reduce number of constraints for triedb types (#9043)

* NodeHandle does not require Hasher

* Node does not require Hasher

* change name of the template typo from I to O
This commit is contained in:
Marek Kotewicz 2018-07-05 17:15:03 +02:00 committed by David
parent 434e018584
commit 802d684994
5 changed files with 53 additions and 45 deletions

1
Cargo.lock generated
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@ -2485,6 +2485,7 @@ dependencies = [
"ethcore-bytes 0.1.0",
"ethereum-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
"hashdb 0.2.0",
"heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
"keccak-hash 0.1.2",
"keccak-hasher 0.1.0",
"log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",

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@ -23,7 +23,7 @@ use heapsize::HeapSizeOf;
use std::collections::HashMap;
use std::{fmt::Debug, hash::Hash};
/// Trait describing an object that can hash a slice of bytes. Used to abstract
/// Trait describing an object that can hash a slice of bytes. Used to abstract
/// other types over the hashing algorithm. Defines a single `hash` method and an
/// `Out` associated type with the necessary bounds.
pub trait Hasher: Sync + Send {

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@ -7,10 +7,11 @@ license = "GPL-3.0"
[dependencies]
elastic-array = "0.10"
ethcore-bytes = { version = "0.1.0", path = "../bytes" }
hashdb = { version = "0.2", path = "../hashdb" }
heapsize = "0.4"
log = "0.3"
rand = "0.4"
hashdb = { version = "0.2", path = "../hashdb" }
ethcore-bytes = { version = "0.1.0", path = "../bytes" }
[dev-dependencies]
env_logger = "0.5"

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@ -18,6 +18,7 @@
extern crate elastic_array;
extern crate ethcore_bytes as bytes;
extern crate hashdb;
extern crate heapsize;
extern crate rand;
#[macro_use]
extern crate log;
@ -277,8 +278,8 @@ impl<'db, H: Hasher, C: NodeCodec<H>> Trie<H, C> for TrieKinds<'db, H, C> {
}
impl<'db, H, C> TrieFactory<H, C>
where
H: Hasher,
where
H: Hasher,
C: NodeCodec<H> + 'db
{
/// Creates new factory.

