The fact that `PRAGMA incremental_vacuum` may return a zero-column
SQLITE_ROW result is documented in `sqlite3_data_count()` documentation:
<https://www.sqlite.org/c3ref/data_count.html>
Previously successful auto_vacuum worked,
but resulted in a "Failed to run incremental vacuum" log.
With existing approach of constructing
the SQL query dynamically I get errors like this:
ephemeral.rs:575: update failed: too many SQL variables: Error code 1: SQL error or missing database
In my case it is trying to delete 143658 messages.
This is the result of importing a Desktop backup
and enabling device auto-deletion on the phone.
Current SQLite limit is 32766 variables
as stated in <https://www.sqlite.org/limits.html>.
This way we can test some recently added config options that we don't want to expose in UI like
DeleteToTrash or SignUnencrypted. Note that persistent config options like DeleteToTrash should
remain anyway because they allow fine-grained (per-account) control. Having them matters for tests
also.
`<meta name="color-scheme" content="light dark" />` is a hint to the browsers
that the page can be rendered in light as well as in dark mode
and that the browser can apply corresponding defaults.
as we do not add css colors on our own,
this is sufficient for letting generated html messasge being rendered
in dark mode.
cmp. https://drafts.csswg.org/css-color-adjust/#color-scheme-propcloses#4146
standard footers meanwhile go the "contact status",
so they are no longer a reason to trigger "full message view".
this was already discussed when the HTML view was introduced at #2125
however, forgotten to change when the "contact status" was added at #2218
this pr will result in a cleaner chat view
with less "Show Full Message..." buttons
and will also save some storage
(in fact, i came over that when reviewing #4129 )
We are currently using libsqlite3-sys 0.25.2,
corresponding to SQLcipher 4.5.2
and SQLite 3.39.2.
SQLite supports ALTER TABLE DROP COLUMN since version 3.35.0,
and it has received critical database corruption bugfixes in 3.35.5.
There have been no fixes to it between SQLite 3.36.0 and 3.41.0,
so it appears stable now.
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.
scripts/update-provider-database.sh checks out the provider database
and updates data.rs file,
making it easier to update.
CI uses this script to check that checked in data.rs
corresponds to the provider database repository.
This makes DC compatible with "multipart/signed" messages thus allowing switching to them someday
from the current "multipart/mixed" unencrypted message format.
try_decrypt() is a CPU-bound task.
When called from async function,
it should be wrapped in tokio::task::spawn_blocking().
Using tokio::task::spawn_blocking() is difficult here
because of &mail, &private_keyring and &public_keyring borrows,
so we should at least use tokio::task::block_in_place()
to avoid blocking the executor.
Previously we used tags like "1.109.0" and "py-1.109.0".
Since Python bindings are always released
at the same time as the core,
it is easier to use a single tag for them.
"v" prefix is added to make matching by "v*" easier
in CI and scripts.
