openethereum/util/src/trie/recorder.rs
2016-12-11 19:30:54 +01:00

243 lines
6.9 KiB
Rust

// Copyright 2015, 2016 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 sha3::Hashable;
use {Bytes, H256};
/// A record of a visited node.
#[derive(PartialEq, Eq, Debug, Clone)]
pub struct Record {
/// The depth of this node.
pub depth: u32,
/// The raw data of the node.
pub data: Bytes,
/// The hash of the data.
pub hash: H256,
}
/// Trie node recorder.
///
/// These are used to record which nodes are visited during a trie query.
/// Inline nodes are not to be recorded, as they are contained within their parent.
pub trait Recorder {
/// Record that the given node has been visited.
///
/// The depth parameter is the depth of the visited node, with the root node having depth 0.
fn record(&mut self, hash: &H256, data: &[u8], depth: u32);
/// Drain all accepted records from the recorder in ascending order by depth.
fn drain(&mut self) -> Vec<Record> where Self: Sized;
}
/// A no-op trie recorder. This ignores everything which is thrown at it.
pub struct NoOp;
impl Recorder for NoOp {
#[inline]
fn record(&mut self, _hash: &H256, _data: &[u8], _depth: u32) {}
#[inline]
fn drain(&mut self) -> Vec<Record> { Vec::new() }
}
/// A simple recorder. Does nothing fancy but fulfills the `Recorder` interface
/// properly.
#[derive(Debug)]
pub struct BasicRecorder {
nodes: Vec<Record>,
min_depth: u32,
}
impl Default for BasicRecorder {
fn default() -> Self {
BasicRecorder::new()
}
}
impl BasicRecorder {
/// Create a new `BasicRecorder` which records all given nodes.
#[inline]
pub fn new() -> Self {
BasicRecorder::with_depth(0)
}
/// Create a `BasicRecorder` which only records nodes beyond a given depth.
pub fn with_depth(depth: u32) -> Self {
BasicRecorder {
nodes: Vec::new(),
min_depth: depth,
}
}
}
impl Recorder for BasicRecorder {
fn record(&mut self, hash: &H256, data: &[u8], depth: u32) {
debug_assert_eq!(data.sha3(), *hash);
if depth >= self.min_depth {
self.nodes.push(Record {
depth: depth,
data: data.into(),
hash: *hash,
})
}
}
fn drain(&mut self) -> Vec<Record> {
::std::mem::replace(&mut self.nodes, Vec::new())
}
}
#[cfg(test)]
mod tests {
use super::*;
use sha3::Hashable;
use ::H256;
#[test]
fn no_op_does_nothing() {
let mut no_op = NoOp;
let (node1, node2) = (&[1], &[2]);
let (hash1, hash2) = (node1.sha3(), node2.sha3());
no_op.record(&hash1, node1, 1);
no_op.record(&hash2, node2, 2);
assert_eq!(no_op.drain(), Vec::new());
}
#[test]
fn basic_recorder() {
let mut basic = BasicRecorder::new();
let node1 = vec![1, 2, 3, 4];
let node2 = vec![4, 5, 6, 7, 8, 9, 10];
let (hash1, hash2) = (node1.sha3(), node2.sha3());
basic.record(&hash1, &node1, 0);
basic.record(&hash2, &node2, 456);
let record1 = Record {
data: node1,
hash: hash1,
depth: 0,
};
let record2 = Record {
data: node2,
hash: hash2,
depth: 456
};
assert_eq!(basic.drain(), vec![record1, record2]);
}
#[test]
fn basic_recorder_min_depth() {
let mut basic = BasicRecorder::with_depth(400);
let node1 = vec![1, 2, 3, 4];
let node2 = vec![4, 5, 6, 7, 8, 9, 10];
