Basic clock interface

node/Cargo.toml

@@ -8,3 +8,4 @@ edition = "2018"
 
 [dependencies]
 clap = "2.33.0"
+chrono = "0.4.9"

node/src/clock/mod.rs

@@ -0,0 +1,57 @@
+#![allow(dead_code)]
+
+#[cfg(test)]
+mod test;
+
+extern crate chrono;
+
+use chrono::{DateTime, NaiveDateTime, SecondsFormat, Utc};
+
+const ISO_FORMAT: &str = "%FT%X.%.9F";
+const EPOCH_DURATION: i8 = 15;
+
+/// ChainEpochClock is used by the system node to assume weak clock synchrony amongst the other
+/// systems.
+pub struct ChainEpochClock {
+    // Chain start time in ISO nano timestamp
+    genesis_time: DateTime<Utc>,
+}
+
+impl ChainEpochClock {
+    /// Returns a ChainEpochClock based on the given genesis_time
+    ///
+    /// # Arguments
+    ///
+    /// * `genesis_time` - An i64 representing a unix timestamp
+    fn new(genesis_time: i64) -> ChainEpochClock {
+        // Convert unix timestamp
+        let native_date_time = NaiveDateTime::from_timestamp(genesis_time, 0);
+
+        // Convert to DateTime
+        let date_time = DateTime::<Utc>::from_utc(native_date_time, Utc);
+
+        // Use nanoseconds
+        date_time.to_rfc3339_opts(SecondsFormat::Nanos, true);
+
+        ChainEpochClock {
+            genesis_time: date_time,
+        }
+    }
+
+    /// Returns the genesis time as a DateTime<Utc>
+    fn get_time(&self) -> DateTime<Utc> {
+        self.genesis_time
+    }
+
+    /// Returns the epoch at a given time
+    ///
+    /// # Arguments
+    ///
+    /// * `time` - A DateTime<Utx> representing the chosen time.
+    ///
+    /// TODO: Should time be a unix time stamp?
+    fn epoch_at_time(&self, time: DateTime<Utc>) {
+        let _difference = time.signed_duration_since(self.genesis_time);
+        // TODO Finish this based on spec
+    }
+}

node/src/clock/test.rs

@@ -0,0 +1,9 @@
+#![cfg(all(test))]
+use crate::clock::ChainEpochClock;
+
+#[test]
+fn create_chain_epoch_clock() {
+    let utc_timestamp = 1574286946904;
+    let clock = ChainEpochClock::new(utc_timestamp);
+    assert_eq!(clock.get_time().timestamp(), utc_timestamp);
+}

node/src/lib.rs

@@ -1 +1 @@
-
+pub mod clock;