--- /dev/null
+//! 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.
+
+#[cfg(feature = "hashbrown")]
+extern crate hashbrown;
+#[cfg(feature = "possiblyrandom")]
+extern crate possiblyrandom;
+
+// 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.
+
+#[cfg(not(feature = "hashbrown"))]
+mod std_hashtables {
+ pub use std::collections::HashMap;
+ pub use std::collections::hash_map::RandomState;
+
+ pub(crate) use std::collections::{HashSet, hash_map};
+
+ 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>;
+
+ /// Builds a new [`HashMap`].
+ pub fn new_hash_map<K, V>() -> HashMap<K, V> { HashMap::new() }
+ /// Builds a new [`HashMap`] with the given capacity.
+ pub 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)
+ }
+
+ 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(not(feature = "hashbrown"))]
+pub use std_hashtables::*;
+
+#[cfg(feature = "hashbrown")]
+pub(crate) use self::hashbrown::hash_map;
+
+#[cfg(feature = "hashbrown")]
+mod hashbrown_tables {
+ #[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};
+
+ #[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,
+ }
+
+ 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(all(not(fuzzing), feature = "possiblyrandom"))] {
+ let mut keys = [0; 16];
+ possiblyrandom::getpossiblyrandom(&mut keys);
+
+ 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(any(fuzzing, not(feature = "possiblyrandom")))] {
+ k0 = 0;
+ k1 = 0;
+ }
+ RandomState { k0, k1 }
+ }
+ }
+
+ impl Default for RandomState {
+ fn default() -> RandomState { RandomState::new() }
+ }
+
+ impl BuildHasher for RandomState {
+ type Hasher = SipHasher;
+ fn build_hasher(&self) -> SipHasher {
+ SipHasher::new_with_keys(self.k0, self.k1)
+ }
+ }
+ }
+
+ pub use hasher::*;
+ use super::*;
+
+ /// 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>;
+
+ 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>;
+
+ /// Builds a new [`HashMap`].
+ pub fn new_hash_map<K, V>() -> HashMap<K, V> {
+ HashMap::with_hasher(RandomState::new())
+ }
+ /// Builds a new [`HashMap`] with the given capacity.
+ pub 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
+ }
+
+ 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(feature = "hashbrown")]
+pub use hashbrown_tables::*;
projects / rust-lightning / blobdiff