garage/src/table/replication/sharded.rs

50 lines
1.3 KiB
Rust

use std::sync::Arc;
use garage_rpc::membership::System;
use garage_rpc::ring::*;
use garage_util::data::*;
use crate::replication::*;
#[derive(Clone)]
pub struct TableShardedReplication {
pub system: Arc<System>,
pub replication_factor: usize,
pub read_quorum: usize,
pub write_quorum: usize,
}
impl TableReplication for TableShardedReplication {
// Sharded replication schema:
// - based on the ring of nodes, a certain set of neighbors
// store entries, given as a function of the position of the
// entry's hash in the ring
// - reads are done on all of the nodes that replicate the data
// - writes as well
fn read_nodes(&self, hash: &Hash) -> Vec<UUID> {
let ring = self.system.ring.borrow().clone();
ring.walk_ring(&hash, self.replication_factor)
}
fn read_quorum(&self) -> usize {
self.read_quorum
}
fn write_nodes(&self, hash: &Hash) -> Vec<UUID> {
let ring = self.system.ring.borrow();
ring.walk_ring(&hash, self.replication_factor)
}
fn write_quorum(&self) -> usize {
self.write_quorum
}
fn max_write_errors(&self) -> usize {
self.replication_factor - self.write_quorum
}
fn partition_of(&self, hash: &Hash) -> Partition {
self.system.ring.borrow().partition_of(hash)
}
fn partitions(&self) -> Vec<(Partition, Hash)> {
self.system.ring.borrow().partitions()
}
}