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.).
This PR adds support for table-valued functions for PRAGMAs (see the
[PRAGMA functions section](https://www.sqlite.org/pragma.html)).
Additionally, it introduces built-in table-valued functions. I
considered using extensions for this, but there are several reasons in
favor of a dedicated mechanism:
* It simplifies the use of internal functions, structs, etc. For
example, when implementing `json_each` and `json_tree`, direct access to
internals was necessary:
https://github.com/tursodatabase/limbo/pull/1088
* It avoids FFI overhead. [Benchmarks](https://github.com/piotrrzysko/li
mbo/blob/pragma_vtabs_bench/core/benches/pragma_benchmarks.rs) on my
hardware show that `pragma_table_info()` implemented as an extension is
2.5× slower than the built-in version.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1642
In preparation for `CREATE VIEW`, we need to have the original sql query
that was used to create the view. I'm using the scanner's offset to
slice into the original input, trimming the newlines, and passing it to
the translate function.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1621
This pull request implements the `libsql_wal_get_frame()` API. To do
that, we also introduce a `wait_for_completion()` API in I/O dispatcher.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1533
Closes#1528 .
- Modified `translate_select` so that the caller can define if the
statement is top-level statement or a subquery.
- Refactored `translate_insert` to offload the translation of multi-row
VALUES and SELECT statements to `translate_select`
- I did not try to change much of `populate_column_registers` as I did
not want to break `translate_virtual_table_insert`. Ideally, I would
want to unite this remaining logic folding `populate_column_registers`
into `populate_columns_multiple_rows` and the
`translate_virtual_table_insert` into `translate_insert`. But, I think
this may be best suited for a separate PR.
## TODO
- ~Tests~ - *Done*
- ~Need to emit a temp table when we are selecting and inserting into
the Same Table -
https://github.com/sqlite/sqlite/blob/master/src/insert.c#L1369~ -
*Done*
- Optimization when table have the exact same schema - open an Issue
about it
- Virtual Tables do not benefit yet from this feature - open an Issue
about it
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1566
- Instead of using a confusing CheckpointStatus for many different things,
introduce the following statuses:
* PagerCacheflushStatus - cacheflush can result in either:
- the WAL being written to disk and fsynced
- but also a checkpoint to the main BD file, and fsyncing the main DB file
Reflect this in the type.
* WalFsyncStatus - previously CheckpointStatus was also used for this, even
though fsyncing the WAL doesn't checkpoint.
* CheckpointStatus/CheckpointResult is now used only for actual checkpointing.
- Rename HaltState to CommitState (program.halt_state -> program.commit_state)
- Make WAL a non-optional property in Pager
* This gets rid of a lot of if let Some(...) boilerplate
* For ephemeral indexes, provide a DummyWAL implementation that does nothing.
- Rename program.halt() to program.commit_txn()
- Add some documentation comments to structs and functions
