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Methods

Queue.new ( loop, maxsize, obj )

Parameter Type Required Description
loop EventLoop ✔ The EventLoop the Queue belongs to
maxsize int ✕ The queue max size. (default = 0)
obj table ✕ The table to turn into a Queue.

Creates a new instance of Queue
This is a FIFO Queue (first in, first out). If maxsize is less than or equal to zero, the queue size is infinite.
/!\ Queue.size might be an approximated value some times (on purpose for internal reasons). Use Queue.real_size if you want to get the real queue size.

Returns:

Type Description
Queue The Queue object

Table structure:

{
  loop = loop, -- The EventLoop the Queue belongs to
  maxsize = maxsize, -- The queue max size
  waiting_free = {}, -- The sleeping tasks that are waiting for a free spot in the queue
  waiting_free_append = 0, -- The "waiting_free append pointer"
  waiting_free_give = 0, -- The "waiting_free give pointer"
  waiting_item = {}, -- The sleeping tasks that are waiting for an item in the queue
  waiting_item_append = 0, -- The "waiting_item append pointer"
  waiting_item_give = 0, -- The "waiting_item give pointer"
  size = 0, -- The queue approximated size (±1)
  real_size = 0 -- The queue real size
}

Queue:full ( )

Checks if the queue is full or not

Returns:

Type Description
boolean Whether the queue is full or not

Queue:empty ( )

Checks if the queue is empty or not

Returns:

Type Description
boolean Whether the queue is empty or not

Queue:trigger_add ( )

Wakes up a Queue:get task that is waiting for an item to be added.
/!\ This method should never be called by the user code.

Returns:

Type Description
boolean Whether a task was triggered or not

Queue:trigger_remove ( )

Wakes up a Queue:add task that is waiting for an item to be removed.
/!\ This method should never be called by the user code.

Returns:

Type Description
boolean Whether a task was triggered or not

Queue:add_nowait ( item, safe )

Parameter Type Required Description
item table ✔ The item to add
safe boolean ✕ Whether to cancel throwing an error if the queue is full (default = false)

Adds an item to the queue without blocking.

Returns:

Type Description
boolean Whether the item was added or not (if safe is false, this will always be true)

Queue.add ( self, item )

Parameter Type Required Description
item table ✔ The item to add

Returns a task that, when awaited, will try to add the item to the queue, and if it cant, it will block until it can.

Returns:

Type Description
Task The task.

Queue:get_nowait ( safe )

Parameter Type Required Description
safe boolean ✕ Whether to cancel throwing an error if the queue is empty (default = false)

Gets an item from the queue without blocking.

Returns:

Type Description
boolean, table false if the queue is empty and safe is false, the item (table) otherwise.

Queue.get ( self )

Returns a task that, when awaited, will try to get an item from the queue, and if it cant, it will block until it can.
The task always returns a table, which is the item.

Returns:

Type Description
Task The task

LifoQueue.new ( loop, maxsize, obj )

Parameter Type Required Description
loop EventLoop ✔ The EventLoop the Queue belongs to
maxsize int ✕ The queue max size. (default = 0)
obj table ✕ The table to turn into a Queue.

Creates a new instance of LifoQueue (which inherits from Queue)
This is a LIFO Queue (last in, first out). If maxsize is less than or equal to zero, the queue size is infinite.
/!\ Queue.size might be an approximated value some times (on purpose for internal reasons). Use Queue.real_size if you want to get the real queue size.

Returns:

Type Description
Queue The Queue object

Table structure:

{
  loop = loop, -- The EventLoop the Queue belongs to
  maxsize = maxsize, -- The queue max size
  waiting_free = {}, -- The sleeping tasks that are waiting for a free spot in the queue
  waiting_free_append = 0, -- The "waiting_free append pointer"
  waiting_free_give = 0, -- The "waiting_free give pointer"
  waiting_item = {}, -- The sleeping tasks that are waiting for an item in the queue
  waiting_item_append = 0, -- The "waiting_item append pointer"
  waiting_item_give = 0, -- The "waiting_item give pointer"
  size = 0, -- The queue approximated size (±1)
  real_size = 0 -- The queue real size
}

LifoQueue:add_nowait ( item, safe )

Parameter Type Required Description
item QueueItem ✔ The item to add
safe boolean ✕ Whether to cancel throwing an error if the queue is full (default = false)

Adds an item to the queue without blocking.

Returns:

Type Description
boolean Whether the item was added or not (if safe is false, this will always be true)

LifoQueue.add ( self, item )

Parameter Type Required Description
item QueueItem ✔ The item to add

Returns a task that, when awaited, will try to add the item to the queue, and if it cant, it will block until then.

Returns:

Type Description
Task The task.