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use super::*;
pub trait Materializer {
type PageFrag;
type Recovery;
#[doc(hidden)]
fn is_null() -> bool
where
Self: Sized,
{
false
}
fn new(
config: Config,
recovered_state: &Option<Self::Recovery>,
) -> Self
where
Self: Sized;
fn merge<'a, I>(&'a self, frags: I) -> Self::PageFrag
where
I: IntoIterator<Item = &'a Self::PageFrag>;
fn recover(
&self,
frag: &Self::PageFrag,
) -> Option<Self::Recovery>;
fn size_in_bytes(&self, frag: &Self::PageFrag) -> usize;
}
#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
pub struct NullMaterializer;
impl Materializer for NullMaterializer {
type PageFrag = ();
type Recovery = ();
#[doc(hidden)]
fn is_null() -> bool {
true
}
fn new(_: Config, _: &Option<Self::Recovery>) -> Self {
NullMaterializer
}
fn merge<'a, I>(&'a self, _frags: I) -> Self::PageFrag
where
I: IntoIterator<Item = &'a Self::PageFrag>,
{
}
fn recover(&self, _: &Self::PageFrag) -> Option<Self::Recovery> {
None
}
fn size_in_bytes(&self, _: &Self::PageFrag) -> usize {
0
}
}