rust
/
dashmap
mirror of https://github.com/xacrimon/dashmap
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clean house baby

This commit is contained in:
Joel Wejdenstål 2023-07-11 19:12:49 +02:00
parent ea4ea24a63
commit e51b514c59
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GPG Key ID: DF03CEFBB1A915AA
24 changed files with 66 additions and 4618 deletions
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16
Cargo.toml
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@ -2,7 +2,7 @@
name = "dashmap"
version = "5.5.0"
authors = ["Acrimon <joel.wejdenstal@gmail.com>"]
edition = "2018"
edition = "2021"
rust-version = "1.64"
license = "MIT"
repository = "https://github.com/xacrimon/dashmap"
@ -13,19 +13,5 @@ documentation = "https://docs.rs/dashmap"
keywords = ["atomic", "concurrent", "hashmap"]
categories = ["concurrency", "algorithms", "data-structures"]
[features]
raw-api = []
inline = ["hashbrown/inline-more"]
[dependencies]
lock_api = "0.4.10"
parking_lot_core = "0.9.8"
hashbrown = { version = "0.14.0", default-features = false }
serde = { version = "1.0.171", optional = true, features = ["derive"] }
cfg-if = "1.0.0"
rayon = { version = "1.7.0", optional = true }
once_cell = "1.18.0"
arbitrary = { version = "1.3.0", optional = true }
[package.metadata.docs.rs]
features = ["rayon", "raw-api", "serde"]

32
src/alias.rs Normal file
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@ -0,0 +1,32 @@
use std::marker::PhantomData;
pub trait Aliasor<T> {
fn alias<const N: usize>(src: *const T, dst: *mut T);
}
pub struct DoCopy<T> {
_marker: PhantomData<T>,
}
impl<T> Aliasor<T> for DoCopy<T> where T:Copy {
fn alias<const N: usize>(src: *const T, dst: *mut T) {
unsafe {
std::ptr::copy_nonoverlapping(src, dst, N);
}
}
}
pub struct DoClone<T> {
_marker: PhantomData<T>,
}
impl<T> Aliasor<T> for DoClone<T> where T:Clone {
fn alias<const N: usize>(src: *const T, dst: *mut T) {
unsafe {
for i in 0..N {
let v = (*src.add(i)).clone();
dst.add(i).write(v);
}
}
}
}

13
src/arbitrary.rs
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@ -1,13 +0,0 @@
use arbitrary::{Arbitrary, Unstructured};
use core::hash::BuildHasher;
impl<'a, K, V, S> Arbitrary<'a> for crate::DashMap<K, V, S>
where
K: Eq + std::hash::Hash + Arbitrary<'a>,
V: Arbitrary<'a>,
S: Default + BuildHasher + Clone,
{
fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
u.arbitrary_iter()?.collect()
}
}

315
src/iter.rs
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@ -1,315 +0,0 @@
use super::mapref::multiple::{RefMulti, RefMutMulti};
use super::util;
use crate::lock::{RwLockReadGuard, RwLockWriteGuard};
use crate::t::Map;
use crate::util::SharedValue;
use crate::{DashMap, HashMap};
use core::hash::{BuildHasher, Hash};
use core::mem;
use hashbrown::hash_map;
use std::collections::hash_map::RandomState;
use std::sync::Arc;
/// Iterator over a DashMap yielding key value pairs.
///
/// # Examples
///
/// ```
/// use dashmap::DashMap;
///
/// let map = DashMap::new();
/// map.insert("hello", "world");
/// map.insert("alex", "steve");
/// let pairs: Vec<(&'static str, &'static str)> = map.into_iter().collect();
/// assert_eq!(pairs.len(), 2);
/// ```
pub struct OwningIter<K, V, S = RandomState> {
map: DashMap<K, V, S>,
shard_i: usize,
current: Option<GuardOwningIter<K, V>>,
}
impl<K: Eq + Hash, V, S: BuildHasher + Clone> OwningIter<K, V, S> {
pub(crate) fn new(map: DashMap<K, V, S>) -> Self {
Self {
map,
shard_i: 0,
current: None,
}
}
}
type GuardOwningIter<K, V> = hash_map::IntoIter<K, SharedValue<V>>;
impl<K: Eq + Hash, V, S: BuildHasher + Clone> Iterator for OwningIter<K, V, S> {
type Item = (K, V);
fn next(&mut self) -> Option<Self::Item> {
loop {
if let Some(current) = self.current.as_mut() {
if let Some((k, v)) = current.next() {
return Some((k, v.into_inner()));
}
}
if self.shard_i == self.map._shard_count() {
return None;
}
//let guard = unsafe { self.map._yield_read_shard(self.shard_i) };
let mut shard_wl = unsafe { self.map._yield_write_shard(self.shard_i) };
let hasher = self.map._hasher();
let map = mem::replace(&mut *shard_wl, HashMap::with_hasher(hasher));
drop(shard_wl);
let iter = map.into_iter();
//unsafe { ptr::write(&mut self.current, Some((arcee, iter))); }
self.current = Some(iter);
self.shard_i += 1;
}
}
}
unsafe impl<K, V, S> Send for OwningIter<K, V, S>
where
K: Eq + Hash + Send,
V: Send,
S: BuildHasher + Clone + Send,
{
}
unsafe impl<K, V, S> Sync for OwningIter<K, V, S>
where
K: Eq + Hash + Sync,
V: Sync,
S: BuildHasher + Clone + Sync,
{
}
type GuardIter<'a, K, V, S> = (
Arc<RwLockReadGuard<'a, HashMap<K, V, S>>>,
hash_map::Iter<'a, K, SharedValue<V>>,
);
type GuardIterMut<'a, K, V, S> = (
Arc<RwLockWriteGuard<'a, HashMap<K, V, S>>>,
hash_map::IterMut<'a, K, SharedValue<V>>,
);
/// Iterator over a DashMap yielding immutable references.
///
/// # Examples
///
/// ```
/// use dashmap::DashMap;
///
/// let map = DashMap::new();
/// map.insert("hello", "world");
/// assert_eq!(map.iter().count(), 1);
/// ```
pub struct Iter<'a, K, V, S = RandomState, M = DashMap<K, V, S>> {
map: &'a M,
shard_i: usize,
current: Option<GuardIter<'a, K, V, S>>,
}
impl<'i, K: Clone + Hash + Eq, V: Clone, S: Clone + BuildHasher> Clone for Iter<'i, K, V, S> {
fn clone(&self) -> Self {
Iter::new(self.map)
}
}
unsafe impl<'a, 'i, K, V, S, M> Send for Iter<'i, K, V, S, M>
where
K: 'a + Eq + Hash + Send,
V: 'a + Send,
S: 'a + BuildHasher + Clone,
M: Map<'a, K, V, S>,
{
}
unsafe impl<'a, 'i, K, V, S, M> Sync for Iter<'i, K, V, S, M>
where
K: 'a + Eq + Hash + Sync,
V: 'a + Sync,
S: 'a + BuildHasher + Clone,
M: Map<'a, K, V, S>,
{
}
impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> Iter<'a, K, V, S, M> {
pub(crate) fn new(map: &'a M) -> Self {
Self {
map,
shard_i: 0,
current: None,
}
}
}
impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> Iterator
for Iter<'a, K, V, S, M>
{
type Item = RefMulti<'a, K, V, S>;
fn next(&mut self) -> Option<Self::Item> {
loop {
if let Some(current) = self.current.as_mut() {
if let Some((k, v)) = current.1.next() {
let guard = current.0.clone();
return unsafe { Some(RefMulti::new(guard, k, v.get())) };
}
}
if self.shard_i == self.map._shard_count() {
return None;
}
let guard = unsafe { self.map._yield_read_shard(self.shard_i) };
let sref: &HashMap<K, V, S> = unsafe { util::change_lifetime_const(&*guard) };
let iter = sref.iter();
self.current = Some((Arc::new(guard), iter));
self.shard_i += 1;
}
}
}
/// Iterator over a DashMap yielding mutable references.
///
/// # Examples
///
/// ```
/// use dashmap::DashMap;
///
/// let map = DashMap::new();
/// map.insert("Johnny", 21);
/// map.iter_mut().for_each(|mut r| *r += 1);
/// assert_eq!(*map.get("Johnny").unwrap(), 22);
/// ```
pub struct IterMut<'a, K, V, S = RandomState, M = DashMap<K, V, S>> {
map: &'a M,
shard_i: usize,
current: Option<GuardIterMut<'a, K, V, S>>,
}
unsafe impl<'a, 'i, K, V, S, M> Send for IterMut<'i, K, V, S, M>
where
K: 'a + Eq + Hash + Send,
V: 'a + Send,
S: 'a + BuildHasher + Clone,
M: Map<'a, K, V, S>,
{
}
unsafe impl<'a, 'i, K, V, S, M> Sync for IterMut<'i, K, V, S, M>
where
K: 'a + Eq + Hash + Sync,
V: 'a + Sync,
S: 'a + BuildHasher + Clone,
M: Map<'a, K, V, S>,
{
}
impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>>
IterMut<'a, K, V, S, M>
{
pub(crate) fn new(map: &'a M) -> Self {
Self {
map,
shard_i: 0,
current: None,
}
}
}
impl<'a, K: Eq + Hash, V, S: 'a + BuildHasher + Clone, M: Map<'a, K, V, S>> Iterator
for IterMut<'a, K, V, S, M>
{
type Item = RefMutMulti<'a, K, V, S>;
fn next(&mut self) -> Option<Self::Item> {
loop {
if let Some(current) = self.current.as_mut() {
if let Some((k, v)) = current.1.next() {
let guard = current.0.clone();
unsafe {
let k = util::change_lifetime_const(k);
let v = &mut *v.as_ptr();
return Some(RefMutMulti::new(guard, k, v));
}
}
}
if self.shard_i == self.map._shard_count() {
return None;
}
let mut guard = unsafe { self.map._yield_write_shard(self.shard_i) };
let sref: &mut HashMap<K, V, S> = unsafe { util::change_lifetime_mut(&mut *guard) };
let iter = sref.iter_mut();
self.current = Some((Arc::new(guard), iter));
self.shard_i += 1;
}
}
}
#[cfg(test)]
mod tests {
use crate::DashMap;
#[test]
fn iter_mut_manual_count() {
let map = DashMap::new();
map.insert("Johnny", 21);
assert_eq!(map.len(), 1);
let mut c = 0;
for shard in map.shards() {
c += shard.write().iter_mut().count();
}
assert_eq!(c, 1);
}
#[test]
fn iter_mut_count() {
let map = DashMap::new();
map.insert("Johnny", 21);
assert_eq!(map.len(), 1);
assert_eq!(map.iter_mut().count(), 1);
}
#[test]
fn iter_count() {
let map = DashMap::new();
map.insert("Johnny", 21);
assert_eq!(map.len(), 1);
assert_eq!(map.iter().count(), 1);
}
}

