Metadata support in the client-client protocol

[cologic]

The best suggestion I've heard to far involves:

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$Supports <blahblah, the usual DC++ supports> Meta <additional specific metadata types supported>|

for example, neglecting the blahblah parts:

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$Supports Meta TTH|

where TTH is tiger tree hashing. One more new client-client command seems necessary:

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$GetMeta <filenameandpath>$<MetaParams>|

Where <MetaParams> could be "Hash$TTH$<TTH depth>". A response would be:

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$MetaLength <sizeinbytes>$<MetaParamsAchieved>|

followed by the information itself. A $PutMeta could be used as well, similarly to the $Send command, but I don't see the need ($Send strikes me as rather redundant).

[sandos]

The best suggestion I've heard to far involves:

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$Supports <blahblah, the usual DC++ supports> Meta <additional specific metadata types supported>|

So the Meta subpart of $Supports ends at the pipe? What if we want to add another supports with a sub-supports? I would like something that clearly marks what belongs to the Meta part.

[cologic]

I didn't mean to imply a hierarchical $Supports statement - though I can see the case for one, that's not what I'm proposing here.

Rather, Meta just happens to be one of the $Supports arguments, and order doesn't particularly matter.

[sandos]

I didn't mean to imply a hierarchical $Supports statement - though I can see the case for one, that's not what I'm proposing here.

Rather, Meta just happens to be one of the $Supports arguments, and order doesn't particularly matter.

Well, yeah. I thought about it a bit and I did eventually guess that you didnt actually meant it in a hierarchal way. Wouldnt this also work then (no ambiguities possible?, slightly more data to tranfser):

$Supports <blah> MetaTTH MetaMP3BR MetaMP3ID3 usw

[ender]

What about

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$Supports something something-else $Meta TTH MP3BR $xyz abc ...|

[Sedulus]

well..
that would limit the hierarchy to 2 levels,
you might wind up with ugliness like
$Supports something something-else $$Meta $Hash TTH SHA-1 $$xyz...|
if you want nesting, I'd go with parentheses or /-notations
BZList Meta(Hash(TTH SHA-1)) Xyz
and
BZList Meta Hash TTH SHA-1 /Hash /Meta Xyz
respectively

the problem with just having Meta and TTH would arise when TTH would be an option for something different than the GetMeta command.
I guess I'd opt for
$Supports bla bla MetaHashTTH bla
to keep it simple..
in any case, we all know that huge commands work fine (see $NickList), so a bit large $Supports list shouldn't matter

[volkris]

This is hopefully a stupid and ignorant question, but why is meta needed again? Why can't it simply be

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$Supports <normal DC++ stuff> <Stuff after the meta>