This commit is contained in:
debris 2015-11-29 00:05:42 +01:00
commit 320b6cb4d9
7 changed files with 357 additions and 12 deletions

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@ -1,9 +1,15 @@
use rustc_serialize::hex::*;
#[derive(Debug)]
pub enum BaseDataError {
NegativelyReferencedHash,
}
#[derive(Debug)]
pub enum EthcoreError {
FromHex(FromHexError),
BadSize
BaseData(BaseDataError),
BadSize,
}
impl From<FromHexError> for EthcoreError {
@ -11,3 +17,23 @@ impl From<FromHexError> for EthcoreError {
EthcoreError::FromHex(err)
}
}
impl From<BaseDataError> for EthcoreError {
fn from(err: BaseDataError) -> EthcoreError {
EthcoreError::BaseData(err)
}
}
// TODO: uncomment below once https://github.com/rust-lang/rust/issues/27336 sorted.
/*#![feature(concat_idents)]
macro_rules! assimilate {
($name:ident) => (
impl From<concat_idents!($name, Error)> for EthcoreError {
fn from(err: concat_idents!($name, Error)) -> EthcoreError {
EthcoreError:: $name (err)
}
}
)
}
assimilate!(FromHex);
assimilate!(BaseData);*/

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@ -237,9 +237,15 @@ macro_rules! impl_hash {
}
}
impl $from {
pub fn hex(&self) -> String {
format!("{}", self)
}
}
}
}
impl_hash!(H32, 4);
impl_hash!(H64, 8);
impl_hash!(H128, 16);
impl_hash!(Address, 20);
@ -260,6 +266,7 @@ mod tests {
assert_eq!(H64::from_str("0123456789abcdef").unwrap(), h);
assert_eq!(format!("{}", h), "0123456789abcdef");
assert_eq!(format!("{:?}", h), "0123456789abcdef");
assert_eq!(h.hex(), "0123456789abcdef");
assert!(h == h);
assert!(h != H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xee]));
assert!(h != H64([0; 8]));

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@ -14,10 +14,10 @@ pub trait HashDB {
/// let mut m = MemoryDB::new();
/// let hello_bytes = "Hello world!".as_bytes();
/// let hash = m.insert(hello_bytes);
/// assert_eq!(m.lookup(&hash).unwrap(), &hello_bytes);
/// assert_eq!(m.lookup(&hash).unwrap(), hello_bytes);
/// }
/// ```
fn lookup(&self, key: &H256) -> Option<&Bytes>;
fn lookup(&self, key: &H256) -> Option<Bytes>;
/// Check for the existance of a hash-key.
///
@ -75,7 +75,7 @@ pub trait HashDB {
/// m.insert(d); // OK - now it's "empty" again.
/// assert!(!m.exists(key));
/// m.insert(d); // OK - now we've
/// assert_eq!(m.lookup(key).unwrap(), &d);
/// assert_eq!(m.lookup(key).unwrap(), d);
/// }
/// ```
fn kill(&mut self, key: &H256);

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@ -23,6 +23,7 @@ pub mod db;
pub mod sha3;
pub mod hashdb;
pub mod memorydb;
pub mod overlaydb;
pub mod math;
//pub mod filter;
pub mod chainfilter;

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@ -4,6 +4,7 @@ use hash::*;
use bytes::*;
use sha3::*;
use hashdb::*;
use std::mem;
use std::collections::HashMap;
#[derive(Debug,Clone)]
@ -25,7 +26,7 @@ use std::collections::HashMap;
///
/// let k = m.insert(d);
/// assert!(m.exists(&k));
/// assert_eq!(m.lookup(&k).unwrap(), &d);
/// assert_eq!(m.lookup(&k).unwrap(), d);
///
/// m.insert(d);
/// assert!(m.exists(&k));
@ -38,7 +39,7 @@ use std::collections::HashMap;
///
/// m.insert(d);
/// assert!(m.exists(&k));
/// assert_eq!(m.lookup(&k).unwrap(), &d);
/// assert_eq!(m.lookup(&k).unwrap(), d);
///
/// m.kill(&k);
/// assert!(!m.exists(&k));
@ -84,12 +85,27 @@ impl MemoryDB {
.collect();
for empty in empties { self.data.remove(&empty); }
}
/// Grab the raw information associated with a key. Returns None if the key
/// doesn't exist.
