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Trie documentation and code consolidation.

This commit is contained in:
Gav Wood 2015-12-07 15:00:54 +01:00
parent 38f0af1aa0
commit fcae9034ac
1 changed files with 265 additions and 186 deletions
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451
src/trie.rs
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@ -15,17 +15,30 @@ use std::collections::HashMap;
pub const NULL_RLP: [u8; 1] = [0x80; 1];
pub const SHA3_NULL_RLP: H256 = H256( [0x56, 0xe8, 0x1f, 0x17, 0x1b, 0xcc, 0x55, 0xa6, 0xff, 0x83, 0x45, 0xe6, 0x92, 0xc0, 0xf8, 0x6e, 0x5b, 0x48, 0xe0, 0x1b, 0x99, 0x6c, 0xad, 0xc0, 0x01, 0x62, 0x2f, 0xb5, 0xe3, 0x63, 0xb4, 0x21] );
/// A key-value datastore implemented as a database-backed modified Merkle tree.
pub trait Trie {
/// Return the root of the trie.
fn root(&self) -> &H256;
/// Is the trie empty?
fn is_empty(&self) -> bool { *self.root() == SHA3_NULL_RLP }
// TODO: consider returning &[u8]...
/// Does the trie contain a given key?
fn contains(&self, key: &[u8]) -> bool;
/// What is the value of the given key in this trie?
fn at<'a, 'key>(&'a self, key: &'key [u8]) -> Option<&'a [u8]> where 'a: 'key;
/// Insert a `key`/`value` pair into the trie. An `empty` value is equivalent to removing
/// `key` from the trie.
fn insert(&mut self, key: &[u8], value: &[u8]);
/// Remove a `key` from the trie. Equivalent to making it equal to the empty
/// value.
fn remove(&mut self, key: &[u8]);
}
/// Alphabet to use when creating words for insertion into tries.
pub enum Alphabet {
All,
Low,
@ -33,21 +46,25 @@ pub enum Alphabet {
Custom(Bytes),
}
/// Standard test map for profiling tries.
pub struct StandardMap {
alphabet: Alphabet,
min_key: usize,
diff_key: usize,
journal_key: usize,
count: usize,
}
impl StandardMap {
fn random_bytes(min_count: usize, diff_count: usize, seed: &mut H256) -> Vec<u8> {
assert!(min_count + diff_count <= 32);
/// Get a bunch of random bytes, at least `min_count` bytes, at most `min_count` + `journal_count` bytes.
/// `seed` is mutated pseudoramdonly and used.
fn random_bytes(min_count: usize, journal_count: usize, seed: &mut H256) -> Vec<u8> {
assert!(min_count + journal_count <= 32);
*seed = seed.sha3();
let r = min_count + (seed.bytes()[31] as usize % (diff_count + 1));
let r = min_count + (seed.bytes()[31] as usize % (journal_count + 1));
seed.bytes()[0..r].to_vec()
}
/// Get a random value. Equal chance of being 1 byte as of 32. `seed` is mutated pseudoramdonly and used.
fn random_value(seed: &mut H256) -> Bytes {
*seed = seed.sha3();
match seed.bytes()[0] % 2 {
@ -56,10 +73,12 @@ impl StandardMap {
}
}
fn random_word(alphabet: &[u8], min_count: usize, diff_count: usize, seed: &mut H256) -> Vec<u8> {
assert!(min_count + diff_count <= 32);
/// Get a random word of, at least `min_count` bytes, at most `min_count` + `journal_count` bytes.
/// Each byte is an item from `alphabet`. `seed` is mutated pseudoramdonly and used.
fn random_word(alphabet: &[u8], min_count: usize, journal_count: usize, seed: &mut H256) -> Vec<u8> {
assert!(min_count + journal_count <= 32);
*seed = seed.sha3();
let r = min_count + (seed.bytes()[31] as usize % (diff_count + 1));
let r = min_count + (seed.bytes()[31] as usize % (journal_count + 1));
let mut ret: Vec<u8> = Vec::with_capacity(r);
for i in 0..r {
ret.push(alphabet[seed.bytes()[i] as usize % alphabet.len()]);
@ -67,6 +86,7 @@ impl StandardMap {
ret
}
/// Create the standard map (set of keys and values) for the object's fields.
pub fn make(&self) -> Vec<(Bytes, Bytes)> {
let low = b"abcdef";
let mid = b"@QWERTYUIOPASDFGHJKLZXCVBNM[/]^_";
@ -75,10 +95,10 @@ impl StandardMap {
let mut seed = H256::new();
for _ in 0..self.count {
let k = match self.alphabet {
Alphabet::All => Self::random_bytes(self.min_key, self.diff_key, &mut seed),
Alphabet::Low => Self::random_word(low, self.min_key, self.diff_key, &mut seed),
Alphabet::Mid => Self::random_word(mid, self.min_key, self.diff_key, &mut seed),
Alphabet::Custom(ref a) => Self::random_word(&a, self.min_key, self.diff_key, &mut seed),
Alphabet::All => Self::random_bytes(self.min_key, self.journal_key, &mut seed),
Alphabet::Low => Self::random_word(low, self.min_key, self.journal_key, &mut seed),
Alphabet::Mid => Self::random_word(mid, self.min_key, self.journal_key, &mut seed),
Alphabet::Custom(ref a) => Self::random_word(&a, self.min_key, self.journal_key, &mut seed),
};
let v = Self::random_value(&mut seed);
d.push((k, v))
@ -87,6 +107,7 @@ impl StandardMap {
}
}
/// Type of node in the trie and essential information thereof.
