Retry

Automatically retries when listener execution fails, supports setting retry count and interval.

Usage

import { retry } from 'fastevent/pipes'; // [!]code ++
emitter.on(
    'connect',
    async () => {
        await connectToServer();
    },
    {
        pipes: [retry(3)], // Retry up to 3 times on failure
    },
);

Retry Interval

The interval parameter is used to specify the retry interval in milliseconds.

emitter.on(
    'sendRequest',
    async () => {
        await apiRequest();
    },
    {
        pipes: [
            retry(2, {
                interval: 1000, // Retry after 1 second
            }),
        ],
    },
);

The interval parameter supports passing a function to dynamically calculate the retry interval. The following example implements exponential backoff for retries.

// Retry with exponential backoff
emitter.on(
    'upload',
    async (msg) => {
        await uploadFile(msg.payload);
    },
    {
        pipes: [
            retry(4, {                 
                interval: (retryCount) => {
                    return 1000 * Math.pow(2, retryCount) 
                }, 
            }),
        ],
    },
);

Discarding Messages

When the retry count exceeds the limit, retry will discard the message. You can specify a function through the drop parameter to perform some operations when discarding messages.

// Custom retry configuration
emitter.on(
    'sendRequest',
    async () => {
        await apiRequest();
    },
    {
        pipes: [
            retry(2, { 
                drop: (msg, error) => console.error('Final failure:', error), 
            }),
        ],
    },
);