71
src/iter_set.rs
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@ -1,71 +0,0 @@
use crate::setref::multiple::RefMulti;
use crate::t::Map;
use core::hash::{BuildHasher, Hash};
pub struct OwningIter<K, S> {
inner: crate::iter::OwningIter<K, (), S>,
}
impl<K: Eq + Hash, S: BuildHasher + Clone> OwningIter<K, S> {
pub(crate) fn new(inner: crate::iter::OwningIter<K, (), S>) -> Self {
Self { inner }
}
}
impl<K: Eq + Hash, S: BuildHasher + Clone> Iterator for OwningIter<K, S> {
type Item = K;
fn next(&mut self) -> Option<Self::Item> {
self.inner.next().map(|(k, _)| k)
}
}
unsafe impl<K, S> Send for OwningIter<K, S>
where
K: Eq + Hash + Send,
S: BuildHasher + Clone + Send,
{
}
unsafe impl<K, S> Sync for OwningIter<K, S>
where
K: Eq + Hash + Sync,
S: BuildHasher + Clone + Sync,
{
}
pub struct Iter<'a, K, S, M> {
inner: crate::iter::Iter<'a, K, (), S, M>,
}
unsafe impl<'a, 'i, K, S, M> Send for Iter<'i, K, S, M>
where
K: 'a + Eq + Hash + Send,
S: 'a + BuildHasher + Clone,
M: Map<'a, K, (), S>,
{
}
unsafe impl<'a, 'i, K, S, M> Sync for Iter<'i, K, S, M>
where
K: 'a + Eq + Hash + Sync,
S: 'a + BuildHasher + Clone,
M: Map<'a, K, (), S>,
{
}
impl<'a, K: Eq + Hash, S: 'a + BuildHasher + Clone, M: Map<'a, K, (), S>> Iter<'a, K, S, M> {
pub(crate) fn new(inner: crate::iter::Iter<'a, K, (), S, M>) -> Self {
Self { inner }
}
}
impl<'a, K: Eq + Hash, S: 'a + BuildHasher + Clone, M: Map<'a, K, (), S>> Iterator
for Iter<'a, K, S, M>
{
type Item = RefMulti<'a, K, S>;
fn next(&mut self) -> Option<Self::Item> {
self.inner.next().map(RefMulti::new)
}
}

1467
src/lib.rs
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300
src/lock.rs
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@ -1,300 +0,0 @@
use core::sync::atomic::{AtomicUsize, Ordering};
use parking_lot_core::{ParkToken, SpinWait, UnparkToken};
pub type RwLock<T> = lock_api::RwLock<RawRwLock, T>;
pub type RwLockReadGuard<'a, T> = lock_api::RwLockReadGuard<'a, RawRwLock, T>;
pub type RwLockWriteGuard<'a, T> = lock_api::RwLockWriteGuard<'a, RawRwLock, T>;
const READERS_PARKED: usize = 0b0001;
const WRITERS_PARKED: usize = 0b0010;
const ONE_READER: usize = 0b0100;
const ONE_WRITER: usize = !(READERS_PARKED | WRITERS_PARKED);
pub struct RawRwLock {
state: AtomicUsize,
}
unsafe impl lock_api::RawRwLock for RawRwLock {
#[allow(clippy::declare_interior_mutable_const)]
const INIT: Self = Self {
state: AtomicUsize::new(0),
};
type GuardMarker = lock_api::GuardNoSend;
#[inline]
fn try_lock_exclusive(&self) -> bool {
self.state
.compare_exchange(0, ONE_WRITER, Ordering::Acquire, Ordering::Relaxed)
.is_ok()
}
#[inline]
fn lock_exclusive(&self) {
if self
.state
.compare_exchange_weak(0, ONE_WRITER, Ordering::Acquire, Ordering::Relaxed)
.is_err()
{
self.lock_exclusive_slow();
}
}
#[inline]
unsafe fn unlock_exclusive(&self) {
if self
.state
.compare_exchange(ONE_WRITER, 0, Ordering::Release, Ordering::Relaxed)
.is_err()
{
self.unlock_exclusive_slow();
}
}
#[inline]
fn try_lock_shared(&self) -> bool {
self.try_lock_shared_fast() || self.try_lock_shared_slow()
}
#[inline]
fn lock_shared(&self) {
if !self.try_lock_shared_fast() {
self.lock_shared_slow();
}
}
#[inline]
unsafe fn unlock_shared(&self) {
let state = self.state.fetch_sub(ONE_READER, Ordering::Release);
if state == (ONE_READER | WRITERS_PARKED) {
self.unlock_shared_slow();
}
}
}
unsafe impl lock_api::RawRwLockDowngrade for RawRwLock {
#[inline]
unsafe fn downgrade(&self) {
let state = self
.state
.fetch_and(ONE_READER | WRITERS_PARKED, Ordering::Release);
if state & READERS_PARKED != 0 {
parking_lot_core::unpark_all((self as *const _ as usize) + 1, UnparkToken(0));
}
}
}
impl RawRwLock {
#[cold]
fn lock_exclusive_slow(&self) {
let mut acquire_with = 0;
loop {
let mut spin = SpinWait::new();
let mut state = self.state.load(Ordering::Relaxed);
loop {
while state & ONE_WRITER == 0 {
match self.state.compare_exchange_weak(
state,
state | ONE_WRITER | acquire_with,
Ordering::Acquire,
Ordering::Relaxed,
) {
Ok(_) => return,
Err(e) => state = e,
}
}
if state & WRITERS_PARKED == 0 {
if spin.spin() {
state = self.state.load(Ordering::Relaxed);
continue;
}
if let Err(e) = self.state.compare_exchange_weak(
state,
state | WRITERS_PARKED,
Ordering::Relaxed,
Ordering::Relaxed,
) {
state = e;
continue;
}
}
let _ = unsafe {
parking_lot_core::park(
self as *const _ as usize,
|| {
let state = self.state.load(Ordering::Relaxed);
(state & ONE_WRITER != 0) && (state & WRITERS_PARKED != 0)
},
|| {},
|_, _| {},
ParkToken(0),
None,
)
};
acquire_with = WRITERS_PARKED;
break;
}
}
}
#[cold]
fn unlock_exclusive_slow(&self) {
let state = self.state.load(Ordering::Relaxed);
assert_eq!(state & ONE_WRITER, ONE_WRITER);
let mut parked = state & (READERS_PARKED | WRITERS_PARKED);
assert_ne!(parked, 0);
if parked != (READERS_PARKED | WRITERS_PARKED) {
if let Err(new_state) =
self.state
.compare_exchange(state, 0, Ordering::Release, Ordering::Relaxed)
{
assert_eq!(new_state, ONE_WRITER | READERS_PARKED | WRITERS_PARKED);
parked = READERS_PARKED | WRITERS_PARKED;
}
}
if parked == (READERS_PARKED | WRITERS_PARKED) {
self.state.store(WRITERS_PARKED, Ordering::Release);
parked = READERS_PARKED;
}
if parked == READERS_PARKED {
return unsafe {
parking_lot_core::unpark_all((self as *const _ as usize) + 1, UnparkToken(0));
};
}
assert_eq!(parked, WRITERS_PARKED);
unsafe {
parking_lot_core::unpark_one(self as *const _ as usize, |_| UnparkToken(0));
}
}
#[inline(always)]
fn try_lock_shared_fast(&self) -> bool {
let state = self.state.load(Ordering::Relaxed);
if let Some(new_state) = state.checked_add(ONE_READER) {
if new_state & ONE_WRITER != ONE_WRITER {
return self
.state
.compare_exchange_weak(state, new_state, Ordering::Acquire, Ordering::Relaxed)
.is_ok();
}
}
false
}
#[cold]
fn try_lock_shared_slow(&self) -> bool {
let mut state = self.state.load(Ordering::Relaxed);
while let Some(new_state) = state.checked_add(ONE_READER) {
if new_state & ONE_WRITER == ONE_WRITER {
break;
}
match self.state.compare_exchange_weak(
state,
new_state,
Ordering::Acquire,
Ordering::Relaxed,
) {
Ok(_) => return true,
Err(e) => state = e,
}
}
false
}
#[cold]
fn lock_shared_slow(&self) {
loop {
let mut spin = SpinWait::new();
let mut state = self.state.load(Ordering::Relaxed);
loop {
let mut backoff = SpinWait::new();
while let Some(new_state) = state.checked_add(ONE_READER) {
assert_ne!(
new_state & ONE_WRITER,
ONE_WRITER,
"reader count overflowed",
);
if self
.state
.compare_exchange_weak(
state,
new_state,
Ordering::Acquire,
Ordering::Relaxed,
)
.is_ok()
{
return;
}
backoff.spin_no_yield();
state = self.state.load(Ordering::Relaxed);
}
if state & READERS_PARKED == 0 {
if spin.spin() {
state = self.state.load(Ordering::Relaxed);
continue;
}
if let Err(e) = self.state.compare_exchange_weak(
state,
state | READERS_PARKED,
Ordering::Relaxed,
Ordering::Relaxed,
) {
state = e;
continue;
}
}
let _ = unsafe {
parking_lot_core::park(
(self as *const _ as usize) + 1,
|| {
let state = self.state.load(Ordering::Relaxed);
(state & ONE_WRITER == ONE_WRITER) && (state & READERS_PARKED != 0)
},
|| {},
|_, _| {},
ParkToken(0),
None,
)
};
break;
}
}
}
#[cold]
fn unlock_shared_slow(&self) {
if self
.state
.compare_exchange(WRITERS_PARKED, 0, Ordering::Relaxed, Ordering::Relaxed)
.is_ok()
{
unsafe {
parking_lot_core::unpark_one(self as *const _ as usize, |_| UnparkToken(0));
}
}
}
}

