OwnedValue has become a powerhouse of madness, mainly because I decided
to do it like that when I first introduced AggContext. I decided it was
enough and I introduced a `Register` struct that contains `OwnedValue`,
`Record` and `Aggregation`, this way we don't use `OwnedValue` for
everything make everyone's life harder.
This is the next step towards making ImmutableRecords the default
because I want to remove unnecessary allocations. Right now we clone
OwnedValues when we generate a record more than needed.
We currently have two value types, `Value` and `OwnedValue`. The
original thinking was that `Value` is external type and `OwnedValue` is
internal type. However, this just results in unnecessary transformation
between the types as data crosses the Limbo library boundary.
Let's just follow SQLite here and consolidate on a single value type
(where `sqlite3_value` is just an alias for the internal `Mem` type).
The way this will eventually work is that we can have bunch of
pre-allocated `OwnedValue` objects in `ProgramState` and basically
return a reference to them all the way to the application itself, which
extracts the actual value.
I am on a bit of a mission to revisit a lot of the ref counting, this
was an easy first win.
It seems to be a linear path of function calls or hashmaps which can own
the completions directly, no cloning needed.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#912
Move result row to `ProgramState` to mimic what SQLite does where `Vdbe`
struct has a `pResultRow` member. This makes it easier to deal with result
lifetime, but more importantly, eventually lazily parse values at the edges of
the API.
Lots of cleanup still left to do. Draft PR for adding support for OPFS
for WASM build (add support for limbo in browser).
Overall explanation of the architecture: this follows the sqlite wasm
architecture for OPFS.
main <> (limbo-worker.js) limbo (VFS - opfs.js) <> opfs-sync-proxy
The main thread loads limbo-worker.js which bootstraps the opfs.js and
opfs-sync-proxy.js and then launches the limbo-wasm.js.
At that point it can be used with worker.postmessage and
worker.onmessage interactions from the main thread.
The VFS provided by opfs.js provides a sync API by offloading async
operations to opfs-sync-proxy.js. This is done through SharedArrayBuffer
and Atomic.wait() to make the actual async operations appear synchronous
for limbo.
resolves#531Closes#594
#514
Introduces a new feature for lazy evaluation in the
`Statement.raw().iterate()` method and includes related changes in both
the test and implementation files. The most important changes include
adding a test case for lazy evaluation, creating a `RowIterator` struct,
and modifying the `iterate` method to use this new struct.
Everything seems to works fine, but suggestions on code improvement and
test use cases are welcoming.
Closes#527
