Even though r2d2 connection pool is removed,
deleting accounts still fails in Windows CI.
This reverts commit e88f21c010.
`try_many_times` documentation is modified to explain
why the workaround is still needed.
Opening the same account (context) from multiple processes is dangerous, can result in duplicate
downloads of the same message etc. Same for account manager, attempts to modify the same
accounts.toml even if done atomically with may result in corrupted files as atomic replacement
procedure does not expect that multiple processes may write to the same temporary file.
accounts.toml cannot be used as a lockfile because it is replaced during atomic update. Therefore, a
new file next to accounts.toml is needed to prevent starting second account manager in the same
directory.
But iOS needs to be able to open accounts from multiple processes at the same time. This is required
as the "share-to-DC extension" is a separate process by iOS design -- this process may or may not be
started while the main app is running. Accounts are not altered however by this extension, so let's
add to the `Accounts::new()` constructor an `rdwr` parameter which allows to read the accounts
config w/o locking the lockfile.
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.
All contexts created by the same account manager
share stock string translations. Setting translation on
a single context automatically sets translations for all other
accounts, so it is enough to set translations on the active account.
This allows account manager to construct a single event channel and
inject it into all created contexts instead of aggregating events from
separate event emitters.
When removing an account, try 60 times with 1 second sleep in between
in case removal of database files fails. This happens on Windows
platform sometimes due to a known bug in r2d2 which may result in 30
seconds delay until all connections are closed [1].
[1] https://github.com/sfackler/r2d2/issues/99
To create encrypted account with account manager, call
dc_accounts_add_closed_account(). Open this account with
dc_context_open() using the passphrase you want to use for encryption.
When application is loaded next time and account manager is created,
it will open all accounts that have no passphrase set. For encrypted
accounts dc_context_is_open() will return 0. To open them, call
dc_context_open() with the correct passphrase. After opening, call
dc_context_start_io() on this account or just dc_accounts_start_io()
to start all accounts that are not started yet.
Support for legacy SQLite-based backup format is removed in this
commit.
- Replace .ok_or_else() and .map_err() with anyhow::Context where possible.
- Use .context() to check Option for None when it's an error
- Resultify Chatlist.get_chat_id()
- Add useful .context() to some errors
- IMAP error handling cleanup
Also make Accounts uncloneable. It is still possible to derive Clone,
but does not make sense to do so, as .clone() creates two separate
account managers which use the same files but different unsynchronized
in-memory data structures.
the WAL files come from sqlite WAL mode,
they have the same name as the database file with an extra `-wal` suffix.
according to https://sqlite.org/wal.html#the_wal_file ,
the WAL file is part of the persistent state of the database
and should be kept with the database if the database is copied or moved.
* accounts: update EventEmitter on add_account
* accounts: do not lock waiting for EventEmitter in dc_accounts_add_account
Otherwise dc_accounts_add_account blocks until an event arrives on
some existing account.
See https://support.delta.chat/t/discussion-how-to-show-error-states/1363/10 <!-- comment -->
It turns out that it's pretty easy to distinguish between lots of states (currently Error/NotConnected, Connecting…, Getting new messages… and Connected). What's not that easy is distinguishing between an actual error and no network, because if the server just doesn't respond, it could mean that we don't have network or that we are trying ipv6, but only ipv4 works.
**WRT debouncing:**
Sending of EVENT_CONNECTIVITY_CHANGED is not debounced, but emitted every time one of the 3 threads (Inbox, Mvbox and Sentbox) has a network error, starts fetching data, or is done fetching data.
This means that it is emitted:
- 9 times when dc_maybe_network() is called or we get network connection
- 12 times when we lose network connection
Some measurements: dc_get_connectivity() takes a little more than 1ms (in my measurements back in March), dc_get_connectivity_html() takes 10-20ms. This means that it's no immmediate problem to call them very often, might increase battery drain though. For the UI it may be a lot of work to update the title everytime; at least Android is smart enough to update the title only once.
Possible problems (we don't have to worry about them now I think):
- Due to the scan_folders feature, if the user has lots of folders, the state could be "Connecting..." for quite a long time, generally DC seemed a little unresponsive to me because it took so long for "Connecting..." to go away. Telegram has a state "Updating..." that sometimes comes after "Connecting...".
To be done in other PRs:
- Better handle the case that the password was changed on the server and authenticating fails, see https://github.com/deltachat/deltachat-core-rust/issues/1923 and https://github.com/deltachat/deltachat-core-rust/issues/1768
- maybe event debouncing (except for "Connected" connectivity events)
fix https://github.com/deltachat/deltachat-android/issues/1760
in most (all?) UIs, import/export works on an already created account,
so, dc_accounts_import_account() does not really help here -
but adds some noise and confusion
eg. as for the other dc_accounts_t functions,
the corrsponding dc_context_t functions must not be called.
if really a new account is required for import,
it seems to be easier to call add_account() before import.
