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Fix mix-in-length issue

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This commit is contained in:
Paul Hauner 2019-04-24 18:13:37 +10:00
parent e12fa58e6e
commit 7563755b15
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GPG Key ID: D362883A9218FCC6
6 changed files with 400 additions and 330 deletions
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302
eth2/utils/tree_hash/src/cached_tree_hash.rs
View File

@ -6,8 +6,10 @@ use std::ops::Range;
pub mod btree_overlay; pub mod btree_overlay;
pub mod impls; pub mod impls;
pub mod resize; pub mod resize;
pub mod tree_hash_cache;
pub use btree_overlay::BTreeOverlay; pub use btree_overlay::BTreeOverlay;
pub use tree_hash_cache::TreeHashCache;
#[derive(Debug, PartialEq)] #[derive(Debug, PartialEq)]
pub struct CachedTreeHasher { pub struct CachedTreeHasher {
@ -79,6 +81,8 @@ pub trait CachedTreeHashSubTree<Item>: TreeHash {
depth: usize, depth: usize,
) -> Result<BTreeOverlay, Error>; ) -> Result<BTreeOverlay, Error>;
fn num_tree_hash_cache_chunks(&self) -> usize;
fn new_tree_hash_cache(&self, depth: usize) -> Result<TreeHashCache, Error>; fn new_tree_hash_cache(&self, depth: usize) -> Result<TreeHashCache, Error>;
fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error>; fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error>;
@ -158,301 +162,3 @@ fn num_unsanitized_leaves(num_bytes: usize) -> usize {
fn num_bytes(num_leaves: usize) -> usize { fn num_bytes(num_leaves: usize) -> usize {
num_leaves * HASHSIZE num_leaves * HASHSIZE
} }
#[derive(Debug, PartialEq, Clone)]
pub struct TreeHashCache {
cache: Vec<u8>,
chunk_modified: Vec<bool>,
overlays: Vec<BTreeOverlay>,
pub chunk_index: usize,
pub overlay_index: usize,
}
impl Into<Vec<u8>> for TreeHashCache {
fn into(self) -> Vec<u8> {
self.cache
}
}
impl TreeHashCache {
pub fn new<T>(item: &T, depth: usize) -> Result<Self, Error>
where
T: CachedTreeHashSubTree<T>,
{
item.new_tree_hash_cache(depth)
}
pub fn from_leaves_and_subtrees<T>(
item: &T,
leaves_and_subtrees: Vec<Self>,
depth: usize,
) -> Result<Self, Error>
where
T: CachedTreeHashSubTree<T>,
{
let overlay = BTreeOverlay::new(item, 0, depth)?;
// Note how many leaves were provided. If is not a power-of-two, we'll need to pad it out
// later.
let num_provided_leaf_nodes = leaves_and_subtrees.len();
// Allocate enough bytes to store the internal nodes and the leaves and subtrees, then fill
// all the to-be-built internal nodes with zeros and append the leaves and subtrees.
let internal_node_bytes = overlay.num_internal_nodes() * BYTES_PER_CHUNK;
let leaves_and_subtrees_bytes = leaves_and_subtrees
.iter()
.fold(0, |acc, t| acc + t.bytes_len());
let mut cache = Vec::with_capacity(leaves_and_subtrees_bytes + internal_node_bytes);
cache.resize(internal_node_bytes, 0);
// Allocate enough bytes to store all the leaves.
let mut leaves = Vec::with_capacity(overlay.num_leaf_nodes() * HASHSIZE);
let mut overlays = Vec::with_capacity(leaves_and_subtrees.len());
if T::tree_hash_type() == TreeHashType::List {
overlays.push(overlay);
}
// Iterate through all of the leaves/subtrees, adding their root as a leaf node and then
// concatenating their merkle trees.
for t in leaves_and_subtrees {
leaves.append(&mut t.root()?.to_vec());
let (mut bytes, _bools, mut t_overlays) = t.into_components();
cache.append(&mut bytes);
overlays.append(&mut t_overlays);
}
// Pad the leaves to an even power-of-two, using zeros.
