This PR fixes#666
Limbo was treating all single byte integers properly in `core/types.rs`,
but when converted in `sqlite3_ondisk`, it was losing the sign for 8 bit
integers, treating them all as unsigned. Sqlite3 specifies in their file
format that the `1` record serial type is "Value is an 8-bit twos-
complement integer." https://www.sqlite.org/fileformat.html
We now properly match sqlite3's output
Closes#667
`balance_non_root` should be as close as possible to `balance_non_root`
in SQLite. This commits extract `balance_non_root` from `balance` and
renames `balance_leaf` to `balance` as it enables future work on a
complete `balance_non_root` procedure.
This PR's genesis is from investigating #532, but I still can't reliably
reproduce it on either `main` or this branch so I don't know if this PR
_fixes_ anything, but I guess it aligns us more with sqlite anyway
---
Anyway: I looked at DBs created with limbo and with sqlite using
[ImHex](https://github.com/WerWolv/ImHex) and the differences seem to
be:
1. SQLite uses varint according to [the
spec](https://www.sqlite.org/fileformat.html#record_format), whereas
limbo always encodes integers as i64
2. Limbo adds 4 bytes of zeros for overflow page pointer (even in cases
where the cell doesnt overflow)
3. Limbo adds a space after `CREATE TABLE name` before the `(` even when
user doesn't specify it?
I implemented the following:
- Fix 1: Varint serialization of i8, i16, i24, i32, i48 and i64
according to payload, instead of always using i64
- Fix 2: Removed the 4 bytes reserved for overflow page pointer in non-
overflow cases
Reviewed-by: Pere Diaz Bou <pere-altea@homail.com>
Closes#550
small follow up to https://github.com/tursodatabase/limbo/pull/539
contains:
- Variable renaming and comments to `btreecursor.insert_into_cell()`
- New utility methods `pagecontent.header_size()`,
`pagecontent.cell_pointer_array_size()`,
`pagecontent.unallocated_region_start()` and
`pagecontent.unallocated_region_size()`
- Refactor of `btreecursor.compute_free_space()` (plus comments and
variable renaming)
- Rename `pagecontent.cell_get_raw_pointer_region()` to
`pagecontent.cell_pointer_array_offset_and_size()` and remove its usage
in `btreecursor.defragment_page()`
Reviewed-by: Pere Diaz Bou <pere-altea@homail.com>
Closes#543
Implements [json_array](https://sqlite.org/json1.html#jarray).
As a side quest, this PR also fixes an issue with the `CHAR` function
which didn't work properly if the parameters were non-leaf AST nodes.
The PR is quite big, because as I mentioned in https://github.com/tursod
atabase/limbo/issues/127#issuecomment-2541307979 we had to modify
`OwnedValue::Text` to support a `subtype` parameter, which is what
SQLite does.
Closes#504
Since page cache is now shared by default, we need to cache pages by
page number and something else. I chose to go with max_frame of
connection, because this connection will have a max_frame set until from
the start of a transaction until the end of it.
With key pairs of (pgno, max_frame) we make sure each connection is
caching based on the snapshot it is at as two different connections
might have the same pageno being using but a different frame. If both
have same max_frame then they will share same page.
Closes#468
Since page cache is now shared by default, we need to cache pages by
page number and something else. I chose to go with max_frame of
connection, because this connection will have a max_frame set until from
the start of a transaction until the end of it.
With key pairs of (pgno, max_frame) we make sure each connection is
caching based on the snapshot it is at as two different connections
might have the same pageno being using but a different frame. If both
have same max_frame then they will share same page.
