This adds a new folder-level configuration `FullBlockIndex`. It controls
whether we maintain the block index for a given folder -- currently
that's always true, now it becomes possible to turn off. The block index
is used for lookup of blocks across files and folders. Effectively, when
syncing a change, for each block, we check:
1. Is the block already present in the old version of the file? If so,
we can reuse (copy) it without network transfer. **This check is always
possible.**
2. Is the block already present in any other file in this folder or
other folders? If so we can copy it. **This check is only possible with
the full block index.**
3. We must transfer the block over the network.
Maintaining the full block index is costly in time, I/O and database
size. With this PR, maintaining the full block index becomes the default
for send-receive and receive-only folders only, with it disabled for
send-only and receive-encrypted folders. The block index is never useful
for encrypted folders, as blocks are encrypted separate for each file.
It is also not useful for send-only folders by themselves, though the
data in the send-only folder could be reused by other receive-type
folders if it were enabled.
For very large folders it may make sense to disable the full block index
regardless of folder type and just accept the resulting decrease in data
reuse.
Disabling or enabling the option in the GUI causes the index to be
destroyed or rebuilt accordingly.
https://github.com/syncthing/docs/pull/1005
---------
Signed-off-by: Jakob Borg <jakob@kastelo.net>
This updates our logging framework from legacy freetext strings using
the `log` package to structured log entries using `log/slog`. I have
updated all INFO or higher level entries, but not yet DEBUG (😓)... So,
at a high level:
There is a slight change in log levels, effectively adding a new warning
level:
- DEBUG is still debug (ideally not for users but developers, though
this is something we need to work on)
- INFO is still info, though I've added more data here, effectively
making Syncthing more verbose by default (more on this below)
- WARNING is a new log level that is different from the _old_ WARNING
(more below)
- ERROR is what was WARNING before -- problems that must be dealt with,
and also bubbled as a popup in the GUI.
A new feature is that the logging level can be set per package to
something other than just debug or info, and hence I feel that we can
add a bit more things into INFO while moving some (in fact, most)
current INFO level warnings into WARNING. For example, I think it's
justified to get a log of synced files in INFO and sync failures in
WARNING. These are things that have historically been tricky to debug
properly, and having more information by default will be useful to many,
while still making it possible get close to told level of inscrutability
by setting the log level to WARNING. I'd like to get to a stage where
DEBUG is never necessary to just figure out what's going on, as opposed
to trying to narrow down a likely bug.
Code wise:
- Our logging object, generally known as `l` in each package, is now a
new adapter object that provides the old API on top of the newer one.
(This should go away once all old log entries are migrated.) This is
only for `l.Debugln` and `l.Debugf`.
- There is a new level tracker that keeps the log level for each
package.
- There is a nested setup of handlers, since the structure mandated by
`log/slog` is slightly convoluted (imho). We do this because we need to
do formatting at a "medium" level internally so we can buffer log lines
in text format but with separate timestamp and log level for the API/GUI
to consume.
- The `debug` API call becomes a `loglevels` API call, which can set the
log level to `DEBUG`, `INFO`, `WARNING` or `ERROR` per package. The GUI
is updated to handle this.
- Our custom `sync` package provided some debugging of mutexes quite
strongly integrated into the old logging framework, only turned on when
`STTRACE` was set to certain values at startup, etc. It's been a long
time since this has been useful; I removed it.
- The `STTRACE` env var remains and can be used the same way as before,
while additionally permitting specific log levels to be specified,
`STTRACE=model:WARN,scanner:DEBUG`.
- There is a new command line option `--log-level=INFO` to set the
default log level.
- The command line options `--log-flags` and `--verbose` go away, but
are currently retained as hidden & ignored options since we set them by
default in some of our startup examples and Syncthing would otherwise
fail to start.
Sample format messages:
```
2009-02-13 23:31:30 INF A basic info line (attr1="val with spaces" attr2=2 attr3="val\"quote" a=a log.pkg=slogutil)
2009-02-13 23:31:30 INF An info line with grouped values (attr1=val1 foo.attr2=2 foo.bar.attr3=3 a=a log.pkg=slogutil)
2009-02-13 23:31:30 INF An info line with grouped values via logger (foo.attr1=val1 foo.attr2=2 a=a log.pkg=slogutil)
2009-02-13 23:31:30 INF An info line with nested grouped values via logger (bar.foo.attr1=val1 bar.foo.attr2=2 a=a log.pkg=slogutil)
2009-02-13 23:31:30 WRN A warning entry (a=a log.pkg=slogutil)
2009-02-13 23:31:30 ERR An error (a=a log.pkg=slogutil)
```
---------
Co-authored-by: Ross Smith II <ross@smithii.com>
This is a draft because I haven't adjusted all the tests yet, I'd like
to get feedback on the change overall first, before spending time on
that.
In my opinion the main win of this change is in it's lower complexity
resp. fewer moving parts. It should also be faster as it only does one
query instead of two, but I have no idea if that's practically
relevant.
This also mirrors the v1 DB, where a block map key had the name
appended. Not that this is an argument for the change, it was mostly
reassuring me that I might not be missing something key here
conceptually (I might still be of course, please tell me :) ).
And the change isn't mainly intrinsically motivated, instead it came
up while fixing a bug in the copier. And the nested nature of that code
makes the fix harder, and "un-nesting" it required me to understand
what's happening. This change fell out of that.
This changes the database structure to use one database per folder, with
a small main database to coordinate. Reverts the prior change to buffer
all files in memory when pulling, meaning there is now a phase where the
WAL file will grow significantly, at least for initial sync of folders
with many directories.
---------
Co-authored-by: bt90 <btom1990@googlemail.com>
