garage/src/table/schema.rs

90 lines
2.3 KiB
Rust
Raw Normal View History

2020-07-08 14:10:53 +00:00
use serde::{Deserialize, Serialize};
use garage_util::data::*;
2021-05-02 21:13:08 +00:00
use crate::crdt::Crdt;
2021-04-06 03:25:28 +00:00
/// Trait for field used to partition data
2020-07-08 14:10:53 +00:00
pub trait PartitionKey {
2021-03-26 18:41:46 +00:00
/// Get the key used to partition
2020-07-08 14:10:53 +00:00
fn hash(&self) -> Hash;
}
impl PartitionKey for String {
2020-07-08 14:10:53 +00:00
fn hash(&self) -> Hash {
blake2sum(self.as_bytes())
2020-07-08 14:10:53 +00:00
}
}
2021-12-14 12:55:11 +00:00
impl PartitionKey for FixedBytes32 {
2020-07-08 14:10:53 +00:00
fn hash(&self) -> Hash {
2021-04-23 19:42:52 +00:00
*self
2020-07-08 14:10:53 +00:00
}
}
2021-04-06 03:25:28 +00:00
/// Trait for field used to sort data
pub trait SortKey {
2021-03-26 18:41:46 +00:00
/// Get the key used to sort
fn sort_key(&self) -> &[u8];
}
2020-07-08 14:10:53 +00:00
impl SortKey for String {
fn sort_key(&self) -> &[u8] {
self.as_bytes()
}
}
2021-12-14 12:55:11 +00:00
impl SortKey for FixedBytes32 {
2020-07-08 14:10:53 +00:00
fn sort_key(&self) -> &[u8] {
self.as_slice()
}
}
2021-03-26 18:41:46 +00:00
/// Trait for an entry in a table. It must be sortable and partitionnable.
pub trait Entry<P: PartitionKey, S: SortKey>:
2021-05-02 21:13:08 +00:00
Crdt + PartialEq + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync
{
2021-03-26 18:41:46 +00:00
/// Get the key used to partition
fn partition_key(&self) -> &P;
2021-03-26 18:41:46 +00:00
/// Get the key used to sort
fn sort_key(&self) -> &S;
2021-03-26 18:41:46 +00:00
/// Is the entry a tombstone? Default implementation always return false
2021-03-12 20:52:19 +00:00
fn is_tombstone(&self) -> bool {
false
}
}
2021-03-26 18:41:46 +00:00
/// Trait for the schema used in a table
2020-07-08 14:10:53 +00:00
pub trait TableSchema: Send + Sync {
2021-12-14 11:34:01 +00:00
/// The name of the table in the database
const TABLE_NAME: &'static str;
2021-03-26 18:41:46 +00:00
/// The partition key used in that table
2020-07-08 14:10:53 +00:00
type P: PartitionKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
2021-03-26 18:41:46 +00:00
/// The sort key used int that table
2020-07-08 14:10:53 +00:00
type S: SortKey + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync;
2021-12-14 11:34:01 +00:00
2021-03-26 18:41:46 +00:00
/// They type for an entry in that table
2020-07-08 14:10:53 +00:00
type E: Entry<Self::P, Self::S>;
2021-12-14 11:34:01 +00:00
/// The type for a filter that can be applied to select entries
/// (e.g. filter out deleted entries)
2020-07-08 14:10:53 +00:00
type Filter: Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync;
2020-07-08 15:34:37 +00:00
// Action to take if not able to decode current version:
// try loading from an older version
2021-03-26 18:41:46 +00:00
/// Try migrating an entry from an older version
2020-07-08 15:34:37 +00:00
fn try_migrate(_bytes: &[u8]) -> Option<Self::E> {
None
}
2020-07-08 14:10:53 +00:00
// 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>) {}
2021-03-26 18:41:46 +00:00
fn matches_filter(entry: &Self::E, filter: &Self::Filter) -> bool;
2020-07-08 14:10:53 +00:00
}