#[derive(Eq, PartialEq, Debug)]
pub enum Node<'a> {
Empty,
@ -95,19 +116,22 @@ pub enum Node<'a> {
Branch([&'a[u8]; 16], Option<&'a [u8]>)
}
/// Type of operation for the backing database - either a new node or a node deletion.
#[derive(Debug)]
enum Operation {
New(H256, Bytes),
Delete(H256),
}
/// A journal of operations on the backing database.
#[derive(Debug)]
struct Diff (Vec<Operation>);
struct Journal (Vec<Operation>);
impl Diff {
fn new() -> Diff { Diff(vec![]) }
impl Journal {
/// Create a new, empty, object.
fn new() -> Journal { Journal(vec![]) }
/// Given the RLP that encodes a node, append a reference to that node `out` and leave `diff`
/// Given the RLP that encodes a node, append a reference to that node `out` and leave `journal`
/// such that the reference is valid, once applied.
fn new_node(&mut self, rlp: Bytes, out: &mut RlpStream) {
if rlp.len() >= 32 {
@ -123,24 +147,23 @@ impl Diff {
}
}
/// Given the RLP that encodes a now-unused node, leave `diff` in such a state that it is noted.
/// Given the RLP that encodes a now-unused node, leave `journal` in such a state that it is noted.
fn delete_node_sha3(&mut self, old_sha3: H256) {
trace!("delete_node: {:?}", old_sha3);
self.0.push(Operation::Delete(old_sha3));
}
fn delete_node(&mut self, old: &Rlp) {
if old.is_data() && old.size() == 32 {
self.delete_node_sha3(H256::decode(old));
/// Register an RLP-encoded node for deletion (given a slice), if it needs to be deleted.
fn delete_node(&mut self, old: &[u8]) {
let r = Rlp::new(old);
if r.is_data() && r.size() == 32 {
self.delete_node_sha3(H256::decode(&r));
}
}
fn delete_node_from_slice(&mut self, old: &[u8]) {
self.delete_node(&Rlp::new(old));
}
}
impl <'a>Node<'a> {
/// Decode the `node_rlp` and return the Node.
fn decoded(node_rlp: &'a [u8]) -> Node<'a> {
let r = Rlp::new(node_rlp);
match r.prototype() {
@ -168,7 +191,10 @@ impl <'a>Node<'a> {
}
}
// todo: should check length before encoding, cause it may just be sha3 of data
/// Encode the node into RLP.
///
/// Will always return the direct node RLP even if it's 32 or more bytes. To get the
/// RLP which would be valid for using in another node, use `encoded_and_added()`.
fn encoded(&self) -> Bytes {
match *self {
Node::Leaf(ref slice, ref value) => {
@ -202,7 +228,9 @@ impl <'a>Node<'a> {
}
}
fn encoded_and_added(&self, diff: &mut Diff) -> Bytes {
/// Encode the node, adding it to `journal` if necessary and return the RLP valid for
/// insertion into a parent node.
fn encoded_and_added(&self, journal: &mut Journal) -> Bytes {
let mut stream = RlpStream::new();
match *self {
Node::Leaf(ref slice, ref value) => {
@ -234,47 +262,96 @@ impl <'a>Node<'a> {
0 ... 31 => node,
_ => {
let mut stream = RlpStream::new();
diff.new_node(node, &mut stream);
journal.new_node(node, &mut stream);
stream.out()
}
}
}
}
//enum ValidationResult<'a> {
//Valid,
//Invalid { node: Node<'a>, depth: usize }
//}
/// A `Trie` implementation using a generic `HashDB` backing database.
///
/// Use it as a `Trie` trait object. You can use `db()` to get the backing database object, `keys`
/// to get the keys belonging to the trie in the backing database, and `db_items_remaining()` to get
/// which items in the backing database do not belong to this trie. If this is the only trie in the
/// backing database, then `db_items_remaining()` should be empty.
///
/// # Example
/// ```
/// extern crate ethcore_util;
/// use ethcore_util::trie::*;
/// fn main() {
/// let mut t = TrieDB::new_memory();
/// assert!(t.is_empty());
/// assert_eq!(*t.root(), SHA3_NULL_RLP);
/// t.insert(b"foo", b"bar");
/// assert!(t.contains(b"foo"));
/// assert_eq!(t.at(b"foo").unwrap(), b"bar");
/// assert!(t.db_items_remaining().is_empty());
/// t.remove(b"foo");
/// assert!(!t.contains(b"foo"));
/// assert!(t.db_items_remaining().is_empty());
/// }
/// ```
pub struct TrieDB {
db: Box<HashDB>,
root: H256,
pub hash_count: usize,
}
impl fmt::Debug for TrieDB {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
try!(writeln!(f, "c={:?} [", self.hash_count));
let root_rlp = self.db.lookup(&self.root).expect("Trie root not found!");
try!(self.fmt_all(Node::decoded(root_rlp), f, 0));
writeln!(f, "]")
}
}
/// Option-like type allowing either a Node object passthrough or Bytes in the case of data alteration.
