diff options
Diffstat (limited to 'src/libstd/collections/hashmap')
| -rw-r--r-- | src/libstd/collections/hashmap/bench.rs | 130 | ||||
| -rw-r--r-- | src/libstd/collections/hashmap/map.rs | 2133 | ||||
| -rw-r--r-- | src/libstd/collections/hashmap/mod.rs | 33 | ||||
| -rw-r--r-- | src/libstd/collections/hashmap/set.rs | 834 | ||||
| -rw-r--r-- | src/libstd/collections/hashmap/table.rs | 907 |
5 files changed, 0 insertions, 4037 deletions
diff --git a/src/libstd/collections/hashmap/bench.rs b/src/libstd/collections/hashmap/bench.rs deleted file mode 100644 index 21bbb38f489..00000000000 --- a/src/libstd/collections/hashmap/bench.rs +++ /dev/null @@ -1,130 +0,0 @@ -// 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; - }) -} diff --git a/src/libstd/collections/hashmap/map.rs b/src/libstd/collections/hashmap/map.rs deleted file mode 100644 index 596e483c2f6..00000000000 --- a/src/libstd/collections/hashmap/map.rs +++ /dev/null @@ -1,2133 +0,0 @@ -// 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::{max, Eq, Equiv, PartialEq}; -use default::Default; -use fmt::{mod, Show}; -use hash::{Hash, Hasher, RandomSipHasher}; -use iter::{mod, Iterator, FromIterator, Extendable}; -use kinds::Sized; -use mem::{mod, replace}; -use num; -use ops::{Deref, Index, IndexMut}; -use option::{Some, None, Option}; -use result::{Result, Ok, Err}; - -use super::table; -use super::table::{ - Bucket, - Empty, - EmptyBucket, - Full, - FullBucket, - FullBucketImm, - FullBucketMut, - RawTable, - SafeHash -}; - -const INITIAL_LOG2_CAP: uint = 5; -pub const INITIAL_CAPACITY: uint = 1 << INITIAL_LOG2_CAP; // 2^5 - -/// The default behavior of HashMap implements a load factor of 90.9%. -/// This behavior is characterized by the following conditions: -/// -/// - if size > 0.909 * capacity: grow -/// - if size < 0.25 * capacity: shrink (if this won't bring capacity lower -/// than the minimum) -#[deriving(Clone)] -struct DefaultResizePolicy { - /// Doubled minimal capacity. The capacity must never drop below - /// the minimum capacity. (The check happens before the capacity - /// is potentially halved.) - minimum_capacity2: uint -} - -impl DefaultResizePolicy { - fn new(new_capacity: uint) -> DefaultResizePolicy { - DefaultResizePolicy { - minimum_capacity2: new_capacity << 1 - } - } - - #[inline] - fn capacity_range(&self, new_size: uint) -> (uint, uint) { - // Here, we are rephrasing the logic by specifying the ranges: - // - // - if `size * 1.1 < cap < size * 4`: don't resize - // - if `cap < minimum_capacity * 2`: don't shrink - // - otherwise, resize accordingly - ((new_size * 11) / 10, max(new_size << 2, self.minimum_capacity2)) - } - - #[inline] - fn reserve(&mut self, new_capacity: uint) { - self.minimum_capacity2 = new_capacity << 1; - } -} - -// The main performance trick in this hashmap is called Robin Hood Hashing. -// It gains its excellent performance from one essential operation: -// -// If an insertion collides with an existing element, and that element's -// "probe distance" (how far away the element is from its ideal location) -// is higher than how far we've already probed, swap the elements. -// -// This massively lowers variance in probe distance, and allows us to get very -// high load factors with good performance. The 90% load factor I use is rather -// conservative. -// -// > Why a load factor of approximately 90%? -// -// In general, all the distances to initial buckets will converge on the mean. -// At a load factor of α, the odds of finding the target bucket after k -// probes is approximately 1-α^k. If we set this equal to 50% (since we converge -// on the mean) and set k=8 (64-byte cache line / 8-byte hash), α=0.92. I round -// this down to make the math easier on the CPU and avoid its FPU. -// Since on average we start the probing in the middle of a cache line, this -// strategy pulls in two cache lines of hashes on every lookup. I think that's -// pretty good, but if you want to trade off some space, it could go down to one -// cache line on average with an α of 0.84. -// -// > Wait, what? Where did you get 1-α^k from? -// -// On the first probe, your odds of a collision with an existing element is α. -// The odds of doing this twice in a row is approximately α^2. For three times, -// α^3, etc. Therefore, the odds of colliding k times is α^k. The odds of NOT -// colliding after k tries is 1-α^k. -// -// The paper from 1986 cited below mentions an implementation which keeps track -// of the distance-to-initial-bucket histogram. This approach is not suitable -// for modern architectures because it requires maintaining an internal data -// structure. This allows very good first guesses, but we are most concerned -// with guessing entire cache lines, not individual indexes. Furthermore, array -// accesses are no longer linear and in one direction, as we have now. There -// is also memory and cache pressure that this would entail that would be very -// difficult to properly see in a microbenchmark. -// -// ## Future Improvements (FIXME!) -// -// Allow the load factor to be changed dynamically and/or at initialization. -// -// Also, would it be possible for us to reuse storage when growing the -// underlying table? This is exactly the use case for 'realloc', and may -// be worth exploring. -// -// ## Future Optimizations (FIXME!) -// -// Another possible design choice that I made without any real reason is -// parameterizing the raw table over keys and values. Technically, all we need -// is the size and alignment of keys and values, and the code should be just as -// efficient (well, we might need one for power-of-two size and one for not...). -// This has the potential to reduce code bloat in rust executables, without -// really losing anything except 4 words (key size, key alignment, val size, -// val alignment) which can be passed in to every call of a `RawTable` function. -// This would definitely be an avenue worth exploring if people start complaining -// about the size of rust executables. -// -// Annotate exceedingly likely branches in `table::make_hash` -// and `search_hashed_generic` to reduce instruction cache pressure -// and mispredictions once it becomes possible (blocked on issue #11092). -// -// Shrinking the table could simply reallocate in place after moving buckets -// to the first half. -// -// The growth algorithm (fragment of the Proof of Correctness) -// -------------------- -// -// The growth algorithm is basically a fast path of the naive reinsertion- -// during-resize algorithm. Other paths should never be taken. -// -// Consider growing a robin hood hashtable of capacity n. Normally, we do this -// by allocating a new table of capacity `2n`, and then individually reinsert -// each element in the old table into the new one. This guarantees that the -// new table is a valid robin hood hashtable with all the desired statistical -// properties. Remark that the order we reinsert the elements in should not -// matter. For simplicity and efficiency, we will consider only linear -// reinsertions, which consist of reinserting all elements in the old table -// into the new one by increasing order of index. However we will not be -// starting our reinsertions from index 0 in general. If we start from index -// i, for the purpose of reinsertion we will consider all elements with real -// index j < i to have virtual index n + j. -// -// Our hash generation scheme consists of generating a 64-bit hash and -// truncating the most significant bits. When moving to the new table, we -// simply introduce a new bit to the front of the hash. Therefore, if an -// elements has ideal index i in the old table, it can have one of two ideal -// locations in the new table. If the new bit is 0, then the new ideal index -// is i. If the new bit is 1, then the new ideal index is n + i. Intutively, -// we are producing two independent tables of size n, and for each element we -// independently choose which table to insert it into with equal probability. -// However the rather than wrapping around themselves on overflowing their -// indexes, the first table overflows into the first, and the first into the -// second. Visually, our new table will look something like: -// -// [yy_xxx_xxxx_xxx|xx_yyy_yyyy_yyy] -// -// Where x's are elements inserted into the first table, y's are elements -// inserted into the second, and _'s are empty sections. We now define a few -// key concepts that we will use later. Note that this is a very abstract -// perspective of the table. A real resized table would be at least half -// empty. -// -// Theorem: A linear robin hood reinsertion from the first ideal element -// produces identical results to a linear naive reinsertion from the same -// element. -// -// FIXME(Gankro, pczarn): review the proof and put it all in a separate doc.rs - -/// A hash map implementation which uses linear probing with Robin -/// Hood bucket stealing. -/// -/// The hashes are all keyed by the task-local random number generator -/// on creation by default. This means that the ordering of the keys is -/// randomized, but makes the tables more resistant to -/// denial-of-service attacks (Hash DoS). This behaviour can be -/// overridden with one of the constructors. -/// -/// It is required that the keys implement the `Eq` and `Hash` traits, although -/// this can frequently be achieved by using `#[deriving(Eq, Hash)]`. -/// -/// Relevant papers/articles: -/// -/// 1. Pedro Celis. ["Robin Hood Hashing"](https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf) -/// 2. Emmanuel Goossaert. ["Robin Hood -/// hashing"](http://codecapsule.com/2013/11/11/robin-hood-hashing/) -/// 3. Emmanuel Goossaert. ["Robin Hood hashing: backward shift -/// deletion"](http://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/) -/// -/// # Example -/// -/// ``` -/// use std::collections::HashMap; -/// -/// // type inference lets us omit an explicit type signature (which -/// // would be `HashMap<&str, &str>` in this example). -/// let mut book_reviews = HashMap::new(); -/// -/// // review some books. -/// book_reviews.insert("Adventures of Huckleberry Finn", "My favorite book."); -/// book_reviews.insert("Grimms' Fairy Tales", "Masterpiece."); -/// book_reviews.insert("Pride and Prejudice", "Very enjoyable."); -/// book_reviews.insert("The Adventures of Sherlock Holmes", "Eye lyked it alot."); -/// -/// // check for a specific one. -/// if !book_reviews.contains_key(&("Les Misérables")) { -/// println!("We've got {} reviews, but Les Misérables ain't one.", -/// book_reviews.len()); -/// } -/// -/// // oops, this review has a lot of spelling mistakes, let's delete it. -/// book_reviews.remove(&("The Adventures of Sherlock Holmes")); -/// -/// // look up the values associated with some keys. -/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"]; -/// for book in to_find.iter() { -/// match book_reviews.find(book) { -/// Some(review) => println!("{}: {}", *book, *review), -/// None => println!("{} is unreviewed.", *book) -/// } -/// } -/// -/// // iterate over everything. -/// for (book, review) in book_reviews.iter() { -/// println!("{}: \"{}\"", *book, *review); -/// } -/// ``` -/// -/// The easiest way to use `HashMap` with a custom type is to derive `Eq` and `Hash`. -/// We must also derive `PartialEq`. -/// -/// ``` -/// use std::collections::HashMap; -/// -/// #[deriving(Hash, Eq, PartialEq, Show)] -/// struct Viking<'a> { -/// name: &'a str, -/// power: uint, -/// } -/// -/// let mut vikings = HashMap::new(); -/// -/// vikings.insert("Norway", Viking { name: "Einar", power: 9u }); -/// vikings.insert("Denmark", Viking { name: "Olaf", power: 4u }); -/// vikings.insert("Iceland", Viking { name: "Harald", power: 8u }); -/// -/// // Use derived implementation to print the vikings. -/// for (land, viking) in vikings.iter() { -/// println!("{} at {}", viking, land); -/// } -/// ``` -#[deriving(Clone)] -pub struct HashMap<K, V, H = RandomSipHasher> { - // All hashes are keyed on these values, to prevent hash collision attacks. - hasher: H, - - table: RawTable<K, V>, - - // We keep this at the end since it might as well have tail padding. - resize_policy: DefaultResizePolicy, -} - -/// Search for a pre-hashed key. -fn search_hashed_generic<K, V, M: Deref<RawTable<K, V>>>(table: M, - hash: &SafeHash, - is_match: |&K| -> bool) - -> SearchResult<K, V, M> { - let size = table.size(); - let mut probe = Bucket::new(table, hash); - let ib = probe.index(); - - while probe.index() != ib + size { - let full = match probe.peek() { - Empty(b) => return TableRef(b.into_table()), // hit an empty bucket - Full(b) => b - }; - - if full.distance() + ib < full.index() { - // We can finish the search early if we hit any bucket - // with a lower distance to initial bucket than we've probed. - return TableRef(full.into_table()); - } - - // If the hash doesn't match, it can't be this one.. - if *hash == full.hash() { - let matched = { - let (k, _) = full.read(); - is_match(k) - }; - - // If the key doesn't match, it can't be this one.. - if matched { - return FoundExisting(full); - } - } - - probe = full.next(); - } - - TableRef(probe.into_table()) -} - -fn search_hashed<K: Eq, V, M: Deref<RawTable<K, V>>>(table: M, hash: &SafeHash, k: &K) - -> SearchResult<K, V, M> { - search_hashed_generic(table, hash, |k_| *k == *k_) -} - -fn pop_internal<K, V>(starting_bucket: FullBucketMut<K, V>) -> (K, V) { - let (empty, retkey, retval) = starting_bucket.take(); - let mut gap = match empty.gap_peek() { - Some(b) => b, - None => return (retkey, retval) - }; - - while gap.full().distance() != 0 { - gap = match gap.shift() { - Some(b) => b, - None => break - }; - } - - // Now we've done all our shifting. Return the value we grabbed earlier. - return (retkey, retval); -} - -/// Perform robin hood bucket stealing at the given `bucket`. You must -/// also pass the position of that bucket's initial bucket so we don't have -/// to recalculate it. -/// -/// `hash`, `k`, and `v` are the elements to "robin hood" into the hashtable. -fn robin_hood<'a, K: 'a, V: 'a>(mut bucket: FullBucketMut<'a, K, V>, - mut ib: uint, - mut hash: SafeHash, - mut k: K, - mut v: V) - -> &'a mut V { - let starting_index = bucket.index(); - let size = { - let table = bucket.table(); // FIXME "lifetime too short". - table.size() - }; - // There can be at most `size - dib` buckets to displace, because - // in the worst case, there are `size` elements and we already are - // `distance` buckets away from the initial one. - let idx_end = starting_index + size - bucket.distance(); - - loop { - let (old_hash, old_key, old_val) = bucket.replace(hash, k, v); - loop { - let probe = bucket.next(); - assert!(probe.index() != idx_end); - - let full_bucket = match probe.peek() { - table::Empty(bucket) => { - // Found a hole! - let b = bucket.put(old_hash, old_key, old_val); - // Now that it's stolen, just read the value's pointer - // right out of the table! - let (_, v) = Bucket::at_index(b.into_table(), starting_index).peek() - .expect_full() - .into_mut_refs(); - return v; - }, - table::Full(bucket) => bucket - }; - - let probe_ib = full_bucket.index() - full_bucket.distance(); - - bucket = full_bucket; - - // Robin hood! Steal the spot. - if ib < probe_ib { - ib = probe_ib; - hash = old_hash; - k = old_key; - v = old_val; - break; - } - } - } -} - -/// A result that works like Option<FullBucket<..