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auto merge of #16628 : pczarn/rust/hashmap-opt, r=nikomatsakis 

This is #15720, rebased and reopened.

cc @nikomatsakis
This commit is contained in:
bors 2014-09-05 17:36:25 +00:00
parent 074d3da7b0 0ad4644ae1
commit 82c052794d
9 changed files with 3800 additions and 3108 deletions
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6
src/librustc/lint/context.rs
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@ -103,7 +103,9 @@ impl LintStore {
}
pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
self.lint_groups.iter().map(|(k, &(ref v, b))| (*k, v.clone(), b)).collect()
self.lint_groups.iter().map(|(k, v)| (*k,
v.ref0().clone(),
*v.ref1())).collect()
}
pub fn register_pass(&mut self, sess: Option<&Session>,
@ -210,7 +212,7 @@ impl LintStore {
match self.by_name.find_equiv(&lint_name.as_slice()) {
Some(&lint_id) => self.set_level(lint_id, (level, CommandLine)),
None => {
match self.lint_groups.iter().map(|(&x, &(ref y, _))| (x, y.clone()))
match self.lint_groups.iter().map(|(&x, pair)| (x, pair.ref0().clone()))
.collect::<HashMap<&'static str, Vec<LintId>>>()
.find_equiv(&lint_name.as_slice()) {
Some(v) => {

2
src/librustdoc/html/render.rs
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@ -312,7 +312,7 @@ pub fn run(mut krate: clean::Crate, external_html: &ExternalHtml, dst: Path) ->
}).unwrap_or(HashMap::new());
let mut cache = Cache {
impls: HashMap::new(),
external_paths: paths.iter().map(|(&k, &(ref v, _))| (k, v.clone()))
external_paths: paths.iter().map(|(&k, v)| (k, v.ref0().clone()))
.collect(),
paths: paths,
implementors: HashMap::new(),

3105
src/libstd/collections/hashmap.rs
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130
src/libstd/collections/hashmap/bench.rs Normal file
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@ -0,0 +1,130 @@
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![cfg(test)]
extern crate test;
use prelude::*;
use self::test::Bencher;
use iter::{range_inclusive};
#[bench]
fn new_drop(b : &mut Bencher) {
use super::HashMap;
b.iter(|| {
let m : HashMap<int, int> = HashMap::new();
assert_eq!(m.len(), 0);
})
}
#[bench]
fn new_insert_drop(b : &mut Bencher) {
use super::HashMap;
b.iter(|| {
let mut m = HashMap::new();
m.insert(0i, 0i);
assert_eq!(m.len(), 1);
})
}
#[bench]
fn grow_by_insertion(b: &mut Bencher) {
use super::HashMap;
let mut m = HashMap::new();
for i in range_inclusive(1i, 1000) {
m.insert(i, i);
}
let mut k = 1001;
b.iter(|| {
m.insert(k, k);
k += 1;
});
}
#[bench]
fn find_existing(b: &mut Bencher) {
use super::HashMap;
let mut m = HashMap::new();
for i in range_inclusive(1i, 1000) {
m.insert(i, i);
}
b.iter(|| {
for i in range_inclusive(1i, 1000) {
m.contains_key(&i);
}
});
}
#[bench]
fn find_nonexisting(b: &mut Bencher) {
use super::HashMap;
let mut m = HashMap::new();
for i in range_inclusive(1i, 1000) {
m.insert(i, i);
}
b.iter(|| {
for i in range_inclusive(1001i, 2000) {
m.contains_key(&i);
}
});
}
#[bench]
fn hashmap_as_queue(b: &mut Bencher) {
use super::HashMap;
let mut m = HashMap::new();
for i in range_inclusive(1i, 1000) {
m.insert(i, i);
}
let mut k = 1i;
b.iter(|| {
m.pop(&k);
m.insert(k + 1000, k + 1000);
k += 1;
});
}
#[bench]
fn find_pop_insert(b: &mut Bencher) {
use super::HashMap;
let mut m = HashMap::new();
for i in range_inclusive(1i, 1000) {
m.insert(i, i);
}
let mut k = 1i;
b.iter(|| {
m.find(&(k + 400));
m.find(&(k + 2000));
m.pop(&k);
m.insert(k + 1000, k + 1000);
k += 1;
})
}

2017
src/libstd/collections/hashmap/map.rs Normal file
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28
src/libstd/collections/hashmap/mod.rs Normal file
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@ -0,0 +1,28 @@
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Unordered containers, implemented as hash-tables
pub use self::map::HashMap;
pub use self::map::Entries;
pub use self::map::MutEntries;
pub use self::map::MoveEntries;
pub use self::map::Keys;
pub use self::map::Values;
pub use self::map::INITIAL_CAPACITY;
pub use self::set::HashSet;
pub use self::set::SetItems;
pub use self::set::SetMoveItems;
pub use self::set::SetAlgebraItems;
mod bench;
mod map;
mod set;
mod table;

703
src/libstd/collections/hashmap/set.rs Normal file
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@ -0,0 +1,703 @@
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// ignore-lexer-test FIXME #15883
use clone::Clone;
use cmp::{Eq, Equiv, PartialEq};
use collections::{Collection, Mutable, Set, MutableSet, Map, MutableMap};
use default::Default;
use fmt::Show;
use fmt;
use hash::{Hash, Hasher, RandomSipHasher};
use iter::{Iterator, FromIterator, FilterMap, Chain, Repeat, Zip, Extendable};
use iter;
use option::{Some, None};
use result::{Ok, Err};
use super::{HashMap, Entries, MoveEntries, INITIAL_CAPACITY};
// Future Optimization (FIXME!)
// =============================
//
// Iteration over zero sized values is a noop. There is no need
// for `bucket.val` in the case of HashSet. I suppose we would need HKT
// to get rid of it properly.
/// An implementation of a hash set using the underlying representation of a
/// HashMap where the value is (). As with the `HashMap` type, a `HashSet`
/// requires that the elements implement the `Eq` and `Hash` traits.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// // Type inference lets us omit an explicit type signature (which
/// // would be `HashSet<&str>` in this example).
/// let mut books = HashSet::new();
///
/// // Add some books.
