Previously the pin states of deleted files stayed in the 'flags'
database and could be inadvertently reused when a new file with the same
name appeared. Now they are deleted.
To make this work right, the meaning of the 'path' column in the 'flags'
table was changed: Previously it never had the .owncloud file suffix.
Now it's the same as in metadata.path.
This takes the safe parts from #7274 for inclusion in 2.6. The more
elaborate database schema changes (why use 'path' the join the two
tables in the first place?) shall go into master.
Previously "no-availability" meant db-error and querying the
availability of a nonexistant path returned AllHydrated.
Now, the availability has a DbError and a NoSuchItem error case.
The idea is that the user's question is "is this folder's data available
offline?" and not "does this folder have AlwaysLocal pin state?".
The the answers to the two questions can differ: an always-local
folder can have subitems that are not always-local and are dehydrated.
The new availability enum intends to describe the answer to the user's
actual question and can be derived from pin states. If pin states aren't
stored in the database the way of calculating availability will depend
on the vfs plugin.
By default, plugins are only searched next to the binary or next to the
other Qt plugins. This optional build variable allows another path to be
configured.
The idea is that on linux the oC packaging probably wants the binary in
something like /opt/owncloud/bin and the plugins in
/opt/owncloud/lib/plugins.
Similarly, distribution packagers probably don't want the plugins next
to the binary or next to the other Qt plugins. This flag allows them to
configure another path that the executable will look in.
That just complicated things. It's ok if Vfs is not a fully abstract
interface class.
The pinstate-in-db methods are instead provided directly on Vfs and
VfsSuffix and VfsOff use them to implement pin states.
The start() method is simply non-virtual and calls into startImpl() for
the plugin-specific startup code.
Since 'placeholder' just means that it's an item of the special type
that the vfs plugin can deal with - no matter whether hydrated or
dehydrated - all done items should become placeholders. Even
directories.
Now every file that passes through updateMetadata() will be converted to
a placeholder if necessary.
Christian Kamm