>> but preserves -/// the reference that grants us access to the table in any case. -enum SearchResult<K, V, M> { - // This is an entry that holds the given key: - FoundExisting(FullBucket<K, V, M>), - - // There was no such entry. The reference is given back: - TableRef(M) -} - -impl<K, V, M> SearchResult<K, V, M> { - fn into_option(self) -> Option<FullBucket<K, V, M>> { - match self { - FoundExisting(bucket) => Some(bucket), - TableRef(_) => None - } - } -} - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> { - fn make_hash<Sized? X: Hash<S>>(&self, x: &X) -> SafeHash { - table::make_hash(&self.hasher, x) - } - - fn search_equiv<'a, Sized? Q: Hash<S> + Equiv<K>>(&'a self, q: &Q) - -> Option<FullBucketImm<'a, K, V>> { - let hash = self.make_hash(q); - search_hashed_generic(&self.table, &hash, |k| q.equiv(k)).into_option() - } - - fn search_equiv_mut<'a, Sized? Q: Hash<S> + Equiv<K>>(&'a mut self, q: &Q) - -> Option<FullBucketMut<'a, K, V>> { - let hash = self.make_hash(q); - search_hashed_generic(&mut self.table, &hash, |k| q.equiv(k)).into_option() - } - - /// Search for a key, yielding the index if it's found in the hashtable. - /// If you already have the hash for the key lying around, use - /// search_hashed. - fn search<'a>(&'a self, k: &K) -> Option<FullBucketImm<'a, K, V>> { - let hash = self.make_hash(k); - search_hashed(&self.table, &hash, k).into_option() - } - - fn search_mut<'a>(&'a mut self, k: &K) -> Option<FullBucketMut<'a, K, V>> { - let hash = self.make_hash(k); - search_hashed(&mut self.table, &hash, k).into_option() - } - - // The caller should ensure that invariants by Robin Hood Hashing hold. - fn insert_hashed_ordered(&mut self, hash: SafeHash, k: K, v: V) { - let cap = self.table.capacity(); - let mut buckets = Bucket::new(&mut self.table, &hash); - let ib = buckets.index(); - - while buckets.index() != ib + cap { - // We don't need to compare hashes for value swap. - // Not even DIBs for Robin Hood. - buckets = match buckets.peek() { - Empty(empty) => { - empty.put(hash, k, v); - return; - } - Full(b) => b.into_bucket() - }; - buckets.next(); - } - panic!("Internal HashMap error: Out of space."); - } -} - -impl<K: Hash + Eq, V> HashMap<K, V, RandomSipHasher> { - /// Create an empty HashMap. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// let mut map: HashMap<&str, int> = HashMap::with_capacity(10); - /// ``` - #[inline] - pub fn new() -> HashMap<K, V, RandomSipHasher> { - let hasher = RandomSipHasher::new(); - HashMap::with_hasher(hasher) - } - - /// Creates an empty hash map with the given initial capacity. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// let mut map: HashMap<&str, int> = HashMap::with_capacity(10); - /// ``` - #[inline] - pub fn with_capacity(capacity: uint) -> HashMap<K, V, RandomSipHasher> { - let hasher = RandomSipHasher::new(); - HashMap::with_capacity_and_hasher(capacity, hasher) - } -} - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> { - /// Creates an empty hashmap which will use the given hasher to hash keys. - /// - /// The creates map has the default initial capacity. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// use std::hash::sip::SipHasher; - /// - /// let h = SipHasher::new(); - /// let mut map = HashMap::with_hasher(h); - /// map.insert(1i, 2u); - /// ``` - #[inline] - pub fn with_hasher(hasher: H) -> HashMap<K, V, H> { - HashMap { - hasher: hasher, - resize_policy: DefaultResizePolicy::new(INITIAL_CAPACITY), - table: RawTable::new(0), - } - } - - /// Create an empty HashMap with space for at least `capacity` - /// elements, using `hasher` to hash the keys. - /// - /// Warning: `hasher` is normally randomly generated, and - /// is designed to allow HashMaps 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::HashMap; - /// use std::hash::sip::SipHasher; - /// - /// let h = SipHasher::new(); - /// let mut map = HashMap::with_capacity_and_hasher(10, h); - /// map.insert(1i, 2u); - /// ``` - #[inline] - pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashMap<K, V, H> { - let cap = num::next_power_of_two(max(INITIAL_CAPACITY, capacity)); - HashMap { - hasher: hasher, - resize_policy: DefaultResizePolicy::new(cap), - table: RawTable::new(cap), - } - } - - /// The hashtable will never try to shrink below this size. You can use - /// this function to reduce reallocations if your hashtable frequently - /// grows and shrinks by large amounts. - /// - /// This function has no effect on the operational semantics of the - /// hashtable, only on performance. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// let mut map: HashMap<&str, int> = HashMap::new(); - /// map.reserve(10); - /// ``` - pub fn reserve(&mut self, new_minimum_capacity: uint) { - let cap = num::next_power_of_two( - max(INITIAL_CAPACITY, new_minimum_capacity)); - - self.resize_policy.reserve(cap); - - if self.table.capacity() < cap { - self.resize(cap); - } - } - - /// Resizes the internal vectors to a new capacity. It's your responsibility to: - /// 1) Make sure the new capacity is enough for all the elements, accounting - /// for the load factor. - /// 2) Ensure new_capacity is a power of two. - fn resize(&mut self, new_capacity: uint) { - assert!(self.table.size() <= new_capacity); - assert!(num::is_power_of_two(new_capacity)); - - let mut old_table = replace(&mut self.table, RawTable::new(new_capacity)); - let old_size = old_table.size(); - - if old_table.capacity() == 0 || old_table.size() == 0 { - return; - } - - if new_capacity < old_table.capacity() { - // Shrink the table. Naive algorithm for resizing: - for (h, k, v) in old_table.into_iter() { - self.insert_hashed_nocheck(h, k, v); - } - } else { - // Grow the table. - // Specialization of the other branch. - let mut bucket = Bucket::first(&mut old_table); - - // "So a few of the first shall be last: for many be called, - // but few chosen." - // - // We'll most likely encounter a few buckets at the beginning that - // have their initial buckets near the end of the table. They were - // placed at the beginning as the probe wrapped around the table - // during insertion. We must skip forward to a bucket that won't - // get reinserted too early and won't unfairly steal others spot. - // This eliminates the need for robin hood. - loop { - bucket = match bucket.peek() { - Full(full) => { - if full.distance() == 0 { - // This bucket occupies its ideal spot. - // It indicates the start of another "cluster". - bucket = full.into_bucket(); - break; - } - // Leaving this bucket in the last cluster for later. - full.into_bucket() - } - Empty(b) => { - // Encountered a hole between clusters. - b.into_bucket() - } - }; - bucket.next(); - } - - // This is how the buckets might be laid out in memory: - // ($ marks an initialized bucket) - // ________________ - // |$$$_$$$$$$_$$$$$| - // - // But we've skipped the entire initial cluster of buckets - // and will continue iteration in this order: - // ________________ - // |$$$$$$_$$$$$ - // ^ wrap around once end is reached - // ________________ - // $$$_____________| - // ^ exit once table.size == 0 - loop { - bucket = match bucket.peek() { - Full(bucket) => { - let h = bucket.hash(); - let (b, k, v) = bucket.take(); - self.insert_hashed_ordered(h, k, v); - { - let t = b.table(); // FIXME "lifetime too short". - if t.size() == 0 { break } - }; - b.into_bucket() - } - Empty(b) => b.into_bucket() - }; - bucket.next(); - } - } - - assert_eq!(self.table.size(), old_size); - } - - /// Performs any necessary resize operations, such that there's space for - /// new_size elements. - fn make_some_room(&mut self, new_size: uint) { - let (grow_at, shrink_at) = self.resize_policy.capacity_range(new_size); - let cap = self.table.capacity(); - - // An invalid value shouldn't make us run out of space. - debug_assert!