Add SortedMap to rustc_data_structures.

This commit is contained in:
Michael Woerister 2018-05-18 11:48:11 +02:00
parent ff8fa5cc69
commit 879eb972ad
2 changed files with 502 additions and 0 deletions

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@ -73,6 +73,7 @@ pub mod control_flow_graph;
pub mod flock;
pub mod sync;
pub mod owning_ref;
pub mod sorted_map;
pub struct OnDrop<F: Fn()>(pub F);

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@ -0,0 +1,501 @@
// Copyright 2018 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.
use std::borrow::Borrow;
use std::cmp::Ordering;
use std::convert::From;
use std::mem;
use std::ops::{RangeBounds, Bound, Index, IndexMut};
#[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
pub struct SortedMap<K: Ord, V> {
data: Vec<(K,V)>
}
impl<K: Ord, V> SortedMap<K, V> {
#[inline]
pub fn new() -> SortedMap<K, V> {
SortedMap {
data: vec![]
}
}
// It is up to the caller to make sure that the elements are sorted by key
// and that there are no duplicates.
#[inline]
pub fn from_presorted_elements(elements: Vec<(K, V)>) -> SortedMap<K, V>
{
debug_assert!(elements.windows(2).all(|w| w[0].0 < w[1].0));
SortedMap {
data: elements
}
}
#[inline]
pub fn insert(&mut self, key: K, mut value: V) -> Option<V> {
let index = self.data.binary_search_by(|&(ref x, _)| x.cmp(&key));
match index {
Ok(index) => {
let mut slot = unsafe {
self.data.get_unchecked_mut(index)
};
mem::swap(&mut slot.1, &mut value);
Some(value)
}
Err(index) => {
self.data.insert(index, (key, value));
None
}
}
}
#[inline]
pub fn remove(&mut self, key: &K) -> Option<V> {
let index = self.data.binary_search_by(|&(ref x, _)| x.cmp(key));
match index {
Ok(index) => {
Some(self.data.remove(index).1)
}
Err(_) => {
None
}
}
}
#[inline]
pub fn get(&self, key: &K) -> Option<&V> {
let index = self.data.binary_search_by(|&(ref x, _)| x.cmp(key));
match index {
Ok(index) => {
unsafe {
Some(&self.data.get_unchecked(index).1)
}
}
Err(_) => {
None
}
}
}
#[inline]
pub fn get_mut(&mut self, key: &K) -> Option<&mut V> {
let index = self.data.binary_search_by(|&(ref x, _)| x.cmp(key));
match index {
Ok(index) => {
unsafe {
Some(&mut self.data.get_unchecked_mut(index).1)
}
}
Err(_) => {
None
}
}
}
#[inline]
pub fn clear(&mut self) {
self.data.clear();
}
/// Iterate over elements, sorted by key
#[inline]
pub fn iter(&self) -> ::std::slice::Iter<(K, V)> {
self.data.iter()
}
/// Iterate over the keys, sorted
#[inline]
pub fn keys(&self) -> impl Iterator<Item=&K> + ExactSizeIterator {
self.data.iter().map(|&(ref k, _)| k)
}
/// Iterate over values, sorted by key
#[inline]
pub fn values(&self) -> impl Iterator<Item=&V> + ExactSizeIterator {
self.data.iter().map(|&(_, ref v)| v)
}
#[inline]
pub fn len(&self) -> usize {
self.data.len()
}
#[inline]
pub fn range<R>(&self, range: R) -> &[(K, V)]
where R: RangeBounds<K>
{
let (start, end) = self.range_slice_indices(range);
(&self.data[start .. end])
}
#[inline]
pub fn range_mut<R>(&mut self, range: R) -> &mut [(K, V)]
where R: RangeBounds<K>
{
let (start, end) = self.range_slice_indices(range);
(&mut self.data[start .. end])
}
#[inline]
pub fn remove_range<R>(&mut self, range: R)
where R: RangeBounds<K>
{
let (start, end) = self.range_slice_indices(range);
self.data.splice(start .. end, ::std::iter::empty());
}
/// Mutate all keys with the given function `f`. This mutation must not
/// change the sort-order of keys.
#[inline]
pub fn offset_keys<F>(&mut self, f: F)
where F: Fn(&mut K)
{
self.data.iter_mut().map(|&mut (ref mut k, _)| k).for_each(f);
}
// It is up to the caller to make sure that the elements are sorted by key
// and that there are no duplicates.