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@ -31,6 +31,8 @@ use std::collections::{HashSet, VecDeque};
use std::marker::PhantomData;
use std::mem;
use std::ops::Index;
use heapsize::HeapSizeOf;
use std::{fmt::Debug, hash::Hash};
// For lookups into the Node storage buffer.
// This is deliberately non-copyable.
@ -39,20 +41,20 @@ struct StorageHandle(usize);
// Handles to nodes in the trie.
#[derive(Debug)]
enum NodeHandle<H: Hasher> {
enum NodeHandle<H> {
/// Loaded into memory.
InMemory(StorageHandle),
/// Either a hash or an inline node
Hash(H::Out),
Hash(H),
}
impl<H: Hasher> From<StorageHandle> for NodeHandle<H> {
impl<H> From<StorageHandle> for NodeHandle<H> {
fn from(handle: StorageHandle) -> Self {
NodeHandle::InMemory(handle)
}
}
fn empty_children<H: Hasher>() -> Box<[Option<NodeHandle<H>>; 16]> {
fn empty_children<H>() -> Box<[Option<NodeHandle<H>>; 16]> {
Box::new([
None, None, None, None, None, None, None, None,
None, None, None, None, None, None, None, None,
@ -61,7 +63,7 @@ fn empty_children<H: Hasher>() -> Box<[Option<NodeHandle<H>>; 16]> {
/// Node types in the Trie.
#[derive(Debug)]
enum Node<H: Hasher> {
enum Node<H> {
/// Empty node.
Empty,
/// A leaf node contains the end of a key and a value.
@ -77,22 +79,24 @@ enum Node<H: Hasher> {
Branch(Box<[Option<NodeHandle<H>>; 16]>, Option<DBValue>)
}
impl<H: Hasher> Node<H> {
impl<O> Node<O> where O: AsRef<[u8]> + AsMut<[u8]> + Default + HeapSizeOf + Debug + PartialEq + Eq + Hash + Send + Sync + Clone + Copy {
// load an inline node into memory or get the hash to do the lookup later.
fn inline_or_hash<C>(node: &[u8], db: &HashDB<H>, storage: &mut NodeStorage<H>) -> NodeHandle<H>
where C: NodeCodec<H>
fn inline_or_hash<C, H>(node: &[u8], db: &HashDB<H>, storage: &mut NodeStorage<H::Out>) -> NodeHandle<H::Out>
where C: NodeCodec<H>,
H: Hasher<Out = O>,
{
C::try_decode_hash(&node)
.map(NodeHandle::Hash)
.unwrap_or_else(|| {
let child = Node::from_encoded::<C>(node, db, storage);
let child = Node::from_encoded::<C, H>(node, db, storage);
NodeHandle::InMemory(storage.alloc(Stored::New(child)))
})
}
// decode a node from encoded bytes without getting its children.
fn from_encoded<C>(data: &[u8], db: &HashDB<H>, storage: &mut NodeStorage<H>) -> Self
where C: NodeCodec<H>
fn from_encoded<C, H>(data: &[u8], db: &HashDB<H>, storage: &mut NodeStorage<H::Out>) -> Self
where C: NodeCodec<H>,
H: Hasher<Out = O>,
{
match C::decode(data).expect("encoded bytes read from db; qed") {
EncodedNode::Empty => Node::Empty,
@ -100,13 +104,13 @@ impl<H: Hasher> Node<H> {
EncodedNode::Extension(key, cb) => {
Node::Extension(
key.encoded(false),
Self::inline_or_hash::<C>(cb, db, storage))
Self::inline_or_hash::<C, H>(cb, db, storage))
}
EncodedNode::Branch(ref encoded_children, val) => {
let mut child = |i:usize| {
let raw = encoded_children[i];
if !C::is_empty_node(raw) {
Some(Self::inline_or_hash::<C>(raw, db, storage))
Some(Self::inline_or_hash::<C, H>(raw, db, storage))
} else {
None
}
@ -125,10 +129,11 @@ impl<H: Hasher> Node<H> {
}
// TODO: parallelize
fn into_encoded<F, C>(self, mut child_cb: F) -> ElasticArray1024<u8>
fn into_encoded<F, C, H>(self, mut child_cb: F) -> ElasticArray1024<u8>
where
C: NodeCodec<H>,
F: FnMut(NodeHandle<H>) -> ChildReference<H::Out>
F: FnMut(NodeHandle<H::Out>) -> ChildReference<H::Out>,
H: Hasher<Out = O>,
{
match self {
Node::Empty => C::empty_node(),
@ -139,7 +144,7 @@ impl<H: Hasher> Node<H> {
// map the `NodeHandle`s from the Branch to `ChildReferences`
children.iter_mut()
.map(Option::take)
.map(|maybe_child|
.map(|maybe_child|
maybe_child.map(|child| child_cb(child))
),
value
@ -150,7 +155,7 @@ impl<H: Hasher> Node<H> {
}
// post-inspect action.
enum Action<H: Hasher> {
enum Action<H> {
