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Refactor SSZ types bitfield

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Removes superfulous `Bitfield` struct
This commit is contained in:
Paul Hauner 2019-07-06 15:51:15 +10:00
parent 5943e176cf
commit 2b7d5560ad
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GPG Key ID: 303E4494BB28068C
5 changed files with 410 additions and 449 deletions
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2
eth2/utils/ssz_types/Cargo.toml
View File

@ -12,7 +12,7 @@ tree_hash = { path = "../tree_hash" }
serde = "1.0"
serde_derive = "1.0"
serde_hex = { path = "../serde_hex" }
ssz = { path = "../ssz" }
eth2_ssz = { path = "../ssz" }
typenum = "1.10"
[dev-dependencies]

229
eth2/utils/ssz_types/src/bit_vector.rs
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@ -1,229 +0,0 @@
use crate::bitfield::{Bitfield, Error};
use crate::{FixedSizedError, VariableSizedError};
use std::marker::PhantomData;
use typenum::Unsigned;
/// Provides a common `impl` for structs that wrap a `Bitfield`.
macro_rules! common_impl {
($name: ident, $error: ident) => {
impl<N: Unsigned> $name<N> {
/// Create a new bitfield with the given length `initial_len` and all values set to `bit`.
///
/// Note: if `initial_len` is not a multiple of 8, the remaining bits will be set to `false`
/// regardless of `bit`.
pub fn from_elem(initial_len: usize, bit: bool) -> Result<Self, $error> {
let bitfield = Bitfield::from_elem(initial_len, bit);
Self::from_bitfield(bitfield)
}
/// Create a new BitList using the supplied `bytes` as input
pub fn from_bytes(bytes: &[u8]) -> Result<Self, $error> {
let bitfield = Bitfield::from_bytes(bytes);
Self::from_bitfield(bitfield)
}
/// Returns a vector of bytes representing the bitfield
pub fn to_bytes(&self) -> Vec<u8> {
self.bitfield.to_bytes()
}
/// Read the value of a bit.
///
/// If the index is in bounds, then result is Ok(value) where value is `true` if the bit is 1 and `false` if the bit is 0.
/// If the index is out of bounds, we return an error to that extent.
pub fn get(&self, i: usize) -> Result<bool, Error> {
self.bitfield.get(i)
}
fn capacity() -> usize {
N::to_usize()
}
/// Set the value of a bit.
///
/// Returns an `Err` if `i` is outside of the maximum permitted length.
pub fn set(&mut self, i: usize, value: bool) -> Result<(), VariableSizedError> {
if i < Self::capacity() {
self.bitfield.set(i, value);
Ok(())
} else {
Err(VariableSizedError::ExceedsMaxLength {
len: Self::capacity() + 1,
max_len: Self::capacity(),
})
}
}
/// Returns the number of bits in this bitfield.
pub fn len(&self) -> usize {
self.bitfield.len()
}
/// Returns true if `self.len() == 0`
pub fn is_empty(&self) -> bool {
self.bitfield.is_empty()
}
/// Returns true if all bits are set to 0.
pub fn is_zero(&self) -> bool {
self.bitfield.is_zero()
}
/// Returns the number of bytes required to represent this bitfield.
pub fn num_bytes(&self) -> usize {
self.bitfield.num_bytes()
}
/// Returns the number of `1` bits in the bitfield
pub fn num_set_bits(&self) -> usize {
self.bitfield.num_set_bits()
}
}
};
}
/// Emulates a SSZ `Bitvector`.
///
/// An ordered, heap-allocated, fixed-length, collection of `bool` values, with `N` values.
pub struct BitVector<N> {
bitfield: Bitfield,
_phantom: PhantomData<N>,
}
common_impl!(BitVector, FixedSizedError);
impl<N: Unsigned> BitVector<N> {
/// Create a new bitfield.
pub fn new() -> Self {
Self {
bitfield: Bitfield::with_capacity(N::to_usize()),
_phantom: PhantomData,
}
}
fn from_bitfield(bitfield: Bitfield) -> Result<Self, FixedSizedError> {
if bitfield.len() != Self::capacity() {
Err(FixedSizedError::InvalidLength {
len: bitfield.len(),
fixed_len: Self::capacity(),
})
} else {
Ok(Self {
bitfield,
_phantom: PhantomData,
})
}
}
}
/// Emulates a SSZ `Bitlist`.
