feat: purge ephemeral storage

Author: ogenev

crates/storage/src/versioned/ephemeral_v1/sql.rs

@@ -76,3 +76,11 @@ pub fn entry_count_and_size(content_type: &ContentType) -> String {
         table_name(content_type)
     )
 }
+
+pub fn purge_by_slot(content_type: &ContentType) -> String {
+    format!(
+        "DELETE FROM {}
+         WHERE slot < :slot",
+        table_name(content_type)
+    )
+}

crates/storage/src/versioned/ephemeral_v1/store.rs

@@ -1,9 +1,15 @@
-use std::marker::PhantomData;
+use std::{
+    marker::PhantomData,
+    sync::Arc,
+    time::{Duration, SystemTime, UNIX_EPOCH},
+};
 
-use ethportal_api::{OverlayContentKey, RawContentValue};
+use alloy::eips::merge::EPOCH_SLOTS;
+use ethportal_api::{jsonrpsee::tokio, OverlayContentKey, RawContentValue};
 use r2d2::Pool;
 use r2d2_sqlite::SqliteConnectionManager;
 use rusqlite::{named_params, types::Type, OptionalExtension};
+use tokio::task::JoinHandle;
 use tracing::{debug, warn};
 use trin_metrics::storage::StorageMetricsReporter;
 
@@ -15,6 +21,9 @@ use crate::{
     ContentId,
 };
 
+pub const BEACON_GENESIS_TIME: u64 = 1606824023;
+pub const SLOTS_PER_HISTORICAL_ROOT: u64 = 8192;
+
 /// The store for storing ephemeral headers, bodies, and receipts.
 #[allow(unused)]
 #[derive(Debug)]
@@ -27,6 +36,8 @@ pub struct EphemeralV1Store<TContentKey: OverlayContentKey> {
     metrics: StorageMetricsReporter,
     /// Phantom Content Key
     _phantom_content_key: PhantomData<TContentKey>,
+    /// Background task handle for periodic purging
+    background_purge_task: Option<JoinHandle<()>>,
 }
 
 impl<TContentKey: OverlayContentKey> VersionedContentStore for EphemeralV1Store<TContentKey> {
@@ -59,6 +70,7 @@ impl<TContentKey: OverlayContentKey> VersionedContentStore for EphemeralV1Store<
             metrics: StorageMetricsReporter::new(subnetwork),
             _phantom_content_key: PhantomData,
             config,
+            background_purge_task: None,
         };
         store.init()?;
         Ok(store)
@@ -71,13 +83,61 @@ impl<TContentKey: OverlayContentKey> EphemeralV1Store<TContentKey> {
     fn init(&mut self) -> Result<(), ContentStoreError> {
         self.init_usage_stats()?;
 
-        // TODO: Prune if necessary.
+        // Purge content based on the last historical summaries update slot
+        let rows_deleted =
+            Self::purge_content_before_last_summary_internal(&Arc::new(self.config.clone()))?;
+
+        if rows_deleted > 0 {
+            debug!(
+                "Purged {} ephemeral content with during initialization",
+                rows_deleted
+            );
+        }
 
         Ok(())
     }
 
     // PUBLIC FUNCTIONS
 
+    /// Starts the background task for periodic purging.
+    /// This can be called explicitly after initialization if needed.
+    pub fn start_background_purge_task(&mut self) -> Result<(), ContentStoreError> {
+        let config = Arc::new(self.config.clone());
+
+        let handle = tokio::spawn(async move {
+            // Run purge immediately when task starts
+            if let Err(e) = Self::purge_content_before_last_summary_internal(&config) {
+                warn!("Error purging content in background task: {}", e);
+            }
+
+            let mut interval = tokio::time::interval(Duration::from_secs(12 * EPOCH_SLOTS)); // One epoch duration
+            loop {
+                interval.tick().await;
+
+                // Check if we're at a historical summaries update boundary
+                let current_epoch = Self::expected_current_epoch();
+                let next_epoch = current_epoch + 1;
+                let period = SLOTS_PER_HISTORICAL_ROOT / EPOCH_SLOTS;
+
+                if next_epoch % period == 0 {
+                    if let Err(e) = Self::purge_content_before_last_summary_internal(&config) {
+                        warn!("Error purging content in background task: {}", e);
+                    }
+                }
+            }
+        });
+
+        self.background_purge_task = Some(handle);
+        Ok(())
+    }
+
+    /// Stops the background purge task if it's running.
+    pub fn stop_background_purge_task(&mut self) {
+        if let Some(handle) = self.background_purge_task.take() {
+            handle.abort();
+        }
+    }
+
     /// Returns whether data associated with the content id is already stored.
     pub fn has_content(&self, content_id: &ContentId) -> Result<bool, ContentStoreError> {
         let timer = self.metrics.start_process_timer("has_content");
@@ -225,6 +285,15 @@ impl<TContentKey: OverlayContentKey> EphemeralV1Store<TContentKey> {
         self.metrics.get_summary()
     }
 
