This PR introduces some modifications to the Program Builder to allow us
to use nested parsing. By focusing the emission of Init and the last
Goto (prologue and epilogue), inside the ProgramBuilder, we can just not
emit them if we are parsing/translating in a nested context. For this
PR, I only migrated insert to use these functions as I need them to
support Insert statements that use `SELECT FROM` syntax. Nested parsing
overall enables code reuse for us and arguably is one of the only ways
to parse deeply nested queries without a lot of code duplication.
#1528Closes#1543
This PR builds on top of
https://github.com/tursodatabase/limbo/pull/1368 and adds few things
like allowing inserting pages with the same page key, fix fuzz tests by
adding transactions and some minor improvements to cacheflush.
Closes#1523
This PR adds a port of [SQLite's CSV virtual table
extension](https://www.sqlite.org/csv.html).
Planned follow-ups:
* Pass detailed error messages from `VTabModule::create`, not just
`ResultCode`s.
* Address the TODO in `VTabModuleImpl::create_schema`.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1544
I was trying to run the TPC-H 9.sql in the CLI, but it kept truncating
my input due to a comment that is present in the query. After removing
it, I can just copy and paste the query and it works. @PThorpe92 is it
safe to remove this? Or is there a particular reason that was included
that I am not aware of?
Closes#1525
One problem we have with PageRef, is that this Page reference can be
unloaded, this means if we read the page again instead of loading the
page onto the same reference, we will have split brain of references.
To solve this we wrap PageRef in `BTreePage` so that if a page is seen
as unloaded, we will replace BTreePage::page with the newest version of
the page.
Previously, fuzz tests increase the size of page cache indefinitely,
therefore the was no problem of reaching the capacity of a page cache.
By adding transactions to fuzz tests we allow pages to remove dirty
flags once insert is finished.
After inserting a page into the wal, we dispose of the modified page.
This is unnecessary as we can simply move new page to the newest
snapshot where this page can be read.
Dirty pages can be deleted in `cacheflush`. Furthermore, there could be
multiple live references in the stack of a cursor so let's allow them to
exist while deleting.
insert() fails if key exists (there shouldn't be two) and panics if
it's different pages, and also fails if it can't make room for the page.
Replaced the limited pop_if_not_dirty() function with make_room_for().
It tries to evict many pages as requested spare capacity. It should come
handy later by resize() and Pager. make_room_for() tries to make room or
fails if it can't evict enough entries.
For make_room_for() I also tried with an all-or-nothing approach, so if
say a query requests a lot more than possible to make room for, it
doesn't evict a bunch of pages from the cache that might be useful. But
implementing this approach got very complicated since it needs to keep
exclusive PageRefs and collecting this caused segfaults. Might be worth
trying again in the future. But beware the rabbit hole.
Updated page cache test logic for new insert rules.
Updated Pager.allocate_page() to handle failure logic but needs further
work. This is to show new cache insert handling. There are many places
to update.
Left comments on callers of pager and page cache needing to update
error handling, for now.
Add error handling and results for insert(), delete(), _delete(),
_detach(), pop_if_not_dirty(), and clear.
Now these functions fail if a page is dirty, locked, or has other
references.
insert() makes room with pop_if_not_dirty() beforehand to handle
cache full and un-evictable, else it would evict this page
silently.
_delete() returns Ok when key is not present in cache and it tries
first to detach the cache entry and clean its page *before*
removing the entry from the map.
detach() checks firstt if it's possible to evict the page and if
there are no other references to the page before taking its
contents.
test_detach_via_delete() and test_detach_via_insert() fixed by
properly checking before and after dropping the page reference.
test_page_cache_fuzz() fixed by reordering and moving reference to
the page into insert.
Other page cache tests fixed to check new function results.
All page cache tests pass.
Error handling and test fixes for Pager and BTree will be added in
a subsequent commit.