///
/// Even when Some is returned, the data is only guaranteed to be useful
/// when the refs > 0.
pub fn raw(&self, key: &H256) -> Option<&(Bytes, i32)> {
self.data.get(key)
}
pub fn drain(&mut self) -> HashMap<H256, (Bytes, i32)> {
let mut data = HashMap::new();
mem::swap(&mut self.data, &mut data);
data
}
}
impl HashDB for MemoryDB {
fn lookup(&self, key: &H256) -> Option<&Bytes> {
fn lookup(&self, key: &H256) -> Option<Bytes> {
match self.data.get(key) {
Some(&(ref d, rc)) if rc > 0 => Some(d),
Some(&(ref d, rc)) if rc > 0 => Some(d.clone()),
_ => None
}
}
@ -116,6 +132,7 @@ impl HashDB for MemoryDB {
}
key
}
fn kill(&mut self, key: &H256) {
if match self.data.get_mut(key) {
Some(&mut (_, ref mut x)) => { *x -= 1; false }

294
src/overlaydb.rs Normal file
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@ -0,0 +1,294 @@
//! Disk-backed HashDB implementation.
use error::*;
use hash::*;
use bytes::*;
use rlp::*;
use hashdb::*;
use memorydb::*;
use std::ops::*;
use std::sync::*;
use std::env;
use rocksdb::{DB, Writable};
#[derive(Clone)]
/// Implementation of the HashDB trait for a disk-backed database with a memory overlay.
///
/// The operations `insert()` and `kill()` take place on the memory overlay; batches of
/// such operations may be flushed to the disk-backed DB with `commit()` or discarded with
/// `revert()`.
///
/// `lookup()` and `exists()` maintain normal behaviour - all `insert()` and `kill()`
/// queries have an immediate effect in terms of these functions.
pub struct OverlayDB {
overlay: MemoryDB,
backing: Arc<DB>,
}
impl OverlayDB {
/// Create a new instance of OverlayDB given a `backing` database.
pub fn new(backing: DB) -> OverlayDB {
OverlayDB{ overlay: MemoryDB::new(), backing: Arc::new(backing) }
}
/// Create a new instance of OverlayDB with an anonymous temporary database.
pub fn new_temp() -> OverlayDB {
let mut dir = env::temp_dir();
dir.push(H32::random().hex());
Self::new(DB::open_default(dir.to_str().unwrap()).unwrap())
}
/// Commit all memory operations to the backing database.
///
/// Returns either an error or the number of items changed in the backing database.
///
/// Will return an error if the number of `kill()`s ever exceeds the number of
/// `insert()`s for any key. This will leave the database in an undeterminate
/// state. Don't ever let it happen.
///
/// # Example
/// ```
/// extern crate ethcore_util;
/// use ethcore_util::hashdb::*;
/// use ethcore_util::overlaydb::*;
/// fn main() {
/// let mut m = OverlayDB::new_temp();
/// let key = m.insert(b"foo"); // insert item.
/// assert!(m.exists(&key)); // key exists (in memory).
/// assert_eq!(m.commit().unwrap(), 1); // 1 item changed.
/// assert!(m.exists(&key)); // key still exists (in backing).
/// m.kill(&key); // delete item.
/// assert!(!m.exists(&key)); // key "doesn't exist" (though still does in backing).
/// m.kill(&key); // oh dear... more kills than inserts for the key...
/// //m.commit().unwrap(); // this commit/unwrap would cause a panic.