enum MaybeChanged<'a> {
Same(Node<'a>),
Changed(Bytes),
}
impl TrieDB {
/// Create a new trie with the boxed backing database `box_db`.
pub fn new_boxed(db_box: Box<HashDB>) -> Self { let mut r = TrieDB{ db: db_box, root: H256::new(), hash_count: 0 }; r.root = r.db.insert(&NULL_RLP); r }
/// Convenience function to create a new trie with the backing database `db`.
pub fn new<T>(db: T) -> Self where T: HashDB + 'static { Self::new_boxed(Box::new(db)) }
/// Convenience function to create a new trie with a new `MemoryDB` based backing database.
pub fn new_memory() -> Self { Self::new(MemoryDB::new()) }
/// Get the backing database.
pub fn db(&self) -> &HashDB { self.db.as_ref() }
/// Determine all the keys in the backing database that belong to the trie.
pub fn keys(&self) -> Vec<H256> {
let mut ret: Vec<H256> = Vec::new();
ret.push(self.root.clone());
self.accumulate_keys(self.root_node(), &mut ret);
ret
}
/// Convert a vector of hashes to a hashmap of hash to occurances.
pub fn to_map(hashes: Vec<H256>) -> HashMap<H256, u32> {
let mut r: HashMap<H256, u32> = HashMap::new();
for h in hashes.into_iter() {
let c = *r.get(&h).unwrap_or(&0);
r.insert(h, c + 1);
}
r
}
/// Determine occurances of items in the backing database which are not related to this
/// trie.
pub fn db_items_remaining(&self) -> HashMap<H256, i32> {
let mut ret = self.db().keys();
for (k, v) in Self::to_map(self.keys()).into_iter() {
let keycount = *ret.get(&k).unwrap_or(&0);
match keycount == v as i32 {
true => ret.remove(&k),
_ => ret.insert(k, keycount - v as i32),
};
}
ret
}
/// Set the trie to a new root node's RLP, inserting the new RLP into the backing database
/// and removing the old.
fn set_root_rlp(&mut self, root_data: &[u8]) {
self.db.kill(&self.root);
self.root = self.db.insert(root_data);
@ -282,9 +359,10 @@ impl TrieDB {
trace!("set_root_rlp {:?} {:?}", root_data.pretty(), self.root);
}
fn apply(&mut self, diff: Diff) {
trace!("applying {:?} changes", diff.0.len());
for d in diff.0.into_iter() {
/// Apply the items in `journal` into the backing database.
fn apply(&mut self, journal: Journal) {
trace!("applying {:?} changes", journal.0.len());
for d in journal.0.into_iter() {
match d {
Operation::Delete(h) => {
trace!("TrieDB::apply --- {:?}", &h);
@ -299,13 +377,7 @@ impl TrieDB {
}
}
pub fn keys(&self) -> Vec<H256> {
let mut ret: Vec<H256> = Vec::new();
ret.push(self.root.clone());
self.accumulate_keys(self.root_node(), &mut ret);
ret
}
/// Recursion helper for `keys`.
fn accumulate_keys(&self, node: Node, acc: &mut Vec<H256>) {
let mut handle_payload = |payload| {
let p = Rlp::new(payload);
@ -323,27 +395,17 @@ impl TrieDB {
}
}
fn to_map(hashes: Vec<H256>) -> HashMap<H256, u32> {
let mut r: HashMap<H256, u32> = HashMap::new();
for h in hashes.into_iter() {
let c = *r.get(&h).unwrap_or(&0);
r.insert(h, c + 1);
}
r
/// Get the root node's RLP.
fn root_node(&self) -> Node {
Node::decoded(self.db.lookup(&self.root).expect("Trie root not found!"))
}
pub fn db_items_remaining(&self) -> HashMap<H256, i32> {
let mut ret = self.db().keys();
for (k, v) in Self::to_map(self.keys()).into_iter() {
let keycount = *ret.get(&k).unwrap_or(&0);
match keycount == v as i32 {
true => ret.remove(&k),
_ => ret.insert(k, keycount - v as i32),
};
}
ret
/// Get the root node as a `Node`.
fn get_node<'a>(&'a self, node: &'a [u8]) -> Node {
Node::decoded(self.get_raw_or_lookup(node))
}
/// Indentation helper for `formal_all`.
fn fmt_indent(&self, f: &mut fmt::Formatter, size: usize) -> fmt::Result {
for _ in 0..size {
try!(write!(f, " "));
@ -351,14 +413,7 @@ impl TrieDB {
Ok(())
}
fn root_node(&self) -> Node {
Node::decoded(self.db.lookup(&self.root).expect("Trie root not found!"))