pad_for_leaf_count(num_provided_leaf_nodes, &mut cache);
// Merkleize the leaves, then split the leaf nodes off them. Then, replace all-zeros
// internal nodes created earlier with the internal nodes generated by `merkleize`.
let mut merkleized = merkleize(leaves);
merkleized.split_off(internal_node_bytes);
cache.splice(0..internal_node_bytes, merkleized);
Ok(Self {
chunk_modified: vec![false; cache.len() / BYTES_PER_CHUNK],
cache,
overlays,
chunk_index: 0,
overlay_index: 0,
})
}
pub fn from_bytes(
bytes: Vec<u8>,
initial_modified_state: bool,
overlay: Option<BTreeOverlay>,
) -> Result<Self, Error> {
if bytes.len() % BYTES_PER_CHUNK > 0 {
return Err(Error::BytesAreNotEvenChunks(bytes.len()));
}
let overlays = match overlay {
Some(overlay) => vec![overlay],
None => vec![],
};
Ok(Self {
chunk_modified: vec![initial_modified_state; bytes.len() / BYTES_PER_CHUNK],
cache: bytes,
overlays,
chunk_index: 0,
overlay_index: 0,
})
}
pub fn get_overlay(
&self,
overlay_index: usize,
chunk_index: usize,
) -> Result<BTreeOverlay, Error> {
let mut overlay = self
.overlays
.get(overlay_index)
.ok_or_else(|| Error::NoOverlayForIndex(overlay_index))?
.clone();
overlay.offset = chunk_index;
Ok(overlay)
}
pub fn reset_modifications(&mut self) {
for chunk_modified in &mut self.chunk_modified {
*chunk_modified = false;
}
}
pub fn replace_overlay(
&mut self,
overlay_index: usize,
chunk_index: usize,
new_overlay: BTreeOverlay,
) -> Result<BTreeOverlay, Error> {
let old_overlay = self.get_overlay(overlay_index, chunk_index)?;
// If the merkle tree required to represent the new list is of a different size to the one
// required for the previous list, then update our cache.
//
// This grows/shrinks the bytes to accomodate the new tree, preserving as much of the tree
// as possible.
if new_overlay.num_leaf_nodes() != old_overlay.num_leaf_nodes() {
// Get slices of the exsiting tree from the cache.
let (old_bytes, old_flags) = self
.slices(old_overlay.chunk_range())
.ok_or_else(|| Error::UnableToObtainSlices)?;
let (new_bytes, new_bools) =
if new_overlay.num_leaf_nodes() > old_overlay.num_leaf_nodes() {
resize::grow_merkle_cache(
old_bytes,
old_flags,
old_overlay.height(),
new_overlay.height(),
)
.ok_or_else(|| Error::UnableToGrowMerkleTree)?
} else {
resize::shrink_merkle_cache(
old_bytes,
old_flags,
old_overlay.height(),
new_overlay.height(),
new_overlay.num_chunks(),
)
.ok_or_else(|| Error::UnableToShrinkMerkleTree)?
};
// Splice the newly created `TreeHashCache` over the existing elements.
self.splice(old_overlay.chunk_range(), new_bytes, new_bools);
}
Ok(std::mem::replace(
&mut self.overlays[overlay_index],
new_overlay,
))
}
pub fn remove_proceeding_child_overlays(&mut self, overlay_index: usize, depth: usize) {
let end = self
.overlays
.iter()
.skip(overlay_index)
.position(|o| o.depth <= depth)
.unwrap_or_else(|| self.overlays.len());
self.overlays.splice(overlay_index..end, vec![]);
}
pub fn update_internal_nodes(&mut self, overlay: &BTreeOverlay) -> Result<(), Error> {
for (parent, children) in overlay.internal_parents_and_children().into_iter().rev() {
if self.either_modified(children)? {
self.modify_chunk(parent, &self.hash_children(children)?)?;
}
}
Ok(())
}
fn bytes_len(&self) -> usize {
self.cache.len()
}
pub fn root(&self) -> Result<&[u8], Error> {
self.cache
.get(0..HASHSIZE)
.ok_or_else(|| Error::NoBytesForRoot)
}
fn splice(&mut self, chunk_range: Range<usize>, bytes: Vec<u8>, bools: Vec<bool>) {
// Update the `chunk_modified` vec, marking all spliced-in nodes as changed.
