garage/src/table/schema.rs
2021-03-12 21:52:19 +01:00

71 lines
1.6 KiB
Rust

use serde::{Deserialize, Serialize};
use garage_util::data::*;
use crate::crdt::CRDT;
pub trait PartitionKey {
fn hash(&self) -> Hash;
}
impl PartitionKey for String {
fn hash(&self) -> Hash {
blake2sum(self.as_bytes())
}
}
impl PartitionKey for Hash {
fn hash(&self) -> Hash {
self.clone()
}
}
pub trait SortKey {
fn sort_key(&self) -> &[u8];
}
impl SortKey for String {
fn sort_key(&self) -> &[u8] {
self.as_bytes()
}
}
impl SortKey for Hash {
fn sort_key(&self) -> &[u8] {
self.as_slice()
}
}
pub trait Entry<P: PartitionKey, S: SortKey>:
CRDT + PartialEq + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync
{
fn partition_key(&self) -> &P;
fn sort_key(&self) -> &S;
fn is_tombstone(&self) -> bool {
false
}
}
pub trait TableSchema: Send + Sync {
type P: PartitionKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
type S: SortKey + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync;
type E: Entry<Self::P, Self::S>;
type Filter: Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync;
// Action to take if not able to decode current version:
// try loading from an older version
fn try_migrate(_bytes: &[u8]) -> Option<Self::E> {
None
}
// Updated triggers some stuff downstream, but it is not supposed to block or fail,
// as the update itself is an unchangeable fact that will never go back
// due to CRDT logic. Typically errors in propagation of info should be logged
// to stderr.
fn updated(&self, _old: Option<Self::E>, _new: Option<Self::E>) {}
fn matches_filter(_entry: &Self::E, _filter: &Self::Filter) -> bool {
true
}
}