}
fn get_node<'a>(&'a self, node: &'a [u8]) -> Node {
Node::decoded(self.get_raw_or_lookup(node))
}
/// Recursion helper for implementation of formatting trait.
fn fmt_all(&self, node: Node, f: &mut fmt::Formatter, deepness: usize) -> fmt::Result {
match node {
Node::Leaf(slice, value) => try!(writeln!(f, "'{:?}: {:?}.", slice, value.pretty())),
@ -394,11 +449,16 @@ impl TrieDB {
Ok(())
}
/// Return optional data for a key given as a `NibbleSlice`. Returns `None` if no data exists.
fn get<'a, 'key>(&'a self, key: &NibbleSlice<'key>) -> Option<&'a [u8]> where 'a: 'key {
let root_rlp = self.db.lookup(&self.root).expect("Trie root not found!");
self.get_from_node(&root_rlp, key)
}
/// Recursible function to retrieve the value given a `node` and a partial `key`. `None` if no
/// value exists for the key.
///
/// Note: Not a public API; use Trie trait functions.
fn get_from_node<'a, 'key>(&'a self, node: &'a [u8], key: &NibbleSlice<'key>) -> Option<&'a [u8]> where 'a: 'key {
match Node::decoded(node) {
Node::Leaf(ref slice, ref value) if key == slice => Some(value),
@ -413,6 +473,9 @@ impl TrieDB {
}
}
/// Given some node-describing data `node`, return the actual node RLP.
/// This could be a simple identity operation in the case that the node is sufficiently small, but
/// may require a database lookup.
fn get_raw_or_lookup<'a>(&'a self, node: &'a [u8]) -> &'a [u8] {
// check if its sha3 + len
let r = Rlp::new(node);
@ -422,20 +485,26 @@ impl TrieDB {
}
}
fn add(&mut self, key: &NibbleSlice, value: &[u8]) {
/// Insert a `key` and `value` pair into the trie.
///
/// Note: Not a public API; use Trie trait functions.
fn insert_ns(&mut self, key: &NibbleSlice, value: &[u8]) {
trace!("ADD: {:?} {:?}", key, value.pretty());
// determine what the new root is, insert new nodes and remove old as necessary.
let mut todo: Diff = Diff::new();
let mut todo: Journal = Journal::new();
let root_rlp = self.augmented(self.db.lookup(&self.root).expect("Trie root not found!"), key, value, &mut todo);
self.apply(todo);
self.set_root_rlp(&root_rlp);
trace!("/");
}
fn delete(&mut self, key: &NibbleSlice) {
/// Remove a `key` and `value` pair from the trie.
///
/// Note: Not a public API; use Trie trait functions.
fn remove_ns(&mut self, key: &NibbleSlice) {
trace!("DELETE: {:?}", key);
// determine what the new root is, insert new nodes and remove old as necessary.
let mut todo: Diff = Diff::new();
let mut todo: Journal = Journal::new();
match self.cleared_from_slice(self.db.lookup(&self.root).expect("Trie root not found!"), key, &mut todo) {
Some(root_rlp) => {
self.apply(todo);
@ -448,6 +517,7 @@ impl TrieDB {
trace!("/");
}
/// Compose a leaf node in RLP given the `partial` key and `value`.
fn compose_leaf(partial: &NibbleSlice, value: &[u8]) -> Bytes {
trace!("compose_leaf {:?} {:?} ({:?})", partial, value.pretty(), partial.encoded(true).pretty());
let mut s = RlpStream::new_list(2);
@ -458,6 +528,7 @@ impl TrieDB {
r
}
/// Compose a raw extension/leaf node in RLP given the `partial` key, `raw_payload` and whether it `is_leaf`.
fn compose_raw(partial: &NibbleSlice, raw_payload: &[u8], is_leaf: bool) -> Bytes {
trace!("compose_raw {:?} {:?} {:?} ({:?})", partial, raw_payload.pretty(), is_leaf, partial.encoded(is_leaf));
let mut s = RlpStream::new_list(2);
@ -468,6 +539,7 @@ impl TrieDB {
r
}
/// Compose a branch node in RLP with a particular `value` sitting in the value position (17th place).
fn compose_stub_branch(value: &[u8]) -> Bytes {
let mut s = RlpStream::new_list(17);
for _ in 0..16 { s.append_empty_data(); }
@ -475,21 +547,14 @@ impl TrieDB {
s.out()
}
/// Compose an extension node's RLP with the `partial` key and `raw_payload`.
fn compose_extension(partial: &NibbleSlice, raw_payload: &[u8]) -> Bytes {
Self::compose_raw(partial, raw_payload, false)
}
fn create_extension(partial: &NibbleSlice, downstream_node: Bytes, diff: &mut Diff) -> Bytes {
trace!("create_extension partial: {:?}, downstream_node: {:?}", partial, downstream_node.pretty());
let mut s = RlpStream::new_list(2);
s.append(&partial.encoded(false));
diff.new_node(downstream_node, &mut s);
s.out()
}
/// Return the bytes encoding the node represented by `rlp`. It will be unlinked from
/// the trie.
fn take_node<'a, 'rlp_view>(&'a self, rlp: &'rlp_view Rlp<'a>, diff: &mut Diff) -> &'a [u8] where 'a: 'rlp_view {
/// Return the bytes encoding the node represented by `rlp`. `journal` will record necessary
/// removal instructions from the backing database.
