WIP big refactoring

4 files changed, 141 insertions, 0 deletions

diff --git a/src/table/replication/fullcopy.rs b/src/table/replication/fullcopy.rs
new file mode 100644
index 00000000..a62a6c3c
--- /dev/null
+++ b/src/table/replication/fullcopy.rs
@@ -0,0 +1,59 @@
+use std::sync::Arc;
+
+use garage_rpc::membership::System;
+use garage_rpc::ring::Ring;
+use garage_util::data::*;
+
+use crate::replication::*;
+
+#[derive(Clone)]
+pub struct TableFullReplication {
+	pub max_faults: usize,
+}
+
+#[derive(Clone)]
+struct Neighbors {
+	ring: Arc<Ring>,
+	neighbors: Vec<UUID>,
+}
+
+impl TableFullReplication {
+	pub fn new(max_faults: usize) -> Self {
+		TableFullReplication { max_faults }
+	}
+}
+
+impl TableReplication for TableFullReplication {
+	// Full replication schema: all nodes store everything
+	// Writes are disseminated in an epidemic manner in the network
+
+	// Advantage: do all reads locally, extremely fast
+	// Inconvenient: only suitable to reasonably small tables
+
+	fn read_nodes(&self, _hash: &Hash, system: &System) -> Vec<UUID> {
+		vec![system.id]
+	}
+	fn read_quorum(&self) -> usize {
+		1
+	}
+
+	fn write_nodes(&self, hash: &Hash, system: &System) -> Vec<UUID> {
+		self.replication_nodes(hash, system.ring.borrow().as_ref())
+	}
+	fn write_quorum(&self, system: &System) -> usize {
+		system.ring.borrow().config.members.len() - self.max_faults
+	}
+	fn max_write_errors(&self) -> usize {
+		self.max_faults
+	}
+
+	fn replication_nodes(&self, _hash: &Hash, ring: &Ring) -> Vec<UUID> {
+		ring.config.members.keys().cloned().collect::<Vec<_>>()
+	}
+	fn split_points(&self, _ring: &Ring) -> Vec<Hash> {
+		let mut ret = vec![];
+		ret.push([0u8; 32].into());
+		ret.push([0xFFu8; 32].into());
+		ret
+	}
+}
diff --git a/src/table/replication/mod.rs b/src/table/replication/mod.rs
new file mode 100644
index 00000000..d43d7f19
--- /dev/null
+++ b/src/table/replication/mod.rs
@@ -0,0 +1,6 @@
+mod parameters;
+
+pub mod fullcopy;
+pub mod sharded;
+
+pub use parameters::*;
diff --git a/src/table/replication/parameters.rs b/src/table/replication/parameters.rs
new file mode 100644
index 00000000..4607b050
--- /dev/null
+++ b/src/table/replication/parameters.rs
@@ -0,0 +1,22 @@
+use garage_rpc::membership::System;
+use garage_rpc::ring::Ring;
+
+use garage_util::data::*;
+
+pub trait TableReplication: Send + Sync {
+	// See examples in table_sharded.rs and table_fullcopy.rs
+	// To understand various replication methods
+
+	// Which nodes to send reads from
+	fn read_nodes(&self, hash: &Hash, system: &System) -> Vec<UUID>;
+	fn read_quorum(&self) -> usize;
+
+	// Which nodes to send writes to
+	fn write_nodes(&self, hash: &Hash, system: &System) -> Vec<UUID>;
+	fn write_quorum(&self, system: &System) -> usize;
+	fn max_write_errors(&self) -> usize;
+
+	// Which are the nodes that do actually replicate the data
+	fn replication_nodes(&self, hash: &Hash, ring: &Ring) -> Vec<UUID>;
+	fn split_points(&self, ring: &Ring) -> Vec<Hash>;
+}
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
+	}
+}