Defined in: async-queuer.ts:157

A flexible asynchronous queue for processing tasks with configurable concurrency, priority, and expiration.

Features:

• Priority queue support via the getPriority option
• Configurable concurrency limit
• Callbacks for task success, error, completion, and queue state changes
• FIFO (First In First Out) or LIFO (Last In First Out) queue behavior
• Pause and resume processing
• Task cancellation
• Item expiration to remove stale items from the queue

Tasks are processed concurrently up to the configured concurrency limit. When a task completes, the next pending task is processed if the concurrency limit allows.

Error Handling:

• If an onError handler is provided, it will be called with the error and queuer instance
• If throwOnError is true (default when no onError handler is provided), the error will be thrown
• If throwOnError is false (default when onError handler is provided), the error will be swallowed
• Both onError and throwOnError can be used together; the handler will be called before any error is thrown
• The error state can be checked using the AsyncQueuer instance

Example usage:

const asyncQueuer = new AsyncQueuer<string>(async (item) => {
  // process item
  return item.toUpperCase();
}, {
  concurrency: 2,
  onSuccess: (result) => {
    console.log(result);
  }
});

asyncQueuer.addItem('hello');
asyncQueuer.start();

const asyncQueuer = new AsyncQueuer<string>(async (item) => {
  // process item
  return item.toUpperCase();
}, {
  concurrency: 2,
  onSuccess: (result) => {
    console.log(result);
  }
});

asyncQueuer.addItem('hello');
asyncQueuer.start();

• TValue

new AsyncQueuer<TValue>(fn, initialOptions): AsyncQueuer<TValue>

new AsyncQueuer<TValue>(fn, initialOptions): AsyncQueuer<TValue>

Defined in: async-queuer.ts:171

(value) => Promise<any>

AsyncQueuerOptions<TValue>

AsyncQueuer<TValue>

addItem(
   item, 
   position, 
   runOnItemsChange): void

addItem(
   item, 
   position, 
   runOnItemsChange): void

Defined in: async-queuer.ts:312

Adds an item to the queue. If the queue is full, the item is rejected and onReject is called. Items can be inserted based on priority or at the front/back depending on configuration.

TValue & object

QueuePosition = ...

boolean = true

void

queuer.addItem({ value: 'task', priority: 10 });
queuer.addItem('task2', 'front');

queuer.addItem({ value: 'task', priority: 10 });
queuer.addItem('task2', 'front');

clear(): void

clear(): void

Defined in: async-queuer.ts:282

Removes all pending items from the queue. Does not affect active tasks.

void

execute(position?): Promise<any>

execute(position?): Promise<any>

Defined in: async-queuer.ts:410

Removes and returns the next item from the queue and executes the task function with it.

QueuePosition

Promise<any>

queuer.execute();
// LIFO
queuer.execute('back');

queuer.execute();
// LIFO
queuer.execute('back');

getConcurrency(): number

getConcurrency(): number

Defined in: async-queuer.ts:215

Returns the current concurrency limit for processing items. If a function is provided, it is called with the queuer instance.

number

getErrorCount(): number

getErrorCount(): number

Defined in: async-queuer.ts:552

Returns the number of items that have failed processing.

number

getExpirationCount(): number

getExpirationCount(): number

Defined in: async-queuer.ts:587

Returns the number of items that have expired and been removed from the queue.

number

getIsEmpty(): boolean

getIsEmpty(): boolean

Defined in: async-queuer.ts:503

Returns true if the queue is empty (no pending items).

boolean

getIsFull(): boolean

getIsFull(): boolean

Defined in: async-queuer.ts:510

Returns true if the queue is full (reached maxSize).

boolean

getIsIdle(): boolean

getIsIdle(): boolean

Defined in: async-queuer.ts:580

Returns true if the queuer is running but has no items to process and no active tasks.

boolean

getIsRunning(): boolean

getIsRunning(): boolean

Defined in: async-queuer.ts:573

Returns true if the queuer is currently running (processing items).

boolean

getNextItem(position): undefined | TValue

getNextItem(position): undefined | TValue

Defined in: async-queuer.ts:380

Removes and returns the next item from the queue without executing the task function. Use for manual queue management. Normally, use execute() to process items.

QueuePosition = ...

undefined | TValue

// FIFO
queuer.getNextItem();
// LIFO
queuer.getNextItem('back');

// FIFO
queuer.getNextItem();
// LIFO
queuer.getNextItem('back');

getOptions(): AsyncQueuerOptions<TValue>

getOptions(): AsyncQueuerOptions<TValue>

Defined in: async-queuer.ts:199

Returns the current queuer options, including defaults and any overrides.

AsyncQueuerOptions<TValue>

getRejectionCount(): number

getRejectionCount(): number

Defined in: async-queuer.ts:566

Returns the number of items that have been rejected from being added to the queue.

number

getSettledCount(): number

getSettledCount(): number

Defined in: async-queuer.ts:559

Returns the number of items that have completed processing (success or error).

number

getSize(): number

getSize(): number

Defined in: async-queuer.ts:517

Returns the number of pending items in the queue.

number

getSuccessCount(): number

getSuccessCount(): number

Defined in: async-queuer.ts:545

Returns the number of items that have been successfully processed.

number

getWait(): number

getWait(): number

Defined in: async-queuer.ts:207

Returns the current wait time (in milliseconds) between processing items. If a function is provided, it is called with the queuer instance.

number

peekActiveItems(): TValue[]

peekActiveItems(): TValue[]

Defined in: async-queuer.ts:531

Returns the items currently being processed (active tasks).

TValue[]

peekAllItems(): TValue[]

peekAllItems(): TValue[]

Defined in: async-queuer.ts:524

Returns a copy of all items in the queue, including active and pending items.

TValue[]

peekNextItem(position): undefined | TValue

peekNextItem(position): undefined | TValue

Defined in: async-queuer.ts:493

Returns the next item in the queue without removing it.

QueuePosition = 'front'

undefined | TValue

queuer.peekNextItem(); // front
queuer.peekNextItem('back'); // back

queuer.peekNextItem(); // front
queuer.peekNextItem('back'); // back

peekPendingItems(): TValue[]

peekPendingItems(): TValue[]

Defined in: async-queuer.ts:538

Returns the items waiting to be processed (pending tasks).

TValue[]

reset(withInitialItems?): void

reset(withInitialItems?): void

Defined in: async-queuer.ts:291

Resets the queuer to its initial state. Optionally repopulates with initial items. Does not affect callbacks or options.

boolean

void

setOptions(newOptions): void

setOptions(newOptions): void

Defined in: async-queuer.ts:192

Updates the queuer options. New options are merged with existing options.

Partial<AsyncQueuerOptions<TValue>>

void

start(): void

start(): void

Defined in: async-queuer.ts:261

Starts processing items in the queue. If already running, does nothing.

void

stop(): void

stop(): void

Defined in: async-queuer.ts:273

Stops processing items in the queue. Does not clear the queue.

void