On 03.12.2012 09:30, Sven Van Caekenberghe wrote:
On 03 Dec 2012, at 07:25, Sven Van Caekenberghe <sven@stfx.eu> wrote:
Hi Mariano,
On 02 Dec 2012, at 23:43, Mariano Martinez Peck <marianopeck@gmail.com> wrote:
This is really really interesting, because it means a speed up of 2x when reading :) Where can I get the last version of ZnBufferedReadStream? I knew you would be interested: it is in the latest Zn, either http://mc.stfx.eu or squeaksource (not in the metacello yet). It should work on binary streams too, I don't know whether it would make a lot of difference, I would guess so. Maybe Fuel uses lots of 'deterministic reading' (size prefixed) instead of parsing. Well, I just tried. The good news is, it works, the bad news is, it does not make a difference, either way:
| data | data := STONTestMap classTreeExtended. [ FLSerializer serialize: data toFileNamed: '/tmp/all.fuel' ] timeToRun. 4967
[ FLMaterializer materializeFromFileNamed: '/tmp/all.fuel' ] timeToRun. 1095
[ '/tmp/all.fuel' asFileReference readStreamDo: [ :fstream | ZnBufferedReadStream on: fstream binary do: [ :stream | FLMaterializer newDefault materializeFrom: stream ] ] ] timeToRun. 1043
So I guess Fuel is already pretty optimised, especially for reading ;-)
I think ZnBufferedReadStream only makes a difference for parsers that are sending lots of little #next, #peek and #atEnd messages in loops. Binary protocols are typically more deterministic, they know ahead what they have to read and don't have to do #peek or #atEnd tests all the time.
Sven
-- Sven Van Caekenberghe http://stfx.eu Smalltalk is the Red Pill The reduced read times you are seeing, is lack of decoding, not lack of buffering.
BufferedReadStream uses readInto:startingAt:count:, which isn't reimplemented for MultiByteFileStream to do proper decoding, and thus inherits the one from StandardFileStream. The filestreams already do read buffering (albeit with a smaller buffer size), so when Fuel uses binary mode (which skips decoding), the performance is pretty much the same. Cheers, Henry