/// m.revert(); // revert both kills.
/// assert!(m.exists(&key)); // key now still exists.
/// }
/// ```
pub fn commit(&mut self) -> Result<u32, EthcoreError> {
let mut ret = 0u32;
for i in self.overlay.drain().into_iter() {
let (key, (value, rc)) = i;
if rc != 0 {
match self.payload(&key) {
Some(x) => {
let (back_value, back_rc) = x;
let total_rc: i32 = back_rc as i32 + rc;
if total_rc < 0 {
return Err(From::from(BaseDataError::NegativelyReferencedHash));
}
self.put_payload(&key, (back_value, total_rc as u32));
}
None => {
if rc < 0 {
return Err(From::from(BaseDataError::NegativelyReferencedHash));
}
self.put_payload(&key, (value, rc as u32));
}
};
ret += 1;
}
}
Ok(ret)
}
/// Revert all operations on this object (i.e. `insert()`s and `kill()`s) since the
/// last `commit()`.
///
/// # Example
/// ```
/// extern crate ethcore_util;
/// use ethcore_util::hashdb::*;
/// use ethcore_util::overlaydb::*;
/// fn main() {
/// let mut m = OverlayDB::new_temp();
/// let foo = m.insert(b"foo"); // insert foo.
/// m.commit().unwrap(); // commit - new operations begin here...
/// let bar = m.insert(b"bar"); // insert bar.
/// m.kill(&foo); // kill foo.
/// assert!(!m.exists(&foo)); // foo is gone.
/// assert!(m.exists(&bar)); // bar is here.
/// m.revert(); // revert the last two operations.
/// assert!(m.exists(&foo)); // foo is here.
/// assert!(!m.exists(&bar)); // bar is gone.
/// }
/// ```
pub fn revert(&mut self) { self.overlay.clear(); }
/// Get the refs and value of the given key.
fn payload(&self, key: &H256) -> Option<(Bytes, u32)> {
self.backing.get(&key.bytes())
.expect("Low-level database error. Some issue with your hard disk?")
.map(|d| {
let r = Rlp::new(d.deref());
(Bytes::decode(&r.at(1).unwrap()).unwrap(), u32::decode(&r.at(0).unwrap()).unwrap())
})
}
/// Get the refs and value of the given key.
fn put_payload(&self, key: &H256, payload: (Bytes, u32)) {
let mut s = RlpStream::new_list(2);
s.append(&payload.1);
s.append(&payload.0);
self.backing.put(&key.bytes(), &s.out().unwrap()).expect("Low-level database error. Some issue with your hard disk?");
}
}
impl HashDB for OverlayDB {
fn lookup(&self, key: &H256) -> Option<Bytes> {
// return ok if positive; if negative, check backing - might be enough references there to make
// it positive again.
let k = self.overlay.raw(key);
match k {
Some(&(ref d, rc)) if rc > 0 => Some(d.clone()),
_ => {
let memrc = k.map(|&(_, rc)| rc).unwrap_or(0);
match self.payload(key) {
Some(x) => {
let (d, rc) = x;
if rc as i32 + memrc > 0 {
Some(d)
}
else {
None
}
}
// Replace above match arm with this once https://github.com/rust-lang/rust/issues/15287 is done.
//Some((d, rc)) if rc + memrc > 0 => Some(d),
_ => None,
}
}
}
}
fn exists(&self, key: &H256) -> bool {
// return ok if positive; if negative, check backing - might be enough references there to make
// it positive again.
let k = self.overlay.raw(key);
match k {
Some(&(_, rc)) if rc > 0 => true,
_ => {
let memrc = k.map(|&(_, rc)| rc).unwrap_or(0);
match self.payload(key) {
Some(x) => {
let (_, rc) = x;
if rc as i32 + memrc > 0 {
true
}
else {
false
}
}
// Replace above match arm with this once https://github.com/rust-lang/rust/issues/15287 is done.