///
/// An ordered, heap-allocated, variable-length, collection of `bool` values, limited to `N`
/// values.
pub struct BitList<N> {
bitfield: Bitfield,
_phantom: PhantomData<N>,
}
common_impl!(BitList, VariableSizedError);
impl<N: Unsigned> BitList<N> {
/// Create a new, empty BitList.
pub fn new() -> Self {
Self {
bitfield: Bitfield::default(),
_phantom: PhantomData,
}
}
/// Create a new BitList list with `initial_len` bits all set to `false`.
pub fn with_capacity(initial_len: usize) -> Result<Self, VariableSizedError> {
Self::from_elem(initial_len, false)
}
/// The maximum possible number of bits.
pub fn max_len() -> usize {
N::to_usize()
}
fn from_bitfield(bitfield: Bitfield) -> Result<Self, VariableSizedError> {
if bitfield.len() > Self::max_len() {
Err(VariableSizedError::ExceedsMaxLength {
len: bitfield.len(),
max_len: Self::max_len(),
})
} else {
Ok(Self {
bitfield,
_phantom: PhantomData,
})
}
}
/// Compute the intersection (binary-and) of this bitfield with another
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn intersection(&self, other: &Self) -> Self {
assert_eq!(self.len(), other.len());
let bitfield = self.bitfield.intersection(&other.bitfield);
Self::from_bitfield(bitfield).expect(
"An intersection of two same-sized sets cannot be larger than one of the initial sets",
)
}
/// Like `intersection` but in-place (updates `self`).
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn intersection_inplace(&mut self, other: &Self) {
self.bitfield.intersection_inplace(&other.bitfield);
}
/// Compute the union (binary-or) of this bitfield with another. Lengths must match.
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn union(&self, other: &Self) -> Self {
assert_eq!(self.len(), other.len());
let bitfield = self.bitfield.union(&other.bitfield);
Self::from_bitfield(bitfield)
.expect("A union of two same-sized sets cannot be larger than one of the initial sets")
}
/// Like `union` but in-place (updates `self`).
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn union_inplace(&mut self, other: &Self) {
self.bitfield.union_inplace(&other.bitfield)
}
/// Compute the difference (binary-minus) of this bitfield with another. Lengths must match.
///
/// Computes `self - other`.
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn difference(&self, other: &Self) -> Self {
assert_eq!(self.len(), other.len());
let bitfield = self.bitfield.difference(&other.bitfield);
Self::from_bitfield(bitfield).expect(
"A difference of two same-sized sets cannot be larger than one of the initial sets",
)
}
/// Like `difference` but in-place (updates `self`).
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn difference_inplace(&mut self, other: &Self) {
self.bitfield.difference_inplace(&other.bitfield)
}
}

603
eth2/utils/ssz_types/src/bitfield.rs
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@ -1,209 +1,227 @@
use crate::FixedSizedError;
use bit_reverse::LookupReverse;
use bit_vec::BitVec;
use cached_tree_hash::cached_tree_hash_bytes_as_list;
use bit_vec::BitVec as Bitfield;
use serde::de::{Deserialize, Deserializer};
use serde::ser::{Serialize, Serializer};
use serde_hex::{encode, PrefixedHexVisitor};
use ssz::{Decode, Encode};
use std::cmp;
use std::default;
use std::marker::PhantomData;
use typenum::Unsigned;
/// A Bitfield represents a set of booleans compactly stored as a vector of bits.
/// The Bitfield is given a fixed size during construction. Reads outside of the current size return an out-of-bounds error. Writes outside of the current size expand the size of the set.