let hash1 = node1.sha3();
let hash2 = node2.sha3();
basic.record(&hash1, &node1, 0);
basic.record(&hash2, &node2, 456);
let records = basic.drain();
assert_eq!(records.len(), 1);
assert_eq!(records[0].clone(), Record {
data: node2,
hash: hash2,
depth: 456,
});
}
#[test]
fn trie_record() {
use trie::{TrieDB, TrieDBMut, Trie, TrieMut};
use memorydb::MemoryDB;
let mut db = MemoryDB::new();
let mut root = H256::default();
{
let mut x = TrieDBMut::new(&mut db, &mut root);
x.insert(b"dog", b"cat").unwrap();
x.insert(b"lunch", b"time").unwrap();
x.insert(b"notdog", b"notcat").unwrap();
x.insert(b"hotdog", b"hotcat").unwrap();
x.insert(b"letter", b"confusion").unwrap();
x.insert(b"insert", b"remove").unwrap();
x.insert(b"pirate", b"aargh!").unwrap();
x.insert(b"yo ho ho", b"and a bottle of rum").unwrap();
}
let trie = TrieDB::new(&db, &root).unwrap();
let mut recorder = BasicRecorder::new();
trie.get_recorded(b"pirate", &mut recorder).unwrap().unwrap();
let nodes: Vec<_> = recorder.drain().into_iter().map(|r| r.data).collect();
assert_eq!(nodes, vec![
vec![
248, 81, 128, 128, 128, 128, 128, 128, 160, 50, 19, 71, 57, 213, 63, 125, 149,
92, 119, 88, 96, 80, 126, 59, 11, 160, 142, 98, 229, 237, 200, 231, 224, 79, 118,
215, 93, 144, 246, 179, 176, 160, 118, 211, 171, 199, 172, 136, 136, 240, 221, 59,
110, 82, 86, 54, 23, 95, 48, 108, 71, 125, 59, 51, 253, 210, 18, 116, 79, 0, 236,
102, 142, 48, 128, 128, 128, 128, 128, 128, 128, 128, 128
],
vec![
248, 60, 206, 134, 32, 105, 114, 97, 116, 101, 134, 97, 97, 114, 103, 104, 33,
128, 128, 128, 128, 128, 128, 128, 128, 221, 136, 32, 111, 32, 104, 111, 32, 104,
111, 147, 97, 110, 100, 32, 97, 32, 98, 111, 116, 116, 108, 101, 32, 111, 102,
32, 114, 117, 109, 128, 128, 128, 128, 128, 128, 128
]
]);
trie.get_recorded(b"letter", &mut recorder).unwrap().unwrap();
let nodes: Vec<_> = recorder.drain().into_iter().map(|r| r.data).collect();
assert_eq!(nodes, vec![
vec![
248, 81, 128, 128, 128, 128, 128, 128, 160, 50, 19, 71, 57, 213, 63, 125, 149,
92, 119, 88, 96, 80, 126, 59, 11, 160, 142, 98, 229, 237, 200, 231, 224, 79, 118,
215, 93, 144, 246, 179, 176, 160, 118, 211, 171, 199, 172, 136, 136, 240, 221,
59, 110, 82, 86, 54, 23, 95, 48, 108, 71, 125, 59, 51, 253, 210, 18, 116, 79,
0, 236, 102, 142, 48, 128, 128, 128, 128, 128, 128, 128, 128, 128
],
vec![
248, 99, 128, 128, 128, 128, 200, 131, 32, 111, 103, 131, 99, 97, 116, 128, 128,
128, 206, 134, 32, 111, 116, 100, 111, 103, 134, 104, 111, 116, 99, 97, 116, 206,
134, 32, 110, 115, 101, 114, 116, 134, 114, 101, 109, 111, 118, 101, 128, 128,
160, 202, 250, 252, 153, 229, 63, 255, 13, 100, 197, 80, 120, 190, 186, 92, 5,
255, 135, 245, 205, 180, 213, 161, 8, 47, 107, 13, 105, 218, 1, 9, 5, 128,
206, 134, 32, 111, 116, 100, 111, 103, 134, 110, 111, 116, 99, 97, 116, 128, 128
],
vec![
235, 128, 128, 128, 128, 128, 128, 208, 133, 53, 116, 116, 101, 114, 137, 99,
111, 110, 102, 117, 115, 105, 111, 110, 202, 132, 53, 110, 99, 104, 132, 116,
105, 109, 101, 128, 128, 128, 128, 128, 128, 128, 128, 128
]
]);
}
}