apollo_propeller: add core unit struct with accessors

Author: sirandreww-starkware

crates/apollo_propeller/src/lib.rs

@@ -9,6 +9,8 @@ pub mod signature;
 #[cfg(test)]
 mod signature_test;
 pub mod types;
+pub mod unit;
 
-pub use merkle::MerkleHash;
+pub use merkle::{MerkleHash, MerkleProof, MerkleTree};
 pub use types::{Channel, MessageRoot, ShardIndex};
+pub use unit::PropellerUnit;

crates/apollo_propeller/src/unit.rs

@@ -0,0 +1,70 @@
+//! Message types for the Propeller protocol.
+
+use libp2p::core::PeerId;
+
+use crate::types::{Channel, MessageRoot, ShardIndex};
+use crate::MerkleProof;
+
+// TODO(AndrewL): consider making fields public and remove
+// constructor, getters and setters.
+
+/// A single shard unit in the Propeller protocol.
+///
+/// Contains one shard of data along with its merkle proof, allowing
+/// receivers to verify the shard is part of the original message.
+#[derive(Debug, PartialEq, Clone)]
+pub struct PropellerUnit {
+    channel: Channel,
+    publisher: PeerId,
+    root: MessageRoot,
+    signature: Vec<u8>,
+    index: ShardIndex,
+    shard: Vec<u8>,
+    proof: MerkleProof,
+}
+
+impl PropellerUnit {
+    pub fn new(
+        channel: Channel,
+        publisher: PeerId,
+        root: MessageRoot,
+        signature: Vec<u8>,
+        index: ShardIndex,
+        shard: Vec<u8>,
+        proof: MerkleProof,
+    ) -> Self {
+        Self { channel, root, publisher, signature, index, shard, proof }
+    }
+
+    pub fn channel(&self) -> Channel {
+        self.channel
+    }
+
+    pub fn publisher(&self) -> PeerId {
+        self.publisher
+    }
+
+    pub fn signature(&self) -> &[u8] {
+        &self.signature
+    }
+
+    pub fn index(&self) -> ShardIndex {
+        self.index
+    }
+
+    pub fn shard(&self) -> &[u8] {
+        &self.shard
+    }
+
+    pub fn shard_mut(&mut self) -> &mut Vec<u8> {
+        &mut self.shard
+    }
+
+    pub fn proof(&self) -> &MerkleProof {
+        &self.proof
+    }
+
+    pub fn root(&self) -> MessageRoot {
+        self.root
+    }
+}