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use crate::data::*;
use crate::rpc::membership::{Ring, System};
use crate::table::*;
#[derive(Clone)]
pub struct TableShardedReplication {
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, system: &System) -> Vec<UUID> {
let ring = 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, system: &System) -> Vec<UUID> {
let ring = system.ring.borrow().clone();
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 epidemic_writes(&self) -> bool {
false
}
fn replication_nodes(&self, hash: &Hash, ring: &Ring) -> Vec<UUID> {
ring.walk_ring(&hash, self.replication_factor)
}
fn split_points(&self, ring: &Ring) -> Vec<Hash> {
let mut ret = vec![];
ret.push([0u8; 32].into());
for entry in ring.ring.iter() {
ret.push(entry.location);
}
ret.push([0xFFu8; 32].into());
ret
}
}
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