[Glass] Is there a #upToEnd kind of read for a none blocking GsSocket?

[Richard Sargent via Glass]

GLASS mailing list wrote
> On Wed, Jul 5, 2017 at 5:44 PM, Richard Sargent via Glass <

> glass at .gemtalksystems

>> wrote:
> 
>> GLASS mailing list wrote
>> > I am trying to use GsHostProcess and provide a polling API for it.
>> > Something like this:
>> >
>> >
>> > ------
>> >
>> > runAndWaitPollingEvery: pollingMsPeriod onExitDo: anExitBlock
>> >
>> >   | process delay outStream errStream |
>> >   delay := Delay forMilliseconds: pollingMsPeriod.
>> >   outStream := WriteStream new.
>> >   errStream := WriteStream new.
>> >
>> >   process := GsHostProcess fork: aCommandString.
>> >
>> >   [ process childHasExited ]
>> >   whileFalse: [
>> > delay wait.
>> >                 "retrieve all we have in the pipes to make room and
>> avoid
>> > locks"
>> > outStream nextPutAll: *process stdout upToEnd.*
>> > errStream nextPutAll: *process stderr upToEnd.*
>> > ].
>> >
>> >   outStream nextPutAll: *process stdout upToEnd.*
>> >   errStream nextPutAll: *process stderr upToEnd.*
>> >
>> >   process stdout close.
>> >   process stderr close.
>> >
>> >   aBlock cull: outStream contents cull: errStream contents
>> >
>> > --------
>> >
>> > I tried to implement an GsSocket >> upToEnd like this:
>>
>> Mariano, I like what you are trying to do. But, I think the name you have
>> chosen is flawed.
>>
>> The fact that you had to write a comment where you used it to explain
>> what
>> you meant is a red flag for that. "retrieve all we have in the pipes" is
>> quite different from the usual Stream implementation for #upToEnd. It
>> sounds
>> like you want to use a name more like #allAvailable. (Note that I don't
>> think that's the best possible name, but I don't have a better one at
>> this
>> moment.)
>>
>>
> Hi Richard,
> 
> Thanks, #allAvailable is indeed better. However, note that such a method
> may be way too general to be put in GsSocket (I don't know). It might only
> make sense when using pipes underneath? I don't know. Probably, I will add
> it as a extension method with my app prefix (#fa) and call it
> #faAllAvailableInPipe (or something to make clear it may only work for
> pipes....if this is the case).
> 
> Aside from the selector, what do you think about the contents? does that
> sound correct?

#read:into:startingAt: claims it "Returns the number of bytes read, or nil
if an error,  or 0 if EOF on the receiver." Structurally, it looks good.
Correct the return value and add the bytes to the stream instead of the
number of bytes and it should work. 

As a matter of style, I would apply de Morgan's rule to the loop to make it
more comprehensible.
[self readWillNotBlock and: [(bytesRead := self read: buffer size into:
buffer startingAt: 1) > 0]]
whileTrue: [newStream nextPutAll: (buffer copyFrom: 1 to: bytesRead)].



> Thanks!
> 
> 
> 
>>
>>
>> > -----
>> > upToEnd
>> > | newStream buffer nextBytes |
>> > buffer := buffer1 species new: 1000.
>> > newStream := WriteStream on: (buffer1 species new: 100).
>> > [self readWillNotBlock not or: [(nextBytes := self read: buffer size
>> into:
>> > buffer startingAt: 1) isEmpty]]
>> > whileFalse: [newStream nextPutAll: nextBytes].
>> > ^ newStream contents
>> > -----
>> >
>> > Does that sound correct?
>> >
>> > Thanks a lot in advance,
>> >
>> >
>> > --
>> > Mariano
>> > http://marianopeck.wordpress.com
>> >
>> > _______________________________________________
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>>
>> > Glass at .gemtalksystems
>>
>> > http://lists.gemtalksystems.com/mailman/listinfo/glass
>>
>>
>>
>>
>>
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>> there-a-upToEnd-kind-of-read-for-a-none-blocking-GsSocket-
>> tp4953564p4953607.html
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>> 

> Glass at .gemtalksystems

>> http://lists.gemtalksystems.com/mailman/listinfo/glass
>>
> 
> 
> 
> -- 
> Mariano
> http://marianopeck.wordpress.com
> 
> _______________________________________________
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