_queue_push_nth (GQueue *queue, gpointer data, gint n);
Inserts a new element into queue at the given position
queue : |
a GQueue |
data : |
the data for the new element |
n : |
the position to insert the new element. If n is negative or
larger than the number of elements in the queue, the element is
added to the end of the queue.
|
Since 2.4
gpointer g_queue_pop_head (GQueue *queue);
Removes the first element of the queue.
queue : |
a GQueue. |
| Returns : | the data of the first element in the queue, or NULL if the queue
is empty.
|
gpointer g_queue_pop_tail (GQueue *queue);
Removes the last element of the queue.
queue : |
a GQueue. |
| Returns : | the data of the last element in the queue, or NULL if the queue
is empty.
|
gpointer g_queue_pop_nth (GQueue *queue, guint n);
Removes the n'th element of queue.
queue : |
a GQueue |
n : |
the position of the element. |
| Returns : | the element's data, or NULL if n is off the end of queue.
|
Since 2.4
gpointer g_queue_peek_head (GQueue *queue);
Returns the first element of the queue.
queue : |
a GQueue. |
| Returns : | the data of the first element in the queue, or NULL if the queue
is empty.
|
gpointer g_queue_peek_tail (GQueue *queue);
Returns the last element of the queue.
queue : |
a GQueue. |
| Returns : | the data of the last element in the queue, or NULL if the queue
is empty.
|
gpointer g_queue_peek_nth (GQueue *queue, guint n);
Returns the n'th element of queue.
queue : |
a GQueue |
n : |
the position of the element. |
| Returns : | The data for the n'th element of queue, or NULL if n is
off the end of queue.
|
Since 2.4
gint g_queue_index (GQueue *queue, gconstpointer data);
Returns the position of the first element in queue which contains data.
queue : |
a GQueue |
data : |
the data to find. |
| Returns : | The position of the first element in queue which contains data, or -1 if no element in queue contains data.
|
Since 2.4
void g_queue_remove (GQueue *queue, gconstpointer data);
Removes the first element in queue that contains data.
queue : |
a GQueue |
data : |
data to remove. |
Since 2.4
void g_queue_remove_all (GQueue *queue, gconstpointer data);
Remove all elemeents in queue which contains data.
queue : |
a GQueue |
data : |
data to remove |
Since 2.4
void g_queue_insert_before (GQueue *queue, GList *sibling, gpointer data);
Inserts data into queue before sibling.
sibling must be part of queue.
Since 2.4
void g_queue_insert_after (GQueue *queue, GList *sibling, gpointer data);
Inserts data into queue after sibling
sibling must be part of queue
Since 2.4
void g_queue_insert_sorted (GQueue *queue, gpointer data, GCompareDataFunc func, gpointer user_data);
Inserts data into queue using func to determine the new position.
queue : |
a GQueue |
data : |
the data to insert |
func : |
the GCompareDataFunc used to compare elements in the queue. It is
called with two elements of the queue and user_data. It should
return 0 if the elements are equal, a negative value if the first
element comes before the second, and a positive value if the second
element comes after the first.
|
user_data : |
user data passed to func.
|
Since 2.4
void g_queue_push_head_link (GQueue *queue, GList *link_);
Adds a new element at the head of the queue.
void g_queue_push_tail_link (GQueue *queue, GList *link_);
Adds a new element at the tail of the queue.
void g_queue_push_nth_link (GQueue *queue, gint n, GList *link_);
Inserts link into queue at the given position.
queue : |
a GQueue |
n : |
the position to insert the link. If this is negative or larger than
the number of elements in queue, the link is added to the end of
queue.
|
link_ : |
the link to add to queue
|
Since 2.4
GList* g_queue_pop_head_link (GQueue *queue);
Removes the first element of the queue.
GList* g_queue_pop_tail_link (GQueue *queue);
Removes the last element of the queue.
GList* g_queue_pop_nth_link (GQueue *queue, guint n);
Removes and returns the link at the given position.
queue : |
a GQueue |
n : |
the link's position |
| Returns : | The n'th link, or NULL if n is off the end of queue.
|
Since 2.4
GList* g_queue_peek_head_link (GQueue *queue);
Returns the first link in queue
queue : |
a GQueue |
| Returns : | the first link in queue, or NULL if queue is empty
|
Since 2.4
GList* g_queue_peek_tail_link (GQueue *queue);
Returns the last link queue.
queue : |
a GQueue |
| Returns : | the last link in queue, or NULL if queue is empty
|
Since 2.4
GList* g_queue_peek_nth_link (GQueue *queue, guint n);
Returns the link at the given position
queue : |
a GQueue |
n : |
the position of the link |
| Returns : | The link at the n'th position, or NULL if n is off the
end of the list
|
Since 2.4
gint g_queue_link_index (GQueue *queue, GList *link_);
Returns the position of link_ in queue.
queue : |
a Gqueue |
link_ : |
A GList link |
| Returns : | The position of link_, or -1 if the link is
not part of queue
|
Since 2.4
void g_queue_unlink (GQueue *queue, GList *link_);
Unlinks link_ so that it will no longer be part of queue. The link is
not freed.
link_ must be part of queue,
Since 2.4
| << Singly-Linked Lists | Trash Stacks >> |