/// books.insert("A Dance With Dragons");
/// books.insert("To Kill a Mockingbird");
/// books.insert("The Odyssey");
/// books.insert("The Great Gatsby");
///
/// // Check for a specific one.
/// if !books.contains(&("The Winds of Winter")) {
/// println!("We have {} books, but The Winds of Winter ain't one.",
/// books.len());
/// }
///
/// // Remove a book.
/// books.remove(&"The Odyssey");
///
/// // Iterate over everything.
/// for book in books.iter() {
/// println!("{}", *book);
/// }
/// ```
///
/// The easiest way to use `HashSet` with a custom type is to derive
/// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the
/// future be implied by `Eq`.
///
/// ```
/// use std::collections::HashSet;
/// #[deriving(Hash, Eq, PartialEq, Show)]
/// struct Viking<'a> {
/// name: &'a str,
/// power: uint,
/// }
///
/// let mut vikings = HashSet::new();
///
/// vikings.insert(Viking { name: "Einar", power: 9u });
/// vikings.insert(Viking { name: "Einar", power: 9u });
/// vikings.insert(Viking { name: "Olaf", power: 4u });
/// vikings.insert(Viking { name: "Harald", power: 8u });
///
/// // Use derived implementation to print the vikings.
/// for x in vikings.iter() {
/// println!("{}", x);
/// }
/// ```
#[deriving(Clone)]
pub struct HashSet<T, H = RandomSipHasher> {
map: HashMap<T, (), H>
}
impl<T: Hash + Eq> HashSet<T, RandomSipHasher> {
/// Create an empty HashSet.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let mut set: HashSet<int> = HashSet::new();
/// ```
#[inline]
pub fn new() -> HashSet<T, RandomSipHasher> {
HashSet::with_capacity(INITIAL_CAPACITY)
}
/// Create an empty HashSet with space for at least `n` elements in
/// the hash table.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let mut set: HashSet<int> = HashSet::with_capacity(10);
/// ```
#[inline]
pub fn with_capacity(capacity: uint) -> HashSet<T, RandomSipHasher> {
HashSet { map: HashMap::with_capacity(capacity) }
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> HashSet<T, H> {
/// Creates a new empty hash set which will use the given hasher to hash
/// keys.
///
/// The hash set is also created with the default initial capacity.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// use std::hash::sip::SipHasher;
///
/// let h = SipHasher::new();
/// let mut set = HashSet::with_hasher(h);
/// set.insert(2u);
/// ```
#[inline]
pub fn with_hasher(hasher: H) -> HashSet<T, H> {
HashSet::with_capacity_and_hasher(INITIAL_CAPACITY, hasher)
}
/// Create an empty HashSet with space for at least `capacity`
/// elements in the hash table, using `hasher` to hash the keys.
///
/// Warning: `hasher` is normally randomly generated, and
/// is designed to allow `HashSet`s to be resistant to attacks that
/// cause many collisions and very poor performance. Setting it
/// manually using this function can expose a DoS attack vector.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// use std::hash::sip::SipHasher;
///
/// let h = SipHasher::new();
/// let mut set = HashSet::with_capacity_and_hasher(10u, h);
/// set.insert(1i);
/// ```
#[inline]
pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashSet<T, H> {
HashSet { map: HashMap::with_capacity_and_hasher(capacity, hasher) }
}
/// Reserve space for at least `n` elements in the hash table.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let mut set: HashSet<int> = HashSet::new();
/// set.reserve(10);
/// ```
pub fn reserve(&mut self, n: uint) {
self.map.reserve(n)
}
/// Returns true if the hash set contains a value equivalent to the
/// given query value.
///
/// # Example
///
/// This is a slightly silly example where we define the number's
/// parity as the equivilance class. It is important that the
/// values hash the same, which is why we implement `Hash`.
///
/// ```
/// use std::collections::HashSet;
/// use std::hash::Hash;
/// use std::hash::sip::SipState;
///
/// #[deriving(Eq, PartialEq)]
/// struct EvenOrOdd {
/// num: uint
/// };
///
/// impl Hash for EvenOrOdd {
/// fn hash(&self, state: &mut SipState) {
/// let parity = self.num % 2;
/// parity.hash(state);
/// }
/// }
///
/// impl Equiv<EvenOrOdd> for EvenOrOdd {
/// fn equiv(&self, other: &EvenOrOdd) -> bool {
/// self.num % 2 == other.num % 2
/// }
/// }
///
/// let mut set = HashSet::new();
/// set.insert(EvenOrOdd { num: 3u });
///
/// assert!(set.contains_equiv(&EvenOrOdd { num: 3u }));
/// assert!(set.contains_equiv(&EvenOrOdd { num: 5u }));
/// assert!(!set.contains_equiv(&EvenOrOdd { num: 4u }));
/// assert!(!set.contains_equiv(&EvenOrOdd { num: 2u }));
///
/// ```
pub fn contains_equiv<Q: Hash<S> + Equiv<T>>(&self, value: &Q) -> bool {
self.map.contains_key_equiv(value)
}
/// An iterator visiting all elements in arbitrary order.
/// Iterator element type is &'a T.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let mut set = HashSet::new();
/// set.insert("a");
/// set.insert("b");
///
/// // Will print in an arbitrary order.
/// for x in set.iter() {
/// println!("{}", x);
/// }
/// ```
pub fn iter<'a>(&'a self) -> SetItems<'a, T> {
self.map.keys()
}
/// Creates a consuming iterator, that is, one that moves each value out
/// of the set in arbitrary order. The set cannot be used after calling
/// this.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let mut set = HashSet::new();
/// set.insert("a".to_string());
/// set.insert("b".to_string());
///
/// // Not possible to collect to a Vec<String> with a regular `.iter()`.
/// let v: Vec<String> = set.move_iter().collect();
///
/// // Will print in an arbitrary order.
/// for x in v.iter() {
/// println!("{}", x);
/// }
/// ```
pub fn move_iter(self) -> SetMoveItems<T> {
self.map.move_iter().map(|(k, _)| k)
}
/// Visit the values representing the difference.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
/// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
///
/// // Can be seen as `a - b`.
