Class VecDeque

java.lang.Object

org.javagi.base.ProxyInstance

org.freedesktop.gstreamer.gst.VecDeque

All Implemented Interfaces:

Proxy

@Generated("org.javagi.JavaGI")
public class VecDeque
extends ProxyInstance

GstVecDeque is an object that provides standard double-ended queue (deque) functionality based on an array instead of linked lists. This reduces the overhead caused by memory management by a large factor.

Since:

1.26

Constructor Summary

Constructors

Constructor	Description
VecDeque(MemorySegment address)	Create a VecDeque proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears queue this VecDeque and frees all memory associated to it.
@Nullable MemorySegment	dropElement(long idx)	Drops the queue element at position idx from queue array.
boolean	dropStruct(long idx, @Nullable MemorySegment pStruct)	Drops the queue element at position idx from queue this VecDeque and copies the data of the element or structure that was removed into pStruct if pStruct is set (not NULL).
long	find(@Nullable CompareFunc func)	Finds an element in the queue array, either by comparing every element with func or by looking up data if no compare function func is provided, and returning the index of the found element.
void	free()	Frees queue this VecDeque and all memory associated to it.
long	getLength()	Returns the length of the queue this VecDeque
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
boolean	isEmpty()	Checks if the queue this VecDeque is empty.
static VecDeque	new_(long initialSize)	Allocates a new GstVecDeque object with an initial queue size of initialSize.
static VecDeque	newForStruct(long structSize, long initialSize)	Allocates a new GstVecDeque object for elements (e.g. structures) of size structSize, with an initial queue size of initialSize.
@Nullable MemorySegment	peekHead()	Returns the head of the queue this VecDeque and does not remove it from the queue.
@Nullable MemorySegment	peekHeadStruct()	Returns the head of the queue this VecDeque without removing it from the queue.
@Nullable MemorySegment	peekNth(long idx)	Returns the item at idx in array, but does not remove it from the queue.
@Nullable MemorySegment	peekNthStruct(long idx)	Returns the item at idx in array, but does not remove it from the queue.
@Nullable MemorySegment	peekTail()	Returns the tail of the queue array, but does not remove it from the queue.
@Nullable MemorySegment	peekTailStruct()	Returns the tail of the queue array, but does not remove it from the queue.
@Nullable MemorySegment	popHead()	Returns and head of the queue this VecDeque and removes it from the queue.
@Nullable MemorySegment	popHeadStruct()	Returns the head of the queue this VecDeque and removes it from the queue.
@Nullable MemorySegment	popTail()	Returns the tail of the queue this VecDeque and removes it from the queue.
@Nullable MemorySegment	popTailStruct()	Returns the tail of the queue this VecDeque and removes it from the queue.
void	pushSorted(@Nullable MemorySegment data, @Nullable CompareDataFunc func)	Pushes data to the queue array, finding the correct position by comparing data with each array element using func.
void	pushSortedStruct(@Nullable MemorySegment pStruct, @Nullable CompareDataFunc func)	Pushes the element at address pStruct into the queue this VecDeque (copying the contents of a structure of the struct_size specified when creating the queue into the array), finding the correct position by comparing the element at pStruct with each element in the array using func.
void	pushTail(@Nullable MemorySegment data)	Pushes data to the tail of the queue array.
void	pushTailStruct(@Nullable MemorySegment pStruct)	Pushes the element at address pStruct to the tail of the queue this VecDeque (Copies the contents of a structure of the struct_size specified when creating the queue into the array).
void	setClearFunc()	Sets a function to clear an element of array.
void	sort(@Nullable CompareDataFunc compareFunc)	Sorts the queue this VecDeque by comparing elements against each other using the provided compareFunc.

Methods inherited from class ProxyInstance

equals, handle, hashCode

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

VecDeque

public VecDeque(MemorySegment address)

Create a VecDeque proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

Method Details

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

new_

public static VecDeque new_(long initialSize)

Allocates a new GstVecDeque object with an initial queue size of initialSize.

Parameters:

initialSize - Initial size of the new queue

Returns:

a new GstVecDeque object

Since:

1.26

newForStruct

public static VecDeque newForStruct(long structSize,
 long initialSize)

Allocates a new GstVecDeque object for elements (e.g. structures) of size structSize, with an initial queue size of initialSize.

Parameters:

structSize - Size of each element (e.g. structure) in the array

initialSize - Initial size of the new queue

Returns:

a new GstVecDeque object

Since:

1.26

clear

public void clear()

Clears queue this VecDeque and frees all memory associated to it.

Since:

1.26

dropElement

public @Nullable MemorySegment dropElement(long idx)

Drops the queue element at position idx from queue array.

Parameters:

idx - index to drop

Returns:

the dropped element

Since:

1.26

dropStruct

public boolean dropStruct(long idx,
 @Nullable MemorySegment pStruct)

Drops the queue element at position idx from queue this VecDeque and copies the data of the element or structure that was removed into pStruct if pStruct is set (not NULL).

