When receiving messages, blobs will be deduplicated with the new
function `create_and_deduplicate_from_bytes()`. For sending files, this
adds a new function `set_file_and_deduplicate()` instead of
deduplicating by default.
This is for
https://github.com/deltachat/deltachat-core-rust/issues/6265; read the
issue description there for more details.
TODO:
- [x] Set files as read-only
- [x] Don't do a write when the file is already identical
- [x] The first 32 chars or so of the 64-character hash are enough. I
calculated that if 10b people (i.e. all of humanity) use DC, and each of
them has 200k distinct blob files (I have 4k in my day-to-day account),
and we used 20 chars, then the expected value for the number of name
collisions would be ~0.0002 (and the probability that there is a least
one name collision is lower than that) [^1]. I added 12 more characters
to be on the super safe side, but this wouldn't be necessary and I could
also make it 20 instead of 32.
- Not 100% sure whether that's necessary at all - it would mainly be
necessary if we might hit a length limit on some file systems (the
blobdir is usually sth like
`accounts/2ff9fc096d2f46b6832b24a1ed99c0d6/dc.db-blobs` (53 chars), plus
64 chars for the filename would be 117).
- [x] "touch" the files to prevent them from being deleted
- [x] TODOs in the code
For later PRs:
- Replace `BlobObject::create(…)` with
`BlobObject::create_and_deduplicate(…)` in order to deduplicate
everytime core creates a file
- Modify JsonRPC to deduplicate blob files
- Possibly rename BlobObject.name to BlobObject.file in order to prevent
confusion (because `name` usually means "user-visible-name", not "name
of the file on disk").
[^1]: Calculated with both https://printfn.github.io/fend/ and
https://www.geogebra.org/calculator, both of which came to the same
result
([1](https://github.com/user-attachments/assets/bbb62550-3781-48b5-88b1-ba0e29c28c0d),
[2](https://github.com/user-attachments/assets/82171212-b797-4117-a39f-0e132eac7252))
---------
Co-authored-by: l <link2xt@testrun.org>
Otherwise location-only messages
that should be sent every 60 seconds
are never sent because location loop
waits until the end of location streaming
and is only interrupted by location streaming
ending in other chats or being enabled in other chats.
as discussed in several chats, this PR starts making it possible to use
Webxdc as integrations to the main app. In other word: selected parts of
the main app can be integrated as Webxdc, eg. Maps [^1]
this PR contains two parts:
- draft an Webxdc Integration API
- use the Webxdc Integration API to create a Maps Integration
to be clear: a Webxdc is not part of this PR. the PR is about marking a
Webxdc being used as a Map - and core then feeds the Webxdc with
location data. from the view of the Webxdc, the normal
`sendUpdate()`/`setUpdateListener()` is used.
things are still marked as "experimental", idea is to get that in to
allow @adbenitez and @nicodh to move forward on the integrations into
android and desktop, as well as improving the maps.xdc itself.
good news is that we currently can change the protocol between Webxdc
and core at any point :)
# Webxdc Integration API
see `dc_init_webxdc_integration()` in `deltachat.h` for overview and
documentation.
rust code is mostly in `webxdc/integration.rs` that is called by other
places as needed. current [user of the API is
deltachat-ios](https://github.com/deltachat/deltachat-ios/pull/1912),
android/desktop will probably follow.
the jsonrpc part is missing and can come in another PR when things are
settled and desktop is really starting [^2] (so we won't need to do all
iterations twice :) makes also sense, when this is done by someone
actually trying that out on desktop
while the API is prepared to allow other types of integrations (photo
editor, compose tools ...) internally, we currently ignore the type. if
that gets more crazy, we probably also need a dedicated table for the
integrations and not just a single param.
# Maps Integration
rust code is mostly in `webxdc/maps_integration.rs` that is called by
`webxdc/integration.rs` as needed.