/// for x in a.difference(&b) {
/// println!("{}", x); // Print 1
/// }
///
/// let diff: HashSet<int> = a.difference(&b).map(|&x| x).collect();
/// assert_eq!(diff, [1i].iter().map(|&x| x).collect());
///
/// // Note that difference is not symmetric,
/// // and `b - a` means something else:
/// let diff: HashSet<int> = b.difference(&a).map(|&x| x).collect();
/// assert_eq!(diff, [4i].iter().map(|&x| x).collect());
/// ```
pub fn difference<'a>(&'a self, other: &'a HashSet<T, H>) -> SetAlgebraItems<'a, T, H> {
Repeat::new(other).zip(self.iter())
.filter_map(|(other, elt)| {
if !other.contains(elt) { Some(elt) } else { None }
})
}
/// Visit the values representing the symmetric difference.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
/// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
///
/// // Print 1, 4 in arbitrary order.
/// for x in a.symmetric_difference(&b) {
/// println!("{}", x);
/// }
///
/// let diff1: HashSet<int> = a.symmetric_difference(&b).map(|&x| x).collect();
/// let diff2: HashSet<int> = b.symmetric_difference(&a).map(|&x| x).collect();
///
/// assert_eq!(diff1, diff2);
/// assert_eq!(diff1, [1i, 4].iter().map(|&x| x).collect());
/// ```
pub fn symmetric_difference<'a>(&'a self, other: &'a HashSet<T, H>)
-> Chain<SetAlgebraItems<'a, T, H>, SetAlgebraItems<'a, T, H>> {
self.difference(other).chain(other.difference(self))
}
/// Visit the values representing the intersection.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
/// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
///
/// // Print 2, 3 in arbitrary order.
/// for x in a.intersection(&b) {
/// println!("{}", x);
/// }
///
/// let diff: HashSet<int> = a.intersection(&b).map(|&x| x).collect();
/// assert_eq!(diff, [2i, 3].iter().map(|&x| x).collect());
/// ```
pub fn intersection<'a>(&'a self, other: &'a HashSet<T, H>)
-> SetAlgebraItems<'a, T, H> {
Repeat::new(other).zip(self.iter())
.filter_map(|(other, elt)| {
if other.contains(elt) { Some(elt) } else { None }
})
}
/// Visit the values representing the union.
///
/// # Example
///
/// ```
/// use std::collections::HashSet;
/// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
/// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
///
/// // Print 1, 2, 3, 4 in arbitrary order.
/// for x in a.union(&b) {
/// println!("{}", x);
/// }
///
/// let diff: HashSet<int> = a.union(&b).map(|&x| x).collect();
/// assert_eq!(diff, [1i, 2, 3, 4].iter().map(|&x| x).collect());
/// ```
pub fn union<'a>(&'a self, other: &'a HashSet<T, H>)
-> Chain<SetItems<'a, T>, SetAlgebraItems<'a, T, H>> {
self.iter().chain(other.difference(self))
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
fn eq(&self, other: &HashSet<T, H>) -> bool {
if self.len() != other.len() { return false; }
self.iter().all(|key| other.contains(key))
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> Collection for HashSet<T, H> {
fn len(&self) -> uint { self.map.len() }
}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> Mutable for HashSet<T, H> {
fn clear(&mut self) { self.map.clear() }
}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> Set<T> for HashSet<T, H> {
fn contains(&self, value: &T) -> bool { self.map.contains_key(value) }
fn is_disjoint(&self, other: &HashSet<T, H>) -> bool {
self.iter().all(|v| !other.contains(v))
}
fn is_subset(&self, other: &HashSet<T, H>) -> bool {
self.iter().all(|v| other.contains(v))
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S>> MutableSet<T> for HashSet<T, H> {
fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) }
fn remove(&mut self, value: &T) -> bool { self.map.remove(value) }
}
impl<T: Eq + Hash<S> + fmt::Show, S, H: Hasher<S>> fmt::Show for HashSet<T, H> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
try!(write!(f, "{{"));
for (i, x) in self.iter().enumerate() {
if i != 0 { try!(write!(f, ", ")); }
try!(write!(f, "{}", *x));
}
write!(f, "}}")
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> FromIterator<T> for HashSet<T, H> {
fn from_iter<I: Iterator<T>>(iter: I) -> HashSet<T, H> {
let (lower, _) = iter.size_hint();
let mut set = HashSet::with_capacity_and_hasher(lower, Default::default());
set.extend(iter);
set
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Extendable<T> for HashSet<T, H> {
fn extend<I: Iterator<T>>(&mut self, mut iter: I) {
for k in iter {
self.insert(k);
}
}
}
impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Default for HashSet<T, H> {
fn default() -> HashSet<T, H> {
HashSet::with_hasher(Default::default())
}
}
/// HashSet iterator
pub type SetItems<'a, K> =
iter::Map<'static, (&'a K, &'a ()), &'a K, Entries<'a, K, ()>>;
/// HashSet move iterator
pub type SetMoveItems<K> =
iter::Map<'static, (K, ()), K, MoveEntries<K, ()>>;
// `Repeat` is used to feed the filter closure an explicit capture
// of a reference to the other set
/// Set operations iterator
pub type SetAlgebraItems<'a, T, H> =
FilterMap<'static, (&'a HashSet<T, H>, &'a T), &'a T,
Zip<Repeat<&'a HashSet<T, H>>, SetItems<'a, T>>>;
#[cfg(test)]
mod test_set {
use prelude::*;
use super::HashSet;
use slice::ImmutablePartialEqSlice;
use collections::Collection;
#[test]
fn test_disjoint() {
let mut xs = HashSet::new();
let mut ys = HashSet::new();
assert!(xs.is_disjoint(&ys));
assert!(ys.is_disjoint(&xs));
assert!(xs.insert(5i));
assert!(ys.insert(11i));
assert!(xs.is_disjoint(&ys));
assert!(ys.is_disjoint(&xs));
assert!(xs.insert(7));
assert!(xs.insert(19));
assert!(xs.insert(4));
assert!(ys.insert(2));
assert!(ys.insert(-11));
assert!(xs.is_disjoint(&ys));
assert!(ys.is_disjoint(&xs));
assert!(ys.insert(7));
assert!(!xs.is_disjoint(&ys));
assert!(!ys.is_disjoint(&xs));
}
#[test]
fn test_subset_and_superset() {
let mut a = HashSet::new();
assert!(a.insert(0i));
