On Mon, Apr 13, 2015 at 5:01 PM, Ivan Zhakov <ivan_at_visualsvn.com> wrote:
> On 13 April 2015 at 17:22, <rhuijben_at_apache.org> wrote:
> > Author: rhuijben
> > Date: Mon Apr 13 14:22:33 2015
> > New Revision: 1673202
> >
> > URL: http://svn.apache.org/r1673202
> > Log:
> > Following up on r1673197, use another optimization suggested by stefan2.
> >
> > * subversion/libsvn_fs_fs/dag.c
> > (svn_fs_fs__dag_has_props): Use expanded size to determine if the
> > representation stores properties vs just an empty list.
> >
> > Modified:
> > subversion/trunk/subversion/libsvn_fs_fs/dag.c
> >
> > Modified: subversion/trunk/subversion/libsvn_fs_fs/dag.c
> > URL:
> http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/dag.c?rev=1673202&r1=1673201&r2=1673202&view=diff
> >
> ==============================================================================
> > --- subversion/trunk/subversion/libsvn_fs_fs/dag.c (original)
> > +++ subversion/trunk/subversion/libsvn_fs_fs/dag.c Mon Apr 13 14:22:33
> 2015
> > @@ -525,15 +525,9 @@ svn_fs_fs__dag_has_props(svn_boolean_t *
> > }
> > else
> > {
> > - apr_hash_t *proplist;
> > -
> > - /* ### Optimize further.
> > - Stefan2 suggested: prop_rep exists and is longer than 4 bytes
> > - */
> > - SVN_ERR(svn_fs_fs__get_proplist(&proplist, node->fs,
> > - noderev, scratch_pool));
> > -
> > - *has_props = proplist ? (0 < apr_hash_count(proplist)) : FALSE;
> > + /* Properties are stored as a standard hash stream,
> > + always ending with "END\n" (4 bytes) */
> > + *has_props = (noderev->prop_rep->expanded_size > 4);
> I'm not sure, but strictly speaking prop representation greater than
> four bytes doesn't mean that there is no props: property
> representation may contain delta resulting empty property list.
>
expanded_size is the size of the undeltified (full-text) representation.
For properties lists, it can only be 0 for PLAIN representations where
the on-disk size is then the full-text size.
On a higher level, the fulltext only contains the serialized "positive"
contents. An incremental representation like for directory reps in
transactions is not supported by svn_hash_read2. The 'structure'
doc does not hint on any support for incremental prop lists nor did
it ever work in a previous release.
-- Stefan^2.
Received on 2015-04-13 19:15:29 CEST