self.chunk_modified.splice(chunk_range.clone(), bools);
self.cache
.splice(node_range_to_byte_range(&chunk_range), bytes);
}
pub fn maybe_update_chunk(&mut self, chunk: usize, to: &[u8]) -> Result<(), Error> {
let start = chunk * BYTES_PER_CHUNK;
let end = start + BYTES_PER_CHUNK;
if !self.chunk_equals(chunk, to)? {
self.cache
.get_mut(start..end)
.ok_or_else(|| Error::NoModifiedFieldForChunk(chunk))?
.copy_from_slice(to);
self.chunk_modified[chunk] = true;
}
Ok(())
}
fn slices(&self, chunk_range: Range<usize>) -> Option<(&[u8], &[bool])> {
Some((
self.cache.get(node_range_to_byte_range(&chunk_range))?,
self.chunk_modified.get(chunk_range)?,
))
}
fn modify_chunk(&mut self, chunk: usize, to: &[u8]) -> Result<(), Error> {
let start = chunk * BYTES_PER_CHUNK;
let end = start + BYTES_PER_CHUNK;
self.cache
.get_mut(start..end)
.ok_or_else(|| Error::NoBytesForChunk(chunk))?
.copy_from_slice(to);
self.chunk_modified[chunk] = true;
Ok(())
}
fn get_chunk(&self, chunk: usize) -> Result<&[u8], Error> {
let start = chunk * BYTES_PER_CHUNK;
let end = start + BYTES_PER_CHUNK;
Ok(self
.cache
.get(start..end)
.ok_or_else(|| Error::NoModifiedFieldForChunk(chunk))?)
}
fn chunk_equals(&mut self, chunk: usize, other: &[u8]) -> Result<bool, Error> {
Ok(self.get_chunk(chunk)? == other)
}
pub fn changed(&self, chunk: usize) -> Result<bool, Error> {
self.chunk_modified
.get(chunk)
.cloned()
.ok_or_else(|| Error::NoModifiedFieldForChunk(chunk))
}
fn either_modified(&self, children: (usize, usize)) -> Result<bool, Error> {
Ok(self.changed(children.0)? | self.changed(children.1)?)
}
fn hash_children(&self, children: (usize, usize)) -> Result<Vec<u8>, Error> {
let mut child_bytes = Vec::with_capacity(BYTES_PER_CHUNK * 2);
child_bytes.append(&mut self.get_chunk(children.0)?.to_vec());
child_bytes.append(&mut self.get_chunk(children.1)?.to_vec());
Ok(hash(&child_bytes))
}
pub fn mix_in_length(&self, chunk: usize, length: usize) -> Result<Vec<u8>, Error> {
let mut bytes = Vec::with_capacity(2 * BYTES_PER_CHUNK);
bytes.append(&mut self.get_chunk(chunk)?.to_vec());
bytes.append(&mut int_to_bytes32(length as u64));
Ok(hash(&bytes))
}
pub fn into_components(self) -> (Vec<u8>, Vec<bool>, Vec<BTreeOverlay>) {
(self.cache, self.chunk_modified, self.overlays)
}
}

43
eth2/utils/tree_hash/src/cached_tree_hash/impls.rs
View File

@ -3,21 +3,58 @@ use super::*;
mod vec; mod vec;
impl CachedTreeHashSubTree<u64> for u64 { impl CachedTreeHashSubTree<u64> for u64 {
fn new_tree_hash_cache(&self, depth: usize) -> Result<TreeHashCache, Error> { fn new_tree_hash_cache(&self, _depth: usize) -> Result<TreeHashCache, Error> {
Ok(TreeHashCache::from_bytes( Ok(TreeHashCache::from_bytes(
merkleize(self.to_le_bytes().to_vec()), merkleize(self.to_le_bytes().to_vec()),
false, false,
// self.tree_hash_cache_overlay(0, depth)?,
None, None,
)?) )?)