(grow_at >= new_size); - - if cap <= grow_at { - let new_capacity = max(cap << 1, INITIAL_CAPACITY); - self.resize(new_capacity); - } else if shrink_at <= cap { - let new_capacity = cap >> 1; - self.resize(new_capacity); - } - } - - /// Insert a pre-hashed key-value pair, without first checking - /// that there's enough room in the buckets. Returns a reference to the - /// newly insert value. - /// - /// If the key already exists, the hashtable will be returned untouched - /// and a reference to the existing element will be returned. - fn insert_hashed_nocheck(&mut self, hash: SafeHash, k: K, v: V) -> &mut V { - self.insert_or_replace_with(hash, k, v, |_, _, _| ()) - } - - fn insert_or_replace_with<'a>(&'a mut self, - hash: SafeHash, - k: K, - v: V, - found_existing: |&mut K, &mut V, V|) - -> &'a mut V { - // Worst case, we'll find one empty bucket among `size + 1` buckets. - let size = self.table.size(); - let mut probe = Bucket::new(&mut self.table, &hash); - let ib = probe.index(); - - loop { - let mut bucket = match probe.peek() { - Empty(bucket) => { - // Found a hole! - let bucket = bucket.put(hash, k, v); - let (_, val) = bucket.into_mut_refs(); - return val; - }, - Full(bucket) => bucket - }; - - if bucket.hash() == hash { - let found_match = { - let (bucket_k, _) = bucket.read_mut(); - k == *bucket_k - }; - if found_match { - let (bucket_k, bucket_v) = bucket.into_mut_refs(); - debug_assert!(k == *bucket_k); - // Key already exists. Get its reference. - found_existing(bucket_k, bucket_v, v); - return bucket_v; - } - } - - let robin_ib = bucket.index() as int - bucket.distance() as int; - - if (ib as int) < robin_ib { - // Found a luckier bucket than me. Better steal his spot. - return robin_hood(bucket, robin_ib as uint, hash, k, v); - } - - probe = bucket.next(); - assert!(probe.index() != ib + size + 1); - } - } - - /// Retrieves a mutable value for the given key. - /// See [`find_mut`](../trait.MutableMap.html#tymethod.find_mut) for a non-panicking - /// alternative. - /// - /// # Failure - /// - /// Fails if the key is not present. - /// - /// # Example - /// - /// ``` - /// # #![allow(deprecated)] - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert("a", 1i); - /// { - /// // val will freeze map to prevent usage during its lifetime - /// let val = map.get_mut(&"a"); - /// *val = 40; - /// } - /// assert_eq!(map["a"], 40); - /// - /// // A more direct way could be: - /// *map.get_mut(&"a") = -2; - /// assert_eq!(map["a"], -2); - /// ``` - #[deprecated = "use indexing instead: `&mut map[key]`"] - pub fn get_mut<'a>(&'a mut self, k: &K) -> &'a mut V { - &mut self[*k] - } - - /// Return true if the map contains a value for the specified key, - /// using equivalence. - /// - /// See [pop_equiv](#method.pop_equiv) for an extended example. - pub fn contains_key_equiv<Sized? Q: Hash<S> + Equiv<K>>(&self, key: &Q) -> bool { - self.search_equiv(key).is_some() - } - - /// Return the value corresponding to the key in the map, using - /// equivalence. - /// - /// See [pop_equiv](#method.pop_equiv) for an extended example. - pub fn find_equiv<'a, Sized? Q: Hash<S> + Equiv<K>>(&'a self, k: &Q) -> Option<&'a V> { - match self.search_equiv(k) { - None => None, - Some(bucket) => { - let (_, v_ref) = bucket.into_refs(); - Some(v_ref) - } - } - } - - /// Remove an equivalent key from the map, returning the value at the - /// key if the key was previously in the map. - /// - /// # Example - /// - /// This is a slightly silly example where we define the number's - /// parity as the equivalence class. It is important that the - /// values hash the same, which is why we implement `Hash`. - /// - /// ``` - /// use std::collections::HashMap; - /// 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 map = HashMap::new(); - /// map.insert(EvenOrOdd { num: 3 }, "foo"); - /// - /// assert!(map.contains_key_equiv(&EvenOrOdd { num: 1 })); - /// assert!(!map.contains_key_equiv(&EvenOrOdd { num: 4 })); - /// - /// assert_eq!(map.find_equiv(&EvenOrOdd { num: 5 }), Some(&"foo")); - /// assert_eq!(map.find_equiv(&EvenOrOdd { num: 2 }), None); - /// - /// assert_eq!(map.pop_equiv(&EvenOrOdd { num: 1 }), Some("foo")); - /// assert_eq!(map.pop_equiv(&EvenOrOdd { num: 2 }), None); - /// - /// ``` - #[experimental] - pub fn pop_equiv<Sized? Q:Hash<S> + Equiv<K>>(&mut self, k: &Q) -> Option<V> { - if self.table.size() == 0 { - return None - } - - let potential_new_size = self.table.size() - 1; - self.make_some_room(potential_new_size); - - match self.search_equiv_mut(k) { - Some(bucket) => { - let (_k, val) = pop_internal(bucket); - Some(val) - } - _ => None - } - } - - /// An iterator visiting all keys in arbitrary order. - /// Iterator element type is `&'a K`. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert("a", 1i); - /// map.insert("b", 2); - /// map.insert("c", 3); - /// - /// for key in map.keys() { - /// println!("{}", key); - /// } - /// ``` - pub fn keys(&self) -> Keys<K, V> { - self.iter().map(|(k, _v)| k) - } - - /// An iterator visiting all values in arbitrary order. - /// Iterator element type is `&'a V`. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert("a", 1i); - /// map.insert("b", 2); - /// map.insert("c", 3); - /// - /// for key in map.values() { - /// println!("{}", key); - /// } - /// ``` - pub fn values(&self) -> Values<K, V> { - self.iter().map(|(_k, v)| v) - } - - /// An iterator visiting all key-value pairs in arbitrary order. - /// Iterator element type is `(&'a K, &'a V)`. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert("a", 1i); - /// map.insert("b", 2); - /// map.insert("c", 3); - /// - /// for (key, val) in map.iter() { - /// println!("key: {} val: {}", key, val); - /// } - /// ``` - pub fn iter(&self) -> Entries<K, V> { - Entries { inner: self.table.iter() } - } - - /// An iterator visiting all key-value pairs in arbitrary order, - /// with mutable references to the values. - /// Iterator element type is `(&'a K, &'a mut V)`. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert("a", 1i); - /// map.insert("b", 2); - /// map.insert("c", 3); - /// - /// // Update all values - /// for (_, val) in map.iter_mut() { - /// *val *= 2; - /// } - /// - /// for (key, val) in map.iter() { - /// println!("key: {} val: {}", key, val); - /// } - /// ``` - pub fn iter_mut(&mut self) -> MutEntries<K, V> { - MutEntries { inner: self.table.iter_mut() } - } - - /// Creates a consuming iterator, that is, one that moves each key-value - /// pair out of the map in arbitrary order. The map cannot be used after - /// calling this. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert("a", 1i); - /// map.insert("b", 2); - /// map.insert("c", 3); - /// - /// // Not possible with .iter() - /// let vec: Vec<(&str, int)> = map.into_iter().collect(); - /// ``` - pub fn into_iter(self) -> MoveEntries<K, V> { - MoveEntries { - inner: self.table.into_iter().map(|(_, k, v)| (k, v)) - } - } - - /// Gets the given key's corresponding entry in the map for in-place manipulation - pub fn entry<'a>(&'a mut self, key: K) -> Entry<'a, K, V> { - // Gotta resize now, and we don't know which direction, so try both? - let size = self.table.size(); - self.make_some_room(size + 1); - if size > 0 { - self.make_some_room(size - 1); - } - - let hash = self.make_hash(&key); - search_entry_hashed(&mut self.table, hash, key) - } - - /// Return the number of elements in the map. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut a = HashMap::new(); - /// assert_eq!(a.len(), 0); - /// a.insert(1u, "a"); - /// assert_eq!(a.len(), 1); - /// ``` - pub fn len(&self) -> uint { self.table.size() } - - /// Return true if the map contains no elements. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut a = HashMap::new(); - /// assert!(a.is_empty()); - /// a.insert(1u, "a"); - /// assert!(!a.is_empty()); - /// ``` - #[inline] - pub fn is_empty(&self) -> bool { self.len() == 0 } - - /// Clears the map, removing all key-value pairs. Keeps the allocated memory - /// for reuse. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut a = HashMap::new(); - /// a.insert(1u, "a"); - /// a.clear(); - /// assert!