Move offset_handler construction into self

This commit is contained in:
Paul Hauner 2019-03-29 13:04:01 +11:00
parent 267c978abb
commit e0104e6199
No known key found for this signature in database
GPG Key ID: D362883A9218FCC6
3 changed files with 35 additions and 32 deletions

View File

@ -25,13 +25,13 @@ pub enum Error {
pub trait CachedTreeHash {
type Item: CachedTreeHash;
fn build_cache(&self) -> Result<TreeHashCache, Error>;
fn leaves_and_subtrees(&self) -> Vec<u8>;
/// Return the number of bytes when this element is encoded as raw SSZ _without_ length
/// prefixes.
fn num_bytes(&self) -> usize;
fn offset_handler(&self, initial_offset: usize) -> Result<OffsetHandler, Error>;
fn offsets(&self) -> Result<Vec<usize>, Error>;
fn num_child_nodes(&self) -> usize;
@ -60,13 +60,17 @@ impl TreeHashCache {
where
T: CachedTreeHash,
{
item.build_cache()
Self::from_leaves_and_subtrees(item.leaves_and_subtrees(), OffsetHandler::new(item, 0)?)
}
pub fn from_leaves_and_subtrees(
mut leaves_and_subtrees: Vec<u8>,
offset_handler: OffsetHandler,
) -> Result<Self, Error> {
// Pad the leaves with zeros if the number of immediate leaf-nodes (without recursing into
// sub-trees) is not an even power-of-two.
pad_for_leaf_count(offset_handler.num_leaf_nodes, &mut leaves_and_subtrees);
// 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 = offset_handler.num_internal_nodes * BYTES_PER_CHUNK;
@ -209,6 +213,13 @@ pub struct OffsetHandler {
}
impl OffsetHandler {
pub fn new<T>(item: &T, initial_offset: usize) -> Result<Self, Error>
where
T: CachedTreeHash,
{
Self::from_lengths(initial_offset, item.offsets()?)
}
fn from_lengths(offset: usize, mut lengths: Vec<usize>) -> Result<Self, Error> {
// Extend it to the next power-of-two, if it is not already.
let num_leaf_nodes = if lengths.len().is_power_of_two() {

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@ -4,15 +4,15 @@ use crate::{ssz_encode, Encodable};
impl CachedTreeHash for u64 {
type Item = Self;
fn build_cache(&self) -> Result<TreeHashCache, Error> {
TreeHashCache::from_bytes(merkleize(ssz_encode(self)))
fn leaves_and_subtrees(&self) -> Vec<u8> {
merkleize(ssz_encode(self))
}
fn num_bytes(&self) -> usize {
8
}
fn offset_handler(&self, _initial_offset: usize) -> Result<OffsetHandler, Error> {
fn offsets(&self) -> Result<Vec<usize>, Error> {
Err(Error::ShouldNotProduceOffsetHandler)
}

View File

@ -12,19 +12,15 @@ pub struct Inner {
impl CachedTreeHash for Inner {
type Item = Self;
fn build_cache(&self) -> Result<TreeHashCache, Error> {
let offset_handler = self.offset_handler(0)?;
fn leaves_and_subtrees(&self) -> Vec<u8> {
let mut leaves_and_subtrees = vec![];
leaves_and_subtrees.append(&mut self.a.build_cache()?.into());
leaves_and_subtrees.append(&mut self.b.build_cache()?.into());
leaves_and_subtrees.append(&mut self.c.build_cache()?.into());
leaves_and_subtrees.append(&mut self.d.build_cache()?.into());
leaves_and_subtrees.append(&mut self.a.leaves_and_subtrees());
leaves_and_subtrees.append(&mut self.b.leaves_and_subtrees());
leaves_and_subtrees.append(&mut self.c.leaves_and_subtrees());
leaves_and_subtrees.append(&mut self.d.leaves_and_subtrees());
pad_for_leaf_count(offset_handler.num_leaf_nodes, &mut leaves_and_subtrees);
TreeHashCache::from_leaves_and_subtrees(leaves_and_subtrees, self.offset_handler(0)?)
leaves_and_subtrees
}
fn num_bytes(&self) -> usize {
@ -38,7 +34,7 @@ impl CachedTreeHash for Inner {
bytes
}
fn offset_handler(&self, initial_offset: usize) -> Result<OffsetHandler, Error> {
fn offsets(&self) -> Result<Vec<usize>, Error> {
let mut offsets = vec![];
offsets.push(self.a.num_child_nodes() + 1);
@ -46,7 +42,7 @@ impl CachedTreeHash for Inner {
offsets.push(self.c.num_child_nodes() + 1);
offsets.push(self.d.num_child_nodes() + 1);
OffsetHandler::from_lengths(initial_offset, offsets)
Ok(offsets)
}
fn num_child_nodes(&self) -> usize {
@ -67,7 +63,7 @@ impl CachedTreeHash for Inner {
cache: &mut TreeHashCache,
chunk: usize,
) -> Result<usize, Error> {
let offset_handler = self.offset_handler(chunk)?;
let offset_handler = OffsetHandler::new(self, chunk)?;
// Skip past the internal nodes and update any changed leaf nodes.
{
@ -98,18 +94,14 @@ pub struct Outer {
impl CachedTreeHash for Outer {
type Item = Self;
fn build_cache(&self) -> Result<TreeHashCache, Error> {
let offset_handler = self.offset_handler(0)?;
fn leaves_and_subtrees(&self) -> Vec<u8> {
let mut leaves_and_subtrees = vec![];
leaves_and_subtrees.append(&mut self.a.build_cache()?.into());
leaves_and_subtrees.append(&mut self.b.build_cache()?.into());
leaves_and_subtrees.append(&mut self.c.build_cache()?.into());
leaves_and_subtrees.append(&mut self.a.leaves_and_subtrees());
leaves_and_subtrees.append(&mut self.b.leaves_and_subtrees());
leaves_and_subtrees.append(&mut self.c.leaves_and_subtrees());
pad_for_leaf_count(offset_handler.num_leaf_nodes, &mut leaves_and_subtrees);
TreeHashCache::from_leaves_and_subtrees(leaves_and_subtrees, self.offset_handler(0)?)
leaves_and_subtrees
}
fn num_bytes(&self) -> usize {
@ -131,14 +123,14 @@ impl CachedTreeHash for Outer {
num_nodes(leaves) + children - 1
}
fn offset_handler(&self, initial_offset: usize) -> Result<OffsetHandler, Error> {
fn offsets(&self) -> Result<Vec<usize>, Error> {
let mut offsets = vec![];
offsets.push(self.a.num_child_nodes() + 1);
offsets.push(self.b.num_child_nodes() + 1);
offsets.push(self.c.num_child_nodes() + 1);
OffsetHandler::from_lengths(initial_offset, offsets)
Ok(offsets)
}
fn cached_hash_tree_root(
@ -147,7 +139,7 @@ impl CachedTreeHash for Outer {
cache: &mut TreeHashCache,
chunk: usize,
) -> Result<usize, Error> {
let offset_handler = self.offset_handler(chunk)?;
let offset_handler = OffsetHandler::new(self, chunk)?;
// Skip past the internal nodes and update any changed leaf nodes.
{
@ -308,7 +300,7 @@ fn outer_builds() {
// Generate reference data.
let mut data = vec![];
data.append(&mut int_to_bytes32(0));
let inner_bytes: Vec<u8> = inner.build_cache().unwrap().into();
let inner_bytes: Vec<u8> = TreeHashCache::new(&inner).unwrap().into();
data.append(&mut int_to_bytes32(5));
let leaves = vec![