fn take_node<'a, 'rlp_view>(&'a self, rlp: &'rlp_view Rlp<'a>, journal: &mut Journal) -> &'a [u8] where 'a: 'rlp_view {
if rlp.is_list() {
trace!("take_node {:?} (inline)", rlp.raw().pretty());
rlp.raw()
@ -498,11 +563,11 @@ impl TrieDB {
let h = H256::decode(rlp);
let r = self.db.lookup(&h).unwrap_or_else(||{
println!("Node not found! rlp={:?}, node_hash={:?}", rlp.raw().pretty(), h);
println!("Diff: {:?}", diff);
println!("Journal: {:?}", journal);
panic!();
});
trace!("take_node {:?} (indirect for {:?})", rlp.raw().pretty(), r);
diff.delete_node_sha3(h);
journal.delete_node_sha3(h);
r
}
else {
@ -511,61 +576,15 @@ impl TrieDB {
}
}
fn augmented_into_transmuted_branch(&self, orig_is_leaf: bool, orig_partial: &NibbleSlice, orig_raw_payload: &[u8], partial: &NibbleSlice, value: &[u8], diff: &mut Diff) -> Bytes {
assert!(orig_is_leaf || !orig_partial.is_empty()); // extension nodes are not allowed to have empty partial keys.
let mut s = RlpStream::new_list(17);
let index = if orig_partial.is_empty() {16} else {orig_partial.at(0)};
for i in 0..17 {
match orig_is_leaf {
// not us - empty.
_ if index != i => { s.append_empty_data(); },
// just replace.
true if i == 16 => { s.append(&value); },
// original has empty slot.
true => diff.new_node(Self::compose_leaf(&orig_partial.mid(1), Rlp::new(orig_raw_payload).data()), &mut s),
//
false if orig_partial.len() > 1 => diff.new_node(Self::compose_extension(&orig_partial.mid(1), orig_raw_payload), &mut s),
false => { s.append_raw(orig_raw_payload, 1); },
}
};
self.augmented(&s.out(), partial, value, diff)
// TODO: implement without having to make an intermediate representation.
}
/// Given a branch node's RLP `orig` together with a `partial` key and `value`, return the
/// RLP-encoded node that accomodates the trie with the new entry. Mutate `diff` so that
/// once applied the returned node is valid.
fn augmented_into_branch(&self, orig: &Rlp, partial: &NibbleSlice, value: &[u8], diff: &mut Diff) -> Bytes {
trace!("augmented_into_branch");
let mut s = RlpStream::new_list(17);
let index = if partial.is_empty() {16} else {partial.at(0) as usize};
for i in 0..17 {
match index == i {
// not us - leave alone.
false => { s.append_raw(orig.at(i).raw(), 1); },
// branch-leaf entry - just replace.
true if i == 16 => { s.append(&value); },
// original had empty slot - place a leaf there.
true if orig.at(i).is_empty() => diff.new_node(Self::compose_leaf(&partial.mid(1), value), &mut s),
// original has something there already; augment.
true => {
let new = self.augmented(self.take_node(&orig.at(i), diff), &partial.mid(1), value, diff);
diff.new_node(new, &mut s);
}
}
}
s.out()
}
/// Determine the RLP of the node, assuming we're inserting `partial` into the
/// node currently of data `old`. This will *not* delete any hash of `old` from the database;
/// it will just return the new RLP that includes the new node.
///
/// The database will be updated so as to make the returned RLP valid through inserting
/// `journal` will record the database updates so as to make the returned RLP valid through inserting
/// and deleting nodes as necessary.
///
/// **This operation will not insert the new node nor destroy the original.**
fn augmented(&self, old: &[u8], partial: &NibbleSlice, value: &[u8], diff: &mut Diff) -> Bytes {
fn augmented(&self, old: &[u8], partial: &NibbleSlice, value: &[u8], journal: &mut Journal) -> Bytes {
trace!("augmented (old: {:?}, partial: {:?}, value: {:?})", old.pretty(), partial, value.pretty());
// already have an extension. either fast_forward, cleve or transmute_to_branch.
let old_rlp = Rlp::new(old);
@ -573,7 +592,24 @@ impl TrieDB {
Prototype::List(17) => {
trace!("branch: ROUTE,AUGMENT");
// already have a branch. route and augment.
self.augmented_into_branch(&old_rlp, partial, value, diff)
let mut s = RlpStream::new_list(17);
let index = if partial.is_empty() {16} else {partial.at(0) as usize};
for i in 0..17 {
match index == i {
// not us - leave alone.
false => { s.append_raw(old_rlp.at(i).raw(), 1); },
// branch-leaf entry - just replace.
true if i == 16 => { s.append(&value); },
// original had empty slot - place a leaf there.
true if old_rlp.at(i).is_empty() => journal.new_node(Self::compose_leaf(&partial.mid(1), value), &mut s),
// original has something there already; augment.
true => {
let new = self.augmented(self.take_node(&old_rlp.at(i), journal), &partial.mid(1), value, journal);
journal.new_node(new, &mut s);
}
}
}
s.out()
},
Prototype::List(2) => {
let existing_key_rlp = old_rlp.at(0);
@ -587,7 +623,24 @@ impl TrieDB {
(_, 0) => {
// one of us isn't empty: transmute to branch here
trace!("no-common-prefix, not-both-empty (exist={:?}; new={:?}): TRANSMUTE,AUGMENT", existing_key.len(), partial.len());
self.augmented_into_transmuted_branch(is_leaf, &existing_key, old_rlp.at(1).raw(), partial, value, diff)
assert!(is_leaf || !existing_key.is_empty()); // extension nodes are not allowed to have empty partial keys.
let mut s = RlpStream::new_list(17);
let index = if existing_key.is_empty() {16} else {existing_key.at(0)};
for i in 0..17 {
match is_leaf {
// not us - empty.