} }
fn num_tree_hash_cache_chunks(&self) -> usize {
1
}
fn tree_hash_cache_overlay( fn tree_hash_cache_overlay(
&self, &self,
chunk_offset: usize, chunk_offset: usize,
depth: usize, depth: usize,
) -> Result<BTreeOverlay, Error> { ) -> Result<BTreeOverlay, Error> {
BTreeOverlay::from_lengths(chunk_offset, 1, depth, vec![1]) panic!("Basic should not produce overlay");
// BTreeOverlay::from_lengths(chunk_offset, 1, depth, vec![1])
}
fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error> {
let leaf = merkleize(self.to_le_bytes().to_vec());
cache.maybe_update_chunk(cache.chunk_index, &leaf)?;
cache.chunk_index += 1;
// cache.overlay_index += 1;
Ok(())
}
}
impl CachedTreeHashSubTree<usize> for usize {
fn new_tree_hash_cache(&self, _depth: usize) -> Result<TreeHashCache, Error> {
Ok(TreeHashCache::from_bytes(
merkleize(self.to_le_bytes().to_vec()),
false,
None,
)?)
}
fn num_tree_hash_cache_chunks(&self) -> usize {
1
}
fn tree_hash_cache_overlay(
&self,
chunk_offset: usize,
depth: usize,
) -> Result<BTreeOverlay, Error> {
panic!("Basic should not produce overlay");
// BTreeOverlay::from_lengths(chunk_offset, 1, depth, vec![1])
} }
fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error> { fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error> {

39
eth2/utils/tree_hash/src/cached_tree_hash/impls/vec.rs
View File

@ -5,7 +5,7 @@ where
T: CachedTreeHashSubTree<T> + TreeHash, T: CachedTreeHashSubTree<T> + TreeHash,
{ {
fn new_tree_hash_cache(&self, depth: usize) -> Result<TreeHashCache, Error> { fn new_tree_hash_cache(&self, depth: usize) -> Result<TreeHashCache, Error> {
let overlay = self.tree_hash_cache_overlay(0, depth)?; let mut overlay = self.tree_hash_cache_overlay(0, depth)?;
let mut cache = match T::tree_hash_type() { let mut cache = match T::tree_hash_type() {
TreeHashType::Basic => TreeHashCache::from_bytes( TreeHashType::Basic => TreeHashCache::from_bytes(
@ -23,13 +23,18 @@ where
} }
}?; }?;
// Mix in the length of the list. cache.add_length_nodes(overlay.chunk_range(), self.len())?;
let root_node = overlay.root();
cache.modify_chunk(root_node, &cache.mix_in_length(root_node, self.len())?)?;
Ok(cache) Ok(cache)
} }
fn num_tree_hash_cache_chunks(&self) -> usize {
BTreeOverlay::new(self, 0, 0)
.and_then(|o| Ok(o.num_chunks()))
.unwrap_or_else(|_| 1)
+ 2
}
fn tree_hash_cache_overlay( fn tree_hash_cache_overlay(
&self, &self,
chunk_offset: usize, chunk_offset: usize,
@ -48,7 +53,7 @@ where
let mut lengths = vec![]; let mut lengths = vec![];
for item in self { for item in self {
lengths.push(BTreeOverlay::new(item, 0, depth)?.num_chunks()) lengths.push(item.num_tree_hash_cache_chunks())
} }
// Disallow zero-length as an empty list still has one all-padding node. // Disallow zero-length as an empty list still has one all-padding node.