278
src/mapref/entry.rs
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@ -1,278 +0,0 @@
use super::one::RefMut;
use crate::lock::RwLockWriteGuard;
use crate::util;
use crate::util::SharedValue;
use crate::HashMap;
use core::hash::{BuildHasher, Hash};
use core::mem;
use core::ptr;
use std::collections::hash_map::RandomState;
pub enum Entry<'a, K, V, S = RandomState> {
Occupied(OccupiedEntry<'a, K, V, S>),
Vacant(VacantEntry<'a, K, V, S>),
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> Entry<'a, K, V, S> {
/// Apply a function to the stored value if it exists.
pub fn and_modify(self, f: impl FnOnce(&mut V)) -> Self {
match self {
Entry::Occupied(mut entry) => {
f(entry.get_mut());
Entry::Occupied(entry)
}
Entry::Vacant(entry) => Entry::Vacant(entry),
}
}
/// Get the key of the entry.
pub fn key(&self) -> &K {
match *self {
Entry::Occupied(ref entry) => entry.key(),
Entry::Vacant(ref entry) => entry.key(),
}
}
/// Into the key of the entry.
pub fn into_key(self) -> K {
match self {
Entry::Occupied(entry) => entry.into_key(),
Entry::Vacant(entry) => entry.into_key(),
}
}
/// Return a mutable reference to the element if it exists,
/// otherwise insert the default and return a mutable reference to that.
pub fn or_default(self) -> RefMut<'a, K, V, S>
where
V: Default,
{
match self {
Entry::Occupied(entry) => entry.into_ref(),
Entry::Vacant(entry) => entry.insert(V::default()),
}
}
/// Return a mutable reference to the element if it exists,
/// otherwise a provided value and return a mutable reference to that.
pub fn or_insert(self, value: V) -> RefMut<'a, K, V, S> {
match self {
Entry::Occupied(entry) => entry.into_ref(),
Entry::Vacant(entry) => entry.insert(value),
}
}
/// Return a mutable reference to the element if it exists,
/// otherwise insert the result of a provided function and return a mutable reference to that.
pub fn or_insert_with(self, value: impl FnOnce() -> V) -> RefMut<'a, K, V, S> {
match self {
Entry::Occupied(entry) => entry.into_ref(),
Entry::Vacant(entry) => entry.insert(value()),
}
}
pub fn or_try_insert_with<E>(
self,
value: impl FnOnce() -> Result<V, E>,
) -> Result<RefMut<'a, K, V, S>, E> {
match self {
Entry::Occupied(entry) => Ok(entry.into_ref()),
Entry::Vacant(entry) => Ok(entry.insert(value()?)),
}
}
/// Sets the value of the entry, and returns a reference to the inserted value.
pub fn insert(self, value: V) -> RefMut<'a, K, V, S> {
match self {
Entry::Occupied(mut entry) => {
entry.insert(value);
entry.into_ref()
}
Entry::Vacant(entry) => entry.insert(value),
}
}
/// Sets the value of the entry, and returns an OccupiedEntry.
///
/// If you are not interested in the occupied entry,
/// consider [`insert`] as it doesn't need to clone the key.
///
/// [`insert`]: Entry::insert
pub fn insert_entry(self, value: V) -> OccupiedEntry<'a, K, V, S>
where
K: Clone,
{
match self {
Entry::Occupied(mut entry) => {
entry.insert(value);
entry
}
Entry::Vacant(entry) => entry.insert_entry(value),
}
}
}
pub struct VacantEntry<'a, K, V, S = RandomState> {
shard: RwLockWriteGuard<'a, HashMap<K, V, S>>,
key: K,
}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Send for VacantEntry<'a, K, V, S> {}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Sync for VacantEntry<'a, K, V, S> {}
impl<'a, K: Eq + Hash, V, S: BuildHasher> VacantEntry<'a, K, V, S> {
pub(crate) unsafe fn new(shard: RwLockWriteGuard<'a, HashMap<K, V, S>>, key: K) -> Self {
Self { shard, key }
}
pub fn insert(mut self, value: V) -> RefMut<'a, K, V, S> {
unsafe {
let c: K = ptr::read(&self.key);
self.shard.insert(self.key, SharedValue::new(value));
let (k, v) = self.shard.get_key_value(&c).unwrap();
let k = util::change_lifetime_const(k);
let v = &mut *v.as_ptr();
let r = RefMut::new(self.shard, k, v);
mem::forget(c);
r
}
}
/// Sets the value of the entry with the VacantEntry’s key, and returns an OccupiedEntry.
pub fn insert_entry(mut self, value: V) -> OccupiedEntry<'a, K, V, S>
where
K: Clone,
{
unsafe {
self.shard.insert(self.key.clone(), SharedValue::new(value));
let (k, v) = self.shard.get_key_value(&self.key).unwrap();
let kptr: *const K = k;
let vptr: *mut V = v.as_ptr();
OccupiedEntry::new(self.shard, self.key, (kptr, vptr))
}
}
pub fn into_key(self) -> K {
self.key
}
pub fn key(&self) -> &K {
&self.key
}
}
pub struct OccupiedEntry<'a, K, V, S = RandomState> {
shard: RwLockWriteGuard<'a, HashMap<K, V, S>>,
elem: (*const K, *mut V),
key: K,
}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Send for OccupiedEntry<'a, K, V, S> {}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Sync for OccupiedEntry<'a, K, V, S> {}
impl<'a, K: Eq + Hash, V, S: BuildHasher> OccupiedEntry<'a, K, V, S> {
pub(crate) unsafe fn new(
shard: RwLockWriteGuard<'a, HashMap<K, V, S>>,
key: K,
elem: (*const K, *mut V),
) -> Self {
Self { shard, elem, key }
}
pub fn get(&self) -> &V {
unsafe { &*self.elem.1 }
}
pub fn get_mut(&mut self) -> &mut V {
unsafe { &mut *self.elem.1 }
}
pub fn insert(&mut self, value: V) -> V {
mem::replace(self.get_mut(), value)
}
pub fn into_ref(self) -> RefMut<'a, K, V, S> {
unsafe { RefMut::new(self.shard, self.elem.0, self.elem.1) }
}
pub fn into_key(self) -> K {
self.key
}
pub fn key(&self) -> &K {
unsafe { &*self.elem.0 }
}
pub fn remove(mut self) -> V {
let key = unsafe { &*self.elem.0 };
self.shard.remove(key).unwrap().into_inner()
}
pub fn remove_entry(mut self) -> (K, V) {
let key = unsafe { &*self.elem.0 };
let (k, v) = self.shard.remove_entry(key).unwrap();
(k, v.into_inner())
}
pub fn replace_entry(mut self, value: V) -> (K, V) {
let nk = self.key;
let key = unsafe { &*self.elem.0 };
let (k, v) = self.shard.remove_entry(key).unwrap();
self.shard.insert(nk, SharedValue::new(value));
(k, v.into_inner())
}
}
#[cfg(test)]
mod tests {
use crate::DashMap;
use super::*;
#[test]
fn test_insert_entry_into_vacant() {
let map: DashMap<u32, u32> = DashMap::new();
let entry = map.entry(1);
assert!(matches!(entry, Entry::Vacant(_)));
let entry = entry.insert_entry(2);
assert_eq!(*entry.get(), 2);
drop(entry);
assert_eq!(*map.get(&1).unwrap(), 2);
}
#[test]
fn test_insert_entry_into_occupied() {
let map: DashMap<u32, u32> = DashMap::new();
map.insert(1, 1000);
let entry = map.entry(1);
assert!(matches!(&entry, Entry::Occupied(entry) if *entry.get() == 1000));
let entry = entry.insert_entry(2);
assert_eq!(*entry.get(), 2);
drop(entry);
assert_eq!(*map.get(&1).unwrap(), 2);
}
}

3
src/mapref/mod.rs
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@ -1,3 +0,0 @@
pub mod entry;
pub mod multiple;
pub mod one;

107
src/mapref/multiple.rs
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@ -1,107 +0,0 @@
use crate::lock::{RwLockReadGuard, RwLockWriteGuard};
use crate::HashMap;
use core::hash::BuildHasher;
use core::hash::Hash;
use core::ops::{Deref, DerefMut};
use std::collections::hash_map::RandomState;
use std::sync::Arc;
pub struct RefMulti<'a, K, V, S = RandomState> {
_guard: Arc<RwLockReadGuard<'a, HashMap<K, V, S>>>,
k: *const K,
v: *const V,
}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Send for RefMulti<'a, K, V, S> {}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Sync for RefMulti<'a, K, V, S> {}
impl<'a, K: Eq + Hash, V, S: BuildHasher> RefMulti<'a, K, V, S> {
pub(crate) unsafe fn new(
guard: Arc<RwLockReadGuard<'a, HashMap<K, V, S>>>,
k: *const K,
v: *const V,
) -> Self {
Self {
_guard: guard,
k,
v,
}
}
pub fn key(&self) -> &K {
self.pair().0
}
pub fn value(&self) -> &V {
self.pair().1
}
pub fn pair(&self) -> (&K, &V) {
unsafe { (&*self.k, &*self.v) }
}
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> Deref for RefMulti<'a, K, V, S> {
type Target = V;
fn deref(&self) -> &V {
self.value()
}
}
pub struct RefMutMulti<'a, K, V, S = RandomState> {
_guard: Arc<RwLockWriteGuard<'a, HashMap<K, V, S>>>,
k: *const K,
v: *mut V,
}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Send for RefMutMulti<'a, K, V, S> {}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Sync for RefMutMulti<'a, K, V, S> {}
impl<'a, K: Eq + Hash, V, S: BuildHasher> RefMutMulti<'a, K, V, S> {
pub(crate) unsafe fn new(
guard: Arc<RwLockWriteGuard<'a, HashMap<K, V, S>>>,
k: *const K,
v: *mut V,
) -> Self {
Self {
_guard: guard,
k,
v,
}
}
pub fn key(&self) -> &K {
self.pair().0
}
pub fn value(&self) -> &V {
self.pair().1
}
pub fn value_mut(&mut self) -> &mut V {
self.pair_mut().1
}
pub fn pair(&self) -> (&K, &V) {
unsafe { (&*self.k, &*self.v) }
}
pub fn pair_mut(&mut self) -> (&K, &mut V) {
unsafe { (&*self.k, &mut *self.v) }
}
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> Deref for RefMutMulti<'a, K, V, S> {
type Target = V;
fn deref(&self) -> &V {
self.value()
}
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> DerefMut for RefMutMulti<'a, K, V, S> {
fn deref_mut(&mut self) -> &mut V {
self.value_mut()
}
}