_ if index != i => { s.append_empty_data(); },
// branch-value: just replace.
true if i == 16 => { s.append_raw(old_rlp.at(1).raw(), 1); },
// direct extension: just replace.
false if existing_key.len() == 1 => { s.append_raw(old_rlp.at(1).raw(), 1); },
// original has empty slot.
true => journal.new_node(Self::compose_leaf(&existing_key.mid(1), old_rlp.at(1).data()), &mut s),
// additional work required after branching.
false => journal.new_node(Self::compose_extension(&existing_key.mid(1), old_rlp.at(1).raw()), &mut s),
}
};
self.augmented(&s.out(), partial, value, journal)
},
(_, cp) if cp == existing_key.len() => {
trace!("complete-prefix (cp={:?}): AUGMENT-AT-END", cp);
@ -595,10 +648,15 @@ impl TrieDB {
// transform to an extension + augmented version of onward node.
let downstream_node: Bytes = match is_leaf {
// no onward node because we're a leaf - create fake stub and use that.
true => self.augmented(&Self::compose_stub_branch(old_rlp.at(1).data()), &partial.mid(cp), value, diff),
false => self.augmented(self.take_node(&old_rlp.at(1), diff), &partial.mid(cp), value, diff),
true => self.augmented(&Self::compose_stub_branch(old_rlp.at(1).data()), &partial.mid(cp), value, journal),
false => self.augmented(self.take_node(&old_rlp.at(1), journal), &partial.mid(cp), value, journal),
};
Self::create_extension(&existing_key, downstream_node, diff)
trace!("create_extension partial: {:?}, downstream_node: {:?}", existing_key, downstream_node.pretty());
let mut s = RlpStream::new_list(2);
s.append(&existing_key.encoded(false));
journal.new_node(downstream_node, &mut s);
s.out()
},
(_, cp) => {
// partially-shared prefix for this extension:
@ -612,12 +670,12 @@ impl TrieDB {
// low (farther from root)
let low = Self::compose_raw(&existing_key.mid(cp), old_rlp.at(1).raw(), is_leaf);
let augmented_low = self.augmented(&low, &partial.mid(cp), value, diff);
let augmented_low = self.augmented(&low, &partial.mid(cp), value, journal);
// high (closer to root)
let mut s = RlpStream::new_list(2);
s.append(&existing_key.encoded_leftmost(cp, false));
diff.new_node(augmented_low, &mut s);
journal.new_node(augmented_low, &mut s);
s.out()
},
}
@ -630,6 +688,7 @@ impl TrieDB {
}
}
/// Given a `MaybeChanged` result `n`, return the node's RLP regardless of whether it changed.
fn encoded(n: MaybeChanged) -> Bytes {
match n {
MaybeChanged::Same(n) => n.encoded(),
@ -637,18 +696,20 @@ impl TrieDB {
}
}
fn fixed_indirection<'a>(n: Node<'a>, diff: &mut Diff) -> MaybeChanged<'a> {
/// Fix the node payload's sizes in `n`, replacing any over-size payloads with the hashed reference
/// and placing the payload DB insertions in the `journal`.
fn fixed_indirection<'a>(n: Node<'a>, journal: &mut Journal) -> MaybeChanged<'a> {
match n {
Node::Extension(partial, payload) if payload.len() >= 32 && Rlp::new(payload).is_list() => {
// make indirect
MaybeChanged::Changed(Node::Extension(partial, &Node::decoded(payload).encoded_and_added(diff)).encoded())
MaybeChanged::Changed(Node::Extension(partial, &Node::decoded(payload).encoded_and_added(journal)).encoded())
},
Node::Branch(payloads, value) => {
// check each child isn't too big
// TODO OPTIMISE - should really check at the point of (re-)constructing the branch.
for i in 0..16 {
if payloads[i].len() >= 32 && Rlp::new(payloads[i]).is_list() {
let n = Node::decoded(payloads[i]).encoded_and_added(diff);
let n = Node::decoded(payloads[i]).encoded_and_added(journal);
let mut new_nodes = payloads;
new_nodes[i] = &n;
return MaybeChanged::Changed(Node::Branch(new_nodes, value).encoded())
@ -668,8 +729,11 @@ impl TrieDB {
/// - Extension node followed by anything other than a Branch node.
/// - Extension node with a child which has too many bytes to be inline.
///
/// `journal` will record the database updates so as to make the returned RLP valid through inserting
/// and deleting nodes as necessary.
