Re: [PATCH v2 2/3] fast-export: improve speed by skipping blobs

> On Mon, May 06, 2013 at 08:08:45AM -0700, Junio C Hamano wrote:
>
>> > I'm also not sure why your claim "we don't care about blobs" is true,
>> > because naively we would want future runs of fast-export to avoid having
>> > to write out the whole blob content when mentioning the blob again.
>>
>> The existing documentation is fairly clear that marks for objects
>> other than commits are not exported, and the import-marks codepath
>> discards anything but commits, so there is no mechanism for the
>> existing fast-export users to leave blob marks in the marks file for
>> later runs of fast-export to take advantage of.  The second
>> invocation cannot refer to such a blob in the first place.
>
> OK. If the argument is "we do not write them, so do not bother reading
> them back in", I think that is reasonable.

> It could hurt anybody trying
> to run "fast-export" against a marks file created by somebody else, but
> that is also the same case that is being helped here (since otherwise,
> we would not be seeing blob entries at all).
>
> I do not offhand know enough about the internals of import/export-style
> remote-helpers to say whether the "hurt" case even exists, let alone how
> common it is.
>
>> By discarding marks on blobs, we may be robbing some optimization
>> possibilities, and by discarding marks on tags, we may be robbing
>> some features, from users of fast-export; we might want to add an
>> option "--use-object-marks={blob,commit,tag}" or something to both
>> fast-export and fast-import, so that the former can optionally write
>> marks for non-commits out, and the latter can omit non commit marks
>> if the user do not need them. But that is a separate issue.
>
> Yeah, that would allow the old behavior (and more) if anybody is hurt by
> this.