#[inline]
pub fn insert_presorted(&mut self, mut elements: Vec<(K, V)>) {
if elements.is_empty() {
return
}
debug_assert!(elements.windows(2).all(|w| w[0].0 < w[1].0));
let index = {
let first_element = &elements[0].0;
self.data.binary_search_by(|&(ref x, _)| x.cmp(first_element))
};
let drain = match index {
Ok(index) => {
let mut drain = elements.drain(..);
self.data[index] = drain.next().unwrap();
drain
}
Err(index) => {
if index == self.data.len() ||
elements.last().unwrap().0 < self.data[index].0 {
// We can copy the whole range without having to mix with
// existing elements.
self.data.splice(index .. index, elements.drain(..));
return
}
let mut drain = elements.drain(..);
self.data.insert(index, drain.next().unwrap());
drain
}
};
// Insert the rest
for (k, v) in drain {
self.insert(k, v);
}
}
#[inline]
fn range_slice_indices<R>(&self, range: R) -> (usize, usize)
where R: RangeBounds<K>
{
let start = match range.start() {
Bound::Included(ref k) => {
match self.data.binary_search_by(|&(ref x, _)| x.cmp(k)) {
Ok(index) | Err(index) => index
}
}
Bound::Excluded(ref k) => {
match self.data.binary_search_by(|&(ref x, _)| x.cmp(k)) {
Ok(index) => index + 1,
Err(index) => index,
}
}
Bound::Unbounded => 0,
};
let end = match range.end() {
Bound::Included(ref k) => {
match self.data.binary_search_by(|&(ref x, _)| x.cmp(k)) {
Ok(index) => index + 1,
Err(index) => index,
}
}
Bound::Excluded(ref k) => {
match self.data.binary_search_by(|&(ref x, _)| x.cmp(k)) {
Ok(index) | Err(index) => index,
}
}
Bound::Unbounded => self.data.len(),
};
(start, end)
}
}
impl<K: Ord, V> IntoIterator for SortedMap<K, V> {
type Item = (K, V);
type IntoIter = ::std::vec::IntoIter<(K, V)>;
fn into_iter(self) -> Self::IntoIter {
self.data.into_iter()
}
}
impl<K: Ord, V, Q: Borrow<K>> Index<Q> for SortedMap<K, V> {
type Output = V;
fn index(&self, index: Q) -> &Self::Output {
let k: &K = index.borrow();
self.get(k).unwrap()
}
}
impl<K: Ord, V, Q: Borrow<K>> IndexMut<Q> for SortedMap<K, V> {
fn index_mut(&mut self, index: Q) -> &mut Self::Output {
let k: &K = index.borrow();
self.get_mut(k).unwrap()
}
}
impl<K: Ord, V, I: Iterator<Item=(K, V)>> From<I> for SortedMap<K, V> {
fn from(data: I) -> Self {
let mut data: Vec<(K, V)> = data.collect();
data.sort_unstable_by(|&(ref k1, _), &(ref k2, _)| k1.cmp(k2));
data.dedup_by(|&mut (ref k1, _), &mut (ref k2, _)| {
k1.cmp(k2) == Ordering::Equal
});
SortedMap {
data
}
}
}
#[cfg(test)]
mod tests {
use super::SortedMap;
use test::{self, Bencher};
#[test]
fn test_insert_and_iter() {
let mut map = SortedMap::new();
let mut expected = Vec::new();
for x in 0 .. 100 {
assert_eq!(map.iter().cloned().collect::<Vec<_>>(), expected);
let x = 1000 - x * 2;
map.insert(x, x);
expected.insert(0, (x, x));
}
}
#[test]
fn test_get_and_index() {
let mut map = SortedMap::new();
let mut expected = Vec::new();
for x in 0 .. 100 {
let x = 1000 - x;
if x & 1 == 0 {
map.insert(x, x);
}
expected.push(x);
}
for mut x in expected {
if x & 1 == 0 {
assert_eq!(map.get(&x), Some(&x));
assert_eq!(map.get_mut(&x), Some(&mut x));
assert_eq!(map[&x], x);
assert_eq!(&mut map[&x], &mut x);
} else {
assert_eq!(map.get(&x), None);
assert_eq!(map.get_mut(&x), None);
}
}
}
#[test]
fn test_range() {
