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| 1 | +use std::collections::BTreeMap; |
| 2 | +use std::collections::BTreeSet; |
| 3 | + |
| 4 | +use openraft::raft::TransferLeaderRequest; |
| 5 | +use openraft::BasicNode; |
| 6 | +use openraft::ReadPolicy; |
| 7 | + |
| 8 | +use crate::app::GroupApp; |
| 9 | +use crate::decode; |
| 10 | +use crate::encode; |
| 11 | +use crate::typ::*; |
| 12 | +use crate::NodeId; |
| 13 | + |
| 14 | +/// Write a key-value pair to the group's state machine |
| 15 | +pub async fn write(app: &mut GroupApp, req: String) -> String { |
| 16 | + let res = app.raft.client_write(decode(&req)).await; |
| 17 | + encode(res) |
| 18 | +} |
| 19 | + |
| 20 | +/// Read a value from the group's state machine using linearizable read |
| 21 | +pub async fn read(app: &mut GroupApp, req: String) -> String { |
| 22 | + let key: String = decode(&req); |
| 23 | + |
| 24 | + let ret = app.raft.get_read_linearizer(ReadPolicy::ReadIndex).await; |
| 25 | + |
| 26 | + let res = match ret { |
| 27 | + Ok(linearizer) => { |
| 28 | + linearizer.await_ready(&app.raft).await.unwrap(); |
| 29 | + |
| 30 | + let state_machine = app.state_machine.state_machine.lock().await; |
| 31 | + let value = state_machine.data.get(&key).cloned(); |
| 32 | + |
| 33 | + let res: Result<String, RaftError<LinearizableReadError>> = Ok(value.unwrap_or_default()); |
| 34 | + res |
| 35 | + } |
| 36 | + Err(e) => Err(e), |
| 37 | + }; |
| 38 | + encode(res) |
| 39 | +} |
| 40 | + |
| 41 | +// ============================================================================ |
| 42 | +// Raft Protocol API |
| 43 | +// ============================================================================ |
| 44 | + |
| 45 | +/// Handle vote request |
| 46 | +pub async fn vote(app: &mut GroupApp, req: String) -> String { |
| 47 | + let res = app.raft.vote(decode(&req)).await; |
| 48 | + encode(res) |
| 49 | +} |
| 50 | + |
| 51 | +/// Handle append entries request |
| 52 | +pub async fn append(app: &mut GroupApp, req: String) -> String { |
| 53 | + let res = app.raft.append_entries(decode(&req)).await; |
| 54 | + encode(res) |
| 55 | +} |
| 56 | + |
| 57 | +/// Receive a snapshot and install it |
| 58 | +pub async fn snapshot(app: &mut GroupApp, req: String) -> String { |
| 59 | + let (vote, snapshot_meta, snapshot_data): (Vote, SnapshotMeta, SnapshotData) = decode(&req); |
| 60 | + let snapshot = Snapshot { |
| 61 | + meta: snapshot_meta, |
| 62 | + snapshot: snapshot_data, |
| 63 | + }; |
| 64 | + let res = app.raft.install_full_snapshot(vote, snapshot).await.map_err(RaftError::<Infallible>::Fatal); |
| 65 | + encode(res) |
| 66 | +} |
| 67 | + |
| 68 | +/// Handle transfer leader request |
| 69 | +pub async fn transfer_leader(app: &mut GroupApp, req: String) -> String { |
| 70 | + let transfer_req: TransferLeaderRequest<crate::TypeConfig> = decode(&req); |
| 71 | + let res = app.raft.handle_transfer_leader(transfer_req).await; |
| 72 | + encode(res) |
| 73 | +} |
| 74 | + |
| 75 | +// ============================================================================ |
| 76 | +// Management API |
| 77 | +// ============================================================================ |
| 78 | + |
| 79 | +/// Add a node as **Learner** to this group. |
| 80 | +/// |
| 81 | +/// This should be done before adding a node as a member into the cluster |
| 82 | +/// (by calling `change-membership`) |
| 83 | +pub async fn add_learner(app: &mut GroupApp, req: String) -> String { |
| 84 | + let node_id: NodeId = decode(&req); |
| 85 | + let node = BasicNode { addr: "".to_string() }; |
| 86 | + let res = app.raft.add_learner(node_id, node, true).await; |
| 87 | + encode(res) |
| 88 | +} |
| 89 | + |
| 90 | +/// Changes specified learners to members, or remove members from this group. |
| 91 | +pub async fn change_membership(app: &mut GroupApp, req: String) -> String { |
| 92 | + let node_ids: BTreeSet<NodeId> = decode(&req); |
| 93 | + let res = app.raft.change_membership(node_ids, false).await; |
| 94 | + encode(res) |
| 95 | +} |
| 96 | + |
| 97 | +/// Initialize a single-node cluster for this group. |
| 98 | +pub async fn init(app: &mut GroupApp) -> String { |
| 99 | + let mut nodes = BTreeMap::new(); |
| 100 | + nodes.insert(app.node_id, BasicNode { addr: "".to_string() }); |
| 101 | + let res = app.raft.initialize(nodes).await; |
| 102 | + encode(res) |
| 103 | +} |
| 104 | + |
| 105 | +/// Get the latest metrics of this Raft group |
| 106 | +pub async fn metrics(app: &mut GroupApp) -> String { |
| 107 | + let metrics = app.raft.metrics().borrow().clone(); |
| 108 | + |
| 109 | + let res: Result<RaftMetrics, Infallible> = Ok(metrics); |
| 110 | + encode(res) |
| 111 | +} |
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