EDIT: the idea of having a split here, is that
`webxdc/maps_integration.rs` really can focus on the json part, on the
communication with the .xdc, including tests
this PR is basic implementation, enabling to move forward on
integrations on iOS, but also on desktop and android.
the current implementation allows already the following:
- global and per-chat maps
- add and display POIs
- show positions and tracks of the last 24 hours
the current maps.xdc uses leaflet, and is in some regards better than
the current android/desktop implementations (much faster, show age of
positions, fade out positions, always show names of POIs, clearer UI).
however, we are also not bound to leaflet, it can be anything
> [**screenshots of the current
state**](https://github.com/deltachat/deltachat-ios/pull/1912)
> 👆
to move forward faster and to keep this PR small, the following will go
to a subsequent PR:
- consider allowing webxdc to use a different timewindow for the
location
- delete POIs
- jsonrpc
[^1]: maps are a good example as anyways barely native (see android
app), did cause a lot of pain on many levels in the past (technically,
bureaucratically), and have a comparable simple api
[^2]: only going for jsonrpc would only make sense if large parts of
android/ios would use jsonrpc, we're not there
---------
Co-authored-by: link2xt <link2xt@testrun.org>
When scheduler is destroyed, e.g. during a key import,
there is some time between destroying the interrupt channel
and the loop task.
To avoid busy looping, tasks should terminate if
receiving from the interrupt loop fails
instead of treating it as the interrupt.
The system clock may be adjusted and even go back, so caching system time in code sections where
it's not supposed to change may even protect from races/bugs.
Message.set_text() and Message.get_text() are modified accordingly
to accept String and return String.
Messages which previously contained None text
are now represented as messages with empty text.
Use Message.set_text("".to_string())
instead of Message.set_text(None).
Moved custom ToSql trait including Send + Sync from lib.rs to sql.rs.
Replaced most params! and paramsv! macro usage with tuples.
Replaced paramsv! and params_iterv! with params_slice!,
because there is no need to construct a vector.
To handle backups the UIs have to make sure they do stop the IO
scheduler and also don't accidentally restart it while working on it.
Since they have to call start_io from a bunch of locations this can be
a bit difficult to manage.
This introduces a mechanism for the core to pause IO for some time,
which is used by the imex function. It interacts well with other
calls to dc_start_io() and dc_stop_io() making sure that when resumed
the scheduler will be running or not as the latest calls to them.
This was a little more invasive then hoped due to the scheduler. The
additional abstraction of the scheduler on the context seems a nice
improvement though.
We do not make all transactions
[IMMEDIATE](https://www.sqlite.org/lang_transaction.html#deferred_immediate_and_exclusive_transactions)
for more parallelism -- at least read transactions can be made DEFERRED to run in parallel
w/o any drawbacks. But if we make write transactions DEFERRED also w/o any external locking,
then they are upgraded from read to write ones on the first write statement. This has some
drawbacks:
- If there are other write transactions, we block the thread and the db connection until
upgraded. Also if some reader comes then, it has to get next, less used connection with a
worse per-connection page cache.
- If a transaction is blocked for more than busy_timeout, it fails with SQLITE_BUSY.
- Configuring busy_timeout is not the best way to manage transaction timeouts, we would
prefer it to be integrated with Rust/tokio asyncs. Moreover, SQLite implements waiting
using sleeps.
- If upon a successful upgrade to a write transaction the db has been modified by another
one, the transaction has to be rolled back and retried. It is an extra work in terms of
CPU/battery.
- Maybe minor, but we lose some fairness in servicing write transactions, i.e. we service
them in the order of the first write statement, not in the order they come.
The only pro of making write transactions DEFERRED w/o the external locking is some
parallelism between them. Also we have an option to make write transactions IMMEDIATE, also
w/o the external locking. But then the most of cons above are still valid. Instead, if we
perform all write transactions under an async mutex, the only cons is losing some
parallelism for write transactions.
.call() interface is safer because it ensures
that blocking operations on SQL connection
are called within tokio::task::block_in_place().
Previously some code called blocking operations
in async context, e.g. add_parts() in receive_imf module.
The underlying implementation of .call()
can later be replaced with an implementation
that does not require block_in_place(),
e.g. a worker pool,
without changing the code using the .call() interface.
