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BTreeMap: test invariants more thoroughly and more readably
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@ssomers
ssomers committed Oct 19, 2020
1 parent c38ddb8 commit 488b999
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Showing 2 changed files with 115 additions and 79 deletions.
89 changes: 10 additions & 79 deletions library/alloc/src/collections/btree/map/tests.rs
View file
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
use super::super::{navigate::Position, node, DeterministicRng};
use super::super::{node, DeterministicRng};
use super::Entry::{Occupied, Vacant};
use super::*;
use crate::boxed::Box;
Expand All @@ -7,7 +7,7 @@ use crate::rc::Rc;
use crate::string::{String, ToString};
use crate::vec::Vec;
use std::convert::TryFrom;
use std::iter::FromIterator;
use std::iter::{self, FromIterator};
use std::mem;
use std::ops::Bound::{self, Excluded, Included, Unbounded};
use std::ops::RangeBounds;
Expand Down Expand Up @@ -42,19 +42,6 @@ fn test_all_refs<'a, T: 'a>(dummy: &mut T, iter: impl Iterator<Item = &'a mut T>
}
}

struct SeriesChecker<T> {
previous: Option<T>,
}

impl<T: Copy + Debug + Ord> SeriesChecker<T> {
fn is_ascending(&mut self, next: T) {
if let Some(previous) = self.previous {
assert!(previous < next, "{:?} >= {:?}", previous, next);
}
self.previous = Some(next);
}
}

impl<'a, K: 'a, V: 'a> BTreeMap<K, V> {
/// Panics if the map (or the code navigating it) is corrupted.
fn check(&self)
Expand All @@ -63,44 +50,10 @@ impl<'a, K: 'a, V: 'a> BTreeMap<K, V> {
{
if let Some(root) = &self.root {
let root_node = root.node_as_ref();
let mut checker = SeriesChecker { previous: None };
let mut internal_length = 0;
let mut internal_kv_count = 0;
let mut leaf_length = 0;
root_node.visit_nodes_in_order(|pos| match pos {
Position::Leaf(node) => {
let is_root = root_node.height() == 0;
let min_len = if is_root { 0 } else { node::MIN_LEN };
assert!(node.len() >= min_len, "{} < {}", node.len(), min_len);

for idx in 0..node.len() {
let key = *unsafe { node.key_at(idx) };
checker.is_ascending(key);
}
leaf_length += node.len();
}
Position::Internal(node) => {
let is_root = root_node.height() == node.height();
let min_len = if is_root { 1 } else { node::MIN_LEN };
assert!(node.len() >= min_len, "{} < {}", node.len(), min_len);

for idx in 0..=node.len() {
let edge = unsafe { node::Handle::new_edge(node, idx) };
assert!(edge.descend().ascend().ok().unwrap() == edge);
}

internal_length += node.len();
}
Position::InternalKV(kv) => {
let key = *kv.into_kv().0;
checker.is_ascending(key);

internal_kv_count += 1;
}
});
assert_eq!(internal_length, internal_kv_count);
assert_eq!(root_node.calc_length(), internal_length + leaf_length);
assert_eq!(self.length, internal_length + leaf_length);
assert!(root_node.ascend().is_err());
root_node.assert_back_pointers();
root_node.assert_ascending();
assert_eq!(self.length, root_node.assert_and_add_lengths());
} else {
assert_eq!(self.length, 0);
}
Expand All @@ -116,28 +69,7 @@ impl<'a, K: 'a, V: 'a> BTreeMap<K, V> {
K: Debug,
{
if let Some(root) = self.root.as_ref() {
let mut result = String::new();
let root_node = root.node_as_ref();
root_node.visit_nodes_in_order(|pos| match pos {
Position::Leaf(leaf) => {
let depth = root_node.height();
let indent = " ".repeat(depth);
result += &format!("\n{}", indent);
for idx in 0..leaf.len() {
if idx > 0 {
result += ", ";
}
result += &format!("{:?}", unsafe { leaf.key_at(idx) });
}
}
Position::Internal(_) => {}
Position::InternalKV(kv) => {
let depth = root_node.height() - kv.into_node().height();
let indent = " ".repeat(depth);
result += &format!("\n{}{:?}", indent, kv.into_kv().0);
}
});
result
root.node_as_ref().dump_keys()
} else {
String::from("not yet allocated")
}
Expand Down Expand Up @@ -170,7 +102,6 @@ fn test_levels() {
let last_key = *map.last_key_value().unwrap().0;
map.insert(last_key + 1, ());
}
println!("{}", map.dump_keys());
map.check();
// Structure:
// - 1 element in internal root node with 2 children
Expand Down Expand Up @@ -372,7 +303,7 @@ fn test_iter_rev() {
fn do_test_iter_mut_mutation<T>(size: usize)
where
T: Copy + Debug + Ord + TryFrom<usize>,
<T as std::convert::TryFrom<usize>>::Error: std::fmt::Debug,
<T as TryFrom<usize>>::Error: Debug,
{
let zero = T::try_from(0).unwrap();
let mut map: BTreeMap<T, T> = (0..size).map(|i| (T::try_from(i).unwrap(), zero)).collect();
Expand Down Expand Up @@ -857,7 +788,7 @@ mod test_drain_filter {
fn consuming_nothing() {
let pairs = (0..3).map(|i| (i, i));
let mut map: BTreeMap<_, _> = pairs.collect();
assert!(map.drain_filter(|_, _| false).eq(std::iter::empty()));
assert!(map.drain_filter(|_, _| false).eq(iter::empty()));
map.check();
}