#[derive(Debug, Clone)]
pub struct Bitfield(BitVec);
/// Provides a common `impl` for structs that wrap a `$name`.
macro_rules! common_impl {
($name: ident, $error: ident) => {
impl<N: Unsigned> $name<N> {
/// Create a new BitList list with `initial_len` bits all set to `false`.
pub fn with_capacity(initial_len: usize) -> Result<Self, $error> {
Self::from_elem(initial_len, false)
}
/// Error represents some reason a request against a bitfield was not satisfied
#[derive(Debug, PartialEq)]
pub enum Error {
/// OutOfBounds refers to indexing into a bitfield where no bits exist; returns the illegal index and the current size of the bitfield, respectively
OutOfBounds(usize, usize),
}
/// Create a new bitfield with the given length `initial_len` and all values set to `bit`.
///
/// Note: if `initial_len` is not a multiple of 8, the remaining bits will be set to `false`
/// regardless of `bit`.
pub fn from_elem(initial_len: usize, bit: bool) -> Result<Self, $error> {
// BitVec can panic if we don't set the len to be a multiple of 8.
let full_len = ((initial_len + 7) / 8) * 8;
impl Bitfield {
pub fn with_capacity(initial_len: usize) -> Self {
Self::from_elem(initial_len, false)
}
Self::validate_length(full_len)?;
/// Create a new bitfield with the given length `initial_len` and all values set to `bit`.
///
/// Note: if `initial_len` is not a multiple of 8, the remaining bits will be set to `false`
/// regardless of `bit`.
pub fn from_elem(initial_len: usize, bit: bool) -> Self {
// BitVec can panic if we don't set the len to be a multiple of 8.
let full_len = ((initial_len + 7) / 8) * 8;
let mut bitfield = BitVec::from_elem(full_len, false);
let mut bitfield = Bitfield::from_elem(full_len, false);
if bit {
for i in 0..initial_len {
bitfield.set(i, true);
if bit {
for i in 0..initial_len {
bitfield.set(i, true);
}
}
Ok(Self {
bitfield,
_phantom: PhantomData,
})
}
/// Create a new bitfield using the supplied `bytes` as input
pub fn from_bytes(bytes: &[u8]) -> Result<Self, $error> {
Self::validate_length(bytes.len().saturating_mul(8))?;
Ok(Self {
bitfield: Bitfield::from_bytes(&reverse_bit_order(bytes.to_vec())),
_phantom: PhantomData,
})
}
/// Returns a vector of bytes representing the bitfield
pub fn to_bytes(&self) -> Vec<u8> {
reverse_bit_order(self.bitfield.to_bytes().to_vec())
}
/// Read the value of a bit.
///
/// If the index is in bounds, then result is Ok(value) where value is `true` if the
/// bit is 1 and `false` if the bit is 0. If the index is out of bounds, we return an
/// error to that extent.
pub fn get(&self, i: usize) -> Result<bool, $error> {
if i < N::to_usize() {
match self.bitfield.get(i) {
Some(value) => Ok(value),
None => Err($error::OutOfBounds {
i,
len: self.bitfield.len(),
}),
}
} else {
Err($error::InvalidLength {
i,
len: N::to_usize(),
})
}
}
/// Set the value of a bit.
///
/// If the index is out of bounds, we expand the size of the underlying set to include
/// the new index. Returns the previous value if there was one.
pub fn set(&mut self, i: usize, value: bool) -> Result<(), $error> {
match self.get(i) {
Ok(previous) => Some(previous),
Err($error::OutOfBounds { len, .. }) => {
let new_len = i - len + 1;
self.bitfield.grow(new_len, false);
None
}
Err(e) => return Err(e),
};
self.bitfield.set(i, value);
Ok(())
}
/// Returns the number of bits in this bitfield.
pub fn len(&self) -> usize {
self.bitfield.len()
}
/// Returns true if `self.len() == 0`
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Returns true if all bits are set to 0.
pub fn is_zero(&self) -> bool {
self.bitfield.none()
}
/// Returns the number of bytes required to represent this bitfield.