@ -64,6 +69,9 @@ where
} }
fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error> { fn update_tree_hash_cache(&self, cache: &mut TreeHashCache) -> Result<(), Error> {
// Skip the length-mixed-in root node.
cache.chunk_index += 1;
let old_overlay = cache.get_overlay(cache.overlay_index, cache.chunk_index)?; let old_overlay = cache.get_overlay(cache.overlay_index, cache.chunk_index)?;
let new_overlay = BTreeOverlay::new(self, cache.chunk_index, old_overlay.depth)?; let new_overlay = BTreeOverlay::new(self, cache.chunk_index, old_overlay.depth)?;
@ -113,9 +121,6 @@ where
// The item existed in the previous list and exists in the current list. // The item existed in the previous list and exists in the current list.
(Some(_old), Some(new)) => { (Some(_old), Some(new)) => {
cache.chunk_index = new.start; cache.chunk_index = new.start;
if cache.chunk_index + 1 < cache.chunk_modified.len() {
cache.chunk_modified[cache.chunk_index + 1] = true;
}
self[i].update_tree_hash_cache(cache)?; self[i].update_tree_hash_cache(cache)?;
} }
@ -169,21 +174,11 @@ where
cache.update_internal_nodes(&new_overlay)?; cache.update_internal_nodes(&new_overlay)?;
// Mix in length. // Mix in length
let root_node = new_overlay.root(); cache.mix_in_length(new_overlay.chunk_range(), self.len())?;
if cache.changed(root_node)? {
cache.modify_chunk(root_node, &cache.mix_in_length(root_node, self.len())?)?;
} else if old_overlay.num_items != new_overlay.num_items {
if new_overlay.num_internal_nodes() == 0 {
cache.modify_chunk(root_node, &cache.mix_in_length(root_node, self.len())?)?;
} else {
let children = new_overlay.child_chunks(0);
cache.modify_chunk(root_node, &cache.hash_children(children)?)?;
cache.modify_chunk(root_node, &cache.mix_in_length(root_node, self.len())?)?;
}
}
cache.chunk_index = new_overlay.next_node(); // Skip an extra node to clear the length node.
cache.chunk_index = new_overlay.next_node() + 1;
Ok(()) Ok(())
} }

329
eth2/utils/tree_hash/src/cached_tree_hash/tree_hash_cache.rs Normal file
View File

@ -0,0 +1,329 @@
use super::*;
#[derive(Debug, PartialEq, Clone)]
pub struct TreeHashCache {
pub cache: Vec<u8>,
pub chunk_modified: Vec<bool>,
pub overlays: Vec<BTreeOverlay>,
pub chunk_index: usize,
pub overlay_index: usize,
}
impl Into<Vec<u8>> for TreeHashCache {
fn into(self) -> Vec<u8> {
self.cache
}
}
impl TreeHashCache {
pub fn new<T>(item: &T, depth: usize) -> Result<Self, Error>
where
T: CachedTreeHashSubTree<T>,
{
item.new_tree_hash_cache(depth)
}
pub fn from_leaves_and_subtrees<T>(
item: &T,
leaves_and_subtrees: Vec<Self>,
depth: usize,
) -> Result<Self, Error>
where
T: CachedTreeHashSubTree<T>,
{
let overlay = BTreeOverlay::new(item, 0, depth)?;
// Note how many leaves were provided. If is not a power-of-two, we'll need to pad it out
// later.
let num_provided_leaf_nodes = leaves_and_subtrees.len();
// Allocate enough bytes to store the internal nodes and the leaves and subtrees, then fill
// all the to-be-built internal nodes with zeros and append the leaves and subtrees.
let internal_node_bytes = overlay.num_internal_nodes() * BYTES_PER_CHUNK;
let leaves_and_subtrees_bytes = leaves_and_subtrees
.iter()
.fold(0, |acc, t| acc + t.bytes_len());
let mut cache = Vec::with_capacity(leaves_and_subtrees_bytes + internal_node_bytes);
cache.resize(internal_node_bytes, 0);
// Allocate enough bytes to store all the leaves.
