openethereum/parity/db/rocksdb/migration.rs

245 lines
7.7 KiB
Rust

// Copyright 2015-2018 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
use std::fs;
use std::io::{Read, Write, Error as IoError, ErrorKind};
use std::path::{Path, PathBuf};
use std::fmt::{Display, Formatter, Error as FmtError};
use super::migration_rocksdb::{self, Manager as MigrationManager, Config as MigrationConfig, ChangeColumns};
use super::kvdb_rocksdb::{CompactionProfile, DatabaseConfig};
use ethcore::client::DatabaseCompactionProfile;
use ethcore::{self, db};
use super::helpers;
use super::blooms::migrate_blooms;
/// The migration from v10 to v11.
/// Adds a column for node info.
pub const TO_V11: ChangeColumns = ChangeColumns {
pre_columns: Some(6),
post_columns: Some(7),
version: 11,
};
/// The migration from v11 to v12.
/// Adds a column for light chain storage.
pub const TO_V12: ChangeColumns = ChangeColumns {
pre_columns: Some(7),
post_columns: Some(8),
version: 12,
};
/// Database is assumed to be at default version, when no version file is found.
const DEFAULT_VERSION: u32 = 5;
/// Current version of database models.
const CURRENT_VERSION: u32 = 13;
/// A version of database at which blooms-db was introduced
const BLOOMS_DB_VERSION: u32 = 13;
/// Defines how many items are migrated to the new version of database at once.
const BATCH_SIZE: usize = 1024;
/// Version file name.
const VERSION_FILE_NAME: &'static str = "db_version";
/// Migration related erorrs.
#[derive(Debug)]
pub enum Error {
/// Returned when current version cannot be read or guessed.
UnknownDatabaseVersion,
/// Existing DB is newer than the known one.
FutureDBVersion,
/// Migration is not possible.
MigrationImpossible,
/// Internal migration error.
Internal(migration_rocksdb::Error),
/// Blooms-db migration error.
BloomsDB(ethcore::error::Error),
/// Migration was completed succesfully,
/// but there was a problem with io.
Io(IoError),
}
impl Display for Error {
fn fmt(&self, f: &mut Formatter) -> Result<(), FmtError> {
let out = match *self {
Error::UnknownDatabaseVersion => "Current database version cannot be read".into(),
Error::FutureDBVersion => "Database was created with newer client version. Upgrade your client or delete DB and resync.".into(),
Error::MigrationImpossible => format!("Database migration to version {} is not possible.", CURRENT_VERSION),
Error::Internal(ref err) => format!("{}", err),
Error::BloomsDB(ref err) => format!("blooms-db migration error: {}", err),
Error::Io(ref err) => format!("Unexpected io error on DB migration: {}.", err),
};
write!(f, "{}", out)
}
}
impl From<IoError> for Error {
fn from(err: IoError) -> Self {
Error::Io(err)
}
}
impl From<migration_rocksdb::Error> for Error {
fn from(err: migration_rocksdb::Error) -> Self {
match err.into() {
migration_rocksdb::ErrorKind::Io(e) => Error::Io(e),
err => Error::Internal(err.into()),
}
}
}
/// Returns the version file path.
fn version_file_path(path: &Path) -> PathBuf {
let mut file_path = path.to_owned();
file_path.push(VERSION_FILE_NAME);
file_path
}
/// Reads current database version from the file at given path.
/// If the file does not exist returns `DEFAULT_VERSION`.
fn current_version(path: &Path) -> Result<u32, Error> {
match fs::File::open(version_file_path(path)) {
Err(ref err) if err.kind() == ErrorKind::NotFound => Ok(DEFAULT_VERSION),
Err(_) => Err(Error::UnknownDatabaseVersion),
Ok(mut file) => {
let mut s = String::new();
file.read_to_string(&mut s).map_err(|_| Error::UnknownDatabaseVersion)?;
u32::from_str_radix(&s, 10).map_err(|_| Error::UnknownDatabaseVersion)
},
}
}
/// Writes current database version to the file.
/// Creates a new file if the version file does not exist yet.
fn update_version(path: &Path) -> Result<(), Error> {
fs::create_dir_all(path)?;
let mut file = fs::File::create(version_file_path(path))?;
file.write_all(format!("{}", CURRENT_VERSION).as_bytes())?;
Ok(())
}
/// Consolidated database path
fn consolidated_database_path(path: &Path) -> PathBuf {
let mut state_path = path.to_owned();
state_path.push("db");
state_path
}
/// Database backup
fn backup_database_path(path: &Path) -> PathBuf {
let mut backup_path = path.to_owned();
backup_path.pop();
backup_path.push("temp_backup");
backup_path
}
/// Default migration settings.
pub fn default_migration_settings(compaction_profile: &CompactionProfile) -> MigrationConfig {
MigrationConfig {
batch_size: BATCH_SIZE,
compaction_profile: *compaction_profile,
}
}
/// Migrations on the consolidated database.
fn consolidated_database_migrations(compaction_profile: &CompactionProfile) -> Result<MigrationManager, Error> {
let mut manager = MigrationManager::new(default_migration_settings(compaction_profile));
manager.add_migration(TO_V11).map_err(|_| Error::MigrationImpossible)?;
manager.add_migration(TO_V12).map_err(|_| Error::MigrationImpossible)?;
Ok(manager)
}
/// Migrates database at given position with given migration rules.
fn migrate_database(version: u32, db_path: &Path, mut migrations: MigrationManager) -> Result<(), Error> {
// check if migration is needed
if !migrations.is_needed(version) {
return Ok(())
}
let backup_path = backup_database_path(&db_path);
// remove the backup dir if it exists
let _ = fs::remove_dir_all(&backup_path);
// migrate old database to the new one
let temp_path = migrations.execute(&db_path, version)?;
// completely in-place migration leads to the paths being equal.
// in that case, no need to shuffle directories.
if temp_path == db_path { return Ok(()) }
// create backup
fs::rename(&db_path, &backup_path)?;
// replace the old database with the new one
if let Err(err) = fs::rename(&temp_path, &db_path) {
// if something went wrong, bring back backup
fs::rename(&backup_path, &db_path)?;
return Err(err.into());
}
// remove backup
fs::remove_dir_all(&backup_path).map_err(Into::into)
}
fn exists(path: &Path) -> bool {
fs::metadata(path).is_ok()
}
/// Migrates the database.
pub fn migrate(path: &Path, compaction_profile: &DatabaseCompactionProfile) -> Result<(), Error> {
let compaction_profile = helpers::compaction_profile(&compaction_profile, path);
// read version file.
let version = current_version(path)?;
// migrate the databases.
// main db directory may already exists, so let's check if we have blocks dir
if version > CURRENT_VERSION {
return Err(Error::FutureDBVersion);
}
// We are in the latest version, yay!
if version == CURRENT_VERSION {
return Ok(())
}
let db_path = consolidated_database_path(path);
// Further migrations
if version < CURRENT_VERSION && exists(&db_path) {
println!("Migrating database from version {} to {}", version, CURRENT_VERSION);
migrate_database(version, &db_path, consolidated_database_migrations(&compaction_profile)?)?;
if version < BLOOMS_DB_VERSION {
println!("Migrating blooms to blooms-db...");
let db_config = DatabaseConfig {
max_open_files: 64,
memory_budget: None,
compaction: compaction_profile,
columns: db::NUM_COLUMNS,
wal: true,
};
migrate_blooms(&db_path, &db_config).map_err(Error::BloomsDB)?;
}
println!("Migration finished");
}
// update version file.
update_version(path)
}