MemoryStoreQueue

Mostrar obsoleto
No creable
No replicado

Provides access to a queue within MemoryStore. A queue is a data structure that provides temporary storage for arbitrary items (up to the maximum item size -- see MemoryStore Limits). Each queue item has a numeric priority: MemoryStore retrieves items with higher priority from the queue first, and it retrieves Items with the same priority in order of addition.

Items in the queue can optionally be set to expire after a certain amount of time. Expired items simply disappear from the queue as if they were never added.

Resumen

Métodos

Ver todos los heredados de Instance
Ver todos los heredados de Object

Propiedades

Ver todos los heredados de Instance
Ver todos los heredados de Object

Métodos

AddAsync

void
Proporciona

Adds an item to the queue.

Parámetros

value: Variant

The value of the item to add to the queue.

expiration: number

Item expiration time, in seconds, after which the item will be automatically removed from the queue.

priority: number

Item priority. Items with higher priority are retrieved from the queue before items with lower priority.

Valor predeterminado: 0

Devuelve

void

ReadAsync

Tuple
Proporciona

Reads one or more items from the queue as a single atomic operation.

This method does not automatically delete the returned items from the queue but makes them invisible to other ReadAsync calls for the period of the invisibility timeout. The items must be explicitly removed from the queue with MemoryStoreQueue:RemoveAsync() before the invisibility timeout expires. The invisibility timeout defaults to 30 seconds unless a different value was provided in MemoryStoreService:GetQueue().

Parámetros

count: number

Number of items to read. The maximum allowed value of this parameter is 100.

allOrNothing: bool

Controls the behavior of the method in the case the queue has fewer than count items: if set to false the method returns all available items; if set to true, it returns no items. The default value is false.

Valor predeterminado: false
waitTimeout: number

The duration, in seconds, for which the method will wait if the required number of items is not immediately available in the queue. Reads are attempted every two seconds during this period. This parameter can be set to zero to indicate no wait. If this parameter is not provided or set to -1, the method will wait indefinitely.

Valor predeterminado: -1

Devuelve

Tuple

A tuple of two elements. The first element is an array of item values read from the queue. The second element is a string identifier that should be passed to MemoryStoreQueue:RemoveAsync() to permanently remove these items from the queue.

Muestras de código

The following code sample demonstrates using MemoryStoreQueue:ReadAsync() and MemoryStoreQueue:RemoveAsync() to reliably read, process, and remove items from a queue. Though this process can be as complicated as necessary, this example simply sets a flag in the corresponding data store item, which guarantees that every item will eventually be processed even if some of the calls encounter errors or the server crashes:

Depending on where the failure happens, it's possible that an item will be processed more than once. You should account for that like the following code sample, in which the end result is the same even if DataStoreService:UpdateAsync() is invoked multiple times.

Using a MemoryStoreQueue
local MemoryStoreService = game:GetService("MemoryStoreService")

local DataStoreService = game:GetService("DataStoreService")



local queue = MemoryStoreService:GetQueue("PlayerQueue")

local dataStore = DataStoreService:GetDataStore("PlayerStore")



while true do

	pcall(function()

		-- wait for an item to process

		local items, id = queue:ReadAsync(1, false, 30)



		-- check if an item was retrieved

		if #items > 0 then

			-- mark the item as processed

			dataStore:UpdateAsync(items[0], function(data)

				data = data or {}

				data.processed = 1

				return data

			end)



			-- remove the item from the queue

			queue:RemoveAsync(id)

		end

	end)

end

RemoveAsync

void
Proporciona

Removes an item or items previously read from the queue. This method uses the identifier returned by MemoryStoreQueue:ReadAsync() to identify the items to remove. If called after the invisibility timeout has expired, the call has no effect.

Parámetros

id: string

Identifies the items to delete. Use the value returned by MemoryStoreQueue:ReadAsync().


Devuelve

void

Muestras de código

The following code sample demonstrates using MemoryStoreQueue:ReadAsync() and MemoryStoreQueue:RemoveAsync() to reliably read, process, and remove items from a queue. Though this process can be as complicated as necessary, this example simply sets a flag in the corresponding data store item, which guarantees that every item will eventually be processed even if some of the calls encounter errors or the server crashes:

Depending on where the failure happens, it's possible that an item will be processed more than once. You should account for that like the following code sample, in which the end result is the same even if DataStoreService:UpdateAsync() is invoked multiple times.

Using a MemoryStoreQueue
local MemoryStoreService = game:GetService("MemoryStoreService")

local DataStoreService = game:GetService("DataStoreService")



local queue = MemoryStoreService:GetQueue("PlayerQueue")

local dataStore = DataStoreService:GetDataStore("PlayerStore")



while true do

	pcall(function()

		-- wait for an item to process

		local items, id = queue:ReadAsync(1, false, 30)



		-- check if an item was retrieved

		if #items > 0 then

			-- mark the item as processed

			dataStore:UpdateAsync(items[0], function(data)

				data = data or {}

				data.processed = 1

				return data

			end)



			-- remove the item from the queue

			queue:RemoveAsync(id)

		end

	end)

end
Ver todos los heredados de Instance
Ver todos los heredados de Object

Eventos

Ver todos los heredados de Instance
Ver todos los heredados de Object