When two files have the same content, and a required content expression
matches one but not the other, dropping the latter file will fail as it
would also remove the content of the required file.
This will slow down drop (w/o --auto), dropunused, mirror, and move, by one
keys db lookup per file. But I did include an optimisation to avoid a
double db lookup in the drop --auto / sync --content case. I suspect that
dropunused could also use PreferredContentChecked True, but haven't
entirely thought it through and it's rarely used with enough files for the
optimisation to matter.
Sponsored-by: Dartmouth College's Datalad project
When the keys db is opened for read, and did not exist yet, it used to
skip creating it, and return mempty values. But that prevents
reconcileStaged from populating associated files information in time for
the read. This fixes the one remaining case I know of where
the fix in a56b151f90 didn't work.
Note that, when there is a permissions error, it still avoids creating
the db and returns mempty for all queries. This does mean that
reconcileStaged does not run and so it may want to drop files that it
should not. However, presumably a permissions error on the keys database
also means that the user does not have permission to delete annex
objects, so they won't be able to drop the files anyway.
Sponsored-by: Dartmouth College's Datalad project
* drop: When two files have the same content, and a preferred content
expression matches one but not the other, do not drop the file.
* sync --content, assistant: Fix an edge case where a file that is not
preferred content did not get dropped.
The sync --content edge case is that handleDropsFrom loaded associated files
and used them without verifying that the information from the database was
not stale.
It seemed best to avoid changing --want-drop's behavior, this way when
debugging a preferred content expression with it, the files matched will
still reflect the expression. So added a note to the --want-drop documentation,
to make clear it may not behave identically to git-annex drop --auto.
While it would be possible to introspect the preferred content
expression to see if it matches on filenames, and only look up the
associated files when it does, it's generally fairly rare for 2 files to
have the same content, and the database lookup is already avoided when
there's only 1 file, so I did not implement that further optimisation.
Note that there are still some situations where the associated files
database does not get locked files recorded in it, which will prevent
this fix from working.
Sponsored-by: Dartmouth College's Datalad project
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.
Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.
(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
Several places assumed this would not happen, and when the AssociatedFile
was Nothing, did nothing.
As part of this, preferred content checks pass the Key around.
Note that checkMatcher is sometimes now called with Just Key and Just File.
It currently constructs a FileMatcher, ignoring the Key. However, if it
constructed a FileKeyMatcher, which contained both, then it might be
possible to speed up parts of Limit, which currently call the somewhat
expensive lookupFileKey to get the Key.
I have not made this optimisation yet, because I am not sure if the key is
always the same. Will need some significant checking to satisfy myself
that's the case..
* get/copy --auto: Transfer data even if it would exceed numcopies,
when preferred content settings want it.
* drop --auto: Fix dropping content when there are no preferred content
settings.
When in a subdir, both the normal filepath, and the filepath relative to
the top of the git repo are needed for matching. The former for key lookup,
and the latter for include/exclude to match against. Previously, key lookup
didn't work in this situation.
Both when queueing downloads, and uploads, consults the preferred content
settings.
I didn't make it check yet when requeing failed transfers or queuing
deferred downloads; dealing with the preferred content settings (or indeed,
other settings) changing while the assistant is running still needs work.