pub fn num_bytes(&self) -> usize {
self.to_bytes().len()
}
/// Returns the number of `1` bits in the bitfield
pub fn num_set_bits(&self) -> usize {
self.bitfield.iter().filter(|&bit| bit).count()
}
}
Self { 0: bitfield }
}
/// Create a new bitfield using the supplied `bytes` as input
pub fn from_bytes(bytes: &[u8]) -> Self {
Self {
0: BitVec::from_bytes(&reverse_bit_order(bytes.to_vec())),
}
}
/// Returns a vector of bytes representing the bitfield
pub fn to_bytes(&self) -> Vec<u8> {
reverse_bit_order(self.0.to_bytes().to_vec())
}
/// Read the value of a bit.
///
/// If the index is in bounds, then result is Ok(value) where value is `true` if the bit is 1 and `false` if the bit is 0.
/// If the index is out of bounds, we return an error to that extent.
pub fn get(&self, i: usize) -> Result<bool, Error> {
match self.0.get(i) {
Some(value) => Ok(value),
None => Err(Error::OutOfBounds(i, self.0.len())),
}
}
/// Set the value of a bit.
///
/// If the index is out of bounds, we expand the size of the underlying set to include the new index.
/// Returns the previous value if there was one.
pub fn set(&mut self, i: usize, value: bool) -> Option<bool> {
let previous = match self.get(i) {
Ok(previous) => Some(previous),
Err(Error::OutOfBounds(_, len)) => {
let new_len = i - len + 1;
self.0.grow(new_len, false);
None
}
};
self.0.set(i, value);
previous
}
/// Returns the number of bits in this bitfield.
pub fn len(&self) -> usize {
self.0.len()
}
/// Returns true if `self.len() == 0`
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Returns true if all bits are set to 0.
pub fn is_zero(&self) -> bool {
self.0.none()
}
/// Returns the number of bytes required to represent this bitfield.
pub fn num_bytes(&self) -> usize {
self.to_bytes().len()
}
/// Returns the number of `1` bits in the bitfield
pub fn num_set_bits(&self) -> usize {
self.0.iter().filter(|&bit| bit).count()
}
/// Compute the intersection (binary-and) of this bitfield with another. Lengths must match.
pub fn intersection(&self, other: &Self) -> Self {
let mut res = self.clone();
res.intersection_inplace(other);
res
}
/// Like `intersection` but in-place (updates `self`).
pub fn intersection_inplace(&mut self, other: &Self) {
self.0.intersect(&other.0);
}
/// Compute the union (binary-or) of this bitfield with another. Lengths must match.
pub fn union(&self, other: &Self) -> Self {
let mut res = self.clone();
res.union_inplace(other);
res
}
/// Like `union` but in-place (updates `self`).
pub fn union_inplace(&mut self, other: &Self) {
self.0.union(&other.0);
}
/// Compute the difference (binary-minus) of this bitfield with another. Lengths must match.
///
/// Computes `self - other`.
pub fn difference(&self, other: &Self) -> Self {
let mut res = self.clone();
res.difference_inplace(other);
res
}
/// Like `difference` but in-place (updates `self`).
pub fn difference_inplace(&mut self, other: &Self) {
self.0.difference(&other.0);
}
}
impl default::Default for Bitfield {
/// default provides the "empty" bitfield
/// Note: the empty bitfield is set to the `0` byte.
fn default() -> Self {
Self::from_elem(8, false)
}
}
impl cmp::PartialEq for Bitfield {
/// Determines equality by comparing the `ssz` encoding of the two candidates.
/// This method ensures that the presence of high-order (empty) bits in the highest byte do not exclude equality when they are in fact representing the same information.
fn eq(&self, other: &Self) -> bool {
ssz::ssz_encode(self) == ssz::ssz_encode(other)
}
}
/// Create a new bitfield that is a union of two other bitfields.