335
src/mapref/one.rs
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@ -1,335 +0,0 @@
use crate::lock::{RwLockReadGuard, RwLockWriteGuard};
use crate::HashMap;
use core::hash::{BuildHasher, Hash};
use core::ops::{Deref, DerefMut};
use std::collections::hash_map::RandomState;
use std::fmt::{Debug, Formatter};
pub struct Ref<'a, K, V, S = RandomState> {
_guard: RwLockReadGuard<'a, HashMap<K, V, S>>,
k: *const K,
v: *const V,
}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Send for Ref<'a, K, V, S> {}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Sync for Ref<'a, K, V, S> {}
impl<'a, K: Eq + Hash, V, S: BuildHasher> Ref<'a, K, V, S> {
pub(crate) unsafe fn new(
guard: RwLockReadGuard<'a, HashMap<K, V, S>>,
k: *const K,
v: *const V,
) -> Self {
Self {
_guard: guard,
k,
v,
}
}
pub fn key(&self) -> &K {
self.pair().0
}
pub fn value(&self) -> &V {
self.pair().1
}
pub fn pair(&self) -> (&K, &V) {
unsafe { (&*self.k, &*self.v) }
}
pub fn map<F, T>(self, f: F) -> MappedRef<'a, K, V, T, S>
where
F: FnOnce(&V) -> &T,
{
MappedRef {
_guard: self._guard,
k: self.k,
v: f(unsafe { &*self.v }),
}
}
pub fn try_map<F, T>(self, f: F) -> Result<MappedRef<'a, K, V, T, S>, Self>
where
F: FnOnce(&V) -> Option<&T>,
{
if let Some(v) = f(unsafe { &*self.v }) {
Ok(MappedRef {
_guard: self._guard,
k: self.k,
v,
})
} else {
Err(self)
}
}
}
impl<'a, K: Eq + Hash + Debug, V: Debug, S: BuildHasher> Debug for Ref<'a, K, V, S> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_struct("Ref")
.field("k", &self.k)
.field("v", &self.v)
.finish()
}
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> Deref for Ref<'a, K, V, S> {
type Target = V;
fn deref(&self) -> &V {
self.value()
}
}
pub struct RefMut<'a, K, V, S = RandomState> {
guard: RwLockWriteGuard<'a, HashMap<K, V, S>>,
k: *const K,
v: *mut V,
}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Send for RefMut<'a, K, V, S> {}
unsafe impl<'a, K: Eq + Hash + Sync, V: Sync, S: BuildHasher> Sync for RefMut<'a, K, V, S> {}
impl<'a, K: Eq + Hash, V, S: BuildHasher> RefMut<'a, K, V, S> {
pub(crate) unsafe fn new(
guard: RwLockWriteGuard<'a, HashMap<K, V, S>>,
k: *const K,
v: *mut V,
) -> Self {
Self { guard, k, v }
}
pub fn key(&self) -> &K {
self.pair().0
}
pub fn value(&self) -> &V {
self.pair().1
}
pub fn value_mut(&mut self) -> &mut V {
self.pair_mut().1
}
pub fn pair(&self) -> (&K, &V) {
unsafe { (&*self.k, &*self.v) }
}
pub fn pair_mut(&mut self) -> (&K, &mut V) {
unsafe { (&*self.k, &mut *self.v) }
}
pub fn downgrade(self) -> Ref<'a, K, V, S> {
unsafe { Ref::new(RwLockWriteGuard::downgrade(self.guard), self.k, self.v) }
}
pub fn map<F, T>(self, f: F) -> MappedRefMut<'a, K, V, T, S>
where
F: FnOnce(&mut V) -> &mut T,
{
MappedRefMut {
_guard: self.guard,
k: self.k,
v: f(unsafe { &mut *self.v }),
}
}
pub fn try_map<F, T>(self, f: F) -> Result<MappedRefMut<'a, K, V, T, S>, Self>
where
F: FnOnce(&mut V) -> Option<&mut T>,
{
let v = match f(unsafe { &mut *(self.v as *mut _) }) {
Some(v) => v,
None => return Err(self),
};
let guard = self.guard;
let k = self.k;
Ok(MappedRefMut {
_guard: guard,
k,
v,
})
}
}
impl<'a, K: Eq + Hash + Debug, V: Debug, S: BuildHasher> Debug for RefMut<'a, K, V, S> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_struct("RefMut")
.field("k", &self.k)
.field("v", &self.v)
.finish()
}
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> Deref for RefMut<'a, K, V, S> {
type Target = V;
fn deref(&self) -> &V {
self.value()
}
}
impl<'a, K: Eq + Hash, V, S: BuildHasher> DerefMut for RefMut<'a, K, V, S> {
fn deref_mut(&mut self) -> &mut V {
self.value_mut()
}
}
pub struct MappedRef<'a, K, V, T, S = RandomState> {
_guard: RwLockReadGuard<'a, HashMap<K, V, S>>,
k: *const K,
v: *const T,
}
impl<'a, K: Eq + Hash, V, T, S: BuildHasher> MappedRef<'a, K, V, T, S> {
pub fn key(&self) -> &K {
self.pair().0
}
pub fn value(&self) -> &T {
self.pair().1
}
pub fn pair(&self) -> (&K, &T) {
unsafe { (&*self.k, &*self.v) }
}
pub fn map<F, T2>(self, f: F) -> MappedRef<'a, K, V, T2, S>
where
F: FnOnce(&T) -> &T2,
{
MappedRef {
_guard: self._guard,
k: self.k,
v: f(unsafe { &*self.v }),
}
}
pub fn try_map<F, T2>(self, f: F) -> Result<MappedRef<'a, K, V, T2, S>, Self>
where
F: FnOnce(&T) -> Option<&T2>,
{
let v = match f(unsafe { &*self.v }) {
Some(v) => v,
None => return Err(self),
};
let guard = self._guard;
Ok(MappedRef {
_guard: guard,
k: self.k,
v,
})
}
}
impl<'a, K: Eq + Hash + Debug, V, T: Debug, S: BuildHasher> Debug for MappedRef<'a, K, V, T, S> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_struct("MappedRef")
.field("k", &self.k)
.field("v", &self.v)
.finish()
}
}
impl<'a, K: Eq + Hash, V, T, S: BuildHasher> Deref for MappedRef<'a, K, V, T, S> {
type Target = T;
fn deref(&self) -> &T {
self.value()
}
}
impl<'a, K: Eq + Hash, V, T: std::fmt::Display> std::fmt::Display for MappedRef<'a, K, V, T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
std::fmt::Display::fmt(self.value(), f)
}
}
impl<'a, K: Eq + Hash, V, T: AsRef<TDeref>, TDeref: ?Sized> AsRef<TDeref>
for MappedRef<'a, K, V, T>
{
fn as_ref(&self) -> &TDeref {
self.value().as_ref()
}
}
pub struct MappedRefMut<'a, K, V, T, S = RandomState> {
_guard: RwLockWriteGuard<'a, HashMap<K, V, S>>,
k: *const K,
v: *mut T,
}
impl<'a, K: Eq + Hash, V, T, S: BuildHasher> MappedRefMut<'a, K, V, T, S> {
pub fn key(&self) -> &K {
self.pair().0
}
pub fn value(&self) -> &T {
self.pair().1
}
pub fn value_mut(&mut self) -> &mut T {
self.pair_mut().1
}
pub fn pair(&self) -> (&K, &T) {
unsafe { (&*self.k, &*self.v) }
}
pub fn pair_mut(&mut self) -> (&K, &mut T) {
unsafe { (&*self.k, &mut *self.v) }
}
pub fn map<F, T2>(self, f: F) -> MappedRefMut<'a, K, V, T2, S>
where
F: FnOnce(&mut T) -> &mut T2,
{
MappedRefMut {
_guard: self._guard,
k: self.k,
v: f(unsafe { &mut *self.v }),
}
}
pub fn try_map<F, T2>(self, f: F) -> Result<MappedRefMut<'a, K, V, T2, S>, Self>
where
F: FnOnce(&mut T) -> Option<&mut T2>,
{
let v = match f(unsafe { &mut *(self.v as *mut _) }) {
Some(v) => v,
None => return Err(self),
};
let guard = self._guard;
let k = self.k;
Ok(MappedRefMut {
_guard: guard,
k,
v,
})
}
}
impl<'a, K: Eq + Hash + Debug, V, T: Debug, S: BuildHasher> Debug for MappedRefMut<'a, K, V, T, S> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_struct("MappedRefMut")
.field("k", &self.k)
.field("v", &self.v)
.finish()
}
}
impl<'a, K: Eq + Hash, V, T, S: BuildHasher> Deref for MappedRefMut<'a, K, V, T, S> {
type Target = T;
fn deref(&self) -> &T {
self.value()
}
}
impl<'a, K: Eq + Hash, V, T, S: BuildHasher> DerefMut for MappedRefMut<'a, K, V, T, S> {
fn deref_mut(&mut self) -> &mut T {
self.value_mut()
}
}

31
src/node.rs Normal file
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@ -0,0 +1,31 @@
use std::mem::MaybeUninit;
use std::mem::ManuallyDrop;
const BRANCHING_FACTOR: usize = 4;
// how many entries we can index with log2_n bits
const fn node_cap(log2_n: usize) -> usize {
1 << log2_n
}
// 2 bits per entry and 8 bits per byte
const fn metadata_len(log2_n: usize) -> usize {
node_cap(log2_n) * 2 / 8
}
#[repr(u8)]
enum Kind {
Empty = 0b00,
Leaf = 0b01,
Branch = 0b10,
}
union Slot<T, N> {
leaf: ManuallyDrop<MaybeUninit<T>>,
branch: *mut N,
}
pub struct Node<const METADATA_BITS: usize, const CAPACITY: usize, T> {
metadata: [u8; METADATA_BITS],
slots: [Slot<T, Self>; CAPACITY],
}