+    /// Manually triggers a purge of content before the last historical summary.
+    /// This can be used to manually control when content is purged, independent of the background
+    /// task.
+    ///
+    /// Returns the number of rows deleted.
+    pub fn trigger_content_purge(&self) -> Result<usize, ContentStoreError> {
+        Self::purge_content_before_last_summary_internal(&Arc::new(self.config.clone()))
+    }
+
     // INTERNAL FUNCTIONS
 
     /// Lookup and set `usage_stats`.
@@ -263,6 +332,61 @@ impl<TContentKey: OverlayContentKey> EphemeralV1Store<TContentKey> {
     ) -> u64 {
         (raw_content_id.len() + raw_content_key.len() + raw_content_value.len()) as u64
     }
+
+    fn expected_current_epoch() -> u64 {
+        let now = SystemTime::now();
+        let now = now.duration_since(UNIX_EPOCH).expect("Time went backwards");
+        let since_genesis = now - Duration::from_secs(BEACON_GENESIS_TIME);
+
+        since_genesis.as_secs() / 12 / EPOCH_SLOTS
+    }
+
+    /// Internal method to purge content, used by both the main thread and background task
+    fn purge_content_before_last_summary_internal(
+        config: &Arc<EphemeralV1StoreConfig>,
+    ) -> Result<usize, ContentStoreError> {
+        let current_epoch = Self::expected_current_epoch();
+        let cutoff_slot = Self::last_summaries_slot(current_epoch);
+
+        let conn = config.sql_connection_pool.get()?;
+        let query = sql::purge_by_slot(&config.content_type);
+
+        let rows_deleted = conn.execute(&query, named_params! { ":slot": cutoff_slot })?;
+        Ok(rows_deleted)
+    }
+
+    /// Computes the slot at which the last historical summary event occurred.
+    /// Historical summary events are appended when the next epoch is a multiple
+    /// of `period = SLOTS_PER_HISTORICAL_ROOT / EPOCH_SLOTS`.
+    ///
+    /// If the current_epoch is less than the first event boundary (and assuming a genesis event
+    /// at epoch 0), then this function returns 0.
+    fn last_summaries_slot(current_epoch: u64) -> u64 {
+        // Calculate the period (in epochs) at which events are appended.
+        let period = SLOTS_PER_HISTORICAL_ROOT / EPOCH_SLOTS;
+        // Compute candidate event epoch:
+        // This candidate is based on (current_epoch + 1) because events are appended
+        // when transitioning to the next epoch.
+        let candidate = ((current_epoch + 1) / period) * period;
+        // If candidate is greater than current_epoch, then that event is in the future,
+        // so the last event occurred one period earlier.
+        let last_summaries_epoch = if candidate > current_epoch {
+            candidate.saturating_sub(period)
+        } else {
+            candidate
+        };
+
+        last_summaries_epoch * EPOCH_SLOTS
+    }
+}
+
+impl<TContentKey: OverlayContentKey> Drop for EphemeralV1Store<TContentKey> {
+    fn drop(&mut self) {
+        // Cancel the background task when the store is dropped
+        if let Some(handle) = self.background_purge_task.take() {
+            handle.abort();
+        }
+    }
 }
 