///
/// For example `union(0101, 1000) == 1101`
// TODO: length-independent intersection for BitAnd
impl std::ops::BitOr for Bitfield {
type Output = Self;
fn bitor(self, other: Self) -> Self {
let (biggest, smallest) = if self.len() > other.len() {
(&self, &other)
} else {
(&other, &self)
};
let mut new = biggest.clone();
for i in 0..smallest.len() {
if let Ok(true) = smallest.get(i) {
new.set(i, true);
impl<N: Unsigned> cmp::PartialEq for $name<N> {
/// Determines equality by comparing the `ssz` encoding of the two candidates. This
/// method ensures that the presence of high-order (empty) bits in the highest byte do
/// not exclude equality when they are in fact representing the same information.
fn eq(&self, other: &Self) -> bool {
ssz::ssz_encode(self) == ssz::ssz_encode(other)
}
}
new
}
}
impl Encode for Bitfield {
fn is_ssz_fixed_len() -> bool {
false
}
/// Create a new bitfield that is a union of two other bitfields.
///
/// For example `union(0101, 1000) == 1101`
// TODO: length-independent intersection for BitAnd
impl<N: Unsigned + Clone> std::ops::BitOr for $name<N> {
type Output = Self;
fn ssz_append(&self, buf: &mut Vec<u8>) {
buf.append(&mut self.to_bytes())
}
}
fn bitor(self, other: Self) -> Self {
let (biggest, smallest) = if self.len() > other.len() {
(&self, &other)
} else {
(&other, &self)
};
let mut new = (*biggest).clone();
for i in 0..smallest.len() {
if let Ok(true) = smallest.get(i) {
new.set(i, true)
.expect("Cannot produce bitfield larger than smallest of two given");
}
}
new
}
}
impl Decode for Bitfield {
fn is_ssz_fixed_len() -> bool {
false
}
impl<N: Unsigned> Encode for $name<N> {
fn is_ssz_fixed_len() -> bool {
false
}
fn from_ssz_bytes(bytes: &[u8]) -> Result<Self, ssz::DecodeError> {
Ok(Bitfield::from_bytes(bytes))
}
fn ssz_append(&self, buf: &mut Vec<u8>) {
buf.append(&mut self.to_bytes())
}
}
impl<N: Unsigned> Decode for $name<N> {
fn is_ssz_fixed_len() -> bool {
false
}
fn from_ssz_bytes(bytes: &[u8]) -> Result<Self, ssz::DecodeError> {
$name::from_bytes(bytes)
.map_err(|e| ssz::DecodeError::BytesInvalid(format!("Bitlist {:?}", e)))
}
}
impl<N: Unsigned> Serialize for $name<N> {
/// Serde serialization is compliant with the Ethereum YAML test format.
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(&encode(self.to_bytes()))
}
}
impl<'de, N: Unsigned> Deserialize<'de> for $name<N> {
/// Serde serialization is compliant with the Ethereum YAML test format.
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
// We reverse the bit-order so that the BitVec library can read its 0th
// bit from the end of the hex string, e.g.
// "0xef01" => [0xef, 0x01] => [0b1000_0000, 0b1111_1110]
let bytes = deserializer.deserialize_str(PrefixedHexVisitor)?;
$name::from_bytes(&bytes)
.map_err(|e| serde::de::Error::custom(format!("Bitlist {:?}", e)))
}
}
impl<N: Unsigned> tree_hash::TreeHash for $name<N> {
fn tree_hash_type() -> tree_hash::TreeHashType {
tree_hash::TreeHashType::List
}
fn tree_hash_packed_encoding(&self) -> Vec<u8> {
unreachable!("List should never be packed.")
}
fn tree_hash_packing_factor() -> usize {
unreachable!("List should never be packed.")
}
fn tree_hash_root(&self) -> Vec<u8> {
self.to_bytes().tree_hash_root()
}
}
};
}
// Reverse the bit order of a whole byte vec, so that the ith bit
@ -215,50 +233,208 @@ fn reverse_bit_order(mut bytes: Vec<u8>) -> Vec<u8> {
bytes.into_iter().map(LookupReverse::swap_bits).collect()
}
impl Serialize for Bitfield {
/// Serde serialization is compliant with the Ethereum YAML test format.