221
src/rayon/map.rs
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@ -1,221 +0,0 @@
use crate::lock::RwLock;
use crate::mapref::multiple::{RefMulti, RefMutMulti};
use crate::util;
use crate::{DashMap, HashMap};
use core::hash::{BuildHasher, Hash};
use rayon::iter::plumbing::UnindexedConsumer;
use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, ParallelIterator};
use std::collections::hash_map::RandomState;
use std::sync::Arc;
impl<K, V, S> ParallelExtend<(K, V)> for DashMap<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = (K, V)>,
{
(&*self).par_extend(par_iter);
}
}
// Since we don't actually need mutability, we can implement this on a
// reference, similar to `io::Write for &File`.
impl<K, V, S> ParallelExtend<(K, V)> for &'_ DashMap<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = (K, V)>,
{
let &mut map = self;
par_iter.into_par_iter().for_each(move |(key, value)| {
map.insert(key, value);
});
}
}
impl<K, V, S> FromParallelIterator<(K, V)> for DashMap<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + Default + BuildHasher,
{
fn from_par_iter<I>(par_iter: I) -> Self
where
I: IntoParallelIterator<Item = (K, V)>,
{
let map = Self::default();
(&map).par_extend(par_iter);
map
}
}
// Implementation note: while the shards will iterate in parallel, we flatten
// sequentially within each shard (`flat_map_iter`), because the standard
// `HashMap` only implements `ParallelIterator` by collecting to a `Vec` first.
// There is real parallel support in the `hashbrown/rayon` feature, but we don't
// always use that map.
impl<K, V, S> IntoParallelIterator for DashMap<K, V, S>
where
K: Send + Eq + Hash,
V: Send,
S: Send + Clone + BuildHasher,
{
type Iter = OwningIter<K, V, S>;
type Item = (K, V);
fn into_par_iter(self) -> Self::Iter {
OwningIter {
shards: self.shards,
}
}
}
pub struct OwningIter<K, V, S = RandomState> {
pub(super) shards: Box<[RwLock<HashMap<K, V, S>>]>,
}
impl<K, V, S> ParallelIterator for OwningIter<K, V, S>
where
K: Send + Eq + Hash,
V: Send,
S: Send + Clone + BuildHasher,
{
type Item = (K, V);
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
Vec::from(self.shards)
.into_par_iter()
.flat_map_iter(|shard| {
shard
.into_inner()
.into_iter()
.map(|(k, v)| (k, v.into_inner()))
})
.drive_unindexed(consumer)
}
}
// This impl also enables `IntoParallelRefIterator::par_iter`
impl<'a, K, V, S> IntoParallelIterator for &'a DashMap<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
type Iter = Iter<'a, K, V, S>;
type Item = RefMulti<'a, K, V, S>;
fn into_par_iter(self) -> Self::Iter {
Iter {
shards: &self.shards,
}
}
}
pub struct Iter<'a, K, V, S = RandomState> {
pub(super) shards: &'a [RwLock<HashMap<K, V, S>>],
}
impl<'a, K, V, S> ParallelIterator for Iter<'a, K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
type Item = RefMulti<'a, K, V, S>;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
self.shards
.into_par_iter()
.flat_map_iter(|shard| {
let guard = shard.read();
let sref: &'a HashMap<K, V, S> = unsafe { util::change_lifetime_const(&*guard) };
let guard = Arc::new(guard);
sref.iter().map(move |(k, v)| {
let guard = Arc::clone(&guard);
unsafe { RefMulti::new(guard, k, v.get()) }
})
})
.drive_unindexed(consumer)
}
}
// This impl also enables `IntoParallelRefMutIterator::par_iter_mut`
impl<'a, K, V, S> IntoParallelIterator for &'a mut DashMap<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
type Iter = IterMut<'a, K, V, S>;
type Item = RefMutMulti<'a, K, V, S>;
fn into_par_iter(self) -> Self::Iter {
IterMut {
shards: &self.shards,
}
}
}
impl<K, V, S> DashMap<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
// Unlike `IntoParallelRefMutIterator::par_iter_mut`, we only _need_ `&self`.
pub fn par_iter_mut(&self) -> IterMut<'_, K, V, S> {
IterMut {
shards: &self.shards,
}
}
}
pub struct IterMut<'a, K, V, S = RandomState> {
shards: &'a [RwLock<HashMap<K, V, S>>],
}
impl<'a, K, V, S> ParallelIterator for IterMut<'a, K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
type Item = RefMutMulti<'a, K, V, S>;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
self.shards
.into_par_iter()
.flat_map_iter(|shard| {
let mut guard = shard.write();
let sref: &'a mut HashMap<K, V, S> =
unsafe { util::change_lifetime_mut(&mut *guard) };
let guard = Arc::new(guard);
sref.iter_mut().map(move |(k, v)| {
let guard = Arc::clone(&guard);
unsafe { RefMutMulti::new(guard, k, v.get_mut()) }
})
})
.drive_unindexed(consumer)
}
}

96
src/rayon/read_only.rs
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@ -1,96 +0,0 @@
use crate::mapref::multiple::RefMulti;
use crate::rayon::map::Iter;
use crate::ReadOnlyView;
use core::hash::{BuildHasher, Hash};
use rayon::iter::IntoParallelIterator;
impl<K, V, S> IntoParallelIterator for ReadOnlyView<K, V, S>
where
K: Send + Eq + Hash,
V: Send,
S: Send + Clone + BuildHasher,
{
type Iter = super::map::OwningIter<K, V, S>;
type Item = (K, V);
fn into_par_iter(self) -> Self::Iter {
super::map::OwningIter {
shards: self.map.shards,
}
}
}
// This impl also enables `IntoParallelRefIterator::par_iter`
impl<'a, K, V, S> IntoParallelIterator for &'a ReadOnlyView<K, V, S>
where
K: Send + Sync + Eq + Hash,
V: Send + Sync,
S: Send + Sync + Clone + BuildHasher,
{
type Iter = Iter<'a, K, V, S>;
type Item = RefMulti<'a, K, V, S>;
fn into_par_iter(self) -> Self::Iter {
Iter {
shards: &self.map.shards,
}
}
}
#[cfg(test)]
mod tests {
use crate::DashMap;
use rayon::iter::{IntoParallelIterator, IntoParallelRefIterator, ParallelIterator};
fn construct_sample_map() -> DashMap<i32, String> {
let map = DashMap::new();
map.insert(1, "one".to_string());
map.insert(10, "ten".to_string());
map.insert(27, "twenty seven".to_string());
map.insert(45, "forty five".to_string());
map
}
#[test]
fn test_par_iter() {
let map = construct_sample_map();
let view = map.clone().into_read_only();
view.par_iter().for_each(|entry| {
let key = *entry.key();
assert!(view.contains_key(&key));
let map_entry = map.get(&key).unwrap();
assert_eq!(view.get(&key).unwrap(), map_entry.value());
let key_value: (&i32, &String) = view.get_key_value(&key).unwrap();
assert_eq!(key_value.0, map_entry.key());
assert_eq!(key_value.1, map_entry.value());
});
}
#[test]
fn test_into_par_iter() {
let map = construct_sample_map();
let view = map.clone().into_read_only();
view.into_par_iter().for_each(|(key, value)| {
let map_entry = map.get(&key).unwrap();
assert_eq!(&key, map_entry.key());
assert_eq!(&value, map_entry.value());
});
}
}

121
src/rayon/set.rs
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@ -1,121 +0,0 @@
use crate::setref::multiple::RefMulti;
use crate::DashSet;
use core::hash::{BuildHasher, Hash};
use rayon::iter::plumbing::UnindexedConsumer;
use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, ParallelIterator};
use std::collections::hash_map::RandomState;
impl<K, S> ParallelExtend<K> for DashSet<K, S>
where
K: Send + Sync + Eq + Hash,
S: Send + Sync + Clone + BuildHasher,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = K>,
{
(&*self).par_extend(par_iter);
}
}
// Since we don't actually need mutability, we can implement this on a
// reference, similar to `io::Write for &File`.
impl<K, S> ParallelExtend<K> for &'_ DashSet<K, S>
where
K: Send + Sync + Eq + Hash,
S: Send + Sync + Clone + BuildHasher,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = K>,
{
let &mut set = self;
par_iter.into_par_iter().for_each(move |key| {
set.insert(key);
});
}
}
impl<K, S> FromParallelIterator<K> for DashSet<K, S>
where
K: Send + Sync + Eq + Hash,
S: Send + Sync + Clone + Default + BuildHasher,
{
fn from_par_iter<I>(par_iter: I) -> Self
where
I: IntoParallelIterator<Item = K>,
{
let set = Self::default();
(&set).par_extend(par_iter);
set
}
}
impl<K, S> IntoParallelIterator for DashSet<K, S>
where
K: Send + Eq + Hash,
S: Send + Clone + BuildHasher,
{
type Iter = OwningIter<K, S>;
type Item = K;
fn into_par_iter(self) -> Self::Iter {
OwningIter {
inner: self.inner.into_par_iter(),
}
}
}
pub struct OwningIter<K, S = RandomState> {
inner: super::map::OwningIter<K, (), S>,
}
impl<K, S> ParallelIterator for OwningIter<K, S>
where
K: Send + Eq + Hash,
S: Send + Clone + BuildHasher,
{
type Item = K;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
self.inner.map(|(k, _)| k).drive_unindexed(consumer)
}
}
// This impl also enables `IntoParallelRefIterator::par_iter`
impl<'a, K, S> IntoParallelIterator for &'a DashSet<K, S>
where
K: Send + Sync + Eq + Hash,
S: Send + Sync + Clone + BuildHasher,
{
type Iter = Iter<'a, K, S>;
type Item = RefMulti<'a, K, S>;
fn into_par_iter(self) -> Self::Iter {
Iter {
inner: (&self.inner).into_par_iter(),
}
}
}
pub struct Iter<'a, K, S = RandomState> {
inner: super::map::Iter<'a, K, (), S>,
}
impl<'a, K, S> ParallelIterator for Iter<'a, K, S>
where
K: Send + Sync + Eq + Hash,
S: Send + Sync + Clone + BuildHasher,
{
type Item = RefMulti<'a, K, S>;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
self.inner.map(RefMulti::new).drive_unindexed(consumer)
}
}