let mut leaves = Vec::with_capacity(overlay.num_leaf_nodes() * HASHSIZE);
let mut overlays = Vec::with_capacity(leaves_and_subtrees.len());
if T::tree_hash_type() == TreeHashType::List {
overlays.push(overlay);
}
// Iterate through all of the leaves/subtrees, adding their root as a leaf node and then
// concatenating their merkle trees.
for t in leaves_and_subtrees {
leaves.append(&mut t.root()?.to_vec());
let (mut bytes, _bools, mut t_overlays) = t.into_components();
cache.append(&mut bytes);
overlays.append(&mut t_overlays);
}
// Pad the leaves to an even power-of-two, using zeros.
pad_for_leaf_count(num_provided_leaf_nodes, &mut cache);
// Merkleize the leaves, then split the leaf nodes off them. Then, replace all-zeros
// internal nodes created earlier with the internal nodes generated by `merkleize`.
let mut merkleized = merkleize(leaves);
merkleized.split_off(internal_node_bytes);
cache.splice(0..internal_node_bytes, merkleized);
Ok(Self {
chunk_modified: vec![false; cache.len() / BYTES_PER_CHUNK],
cache,
overlays,
chunk_index: 0,
overlay_index: 0,
})
}
pub fn from_bytes(
bytes: Vec<u8>,
initial_modified_state: bool,
overlay: Option<BTreeOverlay>,
) -> Result<Self, Error> {
if bytes.len() % BYTES_PER_CHUNK > 0 {
return Err(Error::BytesAreNotEvenChunks(bytes.len()));
}
let overlays = match overlay {
Some(overlay) => vec![overlay],
None => vec![],
};
Ok(Self {
chunk_modified: vec![initial_modified_state; bytes.len() / BYTES_PER_CHUNK],
cache: bytes,
overlays,
chunk_index: 0,
overlay_index: 0,
})
}
pub fn get_overlay(
&self,
overlay_index: usize,
chunk_index: usize,
) -> Result<BTreeOverlay, Error> {
let mut overlay = self
.overlays
.get(overlay_index)
.ok_or_else(|| Error::NoOverlayForIndex(overlay_index))?
.clone();
overlay.offset = chunk_index;
Ok(overlay)
}
pub fn reset_modifications(&mut self) {
for chunk_modified in &mut self.chunk_modified {
*chunk_modified = false;
}
}
pub fn replace_overlay(
&mut self,
overlay_index: usize,
chunk_index: usize,
new_overlay: BTreeOverlay,
) -> Result<BTreeOverlay, Error> {
let old_overlay = self.get_overlay(overlay_index, chunk_index)?;
// If the merkle tree required to represent the new list is of a different size to the one
// required for the previous list, then update our cache.
//
// This grows/shrinks the bytes to accomodate the new tree, preserving as much of the tree
// as possible.
if new_overlay.num_leaf_nodes() != old_overlay.num_leaf_nodes() {
// Get slices of the exsiting tree from the cache.
let (old_bytes, old_flags) = self
.slices(old_overlay.chunk_range())
.ok_or_else(|| Error::UnableToObtainSlices)?;
let (new_bytes, new_bools) =
if new_overlay.num_leaf_nodes() > old_overlay.num_leaf_nodes() {
resize::grow_merkle_cache(
old_bytes,
old_flags,
old_overlay.height(),
new_overlay.height(),
)
.ok_or_else(|| Error::UnableToGrowMerkleTree)?
} else {
resize::shrink_merkle_cache(
old_bytes,
old_flags,
old_overlay.height(),
new_overlay.height(),
new_overlay.num_chunks(),
)
.ok_or_else(|| Error::UnableToShrinkMerkleTree)?
