Use cached consumption value

central_backend/src/app_config.rs

@@ -81,9 +81,13 @@ pub struct AppConfig {
     pub production_margin: i32,
 
     /// Energy refresh operations interval, in seconds
-    #[arg(short('i'), long, env, default_value_t = 20)]
+    #[arg(short('i'), long, env, default_value_t = 25)]
     pub refresh_interval: u64,
 
+    /// Energy refresh operations interval, in seconds
+    #[arg(short('f'), long, env, default_value_t = 5)]
+    pub energy_fetch_interval: u64,
+
     /// Consumption backend provider
     #[clap(subcommand)]
     pub consumption_backend: Option<ConsumptionBackend>,

central_backend/src/energy/consumption_cache.rs

@@ -0,0 +1,85 @@
+use crate::constants;
+use crate::energy::consumption::EnergyConsumption;
+use log::log;
+
+pub struct ConsumptionCache {
+    nb_vals: usize,
+    values: Vec<EnergyConsumption>,
+}
+
+impl ConsumptionCache {
+    pub fn new(nb_vals: usize) -> Self {
+        Self {
+            nb_vals,
+            values: vec![],
+        }
+    }
+
+    pub fn add_value(&mut self, value: EnergyConsumption) {
+        if self.values.len() >= self.nb_vals {
+            self.values.remove(0);
+        }
+
+        self.values.push(value);
+    }
+
+    pub fn median_value(&self) -> EnergyConsumption {
+        if self.values.is_empty() {
+            return constants::FALLBACK_PRODUCTION_VALUE;
+        }
+
+        let mut clone = self.values.clone();
+        clone.sort();
+        let median = clone[clone.len() / 2];
+
+        log::info!("Cached consumption: {:?} / Median: {}", self.values, median);
+
+        median
+    }
+}
+
+#[cfg(test)]
+pub mod test {
+    use crate::constants;
+    use crate::energy::consumption_cache::ConsumptionCache;
+
+    #[test]
+    fn empty_vec() {
+        let cache = ConsumptionCache::new(10);
+        assert_eq!(cache.median_value(), constants::FALLBACK_PRODUCTION_VALUE);
+    }
+
+    #[test]
+    fn single_value() {
+        let mut cache = ConsumptionCache::new(10);
+        cache.add_value(-10);
+        assert_eq!(cache.median_value(), -10);
+    }
+
+    #[test]
+    fn four_values() {
+        let mut cache = ConsumptionCache::new(10);
+        cache.add_value(50);
+        cache.add_value(-10);
+        cache.add_value(-10);
+        cache.add_value(-10000);
+        assert_eq!(cache.median_value(), -10);
+    }
+
+    #[test]
+    fn many_values() {
+        let mut cache = ConsumptionCache::new(6);
+
+        for i in 0..1000 {
+            cache.add_value(-i);
+        }
+
+        cache.add_value(10);
+        cache.add_value(50);
+        cache.add_value(-10);
+        cache.add_value(-10);
+        cache.add_value(-30);
+        cache.add_value(-10000);
+        assert_eq!(cache.median_value(), -10);
+    }
+}

central_backend/src/energy/energy_actor.rs

@@ -6,6 +6,7 @@ use crate::devices::device::{
 use crate::devices::devices_list::DevicesList;
 use crate::energy::consumption;
 use crate::energy::consumption::EnergyConsumption;
+use crate::energy::consumption_cache::ConsumptionCache;
 use crate::energy::engine::EnergyEngine;
 use crate::utils::time_utils::time_secs;
 use actix::prelude::*;
@@ -13,34 +14,55 @@ use openssl::x509::X509Req;
 use std::time::Duration;
 
 pub struct EnergyActor {
-    curr_consumption: EnergyConsumption,
+    consumption_cache: ConsumptionCache,
     devices: DevicesList,
     engine: EnergyEngine,
+    last_engine_refresh: u64,
 }
 
 impl EnergyActor {
     pub async fn new() -> anyhow::Result<Self> {
+        let consumption_cache_size =
+            AppConfig::get().refresh_interval / AppConfig::get().energy_fetch_interval;
+        let curr_consumption = consumption::get_curr_consumption().await?;
+        let mut consumption_cache = ConsumptionCache::new(consumption_cache_size as usize);
+        consumption_cache.add_value(curr_consumption);
+
+        if consumption_cache_size < 1 {
+            panic!("Energy fetch interval must be equal or smaller than refresh interval!");
+        }
+
         Ok(Self {
-            curr_consumption: consumption::get_curr_consumption().await?,
+            consumption_cache,
             devices: DevicesList::load()?,
             engine: EnergyEngine::default(),
+            last_engine_refresh: 0,
         })
     }
 
     async fn refresh(&mut self) -> anyhow::Result<()> {
         // Refresh energy
-        self.curr_consumption = consumption::get_curr_consumption()
-            .await
-            .unwrap_or_else(|e| {
-                log::error!(
+        self.consumption_cache
+            .add_value(
+                consumption::get_curr_consumption()
+                    .await
+                    .unwrap_or_else(|e| {
+                        log::error!(
                     "Failed to fetch latest consumption value, will use fallback value! {e}"
                 );
-                constants::FALLBACK_PRODUCTION_VALUE
-            });
+                        constants::FALLBACK_PRODUCTION_VALUE
+                    }),
+            );
+
+        if self.last_engine_refresh + AppConfig::get().refresh_interval > time_secs() {
+            return Ok(());
+        }
+        self.last_engine_refresh = time_secs();
 
         let devices_list = self.devices.full_list();
 
-        self.engine.refresh(self.curr_consumption, &devices_list);
+        self.engine
+            .refresh(self.consumption_cache.median_value(), &devices_list);
 
         self.engine.persist_relays_state(&devices_list)?;
 
@@ -55,7 +77,7 @@ impl Actor for EnergyActor {
         log::info!("Energy actor successfully started!");
 
         ctx.run_interval(
-            Duration::from_secs(AppConfig::get().refresh_interval),
+            Duration::from_secs(AppConfig::get().energy_fetch_interval),
             |act, _ctx| {
                 log::info!("Performing energy refresh operation");
                 if let Err(e) = futures::executor::block_on(act.refresh()) {
@@ -81,7 +103,7 @@ impl Handler<GetCurrConsumption> for EnergyActor {
     type Result = EnergyConsumption;
 
     fn handle(&mut self, _msg: GetCurrConsumption, _ctx: &mut Context<Self>) -> Self::Result {
-        self.curr_consumption
+        self.consumption_cache.median_value()
     }
 }
 

central_backend/src/energy/mod.rs

@@ -1,4 +1,5 @@
 pub mod consumption;
+pub mod consumption_cache;
 pub mod energy_actor;
 pub mod engine;
 pub mod relay_state_history;