///
/// **This operation will not insert the new node nor destroy the original.**
fn fixed<'a, 'b>(&'a self, n: Node<'b>, diff: &mut Diff) -> MaybeChanged<'b> where 'a: 'b {
fn fixed<'a, 'b>(&'a self, n: Node<'b>, journal: &mut Journal) -> MaybeChanged<'b> where 'a: 'b {
trace!("fixed node={:?}", n);
match n {
Node::Branch(nodes, node_value) => {
@ -681,9 +745,6 @@ impl TrieDB {
Many,
};
let mut used_index = UsedIndex::None;
// 0-15 -> index of a non-null branch
// 16 -> no non-null branch
// 17 -> multiple non-null branches
for i in 0..16 {
match (nodes[i] == NULL_RLP, &used_index) {
(false, &UsedIndex::None) => used_index = UsedIndex::One(i as u8),
@ -699,17 +760,17 @@ impl TrieDB {
// TODO: OPTIMISE: - don't call fixed again but put the right node in straight away here.
// call fixed again since the transmute may cause invalidity.
let new_partial: [u8; 1] = [a; 1];
MaybeChanged::Changed(Self::encoded(self.fixed(Node::Extension(NibbleSlice::new_offset(&new_partial[..], 1), nodes[a as usize]), diff)))
MaybeChanged::Changed(Self::encoded(self.fixed(Node::Extension(NibbleSlice::new_offset(&new_partial[..], 1), nodes[a as usize]), journal)))
},
(UsedIndex::None, Some(value)) => { // one leaf value
// transmute to leaf.
// call fixed again since the transmute may cause invalidity.
MaybeChanged::Changed(Self::encoded(self.fixed(Node::Leaf(NibbleSlice::new(&b""[..]), value), diff)))
MaybeChanged::Changed(Self::encoded(self.fixed(Node::Leaf(NibbleSlice::new(&b""[..]), value), journal)))
}
_ => { // onwards node(s) and/or leaf
// no transmute needed, but should still fix the indirection.
trace!("no-transmute: FIXINDIRECTION");
Self::fixed_indirection(Node::Branch(nodes, node_value), diff)
Self::fixed_indirection(Node::Branch(nodes, node_value), journal)
},
}
},
@ -717,16 +778,16 @@ impl TrieDB {
match Node::decoded(self.get_raw_or_lookup(payload)) {
Node::Extension(sub_partial, sub_payload) => {
// combine with node below
diff.delete_node_from_slice(payload);
MaybeChanged::Changed(Self::encoded(Self::fixed_indirection(Node::Extension(NibbleSlice::new_composed(&partial, &sub_partial), sub_payload), diff)))
journal.delete_node(payload);
MaybeChanged::Changed(Self::encoded(Self::fixed_indirection(Node::Extension(NibbleSlice::new_composed(&partial, &sub_partial), sub_payload), journal)))
},
Node::Leaf(sub_partial, sub_value) => {
// combine with node below
diff.delete_node_from_slice(payload);
MaybeChanged::Changed(Self::encoded(Self::fixed_indirection(Node::Leaf(NibbleSlice::new_composed(&partial, &sub_partial), sub_value), diff)))
journal.delete_node(payload);
MaybeChanged::Changed(Self::encoded(Self::fixed_indirection(Node::Leaf(NibbleSlice::new_composed(&partial, &sub_partial), sub_value), journal)))
},
// no change, might still have an oversize node inline - fix indirection
_ => Self::fixed_indirection(n, diff),
_ => Self::fixed_indirection(n, journal),
}
},
// leaf or empty. no change.
@ -739,34 +800,40 @@ impl TrieDB {
/// it will just return the new RLP that represents the new node.
/// `None` may be returned should no change be needed.
///
/// The database will be updated so as to make the returned RLP valid through inserting
/// `journal` will record the database updates so as to make the returned RLP valid through inserting
/// and deleting nodes as necessary.
///
/// **This operation will not insert the new node nor destroy the original.**
fn cleared_from_slice(&self, old: &[u8], partial: &NibbleSlice, diff: &mut Diff) -> Option<Bytes> {
self.cleared(Node::decoded(old), partial, diff)
fn cleared_from_slice(&self, old: &[u8], partial: &NibbleSlice, journal: &mut Journal) -> Option<Bytes> {
self.cleared(Node::decoded(old), partial, journal)
}
fn cleared(&self, n: Node, partial: &NibbleSlice, diff: &mut Diff) -> Option<Bytes> {
/// Compose the RLP of the node equivalent to `n` except with the `partial` key removed from its (sub-)trie.
///
/// `journal` will record the database updates so as to make the returned RLP valid through inserting
/// and deleting nodes as necessary.
///
/// **This operation will not insert the new node nor destroy the original.**
fn cleared(&self, n: Node, partial: &NibbleSlice, journal: &mut Journal) -> Option<Bytes> {
trace!("cleared old={:?}, partial={:?})", n, partial);
match (n, partial.is_empty()) {
(Node::Empty, _) => None,
(Node::Branch(_, None), true) => { None },
(Node::Branch(payloads, _), true) => Some(Self::encoded(self.fixed(Node::Branch(payloads, None), diff))), // matched as leaf-branch - give back fixed branch with it.
(Node::Branch(payloads, _), true) => Some(Self::encoded(self.fixed(Node::Branch(payloads, None), journal))), // matched as leaf-branch - give back fixed branch with it.