Expand All @@ -878,7 +809,7 @@ mod test_drain_filter {
*v += 6;
false
})
.eq(std::iter::empty())
.eq(iter::empty())
);
assert!(map.keys().copied().eq(0..3));
assert!(map.values().copied().eq(6..9));
Expand Down
105 changes: 105 additions & 0 deletions library/alloc/src/collections/btree/node/tests.rs
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,111 @@
use super::super::navigate;
use super::*;
use crate::fmt::Debug;
use crate::string::String;
use core::cmp::Ordering::*;

impl<'a, K: 'a, V: 'a> NodeRef<marker::Immut<'a>, K, V, marker::LeafOrInternal> {
pub fn assert_back_pointers(self) {
match self.force() {
ForceResult::Leaf(_) => {}
ForceResult::Internal(node) => {
for idx in 0..=node.len() {
let edge = unsafe { Handle::new_edge(node, idx) };
let child = edge.descend();
assert!(child.ascend().ok() == Some(edge));
child.assert_back_pointers();
}
}
}
}

pub fn assert_ascending(self)
where
K: Copy + Debug + Ord,
{
struct SeriesChecker<T> {
previous: Option<T>,
}
impl<T: Copy + Debug + Ord> SeriesChecker<T> {
fn is_ascending(&mut self, next: T) {
if let Some(previous) = self.previous {
assert!(previous < next, "{:?} >= {:?}", previous, next);
}
self.previous = Some(next);
}
}

let mut checker = SeriesChecker { previous: None };
self.visit_nodes_in_order(|pos| match pos {
navigate::Position::Leaf(node) => {
for idx in 0..node.len() {
let key = *unsafe { node.key_at(idx) };
checker.is_ascending(key);
}
}
navigate::Position::InternalKV(kv) => {
let key = *kv.into_kv().0;
checker.is_ascending(key);
}
navigate::Position::Internal(_) => {}
});
}

pub fn assert_and_add_lengths(self) -> usize {
let mut internal_length = 0;
let mut internal_kv_count = 0;
let mut leaf_length = 0;
self.visit_nodes_in_order(|pos| match pos {
navigate::Position::Leaf(node) => {
let is_root = self.height() == 0;
let min_len = if is_root { 0 } else { MIN_LEN };
assert!(node.len() >= min_len, "{} < {}", node.len(), min_len);
leaf_length += node.len();
}
navigate::Position::Internal(node) => {
let is_root = self.height() == node.height();
let min_len = if is_root { 1 } else { MIN_LEN };
assert!(node.len() >= min_len, "{} < {}", node.len(), min_len);
internal_length += node.len();
}
navigate::Position::InternalKV(_) => {
internal_kv_count += 1;
}
});
assert_eq!(internal_length, internal_kv_count);
let total = internal_length + leaf_length;
assert_eq!(self.calc_length(), total);
total
}

pub fn dump_keys(self) -> String
where
K: Debug,
{
let mut result = String::new();
self.visit_nodes_in_order(|pos| match pos {
navigate::Position::Leaf(leaf) => {
let depth = self.height();
let indent = " ".repeat(depth);
result += &format!("\n{}", indent);
for idx in 0..leaf.len() {
if idx > 0 {
result += ", ";
}
result += &format!("{:?}", unsafe { leaf.key_at(idx) });
}
}
navigate::Position::Internal(_) => {}
navigate::Position::InternalKV(kv) => {
let depth = self.height() - kv.into_node().height();
let indent = " ".repeat(depth);
result += &format!("\n{}{:?}", indent, kv.into_kv().0);
}
});
result
}
}

#[test]
fn test_splitpoint() {
for idx in 0..=CAPACITY {
Expand Down

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