Was running the sim with I/O faults enabled and fixed some nasty bugs.
Now, there are some more nasty bugs to fix as well. This is the command
that I use to run the simulator `cargo run -p limbo_sim -- --minimum-
tests 10 --maximum-tests 1000`
This PR mainly fixes the following bugs:
- Not decrementing in flight write counter when `pwrite` fails
- not rolling back the transaction on `step` error
- not rolling back the transaction on `run_once` error
- some functions were just being unwrapped when they could suffer io
errors
- Only change max_frame after wal sync's
Reviewed-by: Pere Diaz Bou <pere-altea@homail.com>
Reviewed-by: Pere Diaz Bou <pere-altea@homail.com>
Closes#1946
This adds a `turso_assert` macro that is Antithesis aware when
`antithesis` feature flag is enabled. I did not yet convert any
call-sites to use it.
Co-authored-by: Nikita Sivukhin <sivukhin@turso.tech>
Page 1 must be initialized and written as soon as possible without
marking page as dirty.
OpenEphemeral now requires a state machine to accomodate new
begin_write_tx semantics.
Closes#1839
Makes it easier to test the feature:
```
$ cargo run -- --experimental-indexes
Limbo v0.0.22
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database
limbo> CREATE TABLE t(x);
limbo> CREATE INDEX t_idx ON t(x);
limbo> DROP INDEX t_idx;
```
Support for simple interactive rollback like:
```sql
create table t (x);
insert into t values (1);
begin;
insert into t values (2);
rollback;
select * from t;
```
This PR also fixes some other issues I found while debugging:
* Checkpoint would never `clear_dirty` on pages in page cache.
* Auto commit for interactive transactions was not respected so any
`insert` after `begin` would flush frames regardless of `auto_commit`
state.
* `max_frame` on wal shared state was being updated after every
`append_frame` which was incorrect, as another transaction would be able
to use that new `max_frame` even tho the transaction could've rolled
back. Instead we update the private copy of `max_frame` and only update
it at the end.
Follow up for later are savepoints which require implementing a
subjournal to track savepoints and their modified pages.
Closes#1825
When `struct Database` is constructed, store `is_empty` as an
`Arc<AtomicBool>` - the value is true if:
1. DB size is zero
2. WAL has no frames
When `struct Pager` is constructed, this `Arc` is simply cloned.
When any connection runs a transaction it will first check `is_empty`,
and if the DB is empty, it will lock `init_lock` and then check `is_empty`
again, and if it's still true, it allocates page1 and stores `false` in
the `is_empty` `AtomicBool` and drops the lock.
---
Note that Limbo can currently have a zero DB and a WAL with frames,
as we have no special logic for folding page1 to the main DB file
during initialization.
Page 1 allocation currently happens on the first transaction (read or
write, due to having to support `select * from sqlite_schema` on an
empty DB; we should really check how SQLite actually does this.).