Parameters:

idx - index to drop

pStruct - address into which to store the data of the dropped structure, or NULL

Returns:

TRUE on success, or FALSE on error

Since:

1.26

find

public long find(@Nullable CompareFunc func)

Finds an element in the queue array, either by comparing every element with func or by looking up data if no compare function func is provided, and returning the index of the found element.

Parameters:

func - comparison function, or null to find data by value

Returns:

Index of the found element or -1 if nothing was found.

Since:

1.26

free

public void free()

Frees queue this VecDeque and all memory associated to it.

Since:

1.26

getLength

public long getLength()

Returns the length of the queue this VecDeque

Returns:

the length of the queue array.

Since:

1.26

isEmpty

public boolean isEmpty()

Checks if the queue this VecDeque is empty.

Returns:

true if the queue this VecDeque is empty

Since:

1.26

peekHead

public @Nullable MemorySegment peekHead()

Returns the head of the queue this VecDeque and does not remove it from the queue.

Returns:

The head of the queue

Since:

1.26

peekHeadStruct

public @Nullable MemorySegment peekHeadStruct()

Returns the head of the queue this VecDeque without removing it from the queue.

Returns:

pointer to element or struct, or NULL if this VecDeque was empty. The data pointed to by the returned pointer stays valid only as long as the queue array is not modified further!

Since:

1.26

peekNth

public @Nullable MemorySegment peekNth(long idx)

Returns the item at idx in array, but does not remove it from the queue.

Returns:

The item, or null if idx was out of bounds

Since:

1.26

peekNthStruct

public @Nullable MemorySegment peekNthStruct(long idx)

Returns the item at idx in array, but does not remove it from the queue.

Returns:

The item, or null if idx was out of bounds

Since:

1.26

peekTail

public @Nullable MemorySegment peekTail()

Returns the tail of the queue array, but does not remove it from the queue.

Returns:

The tail of the queue

Since:

1.26

peekTailStruct

public @Nullable MemorySegment peekTailStruct()

Returns the tail of the queue array, but does not remove it from the queue.

Returns:

The tail of the queue

Since:

1.26

popHead

public @Nullable MemorySegment popHead()

Returns and head of the queue this VecDeque and removes it from the queue.

Returns:

The head of the queue

Since:

1.26

popHeadStruct

public @Nullable MemorySegment popHeadStruct()

Returns the head of the queue this VecDeque and removes it from the queue.

Returns:

pointer to element or struct, or NULL if this VecDeque was empty. The data pointed to by the returned pointer stays valid only as long as the queue array is not modified further!

Since:

1.26

popTail

public @Nullable MemorySegment popTail()

Returns the tail of the queue this VecDeque and removes it from the queue.

Returns:

The tail of the queue

Since:

1.26

popTailStruct

public @Nullable MemorySegment popTailStruct()

Returns the tail of the queue this VecDeque and removes it from the queue.

Returns:

The tail of the queue

Since:

1.26

pushSorted

public void pushSorted(@Nullable MemorySegment data,
 @Nullable CompareDataFunc func)

Pushes data to the queue array, finding the correct position by comparing data with each array element using func.

This has a time complexity of O(n), so depending on the size of the queue and expected access patterns, a different data structure might be better.

Assumes that the array is already sorted. If it is not, make sure to call gst_vec_deque_sort() first.

Parameters:

data - object to push

func - comparison function

Since:

1.26

pushSortedStruct

public void pushSortedStruct(@Nullable MemorySegment pStruct,
 @Nullable CompareDataFunc func)

Pushes the element at address pStruct into the queue this VecDeque (copying the contents of a structure of the struct_size specified when creating the queue into the array), finding the correct position by comparing the element at pStruct with each element in the array using func.

This has a time complexity of O(n), so depending on the size of the queue and expected access patterns, a different data structure might be better.

Assumes that the array is already sorted. If it is not, make sure to call gst_vec_deque_sort() first.

Parameters:

pStruct - address of element or structure to push into the queue

func - comparison function

Since:

1.26

pushTail

public void pushTail(@Nullable MemorySegment data)

Pushes data to the tail of the queue array.

Parameters:

data - object to push

Since:

1.26

pushTailStruct

public void pushTailStruct(@Nullable MemorySegment pStruct)

Pushes the element at address pStruct to the tail of the queue this VecDeque (Copies the contents of a structure of the struct_size specified when creating the queue into the array).

Parameters:

pStruct - address of element or structure to push to the tail of the queue

Since:

1.26

setClearFunc

public void setClearFunc()

Sets a function to clear an element of array.

The clearFunc will be called when an element in the array data segment is removed and when the array is freed and data segment is deallocated as well. clearFunc will be passed a pointer to the element to clear, rather than the element itself.

Note that in contrast with other uses of GDestroyNotify functions, clearFunc is expected to clear the contents of the array element it is given, but not free the element itself.

Since:

1.26

sort

public void sort(@Nullable CompareDataFunc compareFunc)

Sorts the queue this VecDeque by comparing elements against each other using the provided compareFunc.

Parameters:

compareFunc - comparison function

Since:

1.26