271
src/read_only.rs
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@ -1,271 +0,0 @@
use crate::lock::RwLock;
use crate::t::Map;
use crate::{DashMap, HashMap};
use cfg_if::cfg_if;
use core::borrow::Borrow;
use core::fmt;
use core::hash::{BuildHasher, Hash};
use std::collections::hash_map::RandomState;
/// A read-only view into a `DashMap`. Allows to obtain raw references to the stored values.
pub struct ReadOnlyView<K, V, S = RandomState> {
pub(crate) map: DashMap<K, V, S>,
}
impl<K: Eq + Hash + Clone, V: Clone, S: Clone> Clone for ReadOnlyView<K, V, S> {
fn clone(&self) -> Self {
Self {
map: self.map.clone(),
}
}
}
impl<K: Eq + Hash + fmt::Debug, V: fmt::Debug, S: BuildHasher + Clone> fmt::Debug
for ReadOnlyView<K, V, S>
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.map.fmt(f)
}
}
impl<K, V, S> ReadOnlyView<K, V, S> {
pub(crate) fn new(map: DashMap<K, V, S>) -> Self {
Self { map }
}
/// Consumes this `ReadOnlyView`, returning the underlying `DashMap`.
pub fn into_inner(self) -> DashMap<K, V, S> {
self.map
}
}
impl<'a, K: 'a + Eq + Hash, V: 'a, S: BuildHasher + Clone> ReadOnlyView<K, V, S> {
/// Returns the number of elements in the map.
pub fn len(&self) -> usize {
self.map.len()
}
/// Returns `true` if the map contains no elements.
pub fn is_empty(&self) -> bool {
self.map.is_empty()
}
/// Returns the number of elements the map can hold without reallocating.
pub fn capacity(&self) -> usize {
self.map.capacity()
}
/// Returns `true` if the map contains a value for the specified key.
pub fn contains_key<Q>(&'a self, key: &Q) -> bool
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
let hash = self.map.hash_usize(&key);
let idx = self.map.determine_shard(hash);
let shard = unsafe { self.map._get_read_shard(idx) };
shard.contains_key(key)
}
/// Returns a reference to the value corresponding to the key.
pub fn get<Q>(&'a self, key: &Q) -> Option<&'a V>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
let hash = self.map.hash_usize(&key);
let idx = self.map.determine_shard(hash);
let shard = unsafe { self.map._get_read_shard(idx) };
shard.get(key).map(|v| v.get())
}
/// Returns the key-value pair corresponding to the supplied key.
pub fn get_key_value<Q>(&'a self, key: &Q) -> Option<(&'a K, &'a V)>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
let hash = self.map.hash_usize(&key);
let idx = self.map.determine_shard(hash);
let shard = unsafe { self.map._get_read_shard(idx) };
shard.get_key_value(key).map(|(k, v)| (k, v.get()))
}
fn shard_read_iter(&'a self) -> impl Iterator<Item = &'a HashMap<K, V, S>> + 'a {
(0..self.map._shard_count())
.map(move |shard_i| unsafe { self.map._get_read_shard(shard_i) })
}
/// An iterator visiting all key-value pairs in arbitrary order. The iterator element type is `(&'a K, &'a V)`.
pub fn iter(&'a self) -> impl Iterator<Item = (&'a K, &'a V)> + 'a {
self.shard_read_iter()
.flat_map(|shard| shard.iter())
.map(|(k, v)| (k, v.get()))
}
/// An iterator visiting all keys in arbitrary order. The iterator element type is `&'a K`.
pub fn keys(&'a self) -> impl Iterator<Item = &'a K> + 'a {
self.shard_read_iter().flat_map(|shard| shard.keys())
}
/// An iterator visiting all values in arbitrary order. The iterator element type is `&'a V`.
pub fn values(&'a self) -> impl Iterator<Item = &'a V> + 'a {
self.shard_read_iter()
.flat_map(|shard| shard.values())
.map(|v| v.get())
}
cfg_if! {
if #[cfg(feature = "raw-api")] {
/// Allows you to peek at the inner shards that store your data.
/// You should probably not use this unless you know what you are doing.
///
/// Requires the `raw-api` feature to be enabled.
///
/// # Examples
///
/// ```
/// use dashmap::DashMap;
///
/// let map = DashMap::<(), ()>::new().into_read_only();
/// println!("Amount of shards: {}", map.shards().len());
/// ```
pub fn shards(&self) -> &[RwLock<HashMap<K, V, S>>] {
&self.map.shards
}
} else {
#[allow(dead_code)]
pub(crate) fn shards(&self) -> &[RwLock<HashMap<K, V, S>>] {
&self.map.shards
}
}
}
}
#[cfg(test)]
mod tests {
use crate::DashMap;
fn construct_sample_map() -> DashMap<i32, String> {
let map = DashMap::new();
map.insert(1, "one".to_string());
map.insert(10, "ten".to_string());
map.insert(27, "twenty seven".to_string());
map.insert(45, "forty five".to_string());
map
}
#[test]
fn test_properties() {
let map = construct_sample_map();
let view = map.clone().into_read_only();
assert_eq!(view.is_empty(), map.is_empty());
assert_eq!(view.len(), map.len());
assert_eq!(view.capacity(), map.capacity());
let new_map = view.into_inner();
assert_eq!(new_map.is_empty(), map.is_empty());
assert_eq!(new_map.len(), map.len());
assert_eq!(new_map.capacity(), map.capacity());
}
#[test]
fn test_get() {
let map = construct_sample_map();
let view = map.clone().into_read_only();
for key in map.iter().map(|entry| *entry.key()) {
assert!(view.contains_key(&key));
let map_entry = map.get(&key).unwrap();
assert_eq!(view.get(&key).unwrap(), map_entry.value());
let key_value: (&i32, &String) = view.get_key_value(&key).unwrap();
assert_eq!(key_value.0, map_entry.key());
assert_eq!(key_value.1, map_entry.value());
}
}
#[test]
fn test_iters() {
let map = construct_sample_map();
let view = map.clone().into_read_only();
let mut visited_items = Vec::new();
for (key, value) in view.iter() {
map.contains_key(key);
let map_entry = map.get(key).unwrap();
assert_eq!(key, map_entry.key());
assert_eq!(value, map_entry.value());
visited_items.push((key, value));
}
let mut visited_keys = Vec::new();
for key in view.keys() {
map.contains_key(key);
let map_entry = map.get(key).unwrap();
assert_eq!(key, map_entry.key());
assert_eq!(view.get(key).unwrap(), map_entry.value());
visited_keys.push(key);
}
let mut visited_values = Vec::new();
for value in view.values() {
visited_values.push(value);
}
for entry in map.iter() {
let key = entry.key();
let value = entry.value();
assert!(visited_keys.contains(&key));
assert!(visited_values.contains(&value));
assert!(visited_items.contains(&(key, value)));
}
}
}

215
src/serde.rs
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@ -1,215 +0,0 @@
use crate::{mapref, setref, DashMap, DashSet};
use core::fmt;
use core::hash::{BuildHasher, Hash};
use core::marker::PhantomData;
use serde::de::{Deserialize, MapAccess, SeqAccess, Visitor};
use serde::ser::{Serialize, SerializeMap, SerializeSeq, Serializer};
use serde::Deserializer;
pub struct DashMapVisitor<K, V, S> {
marker: PhantomData<fn() -> DashMap<K, V, S>>,
}
impl<K, V, S> DashMapVisitor<K, V, S>
where
K: Eq + Hash,
S: BuildHasher + Clone,
{
fn new() -> Self {
DashMapVisitor {
marker: PhantomData,
}
}
}
impl<'de, K, V, S> Visitor<'de> for DashMapVisitor<K, V, S>
where
K: Deserialize<'de> + Eq + Hash,
V: Deserialize<'de>,
S: BuildHasher + Clone + Default,
{
type Value = DashMap<K, V, S>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a DashMap")
}
fn visit_map<M>(self, mut access: M) -> Result<Self::Value, M::Error>
where
M: MapAccess<'de>,
{
let map =
DashMap::with_capacity_and_hasher(access.size_hint().unwrap_or(0), Default::default());
while let Some((key, value)) = access.next_entry()? {
map.insert(key, value);
}
Ok(map)
}
}
impl<'de, K, V, S> Deserialize<'de> for DashMap<K, V, S>
where
K: Deserialize<'de> + Eq + Hash,
V: Deserialize<'de>,
S: BuildHasher + Clone + Default,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_map(DashMapVisitor::<K, V, S>::new())
}
}
impl<K, V, H> Serialize for DashMap<K, V, H>
where
K: Serialize + Eq + Hash,
V: Serialize,
H: BuildHasher + Clone,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let mut map = serializer.serialize_map(Some(self.len()))?;
for ref_multi in self.iter() {
map.serialize_entry(ref_multi.key(), ref_multi.value())?;
}
map.end()
}
}
pub struct DashSetVisitor<K, S> {
marker: PhantomData<fn() -> DashSet<K, S>>,
}
impl<K, S> DashSetVisitor<K, S>
where
K: Eq + Hash,
S: BuildHasher + Clone,
{
fn new() -> Self {
DashSetVisitor {
marker: PhantomData,
}
}
}
impl<'de, K, S> Visitor<'de> for DashSetVisitor<K, S>
where
K: Deserialize<'de> + Eq + Hash,
S: BuildHasher + Clone + Default,
{
type Value = DashSet<K, S>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a DashSet")
}
fn visit_seq<M>(self, mut access: M) -> Result<Self::Value, M::Error>
where
M: SeqAccess<'de>,
{
let map =
DashSet::with_capacity_and_hasher(access.size_hint().unwrap_or(0), Default::default());
while let Some(key) = access.next_element()? {
map.insert(key);
}
Ok(map)
}
}
impl<'de, K, S> Deserialize<'de> for DashSet<K, S>
where
K: Deserialize<'de> + Eq + Hash,
S: BuildHasher + Clone + Default,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_seq(DashSetVisitor::<K, S>::new())
}
}
impl<K, H> Serialize for DashSet<K, H>
where
K: Serialize + Eq + Hash,
H: BuildHasher + Clone,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let mut seq = serializer.serialize_seq(Some(self.len()))?;
for ref_multi in self.iter() {
seq.serialize_element(ref_multi.key())?;
}
seq.end()
}
}
macro_rules! serialize_impl {
() => {
fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>
where
Ser: serde::Serializer,
{
std::ops::Deref::deref(self).serialize(serializer)
}
};
}
// Map
impl<'a, K: Eq + Hash, V: Serialize, S: BuildHasher> Serialize
for mapref::multiple::RefMulti<'a, K, V, S>
{
serialize_impl! {}
}
impl<'a, K: Eq + Hash, V: Serialize, S: BuildHasher> Serialize
for mapref::multiple::RefMutMulti<'a, K, V, S>
{
serialize_impl! {}
}
impl<'a, K: Eq + Hash, V: Serialize, S: BuildHasher> Serialize for mapref::one::Ref<'a, K, V, S> {
serialize_impl! {}
}
impl<'a, K: Eq + Hash, V: Serialize, S: BuildHasher> Serialize
for mapref::one::RefMut<'a, K, V, S>
{
serialize_impl! {}
}
impl<'a, K: Eq + Hash, V, T: Serialize, S: BuildHasher> Serialize
for mapref::one::MappedRef<'a, K, V, T, S>
{
serialize_impl! {}
}
impl<'a, K: Eq + Hash, V, T: Serialize, S: BuildHasher> Serialize
for mapref::one::MappedRefMut<'a, K, V, T, S>
{
serialize_impl! {}
}
// Set
impl<'a, V: Hash + Eq + Serialize, S: BuildHasher> Serialize
for setref::multiple::RefMulti<'a, V, S>
{
serialize_impl! {}
}
impl<'a, V: Hash + Eq + Serialize, S: BuildHasher> Serialize for setref::one::Ref<'a, V, S> {
serialize_impl! {}
}

