From 8468f09e17390b7b62eedb374520db1ebc3a2a92 Mon Sep 17 00:00:00 2001
From: Dvir Yosef <dvir@starkware.co>
Date: Tue, 17 Dec 2024 12:19:02 +0200
Subject: [PATCH] feat(sequencing): add cende module and main types

---
 .../src/cende/mod.rs                          | 80 +++++++++++++++++++
 .../papyrus_consensus_orchestrator/src/lib.rs |  5 ++
 2 files changed, 85 insertions(+)
 create mode 100644 crates/sequencing/papyrus_consensus_orchestrator/src/cende/mod.rs

diff --git a/crates/sequencing/papyrus_consensus_orchestrator/src/cende/mod.rs b/crates/sequencing/papyrus_consensus_orchestrator/src/cende/mod.rs
new file mode 100644
index 0000000000..ded1b69142
--- /dev/null
+++ b/crates/sequencing/papyrus_consensus_orchestrator/src/cende/mod.rs
@@ -0,0 +1,80 @@
+use std::sync::{Arc, OnceLock};
+
+use async_trait::async_trait;
+use tokio::sync::Mutex;
+use tokio::task::{self};
+use tracing::debug;
+
+// TODO(dvir): add tests when will have more logic.
+
+/// A chunk of all the data to write to Aersopike.
+#[derive(Debug)]
+pub(crate) struct AerospikeBlob {
+    // TODO(yael, dvir): add the blob fields.
+}
+
+#[async_trait]
+pub(crate) trait CendeContext: Send + Sync {
+    /// Write the previous height blob to Aerospike. Returns a cell with an inner boolean indicating
+    /// whether the write was successful.
+    fn write_prev_height_blob(&self) -> Arc<OnceLock<bool>>;
+
+    // Prepares the previous height blob that will be written in the next height.
+    async fn prepare_blob_for_next_height(&self, nfb: NeededForBlob);
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct CendeAmbassador {
+    // TODO(dvir): consider creating enum varaiant instead of the `Option<AerospikeBlob>`.
+    // `None` indicates that there is no blob to write, and therefore, the node can't be the
+    // proposer.
+    prev_height_blob: Arc<Mutex<Option<AerospikeBlob>>>,
+}
+
+impl CendeAmbassador {
+    pub(crate) fn new() -> Self {
+        CendeAmbassador { prev_height_blob: Arc::new(Mutex::new(None)) }
+    }
+}
+
+#[async_trait]
+impl CendeContext for CendeAmbassador {
+    fn write_prev_height_blob(&self) -> Arc<OnceLock<bool>> {
+        let cell = Arc::new(OnceLock::new());
+        let prev_height_blob = self.prev_height_blob.clone();
+        let cloned_cell = cell.clone();
+        task::spawn(async move {
+            let Some(ref _blob) = *prev_height_blob.lock().await else {
+                debug!("No blob to write to Aerospike.");
+                cell.set(false).expect("Cell should be empty");
+                return;
+            };
+            // TODO(dvir): write blob to AS.
+            // TODO(dvir): consider set `prev_height_blob` to `None` after writing to AS.
+            debug!("Writing blob to Aerospike.");
+            cell.set(true).expect("Cell should be empty");
+            debug!("Blob writing to Aerospike completed.");
+        });
+
+        cloned_cell
+    }
+
+    async fn prepare_blob_for_next_height(&self, nfb: NeededForBlob) {
+        // TODO(dvir, yael): make the full creation of blob.
+        // TODO(dvir): as optimization, call the `into` and other preperation when writing to AS.
+        *self.prev_height_blob.lock().await = Some(nfb.into());
+    }
+}
+
+#[derive(Clone, Debug, Default)]
+pub(crate) struct NeededForBlob {
+    // TODO(dvir): add here all the information needed for creating the blob: tranasctions, classes,
+    // block info, BlockExecutionArtifacts.
+}
+
+impl From<NeededForBlob> for AerospikeBlob {
+    fn from(_nfb: NeededForBlob) -> Self {
+        // TODO(yael): make the full creation of blob.
+        AerospikeBlob {}
+    }
+}
diff --git a/crates/sequencing/papyrus_consensus_orchestrator/src/lib.rs b/crates/sequencing/papyrus_consensus_orchestrator/src/lib.rs
index ff7de38c70..72e91009d4 100644
--- a/crates/sequencing/papyrus_consensus_orchestrator/src/lib.rs
+++ b/crates/sequencing/papyrus_consensus_orchestrator/src/lib.rs
@@ -7,3 +7,8 @@
 pub mod papyrus_consensus_context;
 #[allow(missing_docs)]
 pub mod sequencer_consensus_context;
+
+/// Centralized and decentralized communication types and functionallity.
+// TODO(dvir): delete this when using the types in consensus.
+#[allow(dead_code)]
+mod cende;