Add snapshot list message

Author: jpraynaud

mithril-common/src/messages/mod.rs

@@ -6,10 +6,12 @@ mod epoch_settings;
 mod register_signature;
 mod register_signer;
 mod snapshot;
+mod snapshot_list;
 
 pub use certificate::CertificateMessage;
 pub use certificate_pending::{CertificatePendingMessage, SignerMessage};
 pub use epoch_settings::EpochSettingsMessage;
 pub use register_signature::RegisterSignatureMessage;
 pub use register_signer::RegisterSignerMessage;
 pub use snapshot::SnapshotMessage;
+pub use snapshot_list::{SnapshotListItemMessage, SnapshotListMessage};

mithril-common/src/messages/snapshot_list.rs

@@ -0,0 +1,97 @@
+use serde::{Deserialize, Serialize};
+
+// TODO: We should probably not rely on entities when defining the message
+use crate::entities::Beacon;
+
+// TODO: We should probably not rely on entities when defining the message
+#[cfg(any(test, feature = "test_only"))]
+use crate::entities::Epoch;
+/// Message structure of a snapshot list
+pub type SnapshotListMessage = Vec<SnapshotListItemMessage>;
+
+/// Message structure of a snapshot list item
+#[derive(Clone, Debug, PartialEq, Eq, Default, Serialize, Deserialize)]
+pub struct SnapshotListItemMessage {
+    /// Digest that is signed by the signer participants
+    pub digest: String,
+
+    /// Mithril beacon on the Cardano chain
+    pub beacon: Beacon,
+
+    /// Hash of the associated certificate
+    pub certificate_hash: String,
+
+    /// Size of the snapshot file in Bytes
+    pub size: u64,
+
+    /// Date and time at which the snapshot was created
+    pub created_at: String,
+
+    /// Locations where the binary content of the snapshot can be retrieved
+    pub locations: Vec<String>,
+}
+
+impl SnapshotListItemMessage {
+    #[cfg(any(test, feature = "test_only"))]
+    /// Return a dummy test entity (test-only).
+    pub fn dummy() -> Self {
+        Self {
+            digest: "0b9f5ad7f33cc523775c82249294eb8a1541d54f08eb3107cafc5638403ec7c6".to_string(),
+            beacon: Beacon {
+                network: "preview".to_string(),
+                epoch: Epoch(86),
+                immutable_file_number: 1728,
+            },
+            certificate_hash: "d5daf6c03ace4a9c074e951844075b9b373bafc4e039160e3e2af01823e9abfb"
+                .to_string(),
+            size: 807803196,
+            created_at: "2023-01-19T13:43:05.618857482Z".to_string(),
+            locations: vec!["https://host/certificate.tar.gz".to_string()],
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn golden_message() -> SnapshotListMessage {
+        vec![SnapshotListItemMessage {
+            digest: "0b9f5ad7f33cc523775c82249294eb8a1541d54f08eb3107cafc5638403ec7c6".to_string(),
+            beacon: Beacon {
+                network: "preview".to_string(),
+                epoch: Epoch(86),
+                immutable_file_number: 1728,
+            },
+            certificate_hash: "d5daf6c03ace4a9c074e951844075b9b373bafc4e039160e3e2af01823e9abfb"
+                .to_string(),
+            size: 807803196,
+            created_at: "2023-01-19T13:43:05.618857482Z".to_string(),
+            locations: vec!["https://host/certificate.tar.gz".to_string()],
+        }]
+    }
+
+    // Test the retro compatibility with possible future upgrades.
+    #[test]
+    fn test_v1() {
+        let json = r#"[{
+"digest": "0b9f5ad7f33cc523775c82249294eb8a1541d54f08eb3107cafc5638403ec7c6",
+"beacon": {
+  "network": "preview",
+  "epoch": 86,
+  "immutable_file_number": 1728
+},
+"certificate_hash": "d5daf6c03ace4a9c074e951844075b9b373bafc4e039160e3e2af01823e9abfb",
+"size": 807803196,
+"created_at": "2023-01-19T13:43:05.618857482Z",
+"locations": [
+  "https://host/certificate.tar.gz"
+]
+}]"#;
+        let message: SnapshotListMessage = serde_json::from_str(json).expect(
+            "This JSON is expected to be succesfully parsed into a SnapshotListMessage instance.",
+        );
+
+        assert_eq!(golden_message(), message);
+    }
+}