// Replace a node with a new one.
Replace(Node<H>),
// Restore the original node. This trusts that the node is actually the original.
@ -160,14 +165,14 @@ enum Action<H: Hasher> {
}
// post-insert action. Same as action without delete
enum InsertAction<H: Hasher> {
enum InsertAction<H> {
// Replace a node with a new one.
Replace(Node<H>),
// Restore the original node.
Restore(Node<H>),
}
impl<H: Hasher> InsertAction<H> {
impl<H> InsertAction<H> {
fn into_action(self) -> Action<H> {
match self {
InsertAction::Replace(n) => Action::Replace(n),
@ -184,11 +189,11 @@ impl<H: Hasher> InsertAction<H> {
}
// What kind of node is stored here.
enum Stored<H: Hasher> {
enum Stored<H> {
// A new node.
New(Node<H>),
// A cached node, loaded from the DB.
Cached(Node<H>, H::Out),
Cached(Node<H>, H),
}
/// Used to build a collection of child nodes from a collection of `NodeHandle`s
@ -198,12 +203,12 @@ pub enum ChildReference<HO> { // `HO` is e.g. `H256`, i.e. the output of a `Hash
}
/// Compact and cache-friendly storage for Trie nodes.
struct NodeStorage<H: Hasher> {
struct NodeStorage<H> {
nodes: Vec<Stored<H>>,
free_indices: VecDeque<usize>,
}
impl<H: Hasher> NodeStorage<H> {
impl<H> NodeStorage<H> {
/// Create a new storage.
fn empty() -> Self {
NodeStorage {
@ -232,7 +237,7 @@ impl<H: Hasher> NodeStorage<H> {
}
}
impl<'a, H: Hasher> Index<&'a StorageHandle> for NodeStorage<H> {
impl<'a, H> Index<&'a StorageHandle> for NodeStorage<H> {
type Output = Node<H>;
fn index(&self, handle: &'a StorageHandle) -> &Node<H> {
@ -284,10 +289,10 @@ where
H: Hasher + 'a,
C: NodeCodec<H>
{
storage: NodeStorage<H>,
storage: NodeStorage<H::Out>,
db: &'a mut HashDB<H>,
root: &'a mut H::Out,
root_handle: NodeHandle<H>,
root_handle: NodeHandle<H::Out>,
death_row: HashSet<H::Out>,
/// The number of hash operations this trie has performed.
/// Note that none are performed until changes are committed.
@ -347,7 +352,7 @@ where
// cache a node by hash
fn cache(&mut self, hash: H::Out) -> Result<StorageHandle, H::Out, C::Error> {
let node_encoded = self.db.get(&hash).ok_or_else(|| Box::new(TrieError::IncompleteDatabase(hash)))?;
let node = Node::from_encoded::<C>(
let node = Node::from_encoded::<C, H>(
&node_encoded,
&*self.db,
&mut self.storage
@ -357,8 +362,8 @@ where
// inspect a node, choosing either to replace, restore, or delete it.
// if restored or replaced, returns the new node along with a flag of whether it was changed.
fn inspect<F>(&mut self, stored: Stored<H>, inspector: F) -> Result<Option<(Stored<H>, bool)>, H::Out, C::Error>
where F: FnOnce(&mut Self, Node<H>) -> Result<Action<H>, H::Out, C::Error> {
fn inspect<F>(&mut self, stored: Stored<H::Out>, inspector: F) -> Result<Option<(Stored<H::Out>, bool)>, H::Out, C::Error>
where F: FnOnce(&mut Self, Node<H::Out>) -> Result<Action<H::Out>, H::Out, C::Error> {
Ok(match stored {
Stored::New(node) => match inspector(self, node)? {
Action::Restore(node) => Some((Stored::New(node), false)),
@ -380,7 +385,7 @@ where
}
// walk the trie, attempting to find the key's node.
fn lookup<'x, 'key>(&'x self, mut partial: NibbleSlice<'key>, handle: &NodeHandle<H>) -> Result<Option<DBValue>, H::Out, C::Error>
fn lookup<'x, 'key>(&'x self, mut partial: NibbleSlice<'key>, handle: &NodeHandle<H::Out>) -> Result<Option<DBValue>, H::Out, C::Error>
where 'x: 'key
{
let mut handle = handle;
@ -429,7 +434,7 @@ where
}
/// insert a key-value pair into the trie, creating new nodes if necessary.
fn insert_at(&mut self, handle: NodeHandle<H>, partial: NibbleSlice, value: DBValue, old_val: &mut Option<DBValue>) -> Result<(StorageHandle, bool), H::Out, C::Error> {
fn insert_at(&mut self, handle: NodeHandle<H::Out>, partial: NibbleSlice, value: DBValue, old_val: &mut Option<DBValue>) -> Result<(StorageHandle, bool), H::Out, C::Error> {
