If you want to create some function which accepts a stream and can affect
it's state you should be able to destroy the given stream on demand
e.g. when something went wrong and/or you are not interested in receiving data
anymore.
Unfortunately that's impossible with current node readable streams because they:
1. Support multiple consumers
2. Don't have common cleanup interface
So you can't touch another's stream because someone else may use it
and if you could you don't know how.
The absence of ability to pass streams as arguments is a huge flow. You can
build almost nothing
without that. Now someone may wonder: but there are so many useful modules
about streams in npm!?
Right. They all rely on `.pipe()`. For some reason all kind of blog posts,
tutorials and even node's
own documentation teach that for passing readable you can do
`readable.pipe(writable)`.
E.g. http file server could be:
```javascript
var http = require('http')
var fs = require('fs')
http.createServer(function(req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'})
fs.createReadStream(req.url.slice(1)).pipe(res)
}).listen(3000)
```
That's a lie. Exactly for the reasons above `.pipe()` doesn't cleanup any
resources.
Everything works fine until the streaming process completes successfully.
But if something fails you get horrible leaks and hangs.
Almost every module doing stream processing have this flow. Obvious or not.
That all is sad. We need another, simpler API. Although I believe incompatible
changes should be made
to node core that is not what I am calling about (at least not at the first
place).
But we definitely should stop to expose node streams in userland modules,
stop to extend "stream base classes", just stop to use it in userland.
Now the constructive part. Tim Caswell proposed recently simple-stream
<https://github.com/creationix/js-git/blob/master/specs/simple-stream.md> and
build many things on top of it.
Let's just peek this API as a standard and start using it.
Here is readable-to-simple-stream <https://github.com/eldargab/stream-simple>
converter which can be used for dealing with node core.
It also contains slightly more detailed version of original spec which could be
discussed.
That's it.
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