Subj : Re: Byte Arrays in JavaScript
To   : Sajid Raza
From : Brendan Eich
Date : Sun May 23 2004 12:06 am

Sajid Raza wrote:
> My application reads and writes large quantities of data. I would like 
> to present my 'users' with an array like data-structure that contains 
> bytes. The present Array object relies on 32-bit jsvals that may not be 
> as space-efficient as ideally possible. I could hack together a class 
> that emulates byte-arrays, but I was wondering whether there's a nice 
> clean way of doing this. Basically, my concern is that how properties 
> are resolved may not allow me to stuff more data into each jsval in the 
> properties vector. Is there a way for me to store 4 bytes in each slot 
> of an object, and still be able to index each element properly?


You shouldn't use slots at all; see JSPROP_SHARED in jsapi.h.  Use 
resolve to lazily reflect byte-valued properties of the class prototype 
that have the JSPROP_SHARED attribute, and whose getter and setter know 
how to index into a private byte array data struct per instance.

Are these byte arrays typically or always dense?

/be

.