 /// Creates table and indexes if they don't already exist.
@@ -280,6 +404,7 @@ mod tests {
     use anyhow::Result;
     use ethportal_api::{types::network::Subnetwork, IdentityContentKey};
     use tempfile::TempDir;
+    use tokio::time::{sleep, Duration};
 
     use super::*;
     use crate::{test_utils::generate_random_bytes, utils::setup_sql};
@@ -451,4 +576,105 @@ mod tests {
 
         Ok(())
     }
+
+    #[tokio::test]
+    async fn test_background_purge_task() -> Result<()> {
+        let temp_dir = TempDir::new()?;
+        let config = create_config(&temp_dir);
+
+        // Create store without starting background task
+        let mut store = EphemeralV1Store::<IdentityContentKey>::create(
+            ContentType::HistoryEphemeral,
+            config.clone(),
+        )?;
+
+        // Verify background task is not running initially
+        assert!(store.background_purge_task.is_none());
+
+        // Insert test data with slots before and after the cutoff
+        let current_epoch = EphemeralV1Store::<IdentityContentKey>::expected_current_epoch();
+        let cutoff_slot =
+            EphemeralV1Store::<IdentityContentKey>::last_summaries_slot(current_epoch);
+
+        let (key1, value1) = generate_key_value();
+        let (key2, value2) = generate_key_value();
+        let (key3, value3) = generate_key_value();
+
+        // Insert data with slots before cutoff
+        store.insert(&key1, value1, 0, cutoff_slot.saturating_sub(100))?;
+        store.insert(&key2, value2, 0, cutoff_slot.saturating_sub(50))?;
+
+        // Insert data with slot after cutoff
+        store.insert(&key3, value3, 0, cutoff_slot + 100)?;
+
+        // Verify data is present before starting background task
+        assert!(store.has_content(&ContentId::from(key1.content_id()))?);
+        assert!(store.has_content(&ContentId::from(key2.content_id()))?);
+        assert!(store.has_content(&ContentId::from(key3.content_id()))?);
+
+        // Start the background task
+        store.start_background_purge_task()?;
+        // Wait for the background task to run and purge data
+        sleep(Duration::from_secs(1)).await;
+        assert!(store.background_purge_task.is_some());
+
+        // Verify that content before cutoff was purged
+        assert!(
+            !store.has_content(&ContentId::from(key1.content_id()))?,
+            "key1 should be purged"
+        );
+        assert!(
+            !store.has_content(&ContentId::from(key2.content_id()))?,
+            "key2 should be purged"
+        );
+        assert!(
+            store.has_content(&ContentId::from(key3.content_id()))?,
+            "key3 should not be purged"
+        );
+
+        // Stop the background task
+        store.stop_background_purge_task();
+        assert!(store.background_purge_task.is_none());
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_purge_content_during_init() -> Result<()> {
+        let temp_dir = TempDir::new()?;
+        let config = create_config(&temp_dir);
+
+        // Create and populate store with test data
+        let mut store = EphemeralV1Store::<IdentityContentKey>::create(
+            ContentType::HistoryEphemeral,
+            config.clone(),
+        )?;
+
+        // Insert test data with slots before and after the cutoff
+        let current_epoch = EphemeralV1Store::<IdentityContentKey>::expected_current_epoch();
+        let cutoff_slot =
+            EphemeralV1Store::<IdentityContentKey>::last_summaries_slot(current_epoch);
+
+        let (key1, value1) = generate_key_value();
+        let (key2, value2) = generate_key_value();
+        let (key3, value3) = generate_key_value();
+
+        // Insert data with slots before cutoff
+        store.insert(&key1, value1, 0, cutoff_slot.saturating_sub(100))?;
+        store.insert(&key2, value2, 0, cutoff_slot.saturating_sub(50))?;
+
+        // Insert data with slot after cutoff
+        store.insert(&key3, value3, 0, cutoff_slot + 100)?;
+
+        // Create a new store instance to trigger init and purge
+        let new_store =
+            EphemeralV1Store::<IdentityContentKey>::create(ContentType::HistoryEphemeral, config)?;
+
+        // Verify that content before cutoff was purged
+        assert!(!new_store.has_content(&ContentId::from(key1.content_id()))?);
+        assert!(!new_store.has_content(&ContentId::from(key2.content_id()))?);
+        assert!(new_store.has_content(&ContentId::from(key3.content_id()))?);
+
+        Ok(())
+    }
 }