Load a file into javascript and read first line

Question

I have a 1GB file that I would like to load into a javascript buffer and then read the first line of it. I wasn't sure what the correct 'type' to use for this would be. For example, here is the pseudocode I have:

file = new FileBuffer('/user/me/Desktop/file.csv')
first_line = file.getline(0)

What would actually be the proper way to do this in javascript (ArrayBuffer or SharedArrayBuffer or TypedArrayBuffer ?), and what is the suggested 'buffer-type' to use for a utf-8 file with a known size?

Answer 1

Uint8Array is typically used for reading bytes of a file. Reading with a streams API will be much more performant than reading the entire file into memory, especially with large files or files sent over a network.

NodeJS: see Streams and fs.createReadStream(). StringDecoder could be used for converting bytes to strings.

Web: Fetch and Streams could be used with small responses from HTTP range requests. TextDecoder could be used for converting bytes to strings.