change: RaftStore::delete_logs_from() use range instead of (start, end)

async-raft/src/core/append_entries.rs

@@ -118,7 +118,7 @@ impl<D: AppData, R: AppDataResponse, N: RaftNetwork<D>, S: RaftStorage<D, R>> Ra
             // with an index greater than this, then we must delete them per §5.3.
             if self.last_log_id.index > target_entry.log_id.index {
                 self.storage
-                    .delete_logs_from(target_entry.log_id.index + 1, None)
+                    .delete_logs_from(target_entry.log_id.index + 1..)
                     .await
                     .map_err(|err| self.map_fatal_storage_error(err))?;
                 let membership =

async-raft/src/storage.rs

@@ -1,6 +1,8 @@
 //! The Raft storage interface and data types.
 
 use std::error::Error;
+use std::fmt::Debug;
+use std::ops::RangeBounds;
 
 use anyhow::Result;
 use async_trait::async_trait;
@@ -159,11 +161,13 @@ where
     /// Errors returned from this method will cause Raft to go into shutdown.
     async fn get_log_entries(&self, start: u64, stop: u64) -> Result<Vec<Entry<D>>>;
 
-    /// Delete all logs starting from `start` and stopping at `stop`, else continuing to the end
-    /// of the log if `stop` is `None`.
+    /// Delete all logs in a `range`.
     ///
     /// Errors returned from this method will cause Raft to go into shutdown.
-    async fn delete_logs_from(&self, start: u64, stop: Option<u64>) -> Result<()>;
+    async fn delete_logs_from<RNG: RangeBounds<u64> + Clone + Debug + Send + Sync + Iterator>(
+        &self,
+        range: RNG,
+    ) -> Result<()>;
 
     /// Append a payload of entries to the log.
     ///

memstore/src/lib.rs

@@ -6,7 +6,9 @@ mod test;
 use std::cmp::max;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
+use std::fmt::Debug;
 use std::io::Cursor;
+use std::ops::RangeBounds;
 use std::sync::Arc;
 use std::sync::Mutex;
 
@@ -305,6 +307,20 @@ impl MemStore {
         Ok(())
     }
 
+    pub async fn defensive_nonempty_range<RT, RNG: RangeBounds<RT> + Clone + Debug + Send + Iterator>(
+        &self,
+        range: RNG,
+    ) -> anyhow::Result<()> {
+        if !*self.defensive.read().await {
+            return Ok(());
+        }
+        for _ in range.clone() {
+            return Ok(());
+        }
+
+        Err(anyhow::anyhow!("range must be nonempty: {:?}", range))
+    }
+
     pub async fn defensive_apply_log_id_gt_last<D: AppData>(&self, entries: &[&Entry<D>]) -> anyhow::Result<()> {
         if !*self.defensive.read().await {
             return Ok(());
@@ -471,24 +487,20 @@ impl RaftStorage<ClientRequest, ClientResponse> for MemStore {
         Ok(log.range(start..stop).map(|(_, val)| val.clone()).collect())
     }
 
-    #[tracing::instrument(level = "trace", skip(self))]
-    async fn delete_logs_from(&self, start: u64, stop: Option<u64>) -> Result<()> {
-        // TODO(xp): never delete the last applied log
-        if stop.as_ref().map(|stop| &start > stop).unwrap_or(false) {
-            tracing::error!("delete_logs_from: invalid request, start({}) > stop({:?})", start, stop);
-            return Ok(());
-        }
+    #[tracing::instrument(level = "trace", skip(self, range), fields(range=?range))]
+    async fn delete_logs_from<R: RangeBounds<u64> + Clone + Debug + Send + Sync + Iterator>(
+        &self,
+        range: R,
+    ) -> Result<()> {
+        self.defensive_nonempty_range(range.clone()).await?;
+
         let mut log = self.log.write().await;
 