(a.is_empty()); - /// ``` - pub fn clear(&mut self) { - // Prevent reallocations from happening from now on. Makes it possible - // for the map to be reused but has a downside: reserves permanently. - self.resize_policy.reserve(self.table.size()); - - let cap = self.table.capacity(); - let mut buckets = Bucket::first(&mut self.table); - - while buckets.index() != cap { - buckets = match buckets.peek() { - Empty(b) => b.next(), - Full(full) => { - let (b, _, _) = full.take(); - b.next() - } - }; - } - } - - /// Returns a reference to the value corresponding to the key. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert(1u, "a"); - /// assert_eq!(map.find(&1), Some(&"a")); - /// assert_eq!(map.find(&2), None); - /// ``` - pub fn find<'a>(&'a self, k: &K) -> Option<&'a V> { - self.search(k).map(|bucket| { - let (_, v) = bucket.into_refs(); - v - }) - } - - /// Returns true if the map contains a value for the specified key. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert(1u, "a"); - /// assert_eq!(map.contains_key(&1), true); - /// assert_eq!(map.contains_key(&2), false); - /// ``` - pub fn contains_key(&self, k: &K) -> bool { - self.search(k).is_some() - } - - /// Returns a mutable reference to the value corresponding to the key. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert(1u, "a"); - /// match map.find_mut(&1) { - /// Some(x) => *x = "b", - /// None => (), - /// } - /// assert_eq!(map[1], "b"); - /// ``` - pub fn find_mut<'a>(&'a mut self, k: &K) -> Option<&'a mut V> { - match self.search_mut(k) { - Some(bucket) => { - let (_, v) = bucket.into_mut_refs(); - Some(v) - } - _ => None - } - } - - /// Inserts a key-value pair into the map. An existing value for a - /// key is replaced by the new value. Returns `true` if the key did - /// not already exist in the map. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// assert_eq!(map.insert(2u, "value"), true); - /// assert_eq!(map.insert(2, "value2"), false); - /// assert_eq!(map[2], "value2"); - /// ``` - #[inline] - pub fn insert(&mut self, key: K, value: V) -> bool { - self.swap(key, value).is_none() - } - - /// Removes a key-value pair from the map. Returns `true` if the key - /// was present in the map. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// assert_eq!(map.remove(&1u), false); - /// map.insert(1, "a"); - /// assert_eq!(map.remove(&1), true); - /// ``` - #[inline] - pub fn remove(&mut self, key: &K) -> bool { - self.pop(key).is_some() - } - - /// Inserts a key-value pair from the map. If the key already had a value - /// present in the map, that value is returned. Otherwise, `None` is returned. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// assert_eq!(map.swap(37u, "a"), None); - /// assert_eq!(map.is_empty(), false); - /// - /// map.insert(37, "b"); - /// assert_eq!(map.swap(37, "c"), Some("b")); - /// assert_eq!(map[37], "c"); - /// ``` - pub fn swap(&mut self, k: K, v: V) -> Option<V> { - let hash = self.make_hash(&k); - let potential_new_size = self.table.size() + 1; - self.make_some_room(potential_new_size); - - let mut retval = None; - self.insert_or_replace_with(hash, k, v, |_, val_ref, val| { - retval = Some(replace(val_ref, val)); - }); - retval - } - - /// Removes a key from the map, returning the value at the key if the key - /// was previously in the map. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map = HashMap::new(); - /// map.insert(1u, "a"); - /// assert_eq!(map.pop(&1), Some("a")); - /// assert_eq!(map.pop(&1), None); - /// ``` - pub fn pop(&mut self, k: &K) -> Option<V> { - if self.table.size() == 0 { - return None - } - - let potential_new_size = self.table.size() - 1; - self.make_some_room(potential_new_size); - - self.search_mut(k).map(|bucket| { - let (_k, val) = pop_internal(bucket); - val - }) - } -} - -fn search_entry_hashed<'a, K: Eq, V>(table: &'a mut RawTable<K,V>, hash: SafeHash, k: K) - -> Entry<'a, K, V> { - // Worst case, we'll find one empty bucket among `size + 1` buckets. - let size = table.size(); - let mut probe = Bucket::new(table, &hash); - let ib = probe.index(); - - loop { - let bucket = match probe.peek() { - Empty(bucket) => { - // Found a hole! - return Vacant(VacantEntry { - hash: hash, - key: k, - elem: NoElem(bucket), - }); - }, - Full(bucket) => bucket - }; - - if bucket.hash() == hash { - let is_eq = { - let (bucket_k, _) = bucket.read(); - k == *bucket_k - }; - - if is_eq { - return Occupied(OccupiedEntry{ - elem: bucket, - }); - } - } - - let robin_ib = bucket.index() as int - bucket.distance() as int; - - if (ib as int) < robin_ib { - // Found a luckier bucket than me. Better steal his spot. - return Vacant(VacantEntry { - hash: hash, - key: k, - elem: NeqElem(bucket, robin_ib as uint), - }); - } - - probe = bucket.next(); - assert!(probe.index() != ib + size + 1); - } -} - -impl<K: Eq + Hash<S>, V: Clone, S, H: Hasher<S>> HashMap<K, V, H> { - /// Return a copy of the value corresponding to the key. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map: HashMap<uint, String> = HashMap::new(); - /// map.insert(1u, "foo".to_string()); - /// let s: String = map.find_copy(&1).unwrap(); - /// ``` - pub fn find_copy(&self, k: &K) -> Option<V> { - self.find(k).map(|v| (*v).clone()) - } - - /// Return a copy of the value corresponding to the key. - /// - /// # Failure - /// - /// Fails if the key is not present. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashMap; - /// - /// let mut map: HashMap<uint, String> = HashMap::new(); - /// map.insert(1u, "foo".to_string()); - /// let s: String = map.get_copy(&1); - /// ``` - pub fn get_copy(&self, k: &K) -> V { - self[*k].clone() - } -} - -impl<K: Eq + Hash<S>, V: PartialEq, S, H: Hasher<S>> PartialEq for HashMap<K, V, H> { - fn eq(&self, other: &HashMap<K, V, H>) -> bool { - if self.len() != other.len() { return false; } - - self.iter().all(|(key, value)| - other.find(key).map_or(false, |v| *value == *v) - ) - } -} - -impl<K: Eq + Hash<S>, V: Eq, S, H: Hasher<S>> Eq for HashMap<K, V, H> {} - -impl<K: Eq + Hash<S> + Show, V: Show, S, H: Hasher<S>> Show for HashMap<K, V, H> { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - try!(write!(f, "{{")); - - for (i, (k, v)) in self.iter().enumerate() { - if i != 0 { try!(write!(f, ", ")); } - try!(write!(f, "{}: {}", *k, *v)); - } - - write!(f, "}}") - } -} - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Default for HashMap<K, V, H> { - fn default() -> HashMap<K, V, H> { - HashMap::with_hasher(Default::default()) - } -} - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Index<K, V> for HashMap<K, V, H> { - #[inline] - fn index<'a>(&'a self, index: &K) -> &'a V { - self.find(index).expect("no entry found for key") - } -} - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> IndexMut<K, V> for HashMap<K, V, H> { - #[inline] - fn index_mut<'a>(&'a mut self, index: &K) -> &'a mut V { - match self.find_mut(index) { - Some(v) => v, - None => panic!