};
// Splice the newly created `TreeHashCache` over the existing elements.
self.splice(old_overlay.chunk_range(), new_bytes, new_bools);
}
Ok(std::mem::replace(
&mut self.overlays[overlay_index],
new_overlay,
))
}
pub fn remove_proceeding_child_overlays(&mut self, overlay_index: usize, depth: usize) {
let end = self
.overlays
.iter()
.skip(overlay_index)
.position(|o| o.depth <= depth)
.unwrap_or_else(|| self.overlays.len());
self.overlays.splice(overlay_index..end, vec![]);
}
pub fn update_internal_nodes(&mut self, overlay: &BTreeOverlay) -> Result<(), Error> {
for (parent, children) in overlay.internal_parents_and_children().into_iter().rev() {
if self.either_modified(children)? {
self.modify_chunk(parent, &self.hash_children(children)?)?;
}
}
Ok(())
}
fn bytes_len(&self) -> usize {
self.cache.len()
}
pub fn root(&self) -> Result<&[u8], Error> {
self.cache
.get(0..HASHSIZE)
.ok_or_else(|| Error::NoBytesForRoot)
}
pub fn splice(&mut self, chunk_range: Range<usize>, bytes: Vec<u8>, bools: Vec<bool>) {
// Update the `chunk_modified` vec, marking all spliced-in nodes as changed.
self.chunk_modified.splice(chunk_range.clone(), bools);
self.cache
.splice(node_range_to_byte_range(&chunk_range), bytes);
}
pub fn maybe_update_chunk(&mut self, chunk: usize, to: &[u8]) -> Result<(), Error> {
let start = chunk * BYTES_PER_CHUNK;
let end = start + BYTES_PER_CHUNK;
if !self.chunk_equals(chunk, to)? {
self.cache
.get_mut(start..end)
.ok_or_else(|| Error::NoModifiedFieldForChunk(chunk))?
.copy_from_slice(to);
self.chunk_modified[chunk] = true;
}
Ok(())
}
fn slices(&self, chunk_range: Range<usize>) -> Option<(&[u8], &[bool])> {
Some((
self.cache.get(node_range_to_byte_range(&chunk_range))?,
self.chunk_modified.get(chunk_range)?,
))
}
pub fn modify_chunk(&mut self, chunk: usize, to: &[u8]) -> Result<(), Error> {
let start = chunk * BYTES_PER_CHUNK;
let end = start + BYTES_PER_CHUNK;
self.cache
.get_mut(start..end)
.ok_or_else(|| Error::NoBytesForChunk(chunk))?
.copy_from_slice(to);
self.chunk_modified[chunk] = true;
Ok(())
}
fn get_chunk(&self, chunk: usize) -> Result<&[u8], Error> {
let start = chunk * BYTES_PER_CHUNK;
let end = start + BYTES_PER_CHUNK;
Ok(self
.cache
.get(start..end)
.ok_or_else(|| Error::NoModifiedFieldForChunk(chunk))?)
}
fn chunk_equals(&mut self, chunk: usize, other: &[u8]) -> Result<bool, Error> {
Ok(self.get_chunk(chunk)? == other)
}
pub fn changed(&self, chunk: usize) -> Result<bool, Error> {
self.chunk_modified
.get(chunk)
.cloned()
.ok_or_else(|| Error::NoModifiedFieldForChunk(chunk))
}
fn either_modified(&self, children: (usize, usize)) -> Result<bool, Error> {
Ok(self.changed(children.0)? | self.changed(children.1)?)
