Buffer allocation in node.js

Question

I want to use a buffer to store a sparse index. If I allocate a buffer of, say, 1024 bytes, and store effectively 128 bytes in it, how many bytes will be allocated in memory?

Answer 1

According to the constructor doc:

new Buffer(size)#

size Number Allocates a new buffer of size bytes. size must be less than 1,073,741,824 bytes (1 GB) on 32 bits architectures or 2,147,483,648 bytes (2 GB) on 64 bits architectures, otherwise a RangeError is thrown.

Unlike ArrayBuffers, the underlying memory for buffers is not initialized . So the contents of a newly created Buffer are unknown and could contain sensitive data. Use buf.fill(0) to initialize a buffer to zeroes.

It seem that the whole memory is allocated, but not zeroified.