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Drop
ahash
dependency in favor of core's SipHasher
tkaitchuck/aHash#196 bumped the MSRV of `ahash` in a patch release, which makes it rather difficult for us to have it as a dependency. Further, it seems that `ahash` hasn't been particularly robust in the past, notably tkaitchuck/aHash#163 and tkaitchuck/aHash#166. Luckily, `core` provides `SipHasher` even on no-std (sadly its SipHash-2-4 unlike the SipHash-1-3 used by the `DefaultHasher` in `std`). Thus, we drop the `ahash` dependency entirely here and simply wrap `SipHasher` for our `no-std` HashMaps.
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//! Generally LDK uses `std`'s `HashMap`s, however when building for no-std, LDK uses `hashbrown`'s | ||
//! `HashMap`s with the `std` `SipHasher` and uses `getrandom` to opportunistically randomize it, | ||
//! if randomization is available. | ||
//! | ||
//! This module simply re-exports the `HashMap` used in LDK for public consumption. | ||
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#[cfg(feature = "hashbrown")] | ||
extern crate hashbrown; | ||
#[cfg(feature = "possiblyrandom")] | ||
extern crate possiblyrandom; | ||
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// For no-std builds, we need to use hashbrown, however, by default, it doesn't randomize the | ||
// hashing and is vulnerable to HashDoS attacks. Thus, we use the core SipHasher when not using | ||
// std, but use `getrandom` to randomize it if its available. | ||
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#[cfg(not(feature = "hashbrown"))] | ||
mod std_hashtables { | ||
pub use std::collections::HashMap; | ||
pub use std::collections::hash_map::RandomState; | ||
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pub(crate) use std::collections::{HashSet, hash_map}; | ||
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pub(crate) type OccupiedHashMapEntry<'a, K, V> = | ||
std::collections::hash_map::OccupiedEntry<'a, K, V>; | ||
pub(crate) type VacantHashMapEntry<'a, K, V> = | ||
std::collections::hash_map::VacantEntry<'a, K, V>; | ||
} | ||
#[cfg(not(feature = "hashbrown"))] | ||
pub use std_hashtables::*; | ||
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#[cfg(feature = "hashbrown")] | ||
pub(crate) use self::hashbrown::hash_map; | ||
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#[cfg(all(feature = "hashbrown", fuzzing))] | ||
mod nonrandomized_hashbrown { | ||
pub use hashbrown::HashMap; | ||
pub use std::collections::hash_map::RandomState; | ||
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pub(crate) use hashbrown::HashSet; | ||
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pub(crate) type OccupiedHashMapEntry<'a, K, V> = | ||
hashbrown::hash_map::OccupiedEntry<'a, K, V, hashbrown::hash_map::DefaultHashBuilder>; | ||
pub(crate) type VacantHashMapEntry<'a, K, V> = | ||
hashbrown::hash_map::VacantEntry<'a, K, V, hashbrown::hash_map::DefaultHashBuilder>; | ||
} | ||
#[cfg(all(feature = "hashbrown", fuzzing))] | ||
pub use nonrandomized_hashbrown::*; | ||
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#[cfg(all(feature = "hashbrown", not(fuzzing)))] | ||
mod randomized_hashtables { | ||
#[cfg(feature = "std")] | ||
mod hasher { | ||
pub use std::collections::hash_map::RandomState; | ||
} | ||
#[cfg(not(feature = "std"))] | ||
mod hasher { | ||
#![allow(deprecated)] // hash::SipHasher was deprecated in favor of something only in std. | ||
use core::hash::{BuildHasher, SipHasher}; | ||
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#[derive(Clone, Copy)] | ||
/// A simple implementation of [`BuildHasher`] that uses `getrandom` to opportunistically | ||
/// randomize, if the platform supports it. | ||
pub struct RandomState { | ||
k0: u64, k1: u64, | ||
} | ||
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impl RandomState { | ||
/// Constructs a new [`RandomState`] which may or may not be random, depending on the | ||
/// target platform. | ||
pub fn new() -> RandomState { | ||
