Improve how node roles are assigned in Garagev0.5-beta1

- change the terminology: the network configuration becomes the role
  table, the configuration of a nodes becomes a node's role
- the modification of the role table takes place in two steps: first,
  changes are staged in a CRDT data structure. Then, once the user is
  happy with the changes, they can commit them all at once (or revert
  them).
- update documentation
- fix tests
- implement smarter partition assignation algorithm

This patch breaks the format of the network configuration: when
migrating, the cluster will be in a state where no roles are assigned.
All roles must be re-assigned and commited at once. This migration
should not pose an issue.

1 files changed, 0 insertions, 99 deletions

diff --git a/src/table/crdt/map.rs b/src/table/crdt/map.rs
deleted file mode 100644
index 7553cd50..00000000
--- a/src/table/crdt/map.rs
+++ /dev/null
@@ -1,99 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-use crate::crdt::crdt::*;
-
-/// Simple CRDT Map
-///
-/// This types defines a CRDT for a map from keys to values. Values are CRDT types which
-/// can have their own updating logic.
-///
-/// Internally, the map is stored as a vector of keys and values, sorted by ascending key order.
-/// This is why the key type `K` must implement `Ord` (and also to ensure a unique serialization,
-/// such that two values can be compared for equality based on their hashes). As a consequence,
-/// insertions take `O(n)` time. This means that Map should be used for reasonably small maps.
-/// However, note that even if we were using a more efficient data structure such as a `BTreeMap`,
-/// the serialization cost `O(n)` would still have to be paid at each modification, so we are
-/// actually not losing anything here.
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
-pub struct Map<K, V> {
-	vals: Vec<(K, V)>,
-}
-
-impl<K, V> Map<K, V>
-where
-	K: Clone + Ord,
-	V: Clone + Crdt,
-{
-	/// Create a new empty map CRDT
-	pub fn new() -> Self {
-		Self { vals: vec![] }
-	}
-
-	/// Returns a map that contains a single mapping from the specified key to the specified value.
-	/// This can be used to build a delta-mutator:
-	/// when merged with another map, the value will be added or CRDT-merged if a previous
-	/// value already exists.
-	pub fn put_mutator(k: K, v: V) -> Self {
-		Self { vals: vec![(k, v)] }
-	}
-
-	/// Add a value to the map
-	pub fn put(&mut self, k: K, v: V) {
-		self.merge(&Self::put_mutator(k, v));
-	}
-
-	/// Removes all values from the map
-	pub fn clear(&mut self) {
-		self.vals.clear();
-	}
-
-	/// Get a reference to the value assigned to a key
-	pub fn get(&self, k: &K) -> Option<&V> {
-		match self.vals.binary_search_by(|(k2, _)| k2.cmp(k)) {
-			Ok(i) => Some(&self.vals[i].1),
-			Err(_) => None,
-		}
-	}
-	/// Gets a reference to all of the items, as a slice. Usefull to iterate on all map values.
-	pub fn items(&self) -> &[(K, V)] {
-		&self.vals[..]
-	}
-	/// Returns the number of items in the map
-	pub fn len(&self) -> usize {
-		self.vals.len()
-	}
-
-	/// Returns true if the map is empty
-	pub fn is_empty(&self) -> bool {
-		self.len() == 0
-	}
-}
-
-impl<K, V> Crdt for Map<K, V>
-where
-	K: Clone + Ord,
-	V: Clone + Crdt,
-{
-	fn merge(&mut self, other: &Self) {
-		for (k, v2) in other.vals.iter() {
-			match self.vals.binary_search_by(|(k2, _)| k2.cmp(k)) {
-				Ok(i) => {
-					self.vals[i].1.merge(v2);
-				}
-				Err(i) => {
-					self.vals.insert(i, (k.clone(), v2.clone()));
-				}
-			}
-		}
-	}
-}
-
-impl<K, V> Default for Map<K, V>
-where
-	K: Clone + Ord,
-	V: Clone + Crdt,
-{
-	fn default() -> Self {
-		Self::new()
-	}
-}