From c2c699abb9e4461f85c5639991744d3b7d30f5a3 Mon Sep 17 00:00:00 2001
From: Robert Habermeier <rphmeier@gmail.com>
Date: Sun, 26 Feb 2017 18:41:40 +0100
Subject: [PATCH] change migration to v11 to be faster

---
 ethcore/src/migrations/mod.rs |  2 +-
 ethcore/src/migrations/v11.rs | 34 +++++++---------------------------
 parity/migration.rs           |  2 +-
 util/src/migration/mod.rs     | 17 +++++++++++++++++
 4 files changed, 26 insertions(+), 29 deletions(-)

diff --git a/ethcore/src/migrations/mod.rs b/ethcore/src/migrations/mod.rs
index b9a00a15e..6cc4a13a8 100644
--- a/ethcore/src/migrations/mod.rs
+++ b/ethcore/src/migrations/mod.rs
@@ -28,4 +28,4 @@ mod v10;
 pub use self::v10::ToV10;
 
 mod v11;
-pub use self::v11::ToV11;
+pub use self::v11::TO_V11;
diff --git a/ethcore/src/migrations/v11.rs b/ethcore/src/migrations/v11.rs
index 8795cf364..e33de6170 100644
--- a/ethcore/src/migrations/v11.rs
+++ b/ethcore/src/migrations/v11.rs
@@ -14,33 +14,13 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-
 //! Adds a seventh column for node information.
 
-use util::kvdb::Database;
-use util::migration::{Batch, Config, Error, Migration, Progress};
-use std::sync::Arc;
+use util::migration::ChangeColumns;
 
-/// Copies over data for all existing columns.
-#[derive(Default)]
-pub struct ToV11(Progress);
-
-
-impl Migration for ToV11 {
-	fn pre_columns(&self) -> Option<u32> { Some(6) }
-	fn columns(&self) -> Option<u32> { Some(7) }
-
-	fn version(&self) -> u32 { 11 }
-
-	fn migrate(&mut self, source: Arc<Database>, config: &Config, dest: &mut Database, col: Option<u32>) -> Result<(), Error> {
-		// just copy everything over.
-		let mut batch = Batch::new(config, col);
-
-		for (key, value) in source.iter(col) {
-			self.0.tick();
-			batch.insert(key.to_vec(), value.to_vec(), dest)?
-		}
-
-		batch.commit(dest)
-	}
-}
+/// The migration from v10 to v11.
+pub const TO_V11: ChangeColumns = ChangeColumns {
+	pre_columns: Some(6),
+	post_columns: Some(7),
+	version: 11,
+};
diff --git a/parity/migration.rs b/parity/migration.rs
index c2d5c0797..797e8d2d6 100644
--- a/parity/migration.rs
+++ b/parity/migration.rs
@@ -146,7 +146,7 @@ pub fn default_migration_settings(compaction_profile: &CompactionProfile) -> Mig
 fn consolidated_database_migrations(compaction_profile: &CompactionProfile) -> Result<MigrationManager, Error> {
 	let mut manager = MigrationManager::new(default_migration_settings(compaction_profile));
 	manager.add_migration(migrations::ToV10::new()).map_err(|_| Error::MigrationImpossible)?;
-	manager.add_migration(migrations::ToV11::default()).map_err(|_| Error::MigrationImpossible)?;
+	manager.add_migration(migrations::TO_V11).map_err(|_| Error::MigrationImpossible)?;
 	Ok(manager)
 }
 
diff --git a/util/src/migration/mod.rs b/util/src/migration/mod.rs
index 3af86fc5b..3f0a7a806 100644
--- a/util/src/migration/mod.rs
+++ b/util/src/migration/mod.rs
@@ -167,6 +167,23 @@ impl<T: SimpleMigration> Migration for T {
 	}
 }
 
+/// An even simpler migration which just changes the number of columns.
+pub struct ChangeColumns {
+	pub pre_columns: Option<u32>,
+	pub post_columns: Option<u32>,
+	pub version: u32,
+}
+
+impl Migration for ChangeColumns {
+	fn pre_columns(&self) -> Option<u32> { self.pre_columns }
+	fn columns(&self) -> Option<u32> { self.post_columns }
+	fn version(&self) -> u32 { self.version }
+	fn alters_existing(&self) -> bool { false }
+	fn migrate(&mut self, _: Arc<Database>, _: &Config, _: &mut Database, _: Option<u32>) -> Result<(), Error> {
+		Ok(())
+	}
+}
+
 /// Get the path where all databases reside.
 fn database_path(path: &Path) -> PathBuf {
 	let mut temp_path = path.to_owned();