assert!(a.insert(5));
assert!(a.insert(11));
assert!(a.insert(7));
let mut b = HashSet::new();
assert!(b.insert(0i));
assert!(b.insert(7));
assert!(b.insert(19));
assert!(b.insert(250));
assert!(b.insert(11));
assert!(b.insert(200));
assert!(!a.is_subset(&b));
assert!(!a.is_superset(&b));
assert!(!b.is_subset(&a));
assert!(!b.is_superset(&a));
assert!(b.insert(5));
assert!(a.is_subset(&b));
assert!(!a.is_superset(&b));
assert!(!b.is_subset(&a));
assert!(b.is_superset(&a));
}
#[test]
fn test_iterate() {
let mut a = HashSet::new();
for i in range(0u, 32) {
assert!(a.insert(i));
}
let mut observed: u32 = 0;
for k in a.iter() {
observed |= 1 << *k;
}
assert_eq!(observed, 0xFFFF_FFFF);
}
#[test]
fn test_intersection() {
let mut a = HashSet::new();
let mut b = HashSet::new();
assert!(a.insert(11i));
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(77));
assert!(a.insert(103));
assert!(a.insert(5));
assert!(a.insert(-5));
assert!(b.insert(2i));
assert!(b.insert(11));
assert!(b.insert(77));
assert!(b.insert(-9));
assert!(b.insert(-42));
assert!(b.insert(5));
assert!(b.insert(3));
let mut i = 0;
let expected = [3, 5, 11, 77];
for x in a.intersection(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_difference() {
let mut a = HashSet::new();
let mut b = HashSet::new();
assert!(a.insert(1i));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(b.insert(3i));
assert!(b.insert(9));
let mut i = 0;
let expected = [1, 5, 11];
for x in a.difference(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_symmetric_difference() {
let mut a = HashSet::new();
let mut b = HashSet::new();
assert!(a.insert(1i));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(b.insert(-2i));
assert!(b.insert(3));
assert!(b.insert(9));
assert!(b.insert(14));
assert!(b.insert(22));
let mut i = 0;
let expected = [-2, 1, 5, 11, 14, 22];
for x in a.symmetric_difference(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_union() {
let mut a = HashSet::new();
let mut b = HashSet::new();
assert!(a.insert(1i));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(a.insert(16));
assert!(a.insert(19));
assert!(a.insert(24));
assert!(b.insert(-2i));
assert!(b.insert(1));
assert!(b.insert(5));
assert!(b.insert(9));
assert!(b.insert(13));
assert!(b.insert(19));
let mut i = 0;
let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
for x in a.union(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_from_iter() {
let xs = [1i, 2, 3, 4, 5, 6, 7, 8, 9];
let set: HashSet<int> = xs.iter().map(|&x| x).collect();
for x in xs.iter() {
assert!(set.contains(x));
}
}
#[test]
fn test_move_iter() {
let hs = {
let mut hs = HashSet::new();
hs.insert('a');
hs.insert('b');
hs
};
let v = hs.move_iter().collect::<Vec<char>>();
assert!(['a', 'b'] == v.as_slice() || ['b', 'a'] == v.as_slice());
}
#[test]
fn test_eq() {
// These constants once happened to expose a bug in insert().
// I'm keeping them around to prevent a regression.
let mut s1 = HashSet::new();
s1.insert(1i);
s1.insert(2);
s1.insert(3);
let mut s2 = HashSet::new();
s2.insert(1i);
s2.insert(2);
assert!(s1 != s2);
s2.insert(3);
assert_eq!(s1, s2);
}
#[test]
fn test_show() {
let mut set: HashSet<int> = HashSet::new();
let empty: HashSet<int> = HashSet::new();
set.insert(1i);
set.insert(2);
let set_str = format!("{}", set);
assert!(set_str == "{1, 2}".to_string() || set_str == "{2, 1}".to_string());
assert_eq!(format!("{}", empty), "{}".to_string());
}
}

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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// ignore-lexer-test FIXME #15883
use clone::Clone;
use cmp;
use hash::{Hash, Hasher};
use iter::{Iterator, count};
use kinds::marker;
use mem::{min_align_of, size_of};
use mem;
use num::{CheckedAdd, CheckedMul, is_power_of_two};
use ops::{Deref, DerefMut, Drop};
use option::{Some, None, Option};
use ptr::{RawPtr, copy_nonoverlapping_memory, zero_memory};
use ptr;
use rt::heap::{allocate, deallocate};
static EMPTY_BUCKET: u64 = 0u64;
/// The raw hashtable, providing safe-ish access to the unzipped and highly
/// optimized arrays of hashes, keys, and values.
///
/// This design uses less memory and is a lot faster than the naive
/// `Vec<Option<u64, K, V>>`, because we don't pay for the overhead of an
/// option on every element, and we get a generally more cache-aware design.
///
/// Essential invariants of this structure:
///
/// - if t.hashes[i] == EMPTY_BUCKET, then `Bucket::at_index(&t, i).raw`
/// points to 'undefined' contents. Don't read from it. This invariant is
/// enforced outside this module with the `EmptyBucket`, `FullBucket`,
/// and `SafeHash` types.
///
/// - An `EmptyBucket` is only constructed at an index with
/// a hash of EMPTY_BUCKET.
///
/// - A `FullBucket` is only constructed at an index with a
/// non-EMPTY_BUCKET hash.
///
/// - A `SafeHash` is only constructed for non-`EMPTY_BUCKET` hash. We get
/// around hashes of zero by changing them to 0x8000_0000_0000_0000,
/// which will likely map to the same bucket, while not being confused
/// with "empty".
///
/// - All three "arrays represented by pointers" are the same length:
/// `capacity`. This is set at creation and never changes. The arrays
/// are unzipped to save space (we don't have to pay for the padding
/// between odd sized elements, such as in a map from u64 to u8), and
/// be more cache aware (scanning through 8 hashes brings in at most
/// 2 cache lines, since they're all right beside each other).
///
/// You can kind of think of this module/data structure as a safe wrapper
/// around just the "table" part of the hashtable. It enforces some
/// invariants at the type level and employs some performance trickery,
/// but in general is just a tricked out `Vec<Option<u64, K, V>>`.
