Streaming Api Changes

[jorgebay]

(coming from #37)

Create a new method:

var stream = client.stream(query, [params], [consistency], endCallback);

Returns a readable stream2 that emits row objects.
This would probably require a change in how the internal transform streams work.

Rename the method streamRows to eachRow

To avoid confusion with the previous one.

[jorgebay]

Currently, the Protocol stream is being piped to 2 destinations: FrameParser and FrameStreamingParser, this causes that streamIds needs to be synchronized and parsing is done in 2 places.

I propose the following stream pipe:

 Socket        (transform stream)
   |
   |   chunks
   ↓
 Protocol      (transform stream)
   |
   |    header + body chunks
   ↓
 Parser        (transform stream)
   |
   |    header + (row | error)
   ↓
 ResultEmitter  (writable stream)

ResultEmitter emits the following events:

• result
• row: In case is yielding for each
• responseEnd: when the parsing of a frame finished.

[jorgebay]

Now, the Protocol, Parser and ResultEmitter work like explained above.

[bitcloud]

great work!

[jorgebay]

Implemented on master branch.
Thanks to @bitcloud for all the help!

[bitcloud]

You are very welcome.
Thanks for the great driver @jorgebay!