Re: Is there a way to dump the checksums from a svn repo?

Daniel Shahaf <d.s_at_daniel.shahaf.name> writes:

> Philip Martin wrote on Thu, Nov 29, 2012 at 18:26:04 +0000:
>> Daniel Shahaf <d.s_at_daniel.shahaf.name> writes:
>>
>> > Les Mikesell wrote on Thu, Nov 29, 2012 at 09:59:47 -0600:
>> >> But, the copy built by svnsync doesn't necessarily
>> >> get stored the same way, does it?
>> >
>> > I think in 1.8/fsfs it will byte-for-byte identical. (except
>> > rep-cache.db, but you can remove that file without consequences)
>> >
>> > There was a dev@ thread by philipm about this not too long ago.
>>
>> No, an svnsync mirror is usually not identical to the master. It does
>> contain the same versioned data but the representation of that data is
>> different. For example, every failed commit on the master will bump the
>> fsfs sequence number and that will cause the node-revision-ids to be
>> different.
>
> Node-revision-id's in revisions don't embed transaction id's...
>
> For example the noderev header (yes, header, not just id) of
> /subversion/trunk/notes is identical between svn.us and svn.eu.

OK. But the sequence number differences do show up in other places:

svnadmin create repo
svn mkdir -mm file://`pwd`/repo/A # r1
svn mkdir -mm file://`pwd`/repo/A # fail
svn mkdir -mm file://`pwd`/repo/A/B # r2
svnadmin create repo2
svnadmin dump repo | svnadmin load repo2
diff repo/db/revs/0/2 repo2/db/revs/0/2
37c37
< _1.0.t1-2 add-dir false false /A/B

---
> _1.0.t1-1 add-dir false false /A/B
Further, node-revision-ids can vary for other reasons.  Representations
in the revision files are in whatever order the client sends
representations to the server.  There are no defined orders for clients
to use so it is quite likely that commits to the master and the mirror
will use different orders:
mkdir zz
echo foo > zz/f
echo bar > zz/g
echo zigzig > zz/F
echo zagzag > zz/G
svnadmin create repo
svn mkdir -mm file://`pwd`/repo/A
svnadmin create repo2
svnsync init file://`pwd`/repo2 file://`pwd`/repo
svnsync sync file://`pwd`/repo2
I see orders:
   repo/db/revs/0/1: foo, zigzig, zagzag, bar
  repo2/db/revs/0/1: zigzig, zagzag, foo, bar
That affects the offsets in the text: lines, often changing the line
length, which in turn affects the position of the subsequent nodes, and
the position of the nodes affects the node-revision-ids.
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