//Some((d, rc)) if rc + memrc > 0 => true,
_ => false,
}
}
}
}
fn insert(&mut self, value: &[u8]) -> H256 { self.overlay.insert(value) }
fn kill(&mut self, key: &H256) { self.overlay.kill(key); }
}
#[test]
fn overlaydb_overlay_insert_and_kill() {
let mut trie = OverlayDB::new_temp();
let h = trie.insert(b"hello world");
assert_eq!(trie.lookup(&h), Some(b"hello world".to_vec()));
trie.kill(&h);
assert_eq!(trie.lookup(&h), None);
}
#[test]
fn overlaydb_backing_insert_revert() {
let mut trie = OverlayDB::new_temp();
let h = trie.insert(b"hello world");
assert_eq!(trie.lookup(&h), Some(b"hello world".to_vec()));
trie.commit().unwrap();
assert_eq!(trie.lookup(&h), Some(b"hello world".to_vec()));
trie.revert();
assert_eq!(trie.lookup(&h), Some(b"hello world".to_vec()));
}
#[test]
fn overlaydb_backing_kill() {
let mut trie = OverlayDB::new_temp();
let h = trie.insert(b"hello world");
trie.commit().unwrap();
trie.kill(&h);
assert_eq!(trie.lookup(&h), None);
trie.commit().unwrap();
assert_eq!(trie.lookup(&h), None);
trie.revert();
assert_eq!(trie.lookup(&h), None);
}
#[test]
fn overlaydb_backing_kill_revert() {
let mut trie = OverlayDB::new_temp();
let h = trie.insert(b"hello world");
trie.commit().unwrap();
trie.kill(&h);
assert_eq!(trie.lookup(&h), None);
trie.revert();
assert_eq!(trie.lookup(&h), Some(b"hello world".to_vec()));
}
#[test]
fn overlaydb_negative() {
let mut trie = OverlayDB::new_temp();
let h = trie.insert(b"hello world");
trie.commit().unwrap();
trie.kill(&h);
trie.kill(&h); //bad - sends us into negative refs.
assert_eq!(trie.lookup(&h), None);
assert!(trie.commit().is_err());
}
#[test]
fn overlaydb_complex() {
let mut trie = OverlayDB::new_temp();
let hfoo = trie.insert(b"foo");
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
let hbar = trie.insert(b"bar");
assert_eq!(trie.lookup(&hbar), Some(b"bar".to_vec()));
trie.commit().unwrap();
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
assert_eq!(trie.lookup(&hbar), Some(b"bar".to_vec()));
trie.insert(b"foo"); // two refs
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
trie.commit().unwrap();
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
assert_eq!(trie.lookup(&hbar), Some(b"bar".to_vec()));
trie.kill(&hbar); // zero refs - delete
assert_eq!(trie.lookup(&hbar), None);
trie.kill(&hfoo); // one ref - keep
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
trie.commit().unwrap();
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
trie.kill(&hfoo); // zero ref - would delete, but...
assert_eq!(trie.lookup(&hfoo), None);
trie.insert(b"foo"); // one ref - keep after all.
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
trie.commit().unwrap();
assert_eq!(trie.lookup(&hfoo), Some(b"foo".to_vec()));
trie.kill(&hfoo); // zero ref - delete
assert_eq!(trie.lookup(&hfoo), None);
trie.commit().unwrap(); //
assert_eq!(trie.lookup(&hfoo), None);
}
#[test]
fn playpen() {
use std::fs;
{
let db: DB = DB::open_default("/tmp/test").unwrap();
db.put(b"test", b"test2").unwrap();
match db.get(b"test") {
Ok(Some(value)) => println!("Got value {:?}", value.deref()),
Ok(None) => println!("No value for that key"),
Err(..) => println!("Gah"),
}
db.delete(b"test").unwrap();
}
fs::remove_dir_all("/tmp/test").unwrap();
}