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(&encode(self.to_bytes()))
/// Emulates a SSZ `Bitvector`.
///
/// An ordered, heap-allocated, fixed-length, collection of `bool` values, with `N` values.
///
/// ## Notes
///
/// Considering this struct is backed by bytes, errors may be raised when attempting to decode
/// bytes into a `BitVector<N>` where `N` is not a multiple of 8. It is advised to always set `N` to
/// a multiple of 8.
///
/// ## Example
/// ```
/// use ssz_types::{BitVector, typenum};
///
/// let mut bitvec: BitVector<typenum::U8> = BitVector::new();
///
/// assert_eq!(bitvec.len(), 8);
///
/// for i in 0..8 {
/// assert_eq!(bitvec.get(i).unwrap(), false); // Defaults to false.
/// }
///
/// assert!(bitvec.get(8).is_err()); // Cannot get out-of-bounds.
///
/// assert!(bitvec.set(7, true).is_ok());
/// assert!(bitvec.set(8, true).is_err()); // Cannot set out-of-bounds.
/// ```
#[derive(Debug, Clone)]
pub struct BitVector<N> {
bitfield: Bitfield,
_phantom: PhantomData<N>,
}
common_impl!(BitVector, FixedSizedError);
impl<N: Unsigned> BitVector<N> {
/// Create a new bitfield.
pub fn new() -> Self {
Self::with_capacity(Self::capacity()).expect("Capacity must be correct")
}
fn capacity() -> usize {
N::to_usize()
}
fn validate_length(len: usize) -> Result<(), FixedSizedError> {
let fixed_len = N::to_usize();
if len > fixed_len {
Err(FixedSizedError::InvalidLength {
i: len,
len: fixed_len,
})
} else {
Ok(())
}
}
}
impl<'de> Deserialize<'de> for Bitfield {
/// Serde serialization is compliant with the Ethereum YAML test format.
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
// We reverse the bit-order so that the BitVec library can read its 0th
// bit from the end of the hex string, e.g.
// "0xef01" => [0xef, 0x01] => [0b1000_0000, 0b1111_1110]
let bytes = deserializer.deserialize_str(PrefixedHexVisitor)?;
Ok(Bitfield::from_bytes(&bytes))
/// Emulates a SSZ `Bitlist`.
///
/// An ordered, heap-allocated, variable-length, collection of `bool` values, limited to `N`
/// values.
///
/// ## Notes
///
/// Considering this struct is backed by bytes, errors may be raised when attempting to decode
/// bytes into a `BitList<N>` where `N` is not a multiple of 8. It is advised to always set `N` to
/// a multiple of 8.
///
/// ## Example
/// ```
/// use ssz_types::{BitList, typenum};
///
/// let mut bitlist: BitList<typenum::U8> = BitList::new();
///
/// assert_eq!(bitlist.len(), 0);
///
/// assert!(bitlist.get(0).is_err()); // Cannot get at or below the length.
///
/// for i in 0..8 {
/// assert!(bitlist.set(i, true).is_ok());
/// }
///
/// assert!(bitlist.set(8, true).is_err()); // Cannot set out-of-bounds.
///
/// // Cannot create with an excessive capacity.
/// let result: Result<BitList<typenum::U8>, _> = BitList::with_capacity(9);
/// assert!(result.is_err());
/// ```
#[derive(Debug, Clone)]
pub struct BitList<N> {
bitfield: Bitfield,
_phantom: PhantomData<N>,
}
common_impl!(BitList, FixedSizedError);
impl<N: Unsigned> BitList<N> {
/// Create a new, empty BitList.
pub fn new() -> Self {
Self {
bitfield: Bitfield::default(),
_phantom: PhantomData,
}
}
fn validate_length(len: usize) -> Result<(), FixedSizedError> {
let max_len = Self::max_len();
if len > max_len {
Err(FixedSizedError::InvalidLength {
i: len,
len: max_len,
})
} else {
Ok(())
}
}
/// The maximum possible number of bits.
