Struct MemDatabase 

pub struct MemDatabase {
    pub tables: SwissIndex<i32, MemTable>,
    /* private fields */
}

Shared in-memory database backing the VDBE engine’s cursor operations.

Maps root page numbers to in-memory tables. The Connection layer populates this when processing CREATE TABLE and passes it to the engine.

Fields

tables: SwissIndex<i32, MemTable>

Tables indexed by root page number.

Implementations

impl MemDatabase

pub fn new() -> Self

Create a new empty in-memory database.

pub fn set_collation_registry( &mut self, registry: Arc<Mutex<CollationRegistry>>, )

Propagate a shared collation registry to all tracked MemTables.

pub fn table_count(&self) -> i32

Returns the number of tables in the database.

pub fn next_root_page(&self) -> i32

Return the next root page that would be assigned by create_table.

pub fn set_next_root_page(&mut self, val: i32)

Advance the root page counter so future allocations start at val.

Used to prevent MemDatabase root pages from colliding with pager- allocated pages (e.g. when materializing sqlite_master temp tables).

pub fn allocate_root_page(&mut self) -> i32

Allocate and return the next root page number without creating a table.

Used by OpenAutoindex which needs a unique page number for a MemPageStore-backed index cursor but must NOT pollute self.tables (a spurious MemTable entry would cause get_table() to return Some, misleading open_storage_cursor into treating the page as a table B-tree).

pub fn create_table(&mut self, num_columns: usize) -> i32

Create a table and return its root page number.

pub fn create_table_at(&mut self, root_page: i32, num_columns: usize)

Create a table at a specific root page number.

Used by the storage layer (5A.3) when the root page is allocated from the pager rather than auto-assigned. Advances next_root_page past root_page if necessary so that future create_table() calls do not collide.

pub fn get_table(&self, root_page: i32) -> Option<&MemTable>

Get a reference to a table by root page.

pub fn get_table_mut(&mut self, root_page: i32) -> Option<&mut MemTable>

Get a mutable reference to a table by root page.

pub fn undo_version(&self) -> MemDbVersionToken

Return the current undo-version token.

This is the identity captured in snapshots for savepoints/transactions.

pub fn begin_undo(&mut self)

Begin a new undo region (transaction start).

pub fn commit_undo(&mut self)

End the undo region (transaction committed/finished).

pub fn rollback_to(&mut self, token: MemDbVersionToken)

Restore the database to a previously captured undo-version token.

pub fn destroy_table(&mut self, root_page: i32)

Drop a table by root page and record undo information.

pub fn upsert_row<V>(&mut self, root_page: i32, rowid: i64, values: V)

where V: Into<MemRowValues>,

pub fn remove_column_from_rows( &mut self, root_page: i32, removed_slot: usize, ) -> bool

Remove a column slot from every row in a TEMP table.

The pre-rewrite table image is recorded as one undo entry, so an enclosing statement savepoint restores row widths, UNIQUE metadata, and the column count together.

pub fn insert_auto_row<V>( &mut self, root_page: i32, values: V, rowid_value_column: Option<usize>, ) -> Option<i64>

where V: Into<MemRowValues>,

Allocate an implicit rowid and insert the row, recording one undo entry for both the rowid counter advance and the row mutation. If rowid_value_column is present, that column is patched to the allocated rowid before insertion.

pub fn delete_rowid(&mut self, root_page: i32, rowid: i64) -> bool

Delete a row by rowid, recording undo information for rollback.

Trait Implementations

impl Clone for MemDatabase

fn clone(&self) -> MemDatabase

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MemDatabase

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MemDatabase

fn default() -> Self

Returns the “default value” for a type.