Description

Represents a FIFO queue implemented with a dynamic array.

kQueue represents a dynamic, array-based queue of objects or values. The kQueue constructor accepts a kType value that determines the type of items that will be stored in the queue. The queue will automatically grow as new items are added.

kStatus QueueExample()
{
    kQueue queue = kNULL; 
    k32s values[] = { 1, 2, 3, 5, 7, 9 }; 
    kSize i; 
    
    kTry
    {
         //create a queue that can store 32-bit integers
         kTest(kQueue_Construct(&queue, kTypeOf(k32s), 0, kNULL)); 
         
         //add some initial items to the queue
         for (i = 0; i < kCountOf(values); ++i)
         {
             kTest(kQueue_Add(queue, &values[i]); 
         }
         
         //print some information about the queue and its items
         printf("Item type: %s\n", kType_Name(kQueue_ItemType(queue))); 
         printf("Count: %u\n", (k32u) kQueue_Count(queue)); 
 
         for (i = 0; i < kQueue_Count(queue); ++i)
         {
             //the kQueue_As_ macro can be used to get a queue item and cast it to the desired type; 
             //this is equivalent to *(k32s*)kQueue_At(queue, i);
             k32s value = kQueue_As_(queue, i, k32s); 
             printf("Item %u: %d\n", (k32u)i, value);  
         }
    }
    kFinally
    {
         kObject_Destroy(queue); 
         kEndFinally(); 
    }
   
    return kOK; 
}

For queues that contain objects (e.g. kImage) as opposed to values (e.g. k32s), the objects are not automatically destroyed when the queue is destroyed. To recursively destroy both the queue and the queue items, use kObject_Dispose.

Inheritance diagram for kQueue:

Public Member Functions
kSize	kCollection_Count (kCollection collection)
	Gets the collection element count. More...

kIterator	kCollection_GetIterator (kCollection collection)
	Returns an iterator to the first element in the collection. More...

kBool	kCollection_HasNext (kCollection collection, kIterator iterator)
	Determines whether a collection has another item. More...

kType	kCollection_ItemType (kCollection collection)
	Gets the collection element type. More...

void *	kCollection_Next (kCollection collection, kIterator *iterator)
	Gets the next collection element and then advances the iterator. More...

kAlloc	kObject_Alloc (kObject object)
	Gets the memory allocator associated with this object. More...

kStatus	kObject_Clone (kObject *object, kObject source, kAlloc allocator)
	Constructs a new object by copying an existing object, including any aggregated child elements. More...

kStatus	kObject_Destroy (kObject object)
	Destroys the object. More...

kStatus	kObject_Dispose (kObject object)
	Destroys the object and any aggregated child elements. More...

kBool	kObject_Equals (kObject object, kObject other)
	Determines whether the object is equal to another object. More...

kSize	kObject_HashCode (kObject object)
	Gets a hash code representing the state of this object. More...

kBool	kObject_Is (kObject object, kType type)
	Determines whether this object is an instance of the specified type. More...

kBool	kObject_IsShared (kObject object)
	Reports whether the object is currently shared (reference count greater than one). More...

kStatus	kObject_SetPool (kObject object, kObjectPool pool)
	Sets the object pool associated with this object. More...

kStatus	kObject_Share (kObject object)
	Increments the reference count associated with this object. More...

kSize	kObject_Size (kObject object)
	Estimates the memory consumed by this object, including any aggregated child elements. More...

kType	kObject_Type (kObject object)
	Returns the type of the object. More...

kStatus	kQueue_Add (kQueue queue, const void *item)
	Adds the specified item to the end of the queue. More...

kStatus	kQueue_AddCount (kQueue queue, kSize count)
	Increases the queue count by the specified amount. More...

kStatus	kQueue_Allocate (kQueue queue, kType itemType, kSize initialCapacity)
	Reallocates the queue item buffer. More...

kStatus	kQueue_Assign (kQueue queue, kQueue source)
	Performs a shallow copy of the source queue. More...

void *	kQueue_At (kQueue queue, kSize index)
	Returns a pointer to the specified item in the queue buffer. More...

kSize	kQueue_Capacity (kQueue queue)
	Returns the number of elements for which space has been allocated. More...

kStatus	kQueue_Clear (kQueue queue)
	Sets the count of queue items to zero. More...

kStatus	kQueue_Construct (kQueue *queue, kType itemType, kSize initialCapacity, kAlloc allocator)
	Constructs a kQueue object. More...

kSize	kQueue_Count (kQueue queue)
	Returns the current count of items in the queue. More...

kStatus	kQueue_Item (kQueue queue, kSize index, void *item)
	Gets the value of an item. More...

kSize	kQueue_ItemSize (kQueue queue)
	Returns the queue element size. More...

kType	kQueue_ItemType (kQueue queue)
	Returns the queue element type. More...

kStatus	kQueue_Purge (kQueue queue)
	Disposes any elements in the queue and sets the count of queue items to zero. More...

kStatus	kQueue_Remove (kQueue queue, void *item)
	Removes the item at the head of the queue. More...

kStatus	kQueue_RemoveCount (kQueue queue, kSize count)
	Decreases the queue count by the specified amount. More...

kStatus	kQueue_Reserve (kQueue queue, kSize capacity)
	Ensures that capacity is reserved for at least the specified number of queue items. More...

kStatus	kQueue_SetItem (kQueue queue, kSize index, const void *item)
	Sets the value of an item. More...

