This keeps the data we need about sequence numbers and object counts
persistently in the database. The sizeTracker is expanded into a
metadataTracker than handled multiple folders, and the Counts struct is
made protobuf serializable. It gains a Sequence field to assist in
tracking that as well, and a collection of Counts become a CountsSet
(for serialization purposes).
The initial database scan is also a consistency check of the global
entries. This shouldn't strictly be necessary. Nonetheless I added a
created timestamp to the metadata and set a variable to compare against
that. When the time since the metadata creation is old enough, we drop
the metadata and rebuild from scratch like we used to, while also
consistency checking.
A new environment variable STCHECKDBEVERY can override this interval,
and for example be set to zero to force the check immediately.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4547
LGTM: imsodin
So, when first implementing the database layer I added panics on every
unexpected error condition mostly to be sure to flush out bugs and
inconsistencies. Then it became sort of standard, and we don't seem to
have many bugs here any more so the panics are usually caused by things
like checksum errors on read. But it's not an optimal user experience to
crash all the time.
Here I've weeded out most of the panics, while retaining a few "can't
happen" ones like errors on marshalling and write that we really can't
recover from.
For the rest, I'm mostly treating any read error as "entry didn't
exist". This should mean we'll rescan the file and correct the info (if
scanning) or treat it as a new file and do conflict handling (when
pulling). In some cases things like our global stats may be slightly
incorrect until a restart, if a database entry goes suddenly missing
during runtime.
All in all, I think this makes us a bit more robust and friendly without
introducing too many risks for the user. If the database is truly toast,
probably many other things on the system will be toast as well...
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4118
This changes the BEP protocol to use protocol buffer serialization
instead of XDR, and therefore also the database format. The local
discovery protocol is also updated to be protocol buffer format.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3276
LGTM: AudriusButkevicius
This adds a metric for "committed items" to the database instance that I
use in the test code, and a couple of tests that ensure that scans that
don't change anything also don't commit anything.
There was a case in the scanner where we set the invalid bit on files
that are ignored, even though they were already ignored and had the
invalid bit set. I had assumed this would result in an extra database
commit, but it was in fact filtered out by the Set... Anyway, I think we
can save some work on not pushing that change to the Set at all.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3298
We're going to need the db.Instance to keep some state, and for that to
work we need the same one passed around everywhere. Hence this moves the
leveldb-specific file opening stuff into the db package and exports the
dbInstance type.