(Node::Branch(payloads, value), false) => {
// Branch with partial left - route, clear, fix.
let i: usize = partial.at(0) as usize;
trace!("branch-with-partial node[{:?}]={:?}", i, payloads[i].pretty());
self.cleared(self.get_node(payloads[i]), &partial.mid(1), diff).map(|new_payload| {
self.cleared(self.get_node(payloads[i]), &partial.mid(1), journal).map(|new_payload| {
trace!("branch-new-payload={:?}; delete-old={:?}", new_payload.pretty(), payloads[i].pretty());
// downsteam node needed to be changed.
diff.delete_node_from_slice(payloads[i]);
journal.delete_node(payloads[i]);
// return fixed up new node.
let mut new_payloads = payloads;
new_payloads[i] = &new_payload;
Self::encoded(self.fixed(Node::Branch(new_payloads, value), diff))
Self::encoded(self.fixed(Node::Branch(new_payloads, value), journal))
})
},
(Node::Leaf(node_partial, _), _) => {
@ -785,12 +852,12 @@ impl TrieDB {
cp if cp == node_partial.len() => {
trace!("matching-prefix (cp={:?}): SKIP,CLEAR,FIXUP", cp);
// key at end of extension - skip, clear, fix
self.cleared(self.get_node(node_payload), &partial.mid(node_partial.len()), diff).map(|new_payload| {
self.cleared(self.get_node(node_payload), &partial.mid(node_partial.len()), journal).map(|new_payload| {
trace!("extension-new-payload={:?}; delete-old={:?}", new_payload.pretty(), node_payload.pretty());
// downsteam node needed to be changed.
diff.delete_node_from_slice(node_payload);
journal.delete_node(node_payload);
// return fixed up new node.
Self::encoded(self.fixed(Node::Extension(node_partial, &new_payload), diff))
Self::encoded(self.fixed(Node::Extension(node_partial, &new_payload), journal))
})
},
_ => None, // key in the middle of an extension - doesn't exist.
@ -812,11 +879,23 @@ impl Trie for TrieDB {
}
fn insert(&mut self, key: &[u8], value: &[u8]) {
self.add(&NibbleSlice::new(key), value);
match value.is_empty() {
false => self.insert_ns(&NibbleSlice::new(key), value),
true => self.remove_ns(&NibbleSlice::new(key)),
}
}
fn remove(&mut self, key: &[u8]) {
self.delete(&NibbleSlice::new(key));
self.remove_ns(&NibbleSlice::new(key));
}
}
impl fmt::Debug for TrieDB {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
try!(writeln!(f, "c={:?} [", self.hash_count));
let root_rlp = self.db.lookup(&self.root).expect("Trie root not found!");
try!(self.fmt_all(Node::decoded(root_rlp), f, 0));
writeln!(f, "]")
}
}
@ -834,9 +913,9 @@ mod tests {
use std::collections::HashSet;
use bytes::{ToPretty,Bytes};
fn random_key(alphabet: &[u8], min_count: usize, diff_count: usize) -> Vec<u8> {
fn random_key(alphabet: &[u8], min_count: usize, journal_count: usize) -> Vec<u8> {
let mut ret: Vec<u8> = Vec::new();
let r = min_count + if diff_count > 0 {random::<usize>() % diff_count} else {0};
let r = min_count + if journal_count > 0 {random::<usize>() % journal_count} else {0};
for _ in 0..r {
ret.push(alphabet[random::<usize>() % alphabet.len()]);
}
@ -885,18 +964,18 @@ mod tests {
fn playpen() {
env_logger::init().ok();
let maps = map!{
"six-low" => StandardMap{alphabet: Alphabet::Low, min_key: 6, diff_key: 0, count: 1000},
"six-mid" => StandardMap{alphabet: Alphabet::Mid, min_key: 6, diff_key: 0, count: 1000},
"six-all" => StandardMap{alphabet: Alphabet::All, min_key: 6, diff_key: 0, count: 1000},
"mix-mid" => StandardMap{alphabet: Alphabet::Mid, min_key: 1, diff_key: 5, count: 1000}
/*let maps = map!{
"six-low" => StandardMap{alphabet: Alphabet::Low, min_key: 6, journal_key: 0, count: 1000},
"six-mid" => StandardMap{alphabet: Alphabet::Mid, min_key: 6, journal_key: 0, count: 1000},
"six-all" => StandardMap{alphabet: Alphabet::All, min_key: 6, journal_key: 0, count: 1000},
"mix-mid" => StandardMap{alphabet: Alphabet::Mid, min_key: 1, journal_key: 5, count: 1000}
};
for sm in maps {
let m = sm.1.make();
let t = populate_trie(&m);
println!("{:?}: root={:?}, hash_count={:?}", sm.0, t.root(), t.hash_count);
};
panic!();
};*/
// panic!();
for test_i in 0..1 {
if test_i % 50 == 0 {
@ -1156,7 +1235,7 @@ mod tests {
#[test]
fn stress() {
for _ in 0..5000 {
for _ in 0..500 {
let mut x: Vec<(Vec<u8>, Vec<u8>)> = Vec::new();
let alphabet = b"@QWERTYUIOPASDFGHJKLZXCVBNM[/]^_";
for j in 0..4u32 {