let (k0, k1); | ||
#[cfg(feature = "possiblyrandom")] { | ||
let mut keys = [0; 16]; | ||
possiblyrandom::getpossiblyrandom(&mut keys); | ||
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let mut k0_bytes = [0; 8]; | ||
let mut k1_bytes = [0; 8]; | ||
k0_bytes.copy_from_slice(&keys[..8]); | ||
k1_bytes.copy_from_slice(&keys[8..]); | ||
k0 = u64::from_le_bytes(k0_bytes); | ||
k1 = u64::from_le_bytes(k1_bytes); | ||
} | ||
#[cfg(not(feature = "possiblyrandom"))] { | ||
k0 = 0; | ||
k1 = 0; | ||
} | ||
RandomState { k0, k1 } | ||
} | ||
} | ||
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impl Default for RandomState { | ||
fn default() -> RandomState { RandomState::new() } | ||
} | ||
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impl BuildHasher for RandomState { | ||
type Hasher = SipHasher; | ||
fn build_hasher(&self) -> SipHasher { | ||
SipHasher::new_with_keys(self.k0, self.k1) | ||
} | ||
} | ||
} | ||
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pub use hasher::*; | ||
use super::*; | ||
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/// The HashMap type used in LDK. | ||
pub type HashMap<K, V> = hashbrown::HashMap<K, V, RandomState>; | ||
pub(crate) type HashSet<K> = hashbrown::HashSet<K, RandomState>; | ||
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pub(crate) type OccupiedHashMapEntry<'a, K, V> = | ||
hashbrown::hash_map::OccupiedEntry<'a, K, V, RandomState>; | ||
pub(crate) type VacantHashMapEntry<'a, K, V> = | ||
hashbrown::hash_map::VacantEntry<'a, K, V, RandomState>; | ||
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pub(crate) fn new_hash_map<K, V>() -> HashMap<K, V> { | ||
HashMap::with_hasher(RandomState::new()) | ||
} | ||
pub(crate) fn hash_map_with_capacity<K, V>(cap: usize) -> HashMap<K, V> { | ||
HashMap::with_capacity_and_hasher(cap, RandomState::new()) | ||
} | ||
pub(crate) fn hash_map_from_iter<K: core::hash::Hash + Eq, V, I: IntoIterator<Item=(K, V)>>(iter: I) -> HashMap<K, V> { | ||
let iter = iter.into_iter(); | ||
let min_size = iter.size_hint().0; | ||
let mut res = HashMap::with_capacity_and_hasher(min_size, RandomState::new()); | ||
res.extend(iter); | ||
res | ||
} | ||
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pub(crate) fn new_hash_set<K>() -> HashSet<K> { | ||
HashSet::with_hasher(RandomState::new()) | ||
} | ||
pub(crate) fn hash_set_with_capacity<K>(cap: usize) -> HashSet<K> { | ||
HashSet::with_capacity_and_hasher(cap, RandomState::new()) | ||
} | ||
pub(crate) fn hash_set_from_iter<K: core::hash::Hash + Eq, I: IntoIterator<Item=K>>(iter: I) -> HashSet<K> { | ||
let iter = iter.into_iter(); | ||
let min_size = iter.size_hint().0; | ||
let mut res = HashSet::with_capacity_and_hasher(min_size, RandomState::new()); | ||
res.extend(iter); | ||
res | ||
} | ||
} | ||
#[cfg(all(feature = "hashbrown", not(fuzzing)))] | ||
pub use randomized_hashtables::*; | ||
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#[cfg(any(not(feature = "hashbrown"), fuzzing))] | ||
mod hashtable_constructors { | ||
use super::*; | ||
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pub(crate) fn new_hash_map<K, V>() -> HashMap<K, V> { HashMap::new() } | ||
pub(crate) fn hash_map_with_capacity<K, V>(cap: usize) -> HashMap<K, V> { | ||
HashMap::with_capacity(cap) | ||
} | ||
pub(crate) fn hash_map_from_iter<K: core::hash::Hash + Eq, V, I: IntoIterator<Item=(K, V)>>(iter: I) -> HashMap<K, V> { | ||
HashMap::from_iter(iter) | ||
} | ||
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pub(crate) fn new_hash_set<K>() -> HashSet<K> { HashSet::new() } | ||
pub(crate) fn hash_set_with_capacity<K>(cap: usize) -> HashSet<K> { | ||
HashSet::with_capacity(cap) | ||
} | ||
pub(crate) fn hash_set_from_iter<K: core::hash::Hash + Eq, I: IntoIterator<Item=K>>(iter: I) -> HashSet<K> { | ||
HashSet::from_iter(iter) | ||
} | ||
} | ||
#[cfg(any(not(feature = "hashbrown"), fuzzing))] | ||
pub(crate) use hashtable_constructors::*; |
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