Struct RowArena

pub struct RowArena {
    inner: RefCell<Vec<Vec<u8>>>,
}

RowArena is used to hold on to temporary Rows for functions like eval that need to create complex Datums but don’t have a Row to put them in yet.

Fields

inner: RefCell<Vec<Vec<u8>>>

Implementations

impl RowArena

pub fn new() -> Self

pub fn with_capacity(capacity: usize) -> Self

Creates a RowArena with a hint of how many rows will be created in the arena, to avoid reallocations of its internal vector.

pub fn reserve(&self, additional: usize)

Does a reserve on the underlying Vec. Call this when you expect additional more datums to be created in this arena.

pub fn push_bytes<'a>(&'a self, bytes: Vec<u8>) -> &'a [u8]

Take ownership of bytes for the lifetime of the arena.

pub fn push_string<'a>(&'a self, string: String) -> &'a str

Take ownership of string for the lifetime of the arena.

pub fn push_unary_row<'a>(&'a self, row: Row) -> Datum<'a>

Take ownership of row for the lifetime of the arena, returning a reference to the first datum in the row.

If we had an owned datum type, this method would be much clearer, and would be called push_owned_datum.

fn push_unary_row_datum_nested<'a>(&'a self, row: Row) -> DatumNested<'a>

Equivalent to push_unary_row but returns a DatumNested rather than a Datum.

pub fn make_datum<'a, F>(&'a self, f: F) -> Datum<'a>

where F: FnOnce(&mut RowPacker<'_>),

Convenience function to make a new Row containing a single datum, and take ownership of it for the lifetime of the arena

let arena = RowArena::new();
let datum = arena.make_datum(|packer| {
  packer.push_list(&[Datum::String("hello"), Datum::String("world")]);
});
assert_eq!(datum.unwrap_list().iter().collect::<Vec<_>>(), vec![Datum::String("hello"), Datum::String("world")]);

pub fn make_datum_nested<'a, F>(&'a self, f: F) -> DatumNested<'a>

where F: FnOnce(&mut RowPacker<'_>),

Convenience function identical to make_datum but instead returns a DatumNested.

pub fn try_make_datum<'a, F, E>(&'a self, f: F) -> Result<Datum<'a>, E>

where F: FnOnce(&mut RowPacker<'_>) -> Result<(), E>,

Like RowArena::make_datum, but the provided closure can return an error.

pub fn clear(&mut self)

Clear the contents of the arena.

Trait Implementations

impl Debug for RowArena

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

Formats the value using the given formatter.

impl Default for RowArena

fn default() -> RowArena

Returns the “default value” for a type.