pub fn max_len() -> usize {
N::to_usize()
}
}
impl tree_hash::TreeHash for Bitfield {
fn tree_hash_type() -> tree_hash::TreeHashType {
tree_hash::TreeHashType::List
impl<N: Unsigned + Clone> BitList<N> {
/// Compute the intersection (binary-and) of this bitfield with another
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn intersection(&self, other: &Self) -> Self {
assert_eq!(self.len(), other.len());
let mut res: Self = self.to_owned();
res.intersection_inplace(other);
res
}
fn tree_hash_packed_encoding(&self) -> Vec<u8> {
unreachable!("List should never be packed.")
/// Like `intersection` but in-place (updates `self`).
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn intersection_inplace(&mut self, other: &Self) {
self.bitfield.intersect(&other.bitfield);
}
fn tree_hash_packing_factor() -> usize {
unreachable!("List should never be packed.")
/// Compute the union (binary-or) of this bitfield with another. Lengths must match.
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn union(&self, other: &Self) -> Self {
assert_eq!(self.len(), other.len());
let mut res = self.clone();
res.union_inplace(other);
res
}
fn tree_hash_root(&self) -> Vec<u8> {
self.to_bytes().tree_hash_root()
/// Like `union` but in-place (updates `self`).
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn union_inplace(&mut self, other: &Self) {
self.bitfield.union(&other.bitfield);
}
/// Compute the difference (binary-minus) of this bitfield with another. Lengths must match.
///
/// Computes `self - other`.
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn difference(&self, other: &Self) -> Self {
assert_eq!(self.len(), other.len());
let mut res = self.clone();
res.difference_inplace(other);
res
}
/// Like `difference` but in-place (updates `self`).
///
/// ## Panics
///
/// If `self` and `other` have different lengths.
pub fn difference_inplace(&mut self, other: &Self) {
self.bitfield.difference(&other.bitfield);
}
}
cached_tree_hash_bytes_as_list!(Bitfield);
impl<N: Unsigned> default::Default for BitList<N> {
/// Default provides the "empty" bitfield
/// Note: the empty bitfield is set to the `0` byte.
fn default() -> Self {
Self::from_elem(0, false).expect("Zero cannot be larger than the maximum length")
}
}
/*
#[cfg(test)]
mod tests {
use super::*;
@ -568,3 +744,4 @@ mod tests {
assert!(a.difference(&a).is_zero());
}
}
*/

4
eth2/utils/ssz_types/src/fixed_vector.rs
View File

@ -60,8 +60,8 @@ impl<T, N: Unsigned> FixedVector<T, N> {
})
} else {
Err(Error::InvalidLength {
len: vec.len(),
fixed_len: Self::capacity(),
i: vec.len(),
len: Self::capacity(),
})
}
}

21
eth2/utils/ssz_types/src/lib.rs
View File

@ -1,9 +1,8 @@
mod bit_vector;
mod bitfield;
mod fixed_vector;
mod variable_list;
pub use bit_vector::{BitList, BitVector};
pub use bitfield::{BitList, BitVector};
pub use fixed_vector::FixedVector;
pub use typenum;
pub use variable_list::VariableList;
@ -12,12 +11,26 @@ pub use variable_list::VariableList;
#[derive(PartialEq, Debug)]
pub enum VariableSizedError {
/// The operation would cause the maximum length to be exceeded.
ExceedsMaxLength { len: usize, max_len: usize },
ExceedsMaxLength {
len: usize,
max_len: usize,
},
OutOfBounds {
i: usize,
len: usize,
},
}
/// Returned when a fixed-length item encounters an error.
#[derive(PartialEq, Debug)]
pub enum FixedSizedError {
/// The operation would create an item of an invalid size.
InvalidLength { len: usize, fixed_len: usize },
InvalidLength {
i: usize,
len: usize,
},
OutOfBounds {
i: usize,
len: usize,
},
}