}
pub fn hash_children(&self, children: (usize, usize)) -> Result<Vec<u8>, Error> {
let mut child_bytes = Vec::with_capacity(BYTES_PER_CHUNK * 2);
child_bytes.append(&mut self.get_chunk(children.0)?.to_vec());
child_bytes.append(&mut self.get_chunk(children.1)?.to_vec());
Ok(hash(&child_bytes))
}
pub fn add_length_nodes(
&mut self,
chunk_range: Range<usize>,
length: usize,
) -> Result<(), Error> {
self.chunk_modified[chunk_range.start] = true;
let byte_range = node_range_to_byte_range(&chunk_range);
// Add the last node.
self.cache
.splice(byte_range.end..byte_range.end, vec![0; HASHSIZE]);
self.chunk_modified
.splice(chunk_range.end..chunk_range.end, vec![false]);
// Add the first node.
self.cache
.splice(byte_range.start..byte_range.start, vec![0; HASHSIZE]);
self.chunk_modified
.splice(chunk_range.start..chunk_range.start, vec![false]);
self.mix_in_length(chunk_range.start + 1..chunk_range.end + 1, length)?;
Ok(())
}
pub fn mix_in_length(&mut self, chunk_range: Range<usize>, length: usize) -> Result<(), Error> {
// Update the length chunk.
self.maybe_update_chunk(chunk_range.end, &int_to_bytes32(length as u64))?;
// Update the mixed-in root if the main root or the length have changed.
let children = (chunk_range.start, chunk_range.end);
if self.either_modified(children)? {
self.modify_chunk(chunk_range.start - 1, &self.hash_children(children)?)?;
}
Ok(())
}
pub fn into_components(self) -> (Vec<u8>, Vec<bool>, Vec<BTreeOverlay>) {
(self.cache, self.chunk_modified, self.overlays)
}
}

6
eth2/utils/tree_hash/tests/tests.rs
View File

@ -74,9 +74,9 @@ fn test_inner() {
#[test] #[test]
fn test_vec() { fn test_vec() {
let original = vec![1, 2, 3, 4, 5]; let original: Vec<u64> = vec![1, 2, 3, 4, 5];
let modified = vec![ let modified: Vec<Vec<u64>> = vec![
vec![1, 2, 3, 4, 42], vec![1, 2, 3, 4, 42],
vec![1, 2, 3, 4], vec![1, 2, 3, 4],
vec![], vec![],
@ -93,7 +93,7 @@ fn test_vec() {
#[test] #[test]
fn test_nested_list_of_u64() { fn test_nested_list_of_u64() {
let original: Vec<Vec<u64>> = vec![vec![1]]; let original: Vec<Vec<u64>> = vec![vec![42]];
let modified = vec![ let modified = vec![
vec![vec![1]], vec![vec![1]],

11
eth2/utils/tree_hash_derive/src/lib.rs
View File

@ -73,11 +73,17 @@ pub fn subtree_derive(input: TokenStream) -> TokenStream {
Ok(tree) Ok(tree)
} }
fn num_tree_hash_cache_chunks(&self) -> usize {
tree_hash::BTreeOverlay::new(self, 0, 0)
.and_then(|o| Ok(o.num_chunks()))
.unwrap_or_else(|_| 1)
}
fn tree_hash_cache_overlay(&self, chunk_offset: usize, depth: usize) -> Result<tree_hash::BTreeOverlay, tree_hash::Error> { fn tree_hash_cache_overlay(&self, chunk_offset: usize, depth: usize) -> Result<tree_hash::BTreeOverlay, tree_hash::Error> {
let mut lengths = vec![]; let mut lengths = vec![];
#( #(
lengths.push(tree_hash::BTreeOverlay::new(&self.#idents_b, 0, depth)?.num_chunks()); lengths.push(self.#idents_b.num_tree_hash_cache_chunks());
)* )*
tree_hash::BTreeOverlay::from_lengths(chunk_offset, #num_items, depth, lengths) tree_hash::BTreeOverlay::from_lengths(chunk_offset, #num_items, depth, lengths)
@ -97,10 +103,7 @@ pub fn subtree_derive(input: TokenStream) -> TokenStream {
)* )*
// Iterate through the internal nodes, updating them if their children have changed. // Iterate through the internal nodes, updating them if their children have changed.
dbg!("START");
dbg!(overlay.offset);
cache.update_internal_nodes(&overlay)?; cache.update_internal_nodes(&overlay)?;
dbg!("END");
Ok(()) Ok(())
} }