1 files changed, 50 insertions, 0 deletions
diff --git a/src/table/replication/sharded.rs b/src/table/replication/sharded.rs
new file mode 100644
index 00000000..dce74b03
--- /dev/null
+++ b/src/table/replication/sharded.rs
@@ -0,0 +1,50 @@
+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()
+	}
+}