let h = match handle {
NodeHandle::InMemory(h) => h,
NodeHandle::Hash(h) => self.cache(h)?,
@ -443,7 +448,7 @@ where
}
/// the insertion inspector.
fn insert_inspector(&mut self, node: Node<H>, partial: NibbleSlice, value: DBValue, old_val: &mut Option<DBValue>) -> Result<InsertAction<H>, H::Out, C::Error> {
fn insert_inspector(&mut self, node: Node<H::Out>, partial: NibbleSlice, value: DBValue, old_val: &mut Option<DBValue>) -> Result<InsertAction<H::Out>, H::Out, C::Error> {
trace!(target: "trie", "augmented (partial: {:?}, value: {:?})", partial, value.pretty());
Ok(match node {
@ -604,7 +609,7 @@ where
}
/// Remove a node from the trie based on key.
fn remove_at(&mut self, handle: NodeHandle<H>, partial: NibbleSlice, old_val: &mut Option<DBValue>) -> Result<Option<(StorageHandle, bool)>, H::Out, C::Error> {
fn remove_at(&mut self, handle: NodeHandle<H::Out>, partial: NibbleSlice, old_val: &mut Option<DBValue>) -> Result<Option<(StorageHandle, bool)>, H::Out, C::Error> {
let stored = match handle {
NodeHandle::InMemory(h) => self.storage.destroy(h),
NodeHandle::Hash(h) => {
@ -619,7 +624,7 @@ where
}
/// the removal inspector
fn remove_inspector(&mut self, node: Node<H>, partial: NibbleSlice, old_val: &mut Option<DBValue>) -> Result<Action<H>, H::Out, C::Error> {
fn remove_inspector(&mut self, node: Node<H::Out>, partial: NibbleSlice, old_val: &mut Option<DBValue>) -> Result<Action<H::Out>, H::Out, C::Error> {
Ok(match (node, partial.is_empty()) {
(Node::Empty, _) => Action::Delete,
(Node::Branch(c, None), true) => Action::Restore(Node::Branch(c, None)),
@ -705,7 +710,7 @@ where
/// _invalid state_ means:
/// - Branch node where there is only a single entry;
/// - Extension node followed by anything other than a Branch node.
fn fix(&mut self, node: Node<H>) -> Result<Node<H>, H::Out, C::Error> {
fn fix(&mut self, node: Node<H::Out>) -> Result<Node<H::Out>, H::Out, C::Error> {
match node {
Node::Branch(mut children, value) => {
// if only a single value, transmute to leaf/extension and feed through fixed.
@ -825,7 +830,7 @@ where
match self.storage.destroy(handle) {
Stored::New(node) => {
let encoded_root = node.into_encoded::<_, C>(|child| self.commit_child(child) );
let encoded_root = node.into_encoded::<_, C, H>(|child| self.commit_child(child) );
*self.root = self.db.insert(&encoded_root[..]);
self.hash_count += 1;
@ -845,14 +850,14 @@ where
/// case where we can fit the actual data in the `Hasher`s output type, we
/// store the data inline. This function is used as the callback to the
/// `into_encoded` method of `Node`.
fn commit_child(&mut self, handle: NodeHandle<H>) -> ChildReference<H::Out> {
fn commit_child(&mut self, handle: NodeHandle<H::Out>) -> ChildReference<H::Out> {
match handle {
NodeHandle::Hash(hash) => ChildReference::Hash(hash),
NodeHandle::InMemory(storage_handle) => {
match self.storage.destroy(storage_handle) {
Stored::Cached(_, hash) => ChildReference::Hash(hash),
Stored::New(node) => {
let encoded = node.into_encoded::<_, C>(|node_handle| self.commit_child(node_handle) );
let encoded = node.into_encoded::<_, C, H>(|node_handle| self.commit_child(node_handle) );
if encoded.len() >= H::LENGTH {
let hash = self.db.insert(&encoded[..]);
self.hash_count +=1;
@ -871,7 +876,7 @@ where
}
// a hack to get the root node's handle
fn root_handle(&self) -> NodeHandle<H> {
fn root_handle(&self) -> NodeHandle<H::Out> {
match self.root_handle {
NodeHandle::Hash(h) => NodeHandle::Hash(h),
NodeHandle::InMemory(StorageHandle(x)) => NodeHandle::InMemory(StorageHandle(x)),
@ -880,7 +885,7 @@ where
}
impl<'a, H, C> TrieMut<H, C> for TrieDBMut<'a, H, C>
where
where
H: Hasher,
C: NodeCodec<H>
{