### Purpose
This PR contains the set of changes needed to make Syncthing work on iOS
for [my iOS app for
Syncthing](https://github.com/pixelspark/sushitrain).
Most changes originate from [the Mobius Sync
fork](http://github.com/MobiusSync/syncthing/tree/ios). I have removed
the changes from their fork that are not strictly needed for my app
(i.e. their changes to the GUI and command line utilities, for instance)
and squashed it all in a single commit.
In summary, the changes are:
* Resolve non-absolute paths to the 'Documents' folder (basically the
only one an app can/should write user data to by default on iOS)
* Tweaking of build flags/conditions for iOS (i.e. determine which
basicfs_watch, ignoreresult variant to build for iOS)
* Disable upgrade mechanism on iOS
* Make `RequestGlobal` and `PullerProgress` public symbols
* Expose syncthing.app's Model instance (app.M)
* Add no-op stub for SetLowPriority on iOS
I would very much appreciate these changes to be (eventually) merged to
mainline syncthing, as this would allow my iOS app to track the mainline
source code directly and removes the need (for me at least) for
maintaining a separate fork. Perhaps the Mobius folks can also benefit
from this (although as noted this branch does not contain their changes
to e.g. the GUI).
### Testing
This branch has been tested with the iOS app and appears to work fine.
The full set of MobiusSync changes has been used before with success.
### Screenshots
n/a
### Documentation
There should be no visible changes for users due to this set of changes.
---------
Co-authored-by: Simon Pickup <simon@pickupinfinity.com>
This makes a couple of small improvements to the folder summary
mechanism:
- The folder summary includes the local and remote sequence numbers in
clear text, rather than some odd sum that I'm not sure what it was
intended to represent.
- The folder summary event is generated when appropriate, regardless of
whether there is an event listener. We did this before because
generating it was expensive, and we wanted to avoid doing it
unnecessarily. Nowadays, however, it's mostly just reading out
pre-calculated metadata, and anyway, it's nice if it shows up reliably
when running with -verbose.
The point of all this is to make it easier to use these events to judge
when devices are, in fact, in sync. As-is, if I'm looking at two
devices, it's very difficult to reliably determine if they are in sync
or not. The reason is that while we can ask device A if it thinks it's
in sync, we can't see if the answer is "yes" because it has processed
all changes from B, or if it just doesn't know about the changes from B
yet. With proper sequence numbers in the event we can compare the two
and determine the truth. This makes testing a lot easier.
This splits the ignore getting to two methods, one that loads from disk
(the old one) and one that just returns whatever is already loaded (the
new one). The folder summary service which is just interested in stats
now uses the latter method. This means that it, and API calls that call
it, does not get blocked by folder I/O.
One of the causes of "panic: database is closed" is that we try to send
summaries after it's been closed. Calculating summaries can take a long
time and if we have a lot of folders it's not unreasonable to think
that we might be stopped in this loop, so prepare to bail here.
* push
* cmd/syncthing, lib/gui: Separate gui into own package (ref #4085)
* fix tests
* Don't use main as interface name (make old go happy)
* gui->api
* don't leak state via locations and use in-tree config
* let api (un-)subscribe to config
* interface naming and exporting
* lib/ur
* fix tests and lib/foldersummary
* shorter URVersion and ur debug fix
* review
* model.JsonCompletion(FolderCompletion) -> FolderCompletion.Map()
* rename debug facility https -> api
* folder summaries in model
* disassociate unrelated constants
* fix merge fail
* missing id assignement
