openethereum/util/journaldb/src/util.rs

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// 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 ethereum_types::H256;
use rlp::{RlpStream, Encodable, Rlp, DecoderError};
const PADDING : [u8; 10] = [ 0u8; 10 ];
pub struct DatabaseKey {
pub era: u64,
pub index: usize,
}
impl Encodable for DatabaseKey {
fn rlp_append(&self, s: &mut RlpStream) {
s.begin_list(3);
s.append(&self.era);
s.append(&self.index);
s.append(&&PADDING[..]);
}
}
pub struct DatabaseValueView<'a> {
rlp: Rlp<'a>,
}
impl<'a> DatabaseValueView<'a> {
pub fn from_rlp(data: &'a [u8]) -> Self {
DatabaseValueView {
rlp: Rlp::new(data),
}
}
#[inline]
pub fn id(&self) -> Result<H256, DecoderError> {
self.rlp.val_at(0)
}
#[inline]
pub fn inserts(&self) -> Result<Vec<H256>, DecoderError> {
self.rlp.list_at(1)
}
#[inline]
pub fn deletes(&self) -> Result<Vec<H256>, DecoderError> {
self.rlp.list_at(2)
}
}
pub struct DatabaseValueRef<'a> {
pub id: &'a H256,
pub inserts: &'a [H256],
pub deletes: &'a [H256],
}
impl<'a> Encodable for DatabaseValueRef<'a> {
fn rlp_append(&self, s: &mut RlpStream) {
s.begin_list(3);
s.append(self.id);
s.append_list(self.inserts);
s.append_list(self.deletes);
}
}