I'm trying to upload large files (at least 500MB, preferably up to a few GB) using the WebSocket API. The problem is that I can't figure out how to write send this slice of the file, release the resources used then repeat. I was hoping I could avoid using something like Flash/Silverlight for this.

Currently, I'm working with something along the lines of:

function FileSlicer(file) {

    // randomly picked 1MB slices,

    // I don't think this size is important for this experiment

    this.sliceSize = 1024*1024;  

    this.slices = Math.ceil(file.size / this.sliceSize);



    this.currentSlice = 0;



    this.getNextSlice = function() {

        var start = this.currentSlice * this.sliceSize;

        var end = Math.min((this.currentSlice+1) * this.sliceSize, file.size);

        ++this.currentSlice;



        return file.slice(start, end);

    }

}

Then, I would upload using:

function Uploader(url, file) {

    var fs = new FileSlicer(file);

    var socket = new WebSocket(url);



    socket.onopen = function() {

        for(var i = 0; i < fs.slices; ++i) {

            socket.send(fs.getNextSlice()); // see below

        }

    }

}

Basically this returns immediately, bufferedAmount is unchanged (0) and it keeps iterating and adding all the slices to the queue before attempting to send it; there's no socket.afterSend to allow me to queue it properly, which is where I'm stuck.