Re: [Pharo-project] Basic tricks for improving a serializer?

May 17, 2011

      On Tue, May 17, 2011 at 10:31 PM, Sven Van Caekenberghe <sven@beta9.be>wrote:
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On 17 May 2011, at 21:57, Mariano Martinez Peck wrote:
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Sven, I want to make it work :)
so....the missing methods I told you that I need are:
#nextStringPut:
#nextNumber:put:
#nextInt32Put:
#nextWordPut:
I guess these are pretty easy. But I think they clutter the interface of
ZnBufferedWriteStream, so maybe you should make a subclass.
Yeah, don't worry. I can even duplicate the class hehehe
...
...
#contents
Implement #contents I guess it is something like:
ZnBufferedWriteStream >> contents
^ stream contents
Why to you need #contents ?
becasue I am an idiot. No, I don't need it. You are correct. Thanks for
asking.
...
I would say that it goes a bit against the concept of a stream as a sink of
data.
I haven't looked, but I would guess that saying #contents to a FileStream
is not efficient.
...
Those missing methods I need are implemented PositionableStream. I took
the implementation from there and  put it in ZnBufferedWriteStream.
I just added to them a first line "    self flushBufferIfFull."
That is probably OK, except when your string becomes larger than the
buffer. Have a look at #nextPutAll:
I am not sure if I understood. The following are correct for sure then:
 #nextNumber:put:
 #nextInt32Put:
 #nextWordPut:

And #nextStringPut:   is like this:

nextStringPut: s
    "Append the string, s, to the receiver.  Only used by DataStream.  Max
size of 64*256*256*256."

    | length |
    self flushBufferIfFull.
    (length := s size) < 192
        ifTrue: [self nextPut: length]
        ifFalse:
            [self nextPut: (length digitAt: 4)+192.
            self nextPut: (length digitAt: 3).
            self nextPut: (length digitAt: 2).
            self nextPut: (length digitAt: 1)].
    self nextPutAll: s asByteArray.
    ^s

which will finally send #nextPutAll:  that does correct check.
...
...
The way I am creating it is like this:
stream := ZnBufferedWriteStream on: ((FileDirectory default
forceNewFileNamed: 'mariano') binary).
So...is this correct Sven?   My tests are green :)
That seems OK
Ok.
...
...
Still need to try benchmarks.
You might also consider playing with making the buffer larger.
yeah, I was trying that. Just by curious, why you put a 2^X number there?

Ahh and for reading we don't need something special because it is already
buffered? (I have been told that)

Thanks a lot Sven,

-- 
Mariano
http://marianopeck.wordpress.com