Member Function Documentation

kSize kCollection_Count ( kCollection collection )

inherited

Gets the collection element count.

Parameters

collection Collection object.

Returns: Item count.

kIterator kCollection_GetIterator ( kCollection collection )

inherited

Returns an iterator to the first element in the collection.

Parameters

collection Collection object.

Returns: Iterator.

kBool kCollection_HasNext	(	kCollection	collection,
		kIterator	iterator
	)

inherited

Determines whether a collection has another item.

Parameters

collection	Collection object.
iterator	Collection iterator.

Returns: kTRUE if the collection has a next element.

kType kCollection_ItemType ( kCollection collection )

inherited

Gets the collection element type.

Parameters

collection Collection object.

Returns: Item type.

void * kCollection_Next	(	kCollection	collection,
		kIterator *	iterator
	)

inherited

Gets the next collection element and then advances the iterator.

Parameters

collection	Collection object.
iterator	Pointer to collection iterator.

Returns: Pointer to next collection element.

kAlloc kObject_Alloc ( kObject object )

inherited

Gets the memory allocator associated with this object.

Most objects are constructed with an allocator, which is used to allocate the memory required by the object. Objects retain a reference to this allocator to enable further allocations and to free memory when the object is destroyed.

Parameters

object Object.

Returns: Memory allocator.

See also: kAlloc, kObject_Alloc_

kStatus kObject_Clone	(	kObject *	object,
		kObject	source,
		kAlloc	allocator
	)

inherited

Constructs a new object by copying an existing object, including any aggregated child elements.

If the source object is an object collection (e.g. kArrayList<kString>), any aggregated child objects are also cloned. In this case, the kObject_Dispose method can be used to free the cloned collection and its associated elements.

This method will fail if the source object (or an aggregated child element) does not support cloning.

Parameters

object	Receives the constructed object.
source	Source object.
allocator	Memory allocator (or kNULL for default).

Returns: Operation status.

See also: kObject_Dispose

kStatus kObject_Destroy ( kObject object )

inherited

Destroys the object.

The kObject_Destroy method destroys the object itself and any resources that are owned by the object. See Object Destruction for more information.

When an object is destroyed (or disposed), its reference count is decremented. The object is only truly destroyed when the reference count reaches zero. See Reference Counting for more information.

Parameters

object Object (or kNULL).

Returns: Operation status.

See also: Object Destruction, Reference Counting

kStatus kObject_Dispose ( kObject object )

inherited

Destroys the object and any aggregated child elements.

The kObject_Dispose method destroys the object itself, any resources that are owned by the object, and if the object represents a collection of objects, any child objects in the collection. See Object Destruction for more information.

When an object is destroyed (or disposed), its reference count is decremented. The object is only truly destroyed when the reference count reaches zero. See Reference Counting for more information.

Parameters

object Object (or kNULL).

Returns: Operation status.

See also: Object Destruction, Reference Counting

kBool kObject_Equals	(	kObject	object,
		kObject	other
	)

inherited

Determines whether the object is equal to another object.

By default, objects are compared by reference; objects are considered equal if the given handles refer to the same object instance. However, some classes override the Equals method to provide a more meaningful comparison (e.g. kString).

Parameters

object	Object.
other	Object for comparison.

Returns: kTRUE if the objects are equal.

kSize kObject_HashCode ( kObject object )

inherited

Gets a hash code representing the state of this object.

By default, objects return a hash code based on the object handle value. However, some classes override the HashCode method to provide a more useful hash (e.g. kString).

Parameters

object Object.

Returns: Hash code.

kBool kObject_Is	(	kObject	object,
		kType	type
	)

inherited

Determines whether this object is an instance of the specified type.

This function compares the type of this object with the given type. An object is considered to be an instance of a given type if a) the type represents a class and this object inherits from (or instantiates) that class, or b) the type represents an interface and this object implements the interface.

Parameters

object	Object.
type	Type.

Returns: kTRUE if the object is of the specified type; otherwise kFALSE.

See also: kObject_Is_, kType_Is

kBool kObject_IsShared ( kObject object )

inherited

Reports whether the object is currently shared (reference count greater than one).

Objects are initialized with a reference count of one. The kObject_Share method can be used to increment the reference count. The kObject_Destroy and kObject_Dispose methods decrease the reference count, and when the reference count reaches zero, the object is actually destroyed/disposed.

This method can be used to determine if the reference count of an object is currently greater than one.

This method is thread-safe.

Parameters

object Object.

Returns: kTRUE if the object is shared; kFALSE otherwise.

See also: Reference Counting, kObject_Share

kStatus kObject_SetPool	(	kObject	object,
		kObjectPool	pool
	)

inherited

Sets the object pool associated with this object.

