Merge pull request #690 from ethcore/fixjdb

Fix JournalDB era marker

util/src/journaldb/earlymergedb.rs

@@ -64,6 +64,7 @@ pub struct EarlyMergeDB {
 	overlay: MemoryDB,
 	backing: Arc<Database>,
 	refs: Option<Arc<RwLock<HashMap<H256, RefInfo>>>>,
+	latest_era: Option<u64>,
 }
 
 // all keys must be at least 12 bytes
@@ -90,11 +91,13 @@ impl EarlyMergeDB {
 			backing.put(&VERSION_KEY, &encode(&DB_VERSION)).expect("Error writing version to database");
 		}
 
-		let refs = Some(Arc::new(RwLock::new(EarlyMergeDB::read_refs(&backing))));
+		let (latest_era, refs) = EarlyMergeDB::read_refs(&backing);
+		let refs = Some(Arc::new(RwLock::new(refs)));
 		EarlyMergeDB {
 			overlay: MemoryDB::new(),
 			backing: Arc::new(backing),
 			refs: refs,
+			latest_era: latest_era,
 		}
 	}
 
@@ -225,9 +228,9 @@ impl EarlyMergeDB {
 
 	#[cfg(test)]
 	fn can_reconstruct_refs(&self) -> bool {
-		let reconstructed = Self::read_refs(&self.backing);
+		let (latest_era, reconstructed) = Self::read_refs(&self.backing);
 		let refs = self.refs.as_ref().unwrap().write().unwrap();
-		if *refs != reconstructed {
+		if *refs != reconstructed || latest_era != self.latest_era {
 			let clean_refs = refs.iter().filter_map(|(k, v)| if reconstructed.get(k) == Some(v) {None} else {Some((k.clone(), v.clone()))}).collect::<HashMap<_, _>>();
 			let clean_recon = reconstructed.into_iter().filter_map(|(k, v)| if refs.get(&k) == Some(&v) {None} else {Some((k.clone(), v.clone()))}).collect::<HashMap<_, _>>();
 			warn!(target: "jdb", "mem: {:?}  !=  log: {:?}", clean_refs, clean_recon);
@@ -241,10 +244,12 @@ impl EarlyMergeDB {
 		self.backing.get(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?").map(|v| v.to_vec())
 	}
 
-	fn read_refs(db: &Database) -> HashMap<H256, RefInfo> {
+	fn read_refs(db: &Database) -> (Option<u64>, HashMap<H256, RefInfo>) {
 		let mut refs = HashMap::new();
+		let mut latest_era = None;
 		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
 			let mut era = decode::<u64>(&val);
+			latest_era = Some(era);
 			loop {
 				let mut index = 0usize;
 				while let Some(rlp_data) = db.get({
@@ -265,7 +270,7 @@ impl EarlyMergeDB {
 				era -= 1;
 			}
 		}
-		refs
+		(latest_era, refs)
 	}
  }
 
@@ -320,6 +325,7 @@ impl JournalDB for EarlyMergeDB {
 			overlay: MemoryDB::new(),
 			backing: self.backing.clone(),
 			refs: self.refs.clone(),
+			latest_era: self.latest_era.clone(),
 		})
 	}
 
@@ -435,7 +441,10 @@ impl JournalDB for EarlyMergeDB {
 				trace!(target: "jdb.ops", "  Deletes: {:?}", removes);
 			}
 			try!(batch.put(&last, r.as_raw()));
-			try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
+			if self.latest_era.map_or(true, |e| now > e) {
+				try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
+				self.latest_era = Some(now);
+			}
 		}
 
 		// apply old commits' details
@@ -552,6 +561,26 @@ mod tests {
 		assert!(jdb.exists(&x));
 	}
 
+	#[test]
+	fn insert_older_era() {
+		let mut jdb = EarlyMergeDB::new_temp();
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		let bar = jdb.insert(b"bar");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&bar);
+		jdb.commit(0, &b"0b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+	}
+
 	#[test]
 	fn long_history() {
 		// history is 3

util/src/journaldb/overlayrecentdb.rs

@@ -66,7 +66,7 @@ pub struct OverlayRecentDB {
 struct JournalOverlay {
 	backing_overlay: MemoryDB,
 	journal: HashMap<u64, Vec<JournalEntry>>,
-	latest_era: u64,
+	latest_era: Option<u64>,
 }
 
 #[derive(PartialEq)]
@@ -152,10 +152,10 @@ impl OverlayRecentDB {
 		let mut journal = HashMap::new();
 		let mut overlay = MemoryDB::new();
 		let mut count = 0;
-		let mut latest_era = 0;
+		let mut latest_era = None;
 		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
-			latest_era = decode::<u64>(&val);
-			let mut era = latest_era;
+			let mut era = decode::<u64>(&val);
+			latest_era = Some(era);
 			loop {
 				let mut index = 0usize;
 				while let Some(rlp_data) = db.get({
@@ -241,9 +241,9 @@ impl JournalDB for OverlayRecentDB {
 			k.append(&index);
 			k.append(&&PADDING[..]);
 			try!(batch.put(&k.drain(), r.as_raw()));
-			if now >= journal_overlay.latest_era {
+			if journal_overlay.latest_era.map_or(true, |e| now > e) {
 				try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
-				journal_overlay.latest_era = now;
+				journal_overlay.latest_era = Some(now);
 			}
 			journal_overlay.journal.entry(now).or_insert_with(Vec::new).push(JournalEntry { id: id.clone(), insertions: inserted_keys, deletions: removed_keys });
 		}
@@ -870,4 +870,24 @@ mod tests {
 			assert!(!jdb.exists(&bar));
 		}
 	}
+
+	#[test]
+	fn insert_older_era() {
+		let mut jdb = OverlayRecentDB::new_temp();
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		let bar = jdb.insert(b"bar");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&bar);
+		jdb.commit(0, &b"0b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+	}
 }