#[unsafe_no_drop_flag]
pub struct RawTable<K, V> {
capacity: uint,
size: uint,
hashes: *mut u64,
// Because K/V do not appear directly in any of the types in the struct,
// inform rustc that in fact instances of K and V are reachable from here.
marker: marker::CovariantType<(K,V)>,
}
struct RawBucket<K, V> {
hash: *mut u64,
key: *mut K,
val: *mut V
}
pub struct Bucket<K, V, M> {
raw: RawBucket<K, V>,
idx: uint,
table: M
}
pub struct EmptyBucket<K, V, M> {
raw: RawBucket<K, V>,
idx: uint,
table: M
}
pub struct FullBucket<K, V, M> {
raw: RawBucket<K, V>,
idx: uint,
table: M
}
pub type EmptyBucketImm<'table, K, V> = EmptyBucket<K, V, &'table RawTable<K, V>>;
pub type FullBucketImm<'table, K, V> = FullBucket<K, V, &'table RawTable<K, V>>;
pub type EmptyBucketMut<'table, K, V> = EmptyBucket<K, V, &'table mut RawTable<K, V>>;
pub type FullBucketMut<'table, K, V> = FullBucket<K, V, &'table mut RawTable<K, V>>;
pub enum BucketState<K, V, M> {
Empty(EmptyBucket<K, V, M>),
Full(FullBucket<K, V, M>),
}
// A GapThenFull encapsulates the state of two consecutive buckets at once.
// The first bucket, called the gap, is known to be empty.
// The second bucket is full.
struct GapThenFull<K, V, M> {
gap: EmptyBucket<K, V, ()>,
full: FullBucket<K, V, M>,
}
/// A hash that is not zero, since we use a hash of zero to represent empty
/// buckets.
#[deriving(PartialEq)]
pub struct SafeHash {
hash: u64,
}
impl SafeHash {
/// Peek at the hash value, which is guaranteed to be non-zero.
#[inline(always)]
pub fn inspect(&self) -> u64 { self.hash }
}
/// We need to remove hashes of 0. That's reserved for empty buckets.
/// This function wraps up `hash_keyed` to be the only way outside this
/// module to generate a SafeHash.
pub fn make_hash<T: Hash<S>, S, H: Hasher<S>>(hasher: &H, t: &T) -> SafeHash {
match hasher.hash(t) {
// This constant is exceedingly likely to hash to the same
// bucket, but it won't be counted as empty! Just so we can maintain
// our precious uniform distribution of initial indexes.
EMPTY_BUCKET => SafeHash { hash: 0x8000_0000_0000_0000 },
h => SafeHash { hash: h },
}
}
// `replace` casts a `*u64` to a `*SafeHash`. Since we statically
// ensure that a `FullBucket` points to an index with a non-zero hash,
// and a `SafeHash` is just a `u64` with a different name, this is
// safe.
//
// This test ensures that a `SafeHash` really IS the same size as a
// `u64`. If you need to change the size of `SafeHash` (and
// consequently made this test fail), `replace` needs to be
// modified to no longer assume this.
#[test]
fn can_alias_safehash_as_u64() {
assert_eq!(size_of::<SafeHash>(), size_of::<u64>())
}
impl<K, V> RawBucket<K, V> {
unsafe fn offset(self, count: int) -> RawBucket<K, V> {
RawBucket {
hash: self.hash.offset(count),
key: self.key.offset(count),
val: self.val.offset(count),
}
}
}
// For parameterizing over mutability.
impl<'t, K, V> Deref<RawTable<K, V>> for &'t RawTable<K, V> {
fn deref(&self) -> &RawTable<K, V> {
&**self
}
}
impl<'t, K, V> Deref<RawTable<K, V>> for &'t mut RawTable<K, V> {
fn deref(&self) -> &RawTable<K,V> {
&**self
}
}
impl<'t, K, V> DerefMut<RawTable<K, V>> for &'t mut RawTable<K, V> {
fn deref_mut(&mut self) -> &mut RawTable<K,V> {
&mut **self
}
}
// Buckets hold references to the table.
impl<K, V, M> FullBucket<K, V, M> {
/// Borrow a reference to the table.
pub fn table(&self) -> &M {
&self.table
}
/// Move out the reference to the table.
pub fn into_table(self) -> M {
self.table
}
/// Get the raw index.
pub fn index(&self) -> uint {
self.idx
}
}
impl<K, V, M> EmptyBucket<K, V, M> {
/// Borrow a reference to the table.
pub fn table(&self) -> &M {
&self.table
}
/// Move out the reference to the table.
pub fn into_table(self) -> M {
self.table
}
}
impl<K, V, M> Bucket<K, V, M> {
/// Move out the reference to the table.
pub fn into_table(self) -> M {
self.table
}
/// Get the raw index.
pub fn index(&self) -> uint {
self.idx
}
}
impl<K, V, M: Deref<RawTable<K, V>>> Bucket<K, V, M> {
pub fn new(table: M, hash: &SafeHash) -> Bucket<K, V, M> {
Bucket::at_index(table, hash.inspect() as uint)
}
pub fn at_index(table: M, ib_index: uint) -> Bucket<K, V, M> {
let ib_index = ib_index & (table.capacity() - 1);
Bucket {
raw: unsafe {
table.first_bucket_raw().offset(ib_index as int)
},
idx: ib_index,
table: table
}
}
pub fn first(table: M) -> Bucket<K, V, M> {
Bucket {
raw: table.first_bucket_raw(),
idx: 0,
table: table
}
}
/// Reads a bucket at a given index, returning an enum indicating whether
/// it's initialized or not. You need to match on this enum to get
/// the appropriate types to call most of the other functions in
/// this module.
pub fn peek(self) -> BucketState<K, V, M> {
match unsafe { *self.raw.hash } {
EMPTY_BUCKET =>
Empty(EmptyBucket {
raw: self.raw,
idx: self.idx,
table: self.table
}),
_ =>
Full(FullBucket {
raw: self.raw,
idx: self.idx,
table: self.table
})
}
}
/// Modifies the bucket pointer in place to make it point to the next slot.
pub fn next(&mut self) {
// Branchless bucket iteration step.
// As we reach the end of the table...
