openethereum/ethcore/src/migrations/extras/v6.rs
Marek Kotewicz 6279ff32f5 Separate migrations from util (#6690)
* separate migration from util and make its dependencies into libs:

* snappy
* kvdb
* error
* common

* renamed common -> macros

* util error does not depend on snappy module

* ethsync does not depend on util nor ethcore_error

* nibbleslice and nibblevec merged with patricia_trie crate

* removed unused dependencies from util

* util journaldb traits does not need to be public

* util_error

* fixed ethcore compile error

* ignore .swo files

* Update chain.rs
2017-10-10 20:01:27 +02:00

103 lines
2.7 KiB
Rust

// Copyright 2015-2017 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 migration::SimpleMigration;
/// This migration reduces the sizes of keys and moves `ExtrasIndex` byte from back to the front.
pub struct ToV6;
impl ToV6 {
fn migrate_old_key(&self, old_key: Vec<u8>, index: u8, len: usize) -> Vec<u8> {
let mut result = vec![];
result.reserve(len);
unsafe {
result.set_len(len);
}
result[0] = index;
let old_key_start = 33 - len;
result[1..].clone_from_slice(&old_key[old_key_start..32]);
result
}
}
impl SimpleMigration for ToV6 {
fn columns(&self) -> Option<u32> { None }
fn version(&self) -> u32 { 6 }
fn simple_migrate(&mut self, mut key: Vec<u8>, value: Vec<u8>) -> Option<(Vec<u8>, Vec<u8>)> {
//// at this version all extras keys are 33 bytes long.
if key.len() == 33 {
// block details key changes:
// - index is moved to the front
if key[32] == 0 {
return Some((self.migrate_old_key(key, 0, 33), value));
}
// block hash key changes:
// - key is shorter 33 -> 5 bytes
// - index is moved to the front
if key[32] == 1 {
return Some((self.migrate_old_key(key, 1, 5), value));
}
// transaction addresses changes:
// - index is moved to the front
if key[32] == 2 {
return Some((self.migrate_old_key(key, 2, 33), value));
}
// block log blooms are removed
if key[32] == 3 {
return None;
}
// blocks blooms key changes:
// - key is shorter 33 -> 6 bytes
// - index is moved to the front
// - index is changed 4 -> 3
if key[32] == 4 {
key.reverse();
// i have no idea why it was reversed
let reverse = key;
let result = vec![
// new extras index is 3
3,
// 9th (+ prefix) byte was the level. Now it's second.
reverse[9],
reverse[4],
reverse[3],
reverse[2],
reverse[1],
];
return Some((result, value));
}
// blocks receipts key changes:
// - index is moved to the front
// - index is changed 5 -> 4
if key[32] == 5 {
return Some((self.migrate_old_key(key, 4, 33), value));
}
}
Some((key, value))
}
}