From 94f3d287742ff90f179f528421c690b00b71a912 Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Thu, 11 Mar 2021 16:54:15 +0100
Subject: WIP big refactoring

---
 src/table/replication/sharded.rs | 54 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 src/table/replication/sharded.rs

(limited to 'src/table/replication/sharded.rs')

diff --git a/src/table/replication/sharded.rs b/src/table/replication/sharded.rs
new file mode 100644
index 00000000..42a742cd
--- /dev/null
+++ b/src/table/replication/sharded.rs
@@ -0,0 +1,54 @@
+use garage_rpc::membership::System;
+use garage_rpc::ring::Ring;
+use garage_util::data::*;
+
+use crate::replication::*;
+
+#[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, _system: &System) -> usize {
+		self.write_quorum
+	}
+	fn max_write_errors(&self) -> usize {
+		self.replication_factor - self.write_quorum
+	}
+
+	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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