Bloomchain (#1014)

* use bloomchain crate in blockchain module. remove obsole chainfilter submodule

* update database version to 6.0

* removed redundant line

* simple db migration

* make migration slightly more functional

* bloomchain migration

* migration version is just a single unsigned integer

* updated migration v6

* parity migration

* db migration

* removed hardcoded migration dir

* replace ptr::copy with clone_from_slice, removed potential endianess problem from trace/db.rs

* removed superfluous line

* blockchains log blooms config is not exposed any more

util/src/migration/db_impl.rs

@@ -17,9 +17,30 @@
 //! `kvdb::Database` as `migration::Destination`
 
 use std::collections::BTreeMap;
-use kvdb::{Database, DBTransaction};
+use kvdb::{Database, DatabaseIterator, DBTransaction};
 use migration::{Destination, Error};
 
+/// Database iterator with `Item` complient with migration `Manager` interface.
+pub struct MigrationIterator {
+	iter: DatabaseIterator,
+}
+
+impl From<DatabaseIterator> for MigrationIterator {
+	fn from(iter: DatabaseIterator) -> Self {
+		MigrationIterator {
+			iter: iter
+		}
+	}
+}
+
+impl Iterator for MigrationIterator {
+	type Item = (Vec<u8>, Vec<u8>);
+
+	fn next(&mut self) -> Option<Self::Item> {
+		self.iter.next().map(|(k, v)| (k.to_vec(), v.to_vec()))
+	}
+}
+
 impl Destination for Database {
 	fn commit(&mut self, batch: BTreeMap<Vec<u8>, Vec<u8>>) -> Result<(), Error> {
 		let transaction = DBTransaction::new();

util/src/migration/manager.rs

@@ -76,10 +76,6 @@ impl Manager {
 	pub fn execute<D>(&self, db_iter: D, version: u32, destination: &mut Destination) -> Result<(), Error> where
 		D: Iterator<Item = (Vec<u8>, Vec<u8>)> {
 
-		if self.is_latest_version(version) {
-			return Ok(());
-		}
-
 		let migrations = try!(self.migrations_from(version).ok_or(Error::MigrationImpossible));
 
 		let mut batch: BTreeMap<Vec<u8>, Vec<u8>> = BTreeMap::new();
@@ -104,11 +100,11 @@ impl Manager {
 		Ok(())
 	}
 
-	/// Returns true if given string is equal to latest known version.
-	pub fn is_latest_version(&self, version: u32) -> bool {
+	/// Returns true if migration is needed.
+	pub fn is_needed(&self, version: u32) -> bool {
 		match self.migrations.last() {
-			Some(last) => version == last.version(),
-			None => true
+			Some(last) => version < last.version(),
+			None => false,
 		}
 	}
 

util/src/migration/mod.rs

@@ -23,6 +23,7 @@ mod manager;
 mod tests;
 
 pub use self::manager::{Error, Config, Manager};
+pub use self::db_impl::MigrationIterator;
 use std::collections::BTreeMap;
 
 /// Single migration.

util/src/migration/tests.rs

@@ -70,6 +70,7 @@ fn one_simple_migration() {
 }
 
 #[test]
+#[should_panic]
 fn no_migration_needed() {
 	let mut manager = Manager::new(Config::default());
 	let keys = vec![vec![], vec![1u8]];
@@ -79,7 +80,6 @@ fn no_migration_needed() {
 	let mut result = BTreeMap::new();
 	manager.add_migration(Migration0).unwrap();
 	manager.execute(db, 1, &mut result).unwrap();
-	assert!(result.is_empty());
 }
 
 #[test]
@@ -117,3 +117,14 @@ fn second_migration() {
 	manager.execute(db, 1, &mut result).unwrap();
 	assert_eq!(expected_db, result);
 }
+
+#[test]
+fn is_migration_needed() {
+	let mut manager = Manager::new(Config::default());
+	manager.add_migration(Migration0).unwrap();
+	manager.add_migration(Migration1).unwrap();
+
+	assert!(manager.is_needed(0));
+	assert!(manager.is_needed(1));
+	assert!(!manager.is_needed(2));
+}