level-live-stream v1.4.9
level-sublevel v 5.1.1

I'm creating a livestream on a sublevel, and when I do an insert on that sublevel I get multiple data events. Heres some code to duplicate:

var MemDB = require('memdb');
var sublevel = require('level-sublevel')
var LiveStream = require('level-live-stream')

var db = sublevel(MemDB({ valueEncoding: 'json' }));
LiveStream.install(db)
db.posts = db.sublevel('posts')
LiveStream.install(db.posts)
var post = {
  title: 'a title ',
  body: 'lorem ipsum',
  author: 'julian'
};
db.posts.createLiveStream().on('data',console.log)
db.posts.put('1337',post)

heres the output:

{ key: '1337',
  value: { title: 'a title ', body: 'lorem ipsum', author: 'julian' } }
{ key: '1337',
  value: { title: 'a title ', body: 'lorem ipsum', author: 'julian' },
  type: 'put' }

If i listen to the livestream for the root 'db' i get a single event, which makes sense:

{ type: 'put',
  key: 'ÿpostsÿ1337',
  value: { title: 'a title ', body: 'lorem ipsum', author: 'julian' } }

There's a call to removeHook() which apparently is not a function. Had a look into level-hooks and can't see any way currently to remove hooks, so this is most likely the problem.

Let's say on the server you have something like:

var db = sublevel(db);
var foosub = db.sublevel('foo');

// incorrect
liveStream.install(db);

// correct would be
// liveStream.install(foo);

Consuming on the client side like this:

// incorrect
db.liveStream().on('data', console.dir);

// correct would be
// db.sublevel('foo').liveStream().on('data', console.dir);

Since we did this incorrectly (i.e. attached live stream to root level instead of to the sublevels separately) we'll get a stack overflow error in 'json-buffer' due to the _parent on the sublevels which causes a circular reference:

...../node_modules/multilevel/node_modules/mux-demux/node_modules/json-buffer/index.js:34
    return JSON.stringify(/^:/.test(o) ? ':' + o : o)
                               ^
RangeError: Maximum call stack size exceeded

The solution here is to document to not do that and/or detect this earlier and throw a more meaningful error.

hi, thanks for level-live-stream! :)

i'm using the 'sync' event to know when all the historical data has been read in order to emit that data in a chunk before emitting new chunks based on real-time changes.

assuming the 'sync' event is lost because anything that isn't part of the readable stream is lost, can there be a 'notifyOnSync' option that includes a single piece of data in between reading historical data and reading real-time data like

{
  type: 'sync'
}

?

i implemented the above option here. are these changes worthy of a pull request?

I noticed that this library uses min and max instead of start and end, any particular reason?

in time for lxjs

I guess this needs sublevel. How should I use this with level-stream?

Doing db = Sublevel(db) internally might overwrite stuff.

the version of this on npm right now has incorrect dependencies and doesn't match the version in git

i'm currently seeing something to the effect of:

{ 
  key: '[some-key]',
  prefix: [ '[sublevel-name]', 'ttl' ] 
}

it would be nice to know what that means or what operation / hook this event is related to?

No matter what I do I seem to always receive the following error when using multilevel:

/Users/drewp/Dropbox/js/dataminer/node_modules/multilevel/lib/client.js:107
  if (allowed.indexOf(ev) == -1) throw new Error('not supported');
                                 ^

Error: not supported
    at Db.addEventListener.Db.on (/Users/drewp/Dropbox/js/dataminer/node_modules/multilevel/lib/client.js:107:40)
    at post (/Users/drewp/Dropbox/js/dataminer/node_modules/level-post/index.js:56:6)
    at exports.live (/Users/drewp/Dropbox/js/dataminer/node_modules/pull-level/index.js:22:17)
    at Object.exports.read.exports.readStream.exports.createReadStream (/Users/drewp/Dropbox/js/dataminer/node_modules/pull-level/index.js:50:37)
    at module.exports (/Users/drewp/Dropbox/js/dataminer/node_modules/level-live-stream/index.js:14:35)
    at Db.db.liveStream.db.createLiveStream (/Users/drewp/Dropbox/js/dataminer/node_modules/level-live-stream/index.js:25:14)
    at Object.<anonymous> (/Users/drewp/Dropbox/js/dataminer/examples/sw-saber-miner.js:21:4)
    at Module._compile (module.js:425:26)
    at Object.Module._extensions..js (module.js:432:10)
    at Module.load (module.js:356:32)

Relevant code:

// digger.js
var path = require('path');
var net = require('net');
var level = require('level');
var multilevel = require('multilevel/msgpack');
var LevelLiveStream = require('level-live-stream');

var dbpath = path.join(__dirname, path.basename(__filename, '.js') + '.db');
var db = level(dbpath, {
  createIfMissing: true,
  valueEncoding: 'json'
});

LevelLiveStream.install(db);

net.createServer(con => {
  con
    .pipe(multilevel.server(db))
    .pipe(con);
}).listen(3000);

multilevel.writeManifest(db, __dirname + '/manifest.json');

// ...code that puts a bunch
db.put( 'twitter:' + tweet.id_str, { tweet: tweet, sentiment: 0 });

// miner.js
var path = require('path');
var net = require('net');
var multilevel = require('multilevel/msgpack');
var LevelLiveStream = require('level-live-stream');

var manifest = require('./manifest.json');

var db = multilevel.client(manifest);
var con = net.connect(3000);

LevelLiveStream.install(db);

con
  .pipe(db.createRpcStream())
  .pipe(con);

db.createLiveStream().on('data', console.log.bind(console));

And I've verified that my manifest.json loads and does have createLiveStream/liveStream added to it.

Also tried without the manifest and still got the same error.

Relevant packages:

$ npm ls | grep level
├─┬ [email protected]
│ ├─┬ [email protected]
│ │ └─┬ [email protected]
│ │   ├── [email protected]
│ │   ├── [email protected]
│ │   ├── [email protected]
│ │   ├── [email protected]
│ └─┬ [email protected]
│   ├── [email protected]
├─┬ [email protected]
│ ├─┬ [email protected]
│ │ ├─┬ [email protected]
│ │ │ ├─┬ [email protected]
│ │ │ │ └─┬ [email protected]
│ ├─┬ [email protected]
│ │ ├─┬ [email protected]
├─┬ [email protected]
│ ├─┬ [email protected]

Please let me know if there are any more details I can provide!

I just started using this mod because I wanted to watch a range of keys and catch all updates to their values. It seems though that I will only see new key insertions and not any old key insertions. Is this the case?

I am also using this with multi-level.

does not work in the live portion of the stream.

Does this guarantee that events are emitted in the order they are completed?