("no entry found for key") - } - } -} - -/// HashMap iterator -pub struct Entries<'a, K: 'a, V: 'a> { - inner: table::Entries<'a, K, V> -} - -/// HashMap mutable values iterator -pub struct MutEntries<'a, K: 'a, V: 'a> { - inner: table::MutEntries<'a, K, V> -} - -/// HashMap move iterator -pub struct MoveEntries<K, V> { - inner: iter::Map<'static, (SafeHash, K, V), (K, V), table::MoveEntries<K, V>> -} - -/// A view into a single occupied location in a HashMap -pub struct OccupiedEntry<'a, K:'a, V:'a> { - elem: FullBucket<K, V, &'a mut RawTable<K, V>>, -} - -/// A view into a single empty location in a HashMap -pub struct VacantEntry<'a, K:'a, V:'a> { - hash: SafeHash, - key: K, - elem: VacantEntryState<K,V, &'a mut RawTable<K, V>>, -} - -/// A view into a single location in a map, which may be vacant or occupied -pub enum Entry<'a, K:'a, V:'a> { - /// An occupied Entry - Occupied(OccupiedEntry<'a, K, V>), - /// A vacant Entry - Vacant(VacantEntry<'a, K, V>), -} - -/// Possible states of a VacantEntry -enum VacantEntryState<K, V, M> { - /// The index is occupied, but the key to insert has precedence, - /// and will kick the current one out on insertion - NeqElem(FullBucket<K, V, M>, uint), - /// The index is genuinely vacant - NoElem(EmptyBucket<K, V, M>), -} - -impl<'a, K, V> Iterator<(&'a K, &'a V)> for Entries<'a, K, V> { - #[inline] - fn next(&mut self) -> Option<(&'a K, &'a V)> { - self.inner.next() - } - #[inline] - fn size_hint(&self) -> (uint, Option<uint>) { - self.inner.size_hint() - } -} - -impl<'a, K, V> Iterator<(&'a K, &'a mut V)> for MutEntries<'a, K, V> { - #[inline] - fn next(&mut self) -> Option<(&'a K, &'a mut V)> { - self.inner.next() - } - #[inline] - fn size_hint(&self) -> (uint, Option<uint>) { - self.inner.size_hint() - } -} - -impl<K, V> Iterator<(K, V)> for MoveEntries<K, V> { - #[inline] - fn next(&mut self) -> Option<(K, V)> { - self.inner.next() - } - #[inline] - fn size_hint(&self) -> (uint, Option<uint>) { - self.inner.size_hint() - } -} - -impl<'a, K, V> OccupiedEntry<'a, K, V> { - /// Gets a reference to the value in the entry - pub fn get(&self) -> &V { - let (_, v) = self.elem.read(); - v - } - - /// Gets a mutable reference to the value in the entry - pub fn get_mut(&mut self) -> &mut V { - let (_, v) = self.elem.read_mut(); - v - } - - /// Converts the OccupiedEntry into a mutable reference to the value in the entry - /// with a lifetime bound to the map itself - pub fn into_mut(self) -> &'a mut V { - let (_, v) = self.elem.into_mut_refs(); - v - } - - /// Sets the value of the entry, and returns the entry's old value - pub fn set(&mut self, mut value: V) -> V { - let old_value = self.get_mut(); - mem::swap(&mut value, old_value); - value - } - - /// Takes the value out of the entry, and returns it - pub fn take(self) -> V { - let (_, _, v) = self.elem.take(); - v - } -} - -impl<'a, K, V> VacantEntry<'a, K, V> { - /// Sets the value of the entry with the VacantEntry's key, - /// and returns a mutable reference to it - pub fn set(self, value: V) -> &'a mut V { - match self.elem { - NeqElem(bucket, ib) => { - robin_hood(bucket, ib, self.hash, self.key, value) - } - NoElem(bucket) => { - let full = bucket.put(self.hash, self.key, value); - let (_, v) = full.into_mut_refs(); - v - } - } - } -} - -/// HashMap keys iterator -pub type Keys<'a, K, V> = - iter::Map<'static, (&'a K, &'a V), &'a K, Entries<'a, K, V>>; - -/// HashMap values iterator -pub type Values<'a, K, V> = - iter::Map<'static, (&'a K, &'a V), &'a V, Entries<'a, K, V>>; - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> FromIterator<(K, V)> for HashMap<K, V, H> { - fn from_iter<T: Iterator<(K, V)>>(iter: T) -> HashMap<K, V, H> { - let (lower, _) = iter.size_hint(); - let mut map = HashMap::with_capacity_and_hasher(lower, Default::default()); - map.extend(iter); - map - } -} - -impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Extendable<(K, V)> for HashMap<K, V, H> { - fn extend<T: Iterator<(K, V)>>(&mut self, mut iter: T) { - for (k, v) in iter { - self.insert(k, v); - } - } -} - -#[cfg(test)] -mod test_map { - use prelude::*; - - use super::HashMap; - use super::{Occupied, Vacant}; - use cmp::Equiv; - use hash; - use iter::{Iterator,range_inclusive,range_step_inclusive}; - use cell::RefCell; - - struct KindaIntLike(int); - - impl Equiv<int> for KindaIntLike { - fn equiv(&self, other: &int) -> bool { - let KindaIntLike(this) = *self; - this == *other - } - } - impl<S: hash::Writer> hash::Hash<S> for KindaIntLike { - fn hash(&self, state: &mut S) { - let KindaIntLike(this) = *self; - this.hash(state) - } - } - - #[test] - fn test_create_capacity_zero() { - let mut m = HashMap::with_capacity(0); - - assert!(m.insert(1i, 1i)); - - assert!(m.contains_key(&1)); - assert!(!m.contains_key(&0)); - } - - #[test] - fn test_insert() { - let mut m = HashMap::new(); - assert_eq!(m.len(), 0); - assert!(m.insert(1i, 2i)); - assert_eq!(m.len(), 1); - assert!(m.insert(2i, 4i)); - assert_eq!(m.len(), 2); - assert_eq!(*m.find(&1).unwrap(), 2); - assert_eq!(*m.find(&2).unwrap(), 4); - } - - local_data_key!(drop_vector: RefCell<Vec<int>>) - - #[deriving(Hash, PartialEq, Eq)] - struct Dropable { - k: uint - } - - impl Dropable { - fn new(k: uint) -> Dropable { - let v = drop_vector.get().unwrap(); - v.borrow_mut().as_mut_slice()[k] += 1; - - Dropable { k: k } - } - } - - impl Drop for Dropable { - fn drop(&mut self) { - let v = drop_vector.get().unwrap(); - v.borrow_mut().as_mut_slice()[self.k] -= 1; - } - } - - impl Clone for Dropable { - fn clone(&self) -> Dropable { - Dropable::new(self.k) - } - } - - #[test] - fn test_drops() { - drop_vector.replace(Some(RefCell::new(Vec::from_elem(200, 0i)))); - - { - let mut m = HashMap::new(); - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 0); - } - drop(v); - - for i in range(0u, 100) { - let d1 = Dropable::new(i); - let d2 = Dropable::new(i+100); - m.insert(d1, d2); - } - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 1); - } - drop(v); - - for i in range(0u, 50) { - let k = Dropable::new(i); - let v = m.pop(&k); - - assert!(v.is_some()); - - let v = drop_vector.get().unwrap(); - assert_eq!(v.borrow().as_slice()[i], 1); - assert_eq!(v.borrow().as_slice()[i+100], 1); - } - - let v = drop_vector.get().unwrap(); - for i in range(0u, 50) { - assert_eq!(v.borrow().as_slice()[i], 0); - assert_eq!(v.borrow().as_slice()[i+100], 0); - } - - for i in range(50u, 100) { - assert_eq!(v.borrow().as_slice()[i], 1); - assert_eq!(v.borrow().as_slice()[i+100], 1); - } - } - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 0); - } - } - - #[test] - fn test_move_iter_drops() { - drop_vector.replace(Some(RefCell::new(Vec::from_elem(200, 0i)))); - - let hm = { - let mut hm = HashMap::new(); - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 0); - } - drop(v); - - for i in range(0u, 100) { - let d1 = Dropable::new(i); - let d2 = Dropable::new(i+100); - hm.insert(d1, d2); - } - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 1); - } - drop(v); - - hm - }; - - // By the way, ensure that cloning doesn't screw up the dropping. - drop(hm.clone()); - - { - let mut half = hm.into_iter().take(50); - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 1); - } - drop(v); - - for _ in half {} - - let v = drop_vector.get().unwrap(); - let nk = range(0u, 100).filter(|&i| { - v.borrow().as_slice()[i] == 1 - }).count(); - - let nv = range(0u, 100).filter(|&i| { - v.borrow().as_slice()[i+100] == 1 - }).count(); - - assert_eq!(nk, 50); - assert_eq!(nv, 50); - }; - - let v = drop_vector.get().unwrap(); - for i in range(0u, 200) { - assert_eq!(v.borrow().as_slice()[i], 0); - } - } - - #[test] - fn test_empty_pop() { - let mut m: HashMap<int, bool> = HashMap::new(); - assert_eq!(m.pop(&0), None); - } - - #[test] - fn test_lots_of_insertions() { - let mut m = HashMap::new(); - - // Try this a few times to make sure we never screw up the hashmap's - // internal state. - for _ in range(0i, 10) { - assert!(m.is_empty()); - - for i in range_inclusive(1i, 1000) { - assert!(m.insert(i, i)); - - for j in range_inclusive(1, i) { - let r = m.find(&j); - assert_eq!(r, Some(&j)); - } - - for j in range_inclusive(i+1, 1000) { - let r = m.find(&j); - assert_eq!(r, None); - } - } - - for i in range_inclusive(1001i, 2000) { - assert!(!m.contains_key(&i)); - } - - // remove forwards - for i in range_inclusive(1i, 1000) { - assert!(m.remove(&i)); - - for j in range_inclusive(1, i) { - assert!(!m.contains_key(&j)); - } - - for j in range_inclusive(i+1, 1000) { - assert!(m.contains_key(&j)); - } - } - - for i in range_inclusive(1i, 1000) { - assert!(!m.contains_key(&i)); - } - - for i in range_inclusive(1i, 1000) { - assert!