Streamable multipart `_attachments`

[Stepan Stoliarov]

request has no trouble sending multipart/related payloads from ReadableStreams, as long as you provide the Content-Length for it. But db.multipart.insert doesn't support streams, because it expects only Buffers and strings to be attached, and prefers to calculate payload size implicitly. This is obviously problematic when you want to attach multiple huge files at once. (Yeah, I know I shouldn't abuse CouchDB like that, but I still do.)

I propose extending interface of db.multipart.insert to allow following:

var data = fs.createReadStream('rabbit.png'); // why read the whole file when you can stream it?
var length = fs.statSync('rabbit.png').size; // or however you get the size of payload

alice.multipart.insert({ foo: 'bar' }, [{name: 'rabbit.png', data: data, length: length, content_type: 'image/png'}], 'mydoc', function(err, body) {
  if (!err)
    console.log(body);
});

i.e., allow passing .length explicitly as part of attachment object. Pass it further down to request - and it will happily accept data in form of a stream.

[Schmidt]

👍

[Stepan Stoliarov]

Started a PR #300

[Carlos Manuel Duclos Vergara]

Based on the comments on the pull request, it seems that this issue is not relevant anymore (unless CouchDB 1.7+ is required). If so, could you close this issue?

[Stepan Stoliarov]

Oh, db.attachment.insert returns a stream that you can .pipe() into? That's cool. 😎👍

Closing.

[Stepan Stoliarov]

Actually, wait a sec. CouchDB will still hang if you try and feed it Transfer-Encoding: chunked request, which is probably the default in request.

I will reopen in apache/couchdb-nano.