// We take the current idx: 0111111b
// Xor it by its increment: ^ 1000000b
// ------------
// 1111111b
// Then AND with the capacity: & 1000000b
// ------------
// to get the backwards offset: 1000000b
// ... and it's zero at all other times.
let maybe_wraparound_dist = (self.idx ^ (self.idx + 1)) & self.table.capacity();
// Finally, we obtain the offset 1 or the offset -cap + 1.
let dist = 1i - (maybe_wraparound_dist as int);
self.idx += 1;
unsafe {
self.raw = self.raw.offset(dist);
}
}
}
impl<K, V, M: Deref<RawTable<K, V>>> EmptyBucket<K, V, M> {
#[inline]
pub fn next(self) -> Bucket<K, V, M> {
let mut bucket = self.into_bucket();
bucket.next();
bucket
}
#[inline]
pub fn into_bucket(self) -> Bucket<K, V, M> {
Bucket {
raw: self.raw,
idx: self.idx,
table: self.table
}
}
pub fn gap_peek(self) -> Option<GapThenFull<K, V, M>> {
let gap = EmptyBucket {
raw: self.raw,
idx: self.idx,
table: ()
};
match self.next().peek() {
Full(bucket) => {
Some(GapThenFull {
gap: gap,
full: bucket
})
}
Empty(..) => None
}
}
}
impl<K, V, M: DerefMut<RawTable<K, V>>> EmptyBucket<K, V, M> {
/// Puts given key and value pair, along with the key's hash,
/// into this bucket in the hashtable. Note how `self` is 'moved' into
/// this function, because this slot will no longer be empty when
/// we return! A `FullBucket` is returned for later use, pointing to
/// the newly-filled slot in the hashtable.
///
/// Use `make_hash` to construct a `SafeHash` to pass to this function.
pub fn put(mut self, hash: SafeHash, key: K, value: V)
-> FullBucket<K, V, M> {
unsafe {
*self.raw.hash = hash.inspect();
ptr::write(self.raw.key, key);
ptr::write(self.raw.val, value);
}
self.table.size += 1;
FullBucket { raw: self.raw, idx: self.idx, table: self.table }
}
}
impl<K, V, M: Deref<RawTable<K, V>>> FullBucket<K, V, M> {
#[inline]
pub fn next(self) -> Bucket<K, V, M> {
let mut bucket = self.into_bucket();
bucket.next();
bucket
}
#[inline]
pub fn into_bucket(self) -> Bucket<K, V, M> {
Bucket {
raw: self.raw,
idx: self.idx,
table: self.table
}
}
/// Get the distance between this bucket and the 'ideal' location
/// as determined by the key's hash stored in it.
///
/// In the cited blog posts above, this is called the "distance to
/// initial bucket", or DIB. Also known as "probe count".
pub fn distance(&self) -> uint {
// Calculates the distance one has to travel when going from
// `hash mod capacity` onwards to `idx mod capacity`, wrapping around
// if the destination is not reached before the end of the table.
(self.idx - self.hash().inspect() as uint) & (self.table.capacity() - 1)
}
#[inline]
pub fn hash(&self) -> SafeHash {
unsafe {
SafeHash {
hash: *self.raw.hash
}
}
}
/// Gets references to the key and value at a given index.
pub fn read(&self) -> (&K, &V) {
unsafe {
(&*self.raw.key,
&*self.raw.val)
}
}
}
impl<K, V, M: DerefMut<RawTable<K, V>>> FullBucket<K, V, M> {
/// Removes this bucket's key and value from the hashtable.
///
/// This works similarly to `put`, building an `EmptyBucket` out of the
/// taken bucket.
pub fn take(mut self) -> (EmptyBucket<K, V, M>, K, V) {
let key = self.raw.key as *const K;
let val = self.raw.val as *const V;
self.table.size -= 1;
unsafe {
*self.raw.hash = EMPTY_BUCKET;
(
EmptyBucket {
raw: self.raw,
idx: self.idx,
table: self.table
},
ptr::read(key),
ptr::read(val)
)
}
}
pub fn replace(&mut self, h: SafeHash, k: K, v: V) -> (SafeHash, K, V) {
unsafe {
let old_hash = ptr::replace(self.raw.hash as *mut SafeHash, h);
let old_key = ptr::replace(self.raw.key, k);
let old_val = ptr::replace(self.raw.val, v);
(old_hash, old_key, old_val)
}
}
/// Gets mutable references to the key and value at a given index.
pub fn read_mut(&mut self) -> (&mut K, &mut V) {
unsafe {
(&mut *self.raw.key,
&mut *self.raw.val)
}
}
}
impl<'t, K, V, M: Deref<RawTable<K, V>> + 't> FullBucket<K, V, M> {
/// Exchange a bucket state for immutable references into the table.
/// Because the underlying reference to the table is also consumed,
/// no further changes to the structure of the table are possible;
/// in exchange for this, the returned references have a longer lifetime
/// than the references returned by `read()`.
pub fn into_refs(self) -> (&'t K, &'t V) {
unsafe {
(&*self.raw.key,
&*self.raw.val)
}
}
}
impl<'t, K, V, M: DerefMut<RawTable<K, V>> + 't> FullBucket<K, V, M> {
/// This works similarly to `into_refs`, exchanging a bucket state
/// for mutable references into the table.
pub fn into_mut_refs(self) -> (&'t mut K, &'t mut V) {
unsafe {
(&mut *self.raw.key,
&mut *self.raw.val)
}
}
}
impl<K, V, M> BucketState<K, V, M> {
// For convenience.
pub fn expect_full(self) -> FullBucket<K, V, M> {
match self {
Full(full) => full,
Empty(..) => fail!("Expected full bucket")
}
}
}
impl<K, V, M: Deref<RawTable<K, V>>> GapThenFull<K, V, M> {
#[inline]
pub fn full(&self) -> &FullBucket<K, V, M> {
&self.full
}
pub fn shift(mut self) -> Option<GapThenFull<K, V, M>> {
unsafe {
*self.gap.raw.hash = mem::replace(&mut *self.full.raw.hash, EMPTY_BUCKET);
copy_nonoverlapping_memory(self.gap.raw.key, self.full.raw.key as *const K, 1);
copy_nonoverlapping_memory(self.gap.raw.val, self.full.raw.val as *const V, 1);
}
let FullBucket { raw: prev_raw, idx: prev_idx, .. } = self.full;
match self.full.next().peek() {
Full(bucket) => {
self.gap.raw = prev_raw;
self.gap.idx = prev_idx;
self.full = bucket;
Some(self)
}
Empty(..) => None
}
}
}
/// Rounds up to a multiple of a power of two. Returns the closest multiple
/// of `target_alignment` that is higher or equal to `unrounded`.
