How to properly recycle a buffer in JavaScript

Question

This simple code makes app crash with out of memory:

var buf;
console.log(process.memoryUsage())
for(i=0; i<10000000; i++){
    buf = Buffer.alloc(1024)
    buf.clear
    delete buf
    buf = null
}
console.log(process.memoryUsage())

So how properly recycle the buffer so it can be reused? Not sure if clear or delete are appropriate methods but how then? Thank you

That code is working fine for me: `node v10.15.1`. What version are you using?, Not running out of memory, and the memory footprint is quite low. — Marcos Casagrande, Mar 24 '19 at 02:26

score 5 · Accepted Answer · answered Mar 19 '19 at 11:15

As mentioned in one of the answers, the buffer does not have a clear() method to un-allocate/free the allocated buffer memory. You can request the Node's gc to free-up the unused memory by calling gc() method but that option is only available when your application is started with --expose-gc flag.

'use strict';
let buf;
console.log(process.memoryUsage());
for (let i = 0; i < 10000000; i++) {

    buf = Buffer.alloc(1024);
    // Do your stuff
}

if (global.gc) {
    console.log('Requesting gc to free-up unsed memory');
    global.gc(); // Synchronous call, may take longer time and further execution get blocked till it finishes the execution
}

console.log(process.memoryUsage());

Links: How to request the Garbage Collector in node.js to run?

How to properly recycle a buffer in JavaScript

1 Answers1