458
src/set.rs
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@ -1,458 +0,0 @@
use crate::iter_set::{Iter, OwningIter};
#[cfg(feature = "raw-api")]
use crate::lock::RwLock;
use crate::setref::one::Ref;
use crate::DashMap;
#[cfg(feature = "raw-api")]
use crate::HashMap;
use cfg_if::cfg_if;
use core::borrow::Borrow;
use core::fmt;
use core::hash::{BuildHasher, Hash};
use core::iter::FromIterator;
use std::collections::hash_map::RandomState;
/// DashSet is a thin wrapper around [`DashMap`] using `()` as the value type. It uses
/// methods and types which are more convenient to work with on a set.
///
/// [`DashMap`]: struct.DashMap.html
pub struct DashSet<K, S = RandomState> {
pub(crate) inner: DashMap<K, (), S>,
}
impl<K: Eq + Hash + fmt::Debug, S: BuildHasher + Clone> fmt::Debug for DashSet<K, S> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&self.inner, f)
}
}
impl<K: Eq + Hash + Clone, S: Clone> Clone for DashSet<K, S> {
fn clone(&self) -> Self {
Self {
inner: self.inner.clone(),
}
}
fn clone_from(&mut self, source: &Self) {
self.inner.clone_from(&source.inner)
}
}
impl<K, S> Default for DashSet<K, S>
where
K: Eq + Hash,
S: Default + BuildHasher + Clone,
{
fn default() -> Self {
Self::with_hasher(Default::default())
}
}
impl<'a, K: 'a + Eq + Hash> DashSet<K, RandomState> {
/// Creates a new DashSet with a capacity of 0.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let games = DashSet::new();
/// games.insert("Veloren");
/// ```
pub fn new() -> Self {
Self::with_hasher(RandomState::default())
}
/// Creates a new DashMap with a specified starting capacity.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let numbers = DashSet::with_capacity(2);
/// numbers.insert(2);
/// numbers.insert(8);
/// ```
pub fn with_capacity(capacity: usize) -> Self {
Self::with_capacity_and_hasher(capacity, RandomState::default())
}
}
impl<'a, K: 'a + Eq + Hash, S: BuildHasher + Clone> DashSet<K, S> {
/// Creates a new DashMap with a capacity of 0 and the provided hasher.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let games = DashSet::with_hasher(s);
/// games.insert("Veloren");
/// ```
pub fn with_hasher(hasher: S) -> Self {
Self::with_capacity_and_hasher(0, hasher)
}
/// Creates a new DashMap with a specified starting capacity and hasher.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let numbers = DashSet::with_capacity_and_hasher(2, s);
/// numbers.insert(2);
/// numbers.insert(8);
/// ```
pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> Self {
Self {
inner: DashMap::with_capacity_and_hasher(capacity, hasher),
}
}
/// Hash a given item to produce a usize.
/// Uses the provided or default HashBuilder.
pub fn hash_usize<T: Hash>(&self, item: &T) -> usize {
self.inner.hash_usize(item)
}
cfg_if! {
if #[cfg(feature = "raw-api")] {
/// Allows you to peek at the inner shards that store your data.
/// You should probably not use this unless you know what you are doing.
///
/// Requires the `raw-api` feature to be enabled.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let set = DashSet::<()>::new();
/// println!("Amount of shards: {}", set.shards().len());
/// ```
pub fn shards(&self) -> &[RwLock<HashMap<K, (), S>>] {
self.inner.shards()
}
}
}
cfg_if! {
if #[cfg(feature = "raw-api")] {
/// Finds which shard a certain key is stored in.
/// You should probably not use this unless you know what you are doing.
/// Note that shard selection is dependent on the default or provided HashBuilder.
///
/// Requires the `raw-api` feature to be enabled.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let set = DashSet::new();
/// set.insert("coca-cola");
/// println!("coca-cola is stored in shard: {}", set.determine_map("coca-cola"));
/// ```
pub fn determine_map<Q>(&self, key: &Q) -> usize
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
self.inner.determine_map(key)
}
}
}
cfg_if! {
if #[cfg(feature = "raw-api")] {
/// Finds which shard a certain hash is stored in.
///
/// Requires the `raw-api` feature to be enabled.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let set: DashSet<i32> = DashSet::new();
/// let key = "key";
/// let hash = set.hash_usize(&key);
/// println!("hash is stored in shard: {}", set.determine_shard(hash));
/// ```
pub fn determine_shard(&self, hash: usize) -> usize {
self.inner.determine_shard(hash)
}
}
}
/// Inserts a key into the set. Returns true if the key was not already in the set.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let set = DashSet::new();
/// set.insert("I am the key!");
/// ```
pub fn insert(&self, key: K) -> bool {
self.inner.insert(key, ()).is_none()
}
/// Removes an entry from the map, returning the key if it existed in the map.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let soccer_team = DashSet::new();
/// soccer_team.insert("Jack");
/// assert_eq!(soccer_team.remove("Jack").unwrap(), "Jack");
/// ```
pub fn remove<Q>(&self, key: &Q) -> Option<K>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
self.inner.remove(key).map(|(k, _)| k)
}
/// Removes an entry from the set, returning the key
/// if the entry existed and the provided conditional function returned true.
///
/// ```
/// use dashmap::DashSet;
///
/// let soccer_team = DashSet::new();
/// soccer_team.insert("Sam");
/// soccer_team.remove_if("Sam", |player| player.starts_with("Ja"));
/// assert!(soccer_team.contains("Sam"));
/// ```
/// ```
/// use dashmap::DashSet;
///
/// let soccer_team = DashSet::new();
/// soccer_team.insert("Sam");
/// soccer_team.remove_if("Jacob", |player| player.starts_with("Ja"));
/// assert!(!soccer_team.contains("Jacob"));
/// ```
pub fn remove_if<Q>(&self, key: &Q, f: impl FnOnce(&K) -> bool) -> Option<K>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
// TODO: Don't create another closure around f
self.inner.remove_if(key, |k, _| f(k)).map(|(k, _)| k)
}
/// Creates an iterator over a DashMap yielding immutable references.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let words = DashSet::new();
/// words.insert("hello");
/// assert_eq!(words.iter().count(), 1);
/// ```
pub fn iter(&'a self) -> Iter<'a, K, S, DashMap<K, (), S>> {
let iter = self.inner.iter();
Iter::new(iter)
}
/// Get a reference to an entry in the set
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let youtubers = DashSet::new();
/// youtubers.insert("Bosnian Bill");
/// assert_eq!(*youtubers.get("Bosnian Bill").unwrap(), "Bosnian Bill");
/// ```
pub fn get<Q>(&'a self, key: &Q) -> Option<Ref<'a, K, S>>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
self.inner.get(key).map(Ref::new)
}
/// Remove excess capacity to reduce memory usage.
pub fn shrink_to_fit(&self) {
self.inner.shrink_to_fit()
}
/// Retain elements that whose predicates return true
/// and discard elements whose predicates return false.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let people = DashSet::new();
/// people.insert("Albin");
/// people.insert("Jones");
/// people.insert("Charlie");
/// people.retain(|name| name.contains('i'));
/// assert_eq!(people.len(), 2);
/// ```
pub fn retain(&self, mut f: impl FnMut(&K) -> bool) {
self.inner.retain(|k, _| f(k))
}
/// Fetches the total number of keys stored in the set.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let people = DashSet::new();
/// people.insert("Albin");
/// people.insert("Jones");
/// people.insert("Charlie");
/// assert_eq!(people.len(), 3);
/// ```
pub fn len(&self) -> usize {
self.inner.len()
}
/// Checks if the set is empty or not.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let map = DashSet::<()>::new();
/// assert!(map.is_empty());
/// ```
pub fn is_empty(&self) -> bool {
self.inner.is_empty()
}
/// Removes all keys in the set.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let people = DashSet::new();
/// people.insert("Albin");
/// assert!(!people.is_empty());
/// people.clear();
/// assert!(people.is_empty());
/// ```
pub fn clear(&self) {
self.inner.clear()
}
/// Returns how many keys the set can store without reallocating.
pub fn capacity(&self) -> usize {
self.inner.capacity()
}
/// Checks if the set contains a specific key.
///
/// # Examples
///
/// ```
/// use dashmap::DashSet;
///
/// let people = DashSet::new();
/// people.insert("Dakota Cherries");
/// assert!(people.contains("Dakota Cherries"));
/// ```
pub fn contains<Q>(&self, key: &Q) -> bool
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
self.inner.contains_key(key)
}
}
impl<K: Eq + Hash, S: BuildHasher + Clone> IntoIterator for DashSet<K, S> {
type Item = K;
type IntoIter = OwningIter<K, S>;
fn into_iter(self) -> Self::IntoIter {
OwningIter::new(self.inner.into_iter())
}
}
impl<K: Eq + Hash, S: BuildHasher + Clone> Extend<K> for DashSet<K, S> {
fn extend<T: IntoIterator<Item = K>>(&mut self, iter: T) {
let iter = iter.into_iter().map(|k| (k, ()));
self.inner.extend(iter)
}
}
impl<K: Eq + Hash, S: BuildHasher + Clone + Default> FromIterator<K> for DashSet<K, S> {
fn from_iter<I: IntoIterator<Item = K>>(iter: I) -> Self {
let mut set = DashSet::default();
set.extend(iter);
set
}
}
#[cfg(test)]
mod tests {
use crate::DashSet;
#[test]
fn test_basic() {
let set = DashSet::new();
set.insert(0);
assert_eq!(set.get(&0).as_deref(), Some(&0));
}
#[test]
fn test_default() {
let set: DashSet<u32> = DashSet::default();
set.insert(0);
assert_eq!(set.get(&0).as_deref(), Some(&0));
}
#[test]
fn test_multiple_hashes() {
let set = DashSet::<u32>::default();
for i in 0..100 {
assert!(set.insert(i));
}
for i in 0..100 {
assert!(!set.insert(i));
}
for i in 0..100 {
assert_eq!(Some(i), set.remove(&i));
}
for i in 0..100 {
assert_eq!(None, set.remove(&i));
}
}
}