///
/// # Failure
///
/// Fails if `target_alignment` is not a power of two.
fn round_up_to_next(unrounded: uint, target_alignment: uint) -> uint {
assert!(is_power_of_two(target_alignment));
(unrounded + target_alignment - 1) & !(target_alignment - 1)
}
#[test]
fn test_rounding() {
assert_eq!(round_up_to_next(0, 4), 0);
assert_eq!(round_up_to_next(1, 4), 4);
assert_eq!(round_up_to_next(2, 4), 4);
assert_eq!(round_up_to_next(3, 4), 4);
assert_eq!(round_up_to_next(4, 4), 4);
assert_eq!(round_up_to_next(5, 4), 8);
}
// Returns a tuple of (key_offset, val_offset),
// from the start of a mallocated array.
fn calculate_offsets(hashes_size: uint,
keys_size: uint, keys_align: uint,
vals_align: uint)
-> (uint, uint) {
let keys_offset = round_up_to_next(hashes_size, keys_align);
let end_of_keys = keys_offset + keys_size;
let vals_offset = round_up_to_next(end_of_keys, vals_align);
(keys_offset, vals_offset)
}
// Returns a tuple of (minimum required malloc alignment, hash_offset,
// array_size), from the start of a mallocated array.
fn calculate_allocation(hash_size: uint, hash_align: uint,
keys_size: uint, keys_align: uint,
vals_size: uint, vals_align: uint)
-> (uint, uint, uint) {
let hash_offset = 0;
let (_, vals_offset) = calculate_offsets(hash_size,
keys_size, keys_align,
vals_align);
let end_of_vals = vals_offset + vals_size;
let min_align = cmp::max(hash_align, cmp::max(keys_align, vals_align));
(min_align, hash_offset, end_of_vals)
}
#[test]
fn test_offset_calculation() {
assert_eq!(calculate_allocation(128, 8, 15, 1, 4, 4), (8, 0, 148));
assert_eq!(calculate_allocation(3, 1, 2, 1, 1, 1), (1, 0, 6));
assert_eq!(calculate_allocation(6, 2, 12, 4, 24, 8), (8, 0, 48));
assert_eq!(calculate_offsets(128, 15, 1, 4), (128, 144));
assert_eq!(calculate_offsets(3, 2, 1, 1), (3, 5));
assert_eq!(calculate_offsets(6, 12, 4, 8), (8, 24));
}
impl<K, V> RawTable<K, V> {
/// Does not initialize the buckets. The caller should ensure they,
/// at the very least, set every hash to EMPTY_BUCKET.
unsafe fn new_uninitialized(capacity: uint) -> RawTable<K, V> {
if capacity == 0 {
return RawTable {
size: 0,
capacity: 0,
hashes: 0 as *mut u64,
marker: marker::CovariantType,
};
}
// No need for `checked_mul` before a more restrictive check performed
// later in this method.
let hashes_size = capacity * size_of::<u64>();
let keys_size = capacity * size_of::< K >();
let vals_size = capacity * size_of::< V >();
// Allocating hashmaps is a little tricky. We need to allocate three
// arrays, but since we know their sizes and alignments up front,
// we just allocate a single array, and then have the subarrays
// point into it.
//
// This is great in theory, but in practice getting the alignment
// right is a little subtle. Therefore, calculating offsets has been
// factored out into a different function.
let (malloc_alignment, hash_offset, size) =
calculate_allocation(
hashes_size, min_align_of::<u64>(),
keys_size, min_align_of::< K >(),
vals_size, min_align_of::< V >());
// One check for overflow that covers calculation and rounding of size.
let size_of_bucket = size_of::<u64>().checked_add(&size_of::<K>()).unwrap()
.checked_add(&size_of::<V>()).unwrap();
assert!(size >= capacity.checked_mul(&size_of_bucket)
.expect("capacity overflow"),
"capacity overflow");
let buffer = allocate(size, malloc_alignment);
let hashes = buffer.offset(hash_offset as int) as *mut u64;
RawTable {
capacity: capacity,
size: 0,
hashes: hashes,
marker: marker::CovariantType,
}
}
fn first_bucket_raw(&self) -> RawBucket<K, V> {
let hashes_size = self.capacity * size_of::<u64>();
let keys_size = self.capacity * size_of::<K>();
let buffer = self.hashes as *mut u8;
let (keys_offset, vals_offset) = calculate_offsets(hashes_size,
keys_size, min_align_of::<K>(),
min_align_of::<V>());
unsafe {
RawBucket {
hash: self.hashes,
key: buffer.offset(keys_offset as int) as *mut K,
val: buffer.offset(vals_offset as int) as *mut V
}
}
}
/// Creates a new raw table from a given capacity. All buckets are
/// initially empty.
#[allow(experimental)]
pub fn new(capacity: uint) -> RawTable<K, V> {
unsafe {
let ret = RawTable::new_uninitialized(capacity);
zero_memory(ret.hashes, capacity);
ret
}
}
/// The hashtable's capacity, similar to a vector's.
pub fn capacity(&self) -> uint {
self.capacity
}
/// The number of elements ever `put` in the hashtable, minus the number
/// of elements ever `take`n.
pub fn size(&self) -> uint {
self.size
}
fn raw_buckets(&self) -> RawBuckets<K, V> {
RawBuckets {
raw: self.first_bucket_raw(),
hashes_end: unsafe {
self.hashes.offset(self.capacity as int)
}
}
}
pub fn iter(&self) -> Entries<K, V> {
Entries {
iter: self.raw_buckets(),
elems_left: self.size(),
}
}
pub fn mut_iter(&mut self) -> MutEntries<K, V> {
MutEntries {
iter: self.raw_buckets(),
elems_left: self.size(),
}
}
pub fn move_iter(self) -> MoveEntries<K, V> {
MoveEntries {
iter: self.raw_buckets(),
table: self,
}
}
/// Returns an iterator that copies out each entry. Used while the table
/// is being dropped.
