Rust backend (#185)

backend/src/feed.rs

@@ -0,0 +1,140 @@
+use serde::Serialize;
+use serde_json::to_writer;
+use crate::types::{
+    NodeId, NodeDetails, NodeStats, NodeHardware, NodeLocation,
+    BlockNumber, BlockHash, BlockDetails, Timestamp,
+};
+
+pub mod connector;
+
+use connector::Serialized;
+
+pub trait FeedMessage: Serialize {
+    const ACTION: u8;
+}
+
+pub struct FeedMessageSerializer {
+    /// Current buffer,
+    buffer: Vec<u8>,
+}
+
+impl FeedMessageSerializer {
+    pub fn new() -> Self {
+        Self {
+            buffer: Vec::new(),
+        }
+    }
+
+    pub fn clear(&mut self) {
+        self.buffer.clear();
+    }
+
+    pub fn push<Message>(&mut self, msg: Message)
+    where
+        Message: FeedMessage,
+    {
+        let glue = match self.buffer.len() {
+            0 => b'[',
+            _ => b',',
+        };
+
+        self.buffer.push(glue);
+        let _ = to_writer(&mut self.buffer, &Message::ACTION);
+        self.buffer.push(b',');
+        let _ = to_writer(&mut self.buffer, &msg);
+    }
+
+    pub fn finalize(&mut self) -> Option<Serialized> {
+        if self.buffer.len() == 0 {
+            return None;
+        }
+
+        self.buffer.push(b']');
+        let bytes = self.buffer[..].into();
+        self.clear();
+
+        Some(Serialized(bytes))
+    }
+}
+
+macro_rules! actions {
+    ($($action:literal: $t:ty,)*) => {
+        $(
+            impl FeedMessage for $t {
+                const ACTION: u8 = $action;
+            }
+        )*
+    }
+}
+
+actions! {
+    0x00: Version,
+    0x01: BestBlock,
+    0x02: BestFinalized,
+    0x03: AddedNode<'_>,
+    0x04: RemovedNode,
+    0x05: LocatedNode<'_>,
+    0x06: ImportedBlock<'_>,
+    0x07: FinalizedBlock,
+    0x08: NodeStatsUpdate<'_>,
+    0x09: Hardware<'_>,
+    0x0A: TimeSync,
+    0x0B: AddedChain<'_>,
+    0x0C: RemovedChain<'_>,
+    0x0D: SubscribedTo<'_>,
+    0x0E: UnsubscribedFrom<'_>,
+    0x0F: Pong<'_>,
+    0x14: StaleNode,
+}
+
+#[derive(Serialize)]
+pub struct Version(pub usize);
+
+#[derive(Serialize)]
+pub struct BestBlock(pub BlockNumber, pub Timestamp, pub Option<u64>);
+
+#[derive(Serialize)]
+pub struct BestFinalized(pub BlockNumber, pub BlockHash);
+
+#[derive(Serialize)]
+pub struct AddedNode<'a>(pub NodeId, pub &'a NodeDetails, pub &'a NodeStats, pub NodeHardware<'a>,
+                         pub &'a BlockDetails, pub Option<&'a NodeLocation>);
+
+#[derive(Serialize)]
+pub struct RemovedNode(pub NodeId);
+
+#[derive(Serialize)]
+pub struct LocatedNode<'a>(pub NodeId, pub f32, pub f32, pub &'a str);
+
+#[derive(Serialize)]
+pub struct ImportedBlock<'a>(pub NodeId, pub &'a BlockDetails);
+
+#[derive(Serialize)]
+pub struct FinalizedBlock(pub NodeId, pub BlockNumber, pub BlockHash);
+
+#[derive(Serialize)]
+pub struct NodeStatsUpdate<'a>(pub NodeId, pub &'a NodeStats);
+
+#[derive(Serialize)]
+pub struct Hardware<'a>(pub NodeId, pub NodeHardware<'a>);
+
+#[derive(Serialize)]
+pub struct TimeSync(pub u64);
+
+#[derive(Serialize)]
+pub struct AddedChain<'a>(pub &'a str, pub usize);
+
+#[derive(Serialize)]
+pub struct RemovedChain<'a>(pub &'a str);
+
+#[derive(Serialize)]
+pub struct SubscribedTo<'a>(pub &'a str);
+
+#[derive(Serialize)]
+pub struct UnsubscribedFrom<'a>(pub &'a str);
+
+#[derive(Serialize)]
+pub struct Pong<'a>(pub &'a str);
+
+#[derive(Serialize)]
+pub struct StaleNode(pub NodeId);