2
src/setref/mod.rs
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@ -1,2 +0,0 @@
pub mod multiple;
pub mod one;

25
src/setref/multiple.rs
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@ -1,25 +0,0 @@
use crate::mapref;
use core::hash::{BuildHasher, Hash};
use core::ops::Deref;
use std::collections::hash_map::RandomState;
pub struct RefMulti<'a, K, S = RandomState> {
inner: mapref::multiple::RefMulti<'a, K, (), S>,
}
impl<'a, K: Eq + Hash, S: BuildHasher> RefMulti<'a, K, S> {
pub(crate) fn new(inner: mapref::multiple::RefMulti<'a, K, (), S>) -> Self {
Self { inner }
}
pub fn key(&self) -> &K {
self.inner.key()
}
}
impl<'a, K: Eq + Hash, S: BuildHasher> Deref for RefMulti<'a, K, S> {
type Target = K;
fn deref(&self) -> &K {
self.key()
}
}

25
src/setref/one.rs
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@ -1,25 +0,0 @@
use crate::mapref;
use core::hash::{BuildHasher, Hash};
use core::ops::Deref;
use std::collections::hash_map::RandomState;
pub struct Ref<'a, K, S = RandomState> {
inner: mapref::one::Ref<'a, K, (), S>,
}
impl<'a, K: Eq + Hash, S: BuildHasher> Ref<'a, K, S> {
pub(crate) fn new(inner: mapref::one::Ref<'a, K, (), S>) -> Self {
Self { inner }
}
pub fn key(&self) -> &K {
self.inner.key()
}
}
impl<'a, K: Eq + Hash, S: BuildHasher> Deref for Ref<'a, K, S> {
type Target = K;
fn deref(&self) -> &K {
self.key()
}
}

134
src/t.rs
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@ -1,134 +0,0 @@
//! Central map trait to ease modifications and extensions down the road.
use crate::iter::{Iter, IterMut};
use crate::lock::{RwLockReadGuard, RwLockWriteGuard};
use crate::mapref::entry::Entry;
use crate::mapref::one::{Ref, RefMut};
use crate::try_result::TryResult;
use crate::HashMap;
use core::borrow::Borrow;
use core::hash::{BuildHasher, Hash};
/// Implementation detail that is exposed due to generic constraints in public types.
pub trait Map<'a, K: 'a + Eq + Hash, V: 'a, S: 'a + Clone + BuildHasher> {
fn _shard_count(&self) -> usize;
/// # Safety
///
/// The index must not be out of bounds.
unsafe fn _get_read_shard(&'a self, i: usize) -> &'a HashMap<K, V, S>;
/// # Safety
///
/// The index must not be out of bounds.
unsafe fn _yield_read_shard(&'a self, i: usize) -> RwLockReadGuard<'a, HashMap<K, V, S>>;
/// # Safety
///
/// The index must not be out of bounds.
unsafe fn _yield_write_shard(&'a self, i: usize) -> RwLockWriteGuard<'a, HashMap<K, V, S>>;
/// # Safety
///
/// The index must not be out of bounds.
unsafe fn _try_yield_read_shard(
&'a self,
i: usize,
) -> Option<RwLockReadGuard<'a, HashMap<K, V, S>>>;
/// # Safety
///
/// The index must not be out of bounds.
unsafe fn _try_yield_write_shard(
&'a self,
i: usize,
) -> Option<RwLockWriteGuard<'a, HashMap<K, V, S>>>;
fn _insert(&self, key: K, value: V) -> Option<V>;
fn _remove<Q>(&self, key: &Q) -> Option<(K, V)>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _remove_if<Q>(&self, key: &Q, f: impl FnOnce(&K, &V) -> bool) -> Option<(K, V)>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _remove_if_mut<Q>(&self, key: &Q, f: impl FnOnce(&K, &mut V) -> bool) -> Option<(K, V)>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _iter(&'a self) -> Iter<'a, K, V, S, Self>
where
Self: Sized;
fn _iter_mut(&'a self) -> IterMut<'a, K, V, S, Self>
where
Self: Sized;
fn _get<Q>(&'a self, key: &Q) -> Option<Ref<'a, K, V, S>>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _get_mut<Q>(&'a self, key: &Q) -> Option<RefMut<'a, K, V, S>>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _try_get<Q>(&'a self, key: &Q) -> TryResult<Ref<'a, K, V, S>>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _try_get_mut<Q>(&'a self, key: &Q) -> TryResult<RefMut<'a, K, V, S>>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _shrink_to_fit(&self);
fn _retain(&self, f: impl FnMut(&K, &mut V) -> bool);
fn _len(&self) -> usize;
fn _capacity(&self) -> usize;
fn _alter<Q>(&self, key: &Q, f: impl FnOnce(&K, V) -> V)
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _alter_all(&self, f: impl FnMut(&K, V) -> V);
fn _view<Q, R>(&self, key: &Q, f: impl FnOnce(&K, &V) -> R) -> Option<R>
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized;
fn _entry(&'a self, key: K) -> Entry<'a, K, V, S>;
fn _try_entry(&'a self, key: K) -> Option<Entry<'a, K, V, S>>;
fn _hasher(&self) -> S;
// provided
fn _clear(&self) {
self._retain(|_, _| false)
}
fn _contains_key<Q>(&'a self, key: &Q) -> bool
where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,
{
self._get(key).is_some()
}
fn _is_empty(&self) -> bool {
self._len() == 0
}
}

46
src/try_result.rs
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@ -1,46 +0,0 @@
/// Represents the result of a non-blocking read from a [DashMap](crate::DashMap).
#[derive(Debug)]
pub enum TryResult<R> {
/// The value was present in the map, and the lock for the shard was successfully obtained.
Present(R),
/// The shard wasn't locked, and the value wasn't present in the map.
Absent,
/// The shard was locked.
Locked,
}
impl<R> TryResult<R> {
/// Returns `true` if the value was present in the map, and the lock for the shard was successfully obtained.
pub fn is_present(&self) -> bool {
matches!(self, TryResult::Present(_))
}
/// Returns `true` if the shard wasn't locked, and the value wasn't present in the map.
pub fn is_absent(&self) -> bool {
matches!(self, TryResult::Absent)
}
/// Returns `true` if the shard was locked.
pub fn is_locked(&self) -> bool {
matches!(self, TryResult::Locked)
}
/// If `self` is [Present](TryResult::Present), returns the reference to the value in the map.
/// Panics if `self` is not [Present](TryResult::Present).
pub fn unwrap(self) -> R {
match self {
TryResult::Present(r) => r,
TryResult::Locked => panic!("Called unwrap() on TryResult::Locked"),
TryResult::Absent => panic!("Called unwrap() on TryResult::Absent"),
}
}
/// If `self` is [Present](TryResult::Present), returns the reference to the value in the map.
/// If `self` is not [Present](TryResult::Present), returns `None`.
pub fn try_unwrap(self) -> Option<R> {
match self {
TryResult::Present(r) => Some(r),
_ => None,
}
}
}

102
src/util.rs
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@ -1,102 +0,0 @@
//! This module is full of hackery and dark magic.
//! Either spend a day fixing it and quietly submit a PR or don't mention it to anybody.
use core::cell::UnsafeCell;
use core::{mem, ptr};
pub const fn ptr_size_bits() -> usize {
mem::size_of::<usize>() * 8
}
pub fn map_in_place_2<T, U, F: FnOnce(U, T) -> T>((k, v): (U, &mut T), f: F) {
unsafe {
// # Safety
//
// If the closure panics, we must abort otherwise we could double drop `T`
let _promote_panic_to_abort = AbortOnPanic;
ptr::write(v, f(k, ptr::read(v)));
}
}
/// # Safety
///
/// Requires that you ensure the reference does not become invalid.
/// The object has to outlive the reference.
pub unsafe fn change_lifetime_const<'a, 'b, T>(x: &'a T) -> &'b T {
&*(x as *const T)
}
/// # Safety
///
/// Requires that you ensure the reference does not become invalid.
/// The object has to outlive the reference.
pub unsafe fn change_lifetime_mut<'a, 'b, T>(x: &'a mut T) -> &'b mut T {
&mut *(x as *mut T)
}
/// A simple wrapper around `T`
///
/// This is to prevent UB when using `HashMap::get_key_value`, because
/// `HashMap` doesn't expose an api to get the key and value, where
/// the value is a `&mut T`.
///
/// See [#10](https://github.com/xacrimon/dashmap/issues/10) for details
///
/// This type is meant to be an implementation detail, but must be exposed due to the `Dashmap::shards`
#[repr(transparent)]
pub struct SharedValue<T> {
value: UnsafeCell<T>,
}
impl<T: Clone> Clone for SharedValue<T> {
fn clone(&self) -> Self {
let inner = self.get().clone();
Self {
value: UnsafeCell::new(inner),
}
}
}
unsafe impl<T: Send> Send for SharedValue<T> {}
unsafe impl<T: Sync> Sync for SharedValue<T> {}
impl<T> SharedValue<T> {
/// Create a new `SharedValue<T>`
pub const fn new(value: T) -> Self {
Self {
value: UnsafeCell::new(value),
}
}
/// Get a shared reference to `T`
pub fn get(&self) -> &T {
unsafe { &*self.value.get() }
}
/// Get an unique reference to `T`
pub fn get_mut(&mut self) -> &mut T {
unsafe { &mut *self.value.get() }
}
/// Unwraps the value
pub fn into_inner(self) -> T {
self.value.into_inner()
}
/// Get a mutable raw pointer to the underlying value
pub(crate) fn as_ptr(&self) -> *mut T {
self.value.get()
}
}
struct AbortOnPanic;
impl Drop for AbortOnPanic {
fn drop(&mut self) {
if std::thread::panicking() {
std::process::abort()
}
}
}