(m.insert(i, i)); - } - - // remove backwards - for i in range_step_inclusive(1000i, 1, -1) { - assert!(m.remove(&i)); - - for j in range_inclusive(i, 1000) { - assert!(!m.contains_key(&j)); - } - - for j in range_inclusive(1, i-1) { - assert!(m.contains_key(&j)); - } - } - } - } - - #[test] - fn test_find_mut() { - let mut m = HashMap::new(); - assert!(m.insert(1i, 12i)); - assert!(m.insert(2i, 8i)); - assert!(m.insert(5i, 14i)); - let new = 100; - match m.find_mut(&5) { - None => panic!(), Some(x) => *x = new - } - assert_eq!(m.find(&5), Some(&new)); - } - - #[test] - fn test_insert_overwrite() { - let mut m = HashMap::new(); - assert!(m.insert(1i, 2i)); - assert_eq!(*m.find(&1).unwrap(), 2); - assert!(!m.insert(1i, 3i)); - assert_eq!(*m.find(&1).unwrap(), 3); - } - - #[test] - fn test_insert_conflicts() { - let mut m = HashMap::with_capacity(4); - assert!(m.insert(1i, 2i)); - assert!(m.insert(5i, 3i)); - assert!(m.insert(9i, 4i)); - assert_eq!(*m.find(&9).unwrap(), 4); - assert_eq!(*m.find(&5).unwrap(), 3); - assert_eq!(*m.find(&1).unwrap(), 2); - } - - #[test] - fn test_conflict_remove() { - let mut m = HashMap::with_capacity(4); - assert!(m.insert(1i, 2i)); - assert_eq!(*m.find(&1).unwrap(), 2); - assert!(m.insert(5, 3)); - assert_eq!(*m.find(&1).unwrap(), 2); - assert_eq!(*m.find(&5).unwrap(), 3); - assert!(m.insert(9, 4)); - assert_eq!(*m.find(&1).unwrap(), 2); - assert_eq!(*m.find(&5).unwrap(), 3); - assert_eq!(*m.find(&9).unwrap(), 4); - assert!(m.remove(&1)); - assert_eq!(*m.find(&9).unwrap(), 4); - assert_eq!(*m.find(&5).unwrap(), 3); - } - - #[test] - fn test_is_empty() { - let mut m = HashMap::with_capacity(4); - assert!(m.insert(1i, 2i)); - assert!(!m.is_empty()); - assert!(m.remove(&1)); - assert!(m.is_empty()); - } - - #[test] - fn test_pop() { - let mut m = HashMap::new(); - m.insert(1i, 2i); - assert_eq!(m.pop(&1), Some(2)); - assert_eq!(m.pop(&1), None); - } - - #[test] - #[allow(experimental)] - fn test_pop_equiv() { - let mut m = HashMap::new(); - m.insert(1i, 2i); - assert_eq!(m.pop_equiv(&KindaIntLike(1)), Some(2)); - assert_eq!(m.pop_equiv(&KindaIntLike(1)), None); - } - - #[test] - fn test_swap() { - let mut m = HashMap::new(); - assert_eq!(m.swap(1i, 2i), None); - assert_eq!(m.swap(1i, 3i), Some(2)); - assert_eq!(m.swap(1i, 4i), Some(3)); - } - - #[test] - fn test_iterate() { - let mut m = HashMap::with_capacity(4); - for i in range(0u, 32) { - assert!(m.insert(i, i*2)); - } - assert_eq!(m.len(), 32); - - let mut observed: u32 = 0; - - for (k, v) in m.iter() { - assert_eq!(*v, *k * 2); - observed |= 1 << *k; - } - assert_eq!(observed, 0xFFFF_FFFF); - } - - #[test] - fn test_keys() { - let vec = vec![(1i, 'a'), (2i, 'b'), (3i, 'c')]; - let map = vec.into_iter().collect::<HashMap<int, char>>(); - let keys = map.keys().map(|&k| k).collect::<Vec<int>>(); - assert_eq!(keys.len(), 3); - assert!(keys.contains(&1)); - assert!(keys.contains(&2)); - assert!(keys.contains(&3)); - } - - #[test] - fn test_values() { - let vec = vec![(1i, 'a'), (2i, 'b'), (3i, 'c')]; - let map = vec.into_iter().collect::<HashMap<int, char>>(); - let values = map.values().map(|&v| v).collect::<Vec<char>>(); - assert_eq!(values.len(), 3); - assert!(values.contains(&'a')); - assert!(values.contains(&'b')); - assert!(values.contains(&'c')); - } - - #[test] - fn test_find() { - let mut m = HashMap::new(); - assert!(m.find(&1i).is_none()); - m.insert(1i, 2i); - match m.find(&1) { - None => panic!(), - Some(v) => assert_eq!(*v, 2) - } - } - - #[test] - fn test_find_copy() { - let mut m = HashMap::new(); - assert!(m.find(&1i).is_none()); - - for i in range(1i, 10000) { - m.insert(i, i + 7); - match m.find_copy(&i) { - None => panic!(), - Some(v) => assert_eq!(v, i + 7) - } - for j in range(1i, i/100) { - match m.find_copy(&j) { - None => panic!(), - Some(v) => assert_eq!(v, j + 7) - } - } - } - } - - #[test] - fn test_eq() { - let mut m1 = HashMap::new(); - m1.insert(1i, 2i); - m1.insert(2i, 3i); - m1.insert(3i, 4i); - - let mut m2 = HashMap::new(); - m2.insert(1i, 2i); - m2.insert(2i, 3i); - - assert!(m1 != m2); - - m2.insert(3i, 4i); - - assert_eq!(m1, m2); - } - - #[test] - fn test_show() { - let mut map: HashMap<int, int> = HashMap::new(); - let empty: HashMap<int, int> = HashMap::new(); - - map.insert(1i, 2i); - map.insert(3i, 4i); - - let map_str = format!("{}", map); - - assert!(map_str == "{1: 2, 3: 4}".to_string() || map_str == "{3: 4, 1: 2}".to_string()); - assert_eq!(format!("{}", empty), "{}".to_string()); - } - - #[test] - fn test_expand() { - let mut m = HashMap::new(); - - assert_eq!(m.len(), 0); - assert!(m.is_empty()); - - let mut i = 0u; - let old_cap = m.table.capacity(); - while old_cap == m.table.capacity() { - m.insert(i, i); - i += 1; - } - - assert_eq!(m.len(), i); - assert!(!m.is_empty()); - } - - #[test] - fn test_resize_policy() { - let mut m = HashMap::new(); - - assert_eq!(m.len(), 0); - assert_eq!(m.table.capacity(), 0); - assert!(m.is_empty()); - - m.insert(0, 0); - m.remove(&0); - assert!(m.is_empty()); - let initial_cap = m.table.capacity(); - m.reserve(initial_cap * 2); - let cap = m.table.capacity(); - - assert_eq!(cap, initial_cap * 2); - - let mut i = 0u; - for _ in range(0, cap * 3 / 4) { - m.insert(i, i); - i += 1; - } - // three quarters full - - assert_eq!(m.len(), i); - assert_eq!(m.table.capacity(), cap); - - for _ in range(0, cap / 4) { - m.insert(i, i); - i += 1; - } - // half full - - let new_cap = m.table.capacity(); - assert_eq!(new_cap, cap * 2); - - for _ in range(0, cap / 2 - 1) { - i -= 1; - m.remove(&i); - assert_eq!(m.table.capacity(), new_cap); - } - // A little more than one quarter full. - // Shrinking starts as we remove more elements: - for _ in range(0, cap / 2 - 1) { - i -= 1; - m.remove(&i); - } - - assert_eq!(m.len(), i); - assert!(!m.is_empty()); - assert_eq!(m.table.capacity(), cap); - } - - #[test] - fn test_find_equiv() { - let mut m = HashMap::new(); - - let (foo, bar, baz) = (1i,2i,3i); - m.insert("foo".to_string(), foo); - m.insert("bar".to_string(), bar); - m.insert("baz".to_string(), baz); - - - assert_eq!(m.find_equiv("foo"), Some(&foo)); - assert_eq!(m.find_equiv("bar"), Some(&bar)); - assert_eq!(m.find_equiv("baz"), Some(&baz)); - - assert_eq!(m.find_equiv("qux"), None); - } - - #[test] - fn test_from_iter() { - let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; - - let map: HashMap<int, int> = xs.iter().map(|&x| x).collect(); - - for &(k, v) in xs.iter() { - assert_eq!(map.find(&k), Some(&v)); - } - } - - #[test] - fn test_size_hint() { - let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; - - let map: HashMap<int, int> = xs.iter().map(|&x| x).collect(); - - let mut iter = map.iter(); - - for _ in iter.by_ref().take(3) {} - - assert_eq!(iter.size_hint(), (3, Some(3))); - } - - #[test] - fn test_mut_size_hint() { - let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; - - let mut map: HashMap<int, int> = xs.iter().map(|&x| x).collect(); - - let mut iter = map.iter_mut(); - - for _ in iter.by_ref().take(3) {} - - assert_eq!(iter.size_hint(), (3, Some(3))); - } - - #[test] - fn test_index() { - let mut map: HashMap<int, int> = HashMap::new(); - - map.insert(1, 2); - map.insert(2, 1); - map.insert(3, 4); - - assert_eq!(map[2], 1); - } - - #[test] - #[should_fail] - fn test_index_nonexistent() { - let mut map: HashMap<int, int> = HashMap::new(); - - map.insert(1, 2); - map.insert(2, 1); - map.insert(3, 4); - - map[4]; - } - - #[test] - fn test_entry(){ - let xs = [(1i, 10i), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)]; - - let mut map: HashMap<int, int> = xs.iter().map(|&x| x).collect(); - - // Existing key (insert) - match map.entry(1) { - Vacant(_) => unreachable!(), - Occupied(mut view) => { - assert_eq!(view.get(), &10); - assert_eq!(view.set(100), 10); - } - } - assert_eq!