Trait rsdb::Materializer
[−]
[src]
pub trait Materializer { type PageFrag; type Recovery; fn merge(&self, _: &[Self::PageFrag]) -> Self::PageFrag; fn recover(&self, _: &Self::PageFrag) -> Option<Self::Recovery>; }
A user of a PageCache
needs to provide a Materializer
which
handles the merging of page fragments.
Associated Types
type PageFrag
The possibly fragmented page, written to log storage sequentially, and read in parallel from multiple locations on disk when serving a request to read the page. These will be merged to a single version at read time, and possibly cached.
type Recovery
The state returned by a call to PageCache::recover
, as
described by Materializer::recover
Required Methods
fn merge(&self, _: &[Self::PageFrag]) -> Self::PageFrag
Used to compress long chains of partial pages into a condensed form during compaction.
fn recover(&self, _: &Self::PageFrag) -> Option<Self::Recovery>
Used to feed custom recovery information back to a higher-level abstraction during startup. For example, a B-Link tree must know what the current root node is before it can start serving requests.