let mut map = SortedMap::new();
map.insert(1, 1);
map.insert(3, 3);
map.insert(6, 6);
map.insert(9, 9);
let keys = |s: &[(_, _)]| {
s.into_iter().map(|e| e.0).collect::<Vec<u32>>()
};
for start in 0 .. 11 {
for end in 0 .. 11 {
if end < start {
continue
}
let mut expected = vec![1, 3, 6, 9];
expected.retain(|&x| x >= start && x < end);
assert_eq!(keys(map.range(start..end)), expected, "range = {}..{}", start, end);
}
}
}
#[test]
fn test_offset_keys() {
let mut map = SortedMap::new();
map.insert(1, 1);
map.insert(3, 3);
map.insert(6, 6);
map.offset_keys(|k| *k += 1);
let mut expected = SortedMap::new();
expected.insert(2, 1);
expected.insert(4, 3);
expected.insert(7, 6);
assert_eq!(map, expected);
}
fn keys(s: SortedMap<u32, u32>) -> Vec<u32> {
s.into_iter().map(|(k, _)| k).collect::<Vec<u32>>()
}
fn elements(s: SortedMap<u32, u32>) -> Vec<(u32, u32)> {
s.into_iter().collect::<Vec<(u32, u32)>>()
}
#[test]
fn test_remove_range() {
let mut map = SortedMap::new();
map.insert(1, 1);
map.insert(3, 3);
map.insert(6, 6);
map.insert(9, 9);
for start in 0 .. 11 {
for end in 0 .. 11 {
if end < start {
continue
}
let mut expected = vec![1, 3, 6, 9];
expected.retain(|&x| x < start || x >= end);
let mut map = map.clone();
map.remove_range(start .. end);
assert_eq!(keys(map), expected, "range = {}..{}", start, end);
}
}
}
#[test]
fn test_remove() {
let mut map = SortedMap::new();
let mut expected = Vec::new();
for x in 0..10 {
map.insert(x, x);
expected.push((x, x));
}
for x in 0 .. 10 {
let mut map = map.clone();
let mut expected = expected.clone();
assert_eq!(map.remove(&x), Some(x));
expected.remove(x as usize);
assert_eq!(map.iter().cloned().collect::<Vec<_>>(), expected);
}
}
#[test]
fn test_insert_presorted_non_overlapping() {
let mut map = SortedMap::new();
map.insert(2, 0);
map.insert(8, 0);
map.insert_presorted(vec![(3, 0), (7, 0)]);
let expected = vec![2, 3, 7, 8];
assert_eq!(keys(map), expected);
}
#[test]
fn test_insert_presorted_first_elem_equal() {
let mut map = SortedMap::new();
map.insert(2, 2);
map.insert(8, 8);
map.insert_presorted(vec![(2, 0), (7, 7)]);
let expected = vec![(2, 0), (7, 7), (8, 8)];
assert_eq!(elements(map), expected);
}
#[test]
fn test_insert_presorted_last_elem_equal() {
let mut map = SortedMap::new();
map.insert(2, 2);
map.insert(8, 8);
map.insert_presorted(vec![(3, 3), (8, 0)]);
let expected = vec![(2, 2), (3, 3), (8, 0)];
assert_eq!(elements(map), expected);
}
#[test]
fn test_insert_presorted_shuffle() {
let mut map = SortedMap::new();
map.insert(2, 2);
map.insert(7, 7);
map.insert_presorted(vec![(1, 1), (3, 3), (8, 8)]);
let expected = vec![(1, 1), (2, 2), (3, 3), (7, 7), (8, 8)];
assert_eq!(elements(map), expected);
}
macro_rules! mk_bench {
($name:ident, $size:expr) => (
#[bench]
fn $name(b: &mut Bencher) {
let mut map = SortedMap::new();
for x in 0 .. $size {
map.insert(x * 3, 0);
}
b.iter(|| {
test::black_box(map.range(..));
test::black_box(map.range( $size / 2.. $size ));
test::black_box(map.range( 0 .. $size / 3 ));
test::black_box(map.range( $size / 4 .. $size / 3 ));
})
}
)
}
mk_bench!(bench_range_1, 1);
mk_bench!(bench_range_2, 2);
mk_bench!(bench_range_5, 5);
mk_bench!(bench_range_10, 10);
mk_bench!(bench_range_32, 32);
mk_bench!(bench_range_1000, 1000);
}