start distributing meilisearch

cluster/src/lib.rs

@@ -0,0 +1,79 @@
+use std::net::ToSocketAddrs;
+
+use ductile::{connect_channel, ChannelReceiver, ChannelSender};
+use meilisearch_types::tasks::KindWithContent;
+use serde::{Deserialize, Serialize};
+
+mod leader;
+
+pub use leader::Leader;
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("Network issue occured")]
+    NetworkIssue,
+    #[error("Internal error: {0}")]
+    SerdeJson(#[from] serde_json::Error),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum LeaderMsg {
+    // Starts a new batch
+    StartBatch { id: u32, batch: Vec<u32> },
+    // Tell the follower to commit the update asap
+    Commit(u32),
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum FollowerMsg {
+    // Let the leader knows you're ready to commit
+    ReadyToCommit(u32),
+    RegisterNewTask(KindWithContent),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Consistency {
+    Zero,
+    One,
+    Two,
+    Quorum,
+    All,
+}
+
+pub struct Follower {
+    sender: ChannelSender<FollowerMsg>,
+    receiver: ChannelReceiver<LeaderMsg>,
+    batch_id: u32,
+}
+
+impl Follower {
+    pub fn join(leader: impl ToSocketAddrs) -> Follower {
+        let (sender, receiver) = connect_channel(leader).unwrap();
+        Follower { sender, receiver, batch_id: 0 }
+    }
+
+    pub fn get_new_batch(&mut self) -> Vec<u32> {
+        loop {
+            match self.receiver.recv() {
+                Ok(LeaderMsg::StartBatch { id, batch }) if id == self.batch_id => {
+                    self.batch_id = id;
+                    break batch;
+                }
+                Err(_) => log::error!("lost connection to the leader"),
+                _ => (),
+            }
+        }
+    }
+
+    pub fn ready_to_commit(&mut self) {
+        self.sender.send(FollowerMsg::ReadyToCommit(self.batch_id)).unwrap();
+
+        loop {
+            match self.receiver.recv() {
+                Ok(LeaderMsg::Commit(id)) if id == self.batch_id => break,
+                Err(_) => panic!("lost connection to the leader"),
+                _ => (),
+            }
+        }
+    }
+}