-        // If a stop point was specified, delete from start until the given stop point.
-        if let Some(stop) = stop.as_ref() {
-            for key in start..*stop {
-                log.remove(&key);
-            }
-            return Ok(());
+        let keys = log.range(range).map(|(k, _v)| *k).collect::<Vec<_>>();
+        for key in keys {
+            log.remove(&key);
         }
-        // Else, just split off the remainder.
-        log.split_off(&start);
+
         Ok(())
     }
 

memstore/src/test.rs

@@ -507,23 +507,12 @@ where
     }
 
     pub async fn delete_logs_from(builder: &B) -> Result<()> {
-        tracing::info!("--- delete start > stop");
-        {
-            let store = builder.new_store(NODE_ID).await;
-            Self::feed_10_logs_vote_self(&store).await?;
-
-            store.delete_logs_from(10, Some(1)).await?;
-
-            let logs = store.get_log_entries(1, 11).await?;
-            assert_eq!(logs.len(), 10, "expected all (10) logs to be preserved");
-        }
-
         tracing::info!("--- delete start == stop");
         {
             let store = builder.new_store(NODE_ID).await;
             Self::feed_10_logs_vote_self(&store).await?;
 
-            store.delete_logs_from(1, Some(1)).await?;
+            store.delete_logs_from(1..1).await?;
 
             let logs = store.get_log_entries(1, 11).await?;
             assert_eq!(logs.len(), 10, "expected all (10) logs to be preserved");
@@ -534,7 +523,7 @@ where
             let store = builder.new_store(NODE_ID).await;
             Self::feed_10_logs_vote_self(&store).await?;
 
-            store.delete_logs_from(1, Some(4)).await?;
+            store.delete_logs_from(1..4).await?;
 
             let logs = store.get_log_entries(0, 100).await?;
             assert_eq!(logs.len(), 7);
@@ -546,7 +535,7 @@ where
             let store = builder.new_store(NODE_ID).await;
             Self::feed_10_logs_vote_self(&store).await?;
 
-            store.delete_logs_from(1, Some(1000)).await?;
+            store.delete_logs_from(1..1000).await?;
             let logs = store.get_log_entries(0, 100).await?;
 
             assert_eq!(logs.len(), 0);
@@ -557,7 +546,7 @@ where
             let store = builder.new_store(NODE_ID).await;
             Self::feed_10_logs_vote_self(&store).await?;
 
-            store.delete_logs_from(1, None).await?;
+            store.delete_logs_from(1..).await?;
             let logs = store.get_log_entries(0, 100).await?;
 
             assert_eq!(logs.len(), 0);
@@ -734,7 +723,7 @@ where
         run_fut(Suite::df_get_membership_config_dirty_log(builder))?;
         run_fut(Suite::df_get_initial_state_dirty_log(builder))?;
         run_fut(Suite::df_save_hard_state_ascending(builder))?;
-        run_fut(Suite::df_delete_logs_from(builder))?;
+        run_fut(Suite::df_delete_logs_from_nonempty_range(builder))?;
         run_fut(Suite::df_append_to_log_nonempty_input(builder))?;
         run_fut(Suite::df_append_to_log_nonconsecutive_input(builder))?;
         run_fut(Suite::df_append_to_log_eq_last_plus_one(builder))?;
@@ -930,8 +919,16 @@ where
         Ok(())
     }
 
-    pub async fn df_delete_logs_from(_builder: &B) -> Result<()> {
-        // TODO(xp): what should we test about this?
+    pub async fn df_delete_logs_from_nonempty_range(builder: &B) -> Result<()> {
+        let store = builder.new_store(NODE_ID).await;
+        Self::feed_10_logs_vote_self(&store).await?;
+
+        let res = store.delete_logs_from(10..1).await;
+        assert!(res.is_err());
+
+        let res = store.delete_logs_from(10..10).await;
+        assert!(res.is_err());
+
         Ok(())
     }
 
@@ -1039,7 +1036,7 @@ where
             ])
             .await?;
 
-        store.delete_logs_from(1, Some(2)).await?;
+        store.delete_logs_from(1..2).await?;
 
         let res = store
             .append_to_log(&[&Entry {
@@ -1115,7 +1112,7 @@ where
             ])
             .await?;
 
-        store.delete_logs_from(1, Some(2)).await?;
+        store.delete_logs_from(1..2).await?;
 
         let res = store
             .append_to_log(&[&Entry {