(map.find(&1).unwrap(), &100); - assert_eq!(map.len(), 6); - - - // Existing key (update) - match map.entry(2) { - Vacant(_) => unreachable!(), - Occupied(mut view) => { - let v = view.get_mut(); - let new_v = (*v) * 10; - *v = new_v; - } - } - assert_eq!(map.find(&2).unwrap(), &200); - assert_eq!(map.len(), 6); - - // Existing key (take) - match map.entry(3) { - Vacant(_) => unreachable!(), - Occupied(view) => { - assert_eq!(view.take(), 30); - } - } - assert_eq!(map.find(&3), None); - assert_eq!(map.len(), 5); - - - // Inexistent key (insert) - match map.entry(10) { - Occupied(_) => unreachable!(), - Vacant(view) => { - assert_eq!(*view.set(1000), 1000); - } - } - assert_eq!(map.find(&10).unwrap(), &1000); - assert_eq!(map.len(), 6); - } -} diff --git a/src/libstd/collections/hashmap/mod.rs b/src/libstd/collections/hashmap/mod.rs deleted file mode 100644 index 6508d4609f1..00000000000 --- a/src/libstd/collections/hashmap/mod.rs +++ /dev/null @@ -1,33 +0,0 @@ -// 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::Entry; -pub use self::map::Occupied; -pub use self::map::Vacant; -pub use self::map::OccupiedEntry; -pub use self::map::VacantEntry; -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; diff --git a/src/libstd/collections/hashmap/set.rs b/src/libstd/collections/hashmap/set.rs deleted file mode 100644 index 69f3812425f..00000000000 --- a/src/libstd/collections/hashmap/set.rs +++ /dev/null @@ -1,834 +0,0 @@ -// 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 core::kinds::Sized; -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 equivalance 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<Sized? 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() - } - - /// Deprecated: use `into_iter`. - #[deprecated = "use into_iter"] - pub fn move_iter(self) -> SetMoveItems<T> { - self.into_iter() - } - - /// 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.into_iter().collect(); - /// - /// // Will print in an arbitrary order. - /// for x in v.iter() { - /// println!("{}", x); - /// } - /// ``` - pub fn into_iter(self) -> SetMoveItems<T> { - self.map.into_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)) - } - - /// Return the number of elements in the set - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let mut v = HashSet::new(); - /// assert_eq!(v.len(), 0); - /// v.insert(1u); - /// assert_eq!(v.len(), 1); - /// ``` - pub fn len(&self) -> uint { self.map.len() } - - /// Returns true if the set contains no elements - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let mut v = HashSet::new(); - /// assert!(v.is_empty()); - /// v.insert(1u); - /// assert!(!v.is_empty()); - /// ``` - pub fn is_empty(&self) -> bool { self.map.len() == 0 } - - /// Clears the set, removing all values. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let mut v = HashSet::new(); - /// v.insert(1u); - /// v.clear(); - /// assert!(v.is_empty()); - /// ``` - pub fn clear(&mut self) { self.map.clear() } - - /// Returns `true` if the set contains a value. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let set: HashSet<uint> = [1, 2, 3].iter().map(|&x| x).collect(); - /// assert_eq!(set.contains(&1), true); - /// assert_eq!(set.contains(&4), false); - /// ``` - pub fn contains(&self, value: &T) -> bool { self.map.contains_key(value) } - - /// Returns `true` if the set has no elements in common with `other`. - /// This is equivalent to checking for an empty intersection. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let a: HashSet<uint> = [1, 2, 3].iter().map(|&x| x).collect(); - /// let mut b: HashSet<uint> = HashSet::new(); - /// - /// assert_eq!(a.is_disjoint(&b), true); - /// b.insert(4); - /// assert_eq!(a.is_disjoint(&b), true); - /// b.insert(1); - /// assert_eq!(a.is_disjoint(&b), false); - /// ``` - pub fn is_disjoint(&self, other: &HashSet<T, H>) -> bool { - self.iter().all(|v| !other.contains(v)) - } - - /// Returns `true` if the set is a subset of another. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let sup: HashSet<uint> = [1, 2, 3].iter().map(|&x| x).collect(); - /// let mut set: HashSet<uint> = HashSet::new(); - /// - /// assert_eq!(set.is_subset(&sup), true); - /// set.insert(2); - /// assert_eq!(set.is_subset(&sup), true); - /// set.insert(4); - /// assert_eq!(set.is_subset(&sup), false); - /// ``` - pub fn is_subset(&self, other: &HashSet<T, H>) -> bool { - self.iter().all(|v| other.contains(v)) - } - - /// Returns `true` if the set is a superset of another. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let sub: HashSet<uint> = [1, 2].iter().map(|&x| x).collect(); - /// let mut set: HashSet<uint> = HashSet::new(); - /// - /// assert_eq!(set.is_superset(&sub), false); - /// - /// set.insert(0); - /// set.insert(1); - /// assert_eq!(set.is_superset(&sub), false); - /// - /// set.insert(2); - /// assert_eq!(set.is_superset(&sub), true); - /// ``` - #[inline] - pub fn is_superset(&self, other: &HashSet<T, H>) -> bool { - other.is_subset(self) - } - - /// Adds a value to the set. Returns `true` if the value was not already - /// present in the set. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let mut set = HashSet::new(); - /// - /// assert_eq!(set.insert(2u), true); - /// assert_eq!(set.insert(2), false); - /// assert_eq!(set.len(), 1); - /// ``` - pub fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) } - - /// Removes a value from the set. Returns `true` if the value was - /// present in the set. - /// - /// # Example - /// - /// ``` - /// use std::collections::HashSet; - /// - /// let mut set = HashSet::new(); - /// - /// set.insert(2u); - /// assert_eq!(set.remove(&2), true); - /// assert_eq!(set.remove(&2), false); - /// ``` - pub fn remove(&mut self, value: &T) -> bool { self.map.remove(value) } -} - -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> + 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; - - #[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.into_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()); - } -} diff --git a/src/libstd/collections/hashmap/table.rs b/src/libstd/collections/hashmap/table.rs deleted file mode 100644 index 4d73029b7b0..00000000000 --- a/src/libstd/collections/hashmap/table.rs +++ /dev/null @@ -1,907 +0,0 @@ -// 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::{Sized, 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}; - -const 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<Sized? 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(..) => panic!("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); - if buffer.is_null() { ::alloc::oom() } - - 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) - }, - marker: marker::ContravariantLifetime, - } - } - - pub fn iter(&self) -> Entries<K, V> { - Entries { - iter: self.raw_buckets(), - elems_left: self.size(), - } - } - - pub fn iter_mut(&mut self) -> MutEntries<K, V> { - MutEntries { - iter: self.raw_buckets(), - elems_left: self.size(), - } - } - - pub fn into_iter(self) -> MoveEntries<K, V> { - let RawBuckets { raw, hashes_end, .. } = self.raw_buckets(); - // Replace the marker regardless of lifetime bounds on parameters. - MoveEntries { - iter: RawBuckets { - raw: raw, - hashes_end: hashes_end, - marker: marker::ContravariantLifetime, - }, - 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, - marker: marker::ContravariantLifetime, - } - } -} - -/// 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, - marker: marker::ContravariantLifetime<'a>, -} - -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, - marker: marker::ContravariantLifetime<'a>, -} - -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(); - ptr::write(new_buckets.raw.key, k); - ptr::write(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 `.into_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. - } - } -} |