At the moment this part synchronously reads every asset file from disk to memory, potentially blocking the process for a long time. I think we should consider preparing for a few optimizations (some of these we've already been doing in expo publish):

[jkhales]

At the moment this part synchronously reads every asset file from disk to memory, potentially blocking the process for a long time. I think we should consider preparing for a few optimizations (some of these we've already been doing in expo publish):

• Parallelize hash calculation
• Parallelize uploading
• Pipe the file read stream to upload request (i.e. uploadWithPresignedPostAsync(fs.createReadStream(filename)), ...)
• Possibly show a progress bar while reading/hashing/uploading files in the future

Perhaps we should already make RawAsset have a filename field instead of buffer. This way we don't keep every asset of the app (which could easily be hundreds of megabytes) in memory for the duration of the command, but instead they're only read as needed and can be garbage collected as soon as that particular asset is done.

Originally posted by @fson in #147 (comment)