garage/src/table/schema.rs

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use serde::{Deserialize, Serialize};
use garage_util::data::*;
pub trait PartitionKey {
fn hash(&self) -> Hash;
}
impl PartitionKey for String {
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fn hash(&self) -> Hash {
sha256sum(self.as_bytes())
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}
}
impl PartitionKey for Hash {
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fn hash(&self) -> Hash {
self.clone()
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}
}
pub trait SortKey {
fn sort_key(&self) -> &[u8];
}
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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>:
PartialEq + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync
{
fn partition_key(&self) -> &P;
fn sort_key(&self) -> &S;
fn merge(&mut self, other: &Self);
}
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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;
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// 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
}
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// 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>) {}
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fn matches_filter(_entry: &Self::E, _filter: &Self::Filter) -> bool {
true
}
}