Object pools can be used to implement custom lifecycle management. If an object has an assigned pool, then the kObjectPool_Reclaim method will be called just prior to destruction, to provide an opportunity for the object to be reclaimed.

Parameters

object	Object.
pool	Pool object (or kNULL to clear the pool assignment).

Returns: Operation status.

kStatus kObject_Share ( kObject object )

inherited

Increments the reference count associated with this object.

This method is thread-safe.

Parameters

object Object.

Returns: Operation status.

See also: reference-counting

kSize kObject_Size ( kObject object )

inherited

Estimates the memory consumed by this object, including any aggregated child elements.

This method can be optionally overridden by kObject-derived classes to report the amount of memory consumed by an object. The default implementation reports only the size of the class instance (additional allocations performed by the class are excluded).

Parameters

object Object.

Returns: Object size, in bytes.

kType kObject_Type ( kObject object )

inherited

Returns the type of the object.

Each object is an instance of a specific class type. The type handle returned by this function can be used to learn about the class.

Parameters

object Object.

Returns: Type.

See also: kType, kObject_Type_

kStatus kQueue_Add	(	kQueue	queue,
		const void *	item
	)

Adds the specified item to the end of the queue.

Parameters

queue	Queue object.
item	Pointer to item that will be copied (by value) into the queue.

Returns: Operation status.

kStatus kQueue_AddCount	(	kQueue	queue,
		kSize	count
	)

Increases the queue count by the specified amount.

Increases queue capacity if necessary; existing queue items are preserved. New items are not initialized.

Parameters

queue	Queue object.
count	Amount to add to the existing count.

Returns: Operation status.

kStatus kQueue_Allocate	(	kQueue	queue,
		kType	itemType,
		kSize	initialCapacity
	)

Reallocates the queue item buffer.

Parameters

queue	Queue object.
itemType	Type of queue element.
initialCapacity	Capacity initially reserved for queue items.

Returns: Operation status.

kStatus kQueue_Assign	(	kQueue	queue,
		kQueue	source
	)

Performs a shallow copy of the source queue.

Source items are copied by value; if the source queue contains objects, the object handles are copied but the objects are not cloned.

Parameters

queue	Queue object.
source	Source queue to be copied.

Returns: Operation status.

void * kQueue_At	(	kQueue	queue,
		kSize	index
	)

Returns a pointer to the specified item in the queue buffer.

Parameters

queue	Queue object.
index	Item index.

Returns: Pointer to queue element.

kSize kQueue_Capacity ( kQueue queue )

Returns the number of elements for which space has been allocated.

Parameters

queue Queue object.

Returns: Queue capacity.

kStatus kQueue_Clear ( kQueue queue )

Sets the count of queue items to zero.

Parameters

queue Queue object.

Returns: Operation status.

kStatus kQueue_Construct	(	kQueue *	queue,
		kType	itemType,
		kSize	initialCapacity,
		kAlloc	allocator
	)

Constructs a kQueue object.

Parameters

queue	Receives constructed queue object.
itemType	Type of queue element.
initialCapacity	Capacity initially reserved for queue items.
allocator	Memory allocator (or kNULL for default).

Returns: Operation status.

kSize kQueue_Count ( kQueue queue )

Returns the current count of items in the queue.

Parameters

queue Queue object.

Returns: Current count of items.

kStatus kQueue_Item	(	kQueue	queue,
		kSize	index,
		void *	item
	)

Gets the value of an item.

Parameters

queue	Queue object.
index	Item index.
item	Destination for item that will be copied (by value) from the queue.

Returns: Operation status.

kSize kQueue_ItemSize ( kQueue queue )

Returns the queue element size.

Parameters

queue Queue object.

Returns: Item size, in bytes.

kType kQueue_ItemType ( kQueue queue )

Returns the queue element type.

Parameters

queue Queue object.

Returns: Item type.

kStatus kQueue_Purge ( kQueue queue )

Disposes any elements in the queue and sets the count of queue items to zero.

Parameters

queue Queue object.

Returns: Operation status.

kStatus kQueue_Remove	(	kQueue	queue,
		void *	item
	)

Removes the item at the head of the queue.

Parameters

queue	Queue object.
item	Destination for the removed item (copied by value, can be null).

Returns: Operation status.

kStatus kQueue_RemoveCount	(	kQueue	queue,
		kSize	count
	)

Decreases the queue count by the specified amount.

Parameters

queue	Queue object.
count	Amount to remove from the existing count.

Returns: Operation status.

kStatus kQueue_Reserve	(	kQueue	queue,
		kSize	capacity
	)

Ensures that capacity is reserved for at least the specified number of queue items.

Existing queue items are preserved.

Parameters

queue	Queue object.
capacity	Queue capacity, in items.

Returns: Operation status.

kStatus kQueue_SetItem	(	kQueue	queue,
		kSize	index,
		const void *	item
	)

Sets the value of an item.

Parameters

queue	Queue object.
index	Item index.
item	Item that will be copied into the queue.

Returns: Operation status.

The documentation for this class was generated from the following file:

Data/kQueue.h

Description

Public Member Functions

Member Function Documentation