unsafe fn rev_move_buckets(&mut self) -> RevMoveBuckets<K, V> {
let raw_bucket = self.first_bucket_raw();
RevMoveBuckets {
raw: raw_bucket.offset(self.capacity as int),
hashes_end: raw_bucket.hash,
elems_left: self.size
}
}
}
/// A raw iterator. The basis for some other iterators in this module. Although
/// this interface is safe, it's not used outside this module.
struct RawBuckets<'a, K, V> {
raw: RawBucket<K, V>,
hashes_end: *mut u64
}
impl<'a, K, V> Iterator<RawBucket<K, V>> for RawBuckets<'a, K, V> {
fn next(&mut self) -> Option<RawBucket<K, V>> {
while self.raw.hash != self.hashes_end {
unsafe {
// We are swapping out the pointer to a bucket and replacing
// it with the pointer to the next one.
let prev = ptr::replace(&mut self.raw, self.raw.offset(1));
if *prev.hash != EMPTY_BUCKET {
return Some(prev);
}
}
}
None
}
}
/// An iterator that moves out buckets in reverse order. It leaves the table
/// in an an inconsistent state and should only be used for dropping
/// the table's remaining entries. It's used in the implementation of Drop.
struct RevMoveBuckets<'a, K, V> {
raw: RawBucket<K, V>,
hashes_end: *mut u64,
elems_left: uint
}
impl<'a, K, V> Iterator<(K, V)> for RevMoveBuckets<'a, K, V> {
fn next(&mut self) -> Option<(K, V)> {
if self.elems_left == 0 {
return None;
}
loop {
debug_assert!(self.raw.hash != self.hashes_end);
unsafe {
self.raw = self.raw.offset(-1);
if *self.raw.hash != EMPTY_BUCKET {
self.elems_left -= 1;
return Some((
ptr::read(self.raw.key as *const K),
ptr::read(self.raw.val as *const V)
));
}
}
}
}
}
/// Iterator over shared references to entries in a table.
pub struct Entries<'a, K: 'a, V: 'a> {
iter: RawBuckets<'a, K, V>,
elems_left: uint,
}
/// Iterator over mutable references to entries in a table.
pub struct MutEntries<'a, K: 'a, V: 'a> {
iter: RawBuckets<'a, K, V>,
elems_left: uint,
}
/// Iterator over the entries in a table, consuming the table.
pub struct MoveEntries<K, V> {
table: RawTable<K, V>,
iter: RawBuckets<'static, K, V>
}
impl<'a, K, V> Iterator<(&'a K, &'a V)> for Entries<'a, K, V> {
fn next(&mut self) -> Option<(&'a K, &'a V)> {
self.iter.next().map(|bucket| {
self.elems_left -= 1;
unsafe {
(&*bucket.key,
&*bucket.val)
}
})
}
fn size_hint(&self) -> (uint, Option<uint>) {
(self.elems_left, Some(self.elems_left))
}
}
impl<'a, K, V> Iterator<(&'a K, &'a mut V)> for MutEntries<'a, K, V> {
fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
self.iter.next().map(|bucket| {
self.elems_left -= 1;
unsafe {
(&*bucket.key,
&mut *bucket.val)
}
})
}
fn size_hint(&self) -> (uint, Option<uint>) {
(self.elems_left, Some(self.elems_left))
}
}
impl<K, V> Iterator<(SafeHash, K, V)> for MoveEntries<K, V> {
fn next(&mut self) -> Option<(SafeHash, K, V)> {
self.iter.next().map(|bucket| {
self.table.size -= 1;
unsafe {
(
SafeHash {
hash: *bucket.hash,
},
ptr::read(bucket.key as *const K),
ptr::read(bucket.val as *const V)
)
}
})
}
fn size_hint(&self) -> (uint, Option<uint>) {
let size = self.table.size();
(size, Some(size))
}
}
impl<K: Clone, V: Clone> Clone for RawTable<K, V> {
fn clone(&self) -> RawTable<K, V> {
unsafe {
let mut new_ht = RawTable::new_uninitialized(self.capacity());
{
let cap = self.capacity();
let mut new_buckets = Bucket::first(&mut new_ht);
let mut buckets = Bucket::first(self);
while buckets.index() != cap {
match buckets.peek() {
Full(full) => {
let (h, k, v) = {
let (k, v) = full.read();
(full.hash(), k.clone(), v.clone())
};
*new_buckets.raw.hash = h.inspect();
mem::overwrite(new_buckets.raw.key, k);
mem::overwrite(new_buckets.raw.val, v);
}
Empty(..) => {
*new_buckets.raw.hash = EMPTY_BUCKET;
}
}
new_buckets.next();
buckets.next();
}
};
new_ht.size = self.size();
new_ht
}
}
}
#[unsafe_destructor]
impl<K, V> Drop for RawTable<K, V> {
fn drop(&mut self) {
if self.hashes.is_null() {
return;
}
// This is done in reverse because we've likely partially taken
// some elements out with `.move_iter()` from the front.
// Check if the size is 0, so we don't do a useless scan when
// dropping empty tables such as on resize.
// Also avoid double drop of elements that have been already moved out.
unsafe {
for _ in self.rev_move_buckets() {}
}
let hashes_size = self.capacity * size_of::<u64>();
let keys_size = self.capacity * size_of::<K>();
let vals_size = self.capacity * size_of::<V>();
let (align, _, size) = calculate_allocation(hashes_size, min_align_of::<u64>(),
keys_size, min_align_of::<K>(),
vals_size, min_align_of::<V>());
unsafe {
deallocate(self.hashes as *mut u8, size, align);
// Remember how everything was allocated out of one buffer
// during initialization? We only need one call to free here.
}
}
}

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src/test/run-fail/hashmap-capacity-overflow.rs Normal file
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@ -0,0 +1,21 @@
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// error-pattern:capacity overflow
use std::collections::hashmap::HashMap;
use std::uint;
use std::mem::size_of;
fn main() {
let threshold = uint::MAX / size_of::<(u64, u64, u64)>();
let mut h = HashMap::<u64, u64>::with_capacity(threshold + 100);
h.insert(0, 0);
}