Method clone_structure

crates/table/src/table.rs:1595–1615

Clones the structure of this table into a new one with the same schema, visitor program, and indices. The new table will be completely empty and will use the given `squashed_offset` instead of that of `self`.

(&self, squashed_offset: SquashedOffset)

    /// The new table will be completely empty
    /// and will use the given `squashed_offset` instead of that of `self`.
    pub fn clone_structure(&self, squashed_offset: SquashedOffset) -> Self {
        // Clone a bunch of static data.
        // NOTE(centril): It's important that these be cheap to clone.
        // This is why they are all `Arc`ed or have some sort of small-vec optimization.
        let schema = self.schema.clone();
        let layout = self.row_layout().clone();
        let sbl = self.inner.static_layout.clone();
        let visitor = self.inner.visitor_prog.clone();

        // If we had a pointer map, we'll have one in the cloned one as well, but empty.
        let pm = self.pointer_map.as_ref().map(|_| PointerMap::default());

        // Make the new table.
        let mut new = Table::new_raw(schema, layout, sbl, visitor, squashed_offset, pm);

        // Clone the index structure. The table is empty, so no need to `build_from_rows`.
        for (&index_id, index) in self.indexes.iter() {
            new.indexes.insert(index_id, index.clone_structure());
        }
        new
    }

    /// Returns the number of bytes occupied by the pages and the blob store.
    /// Note that result can be more than the actual physical size occupied by the table