Extract a node_storage

This commit is contained in:
Gwilym Kuiper 2022-03-18 00:05:03 +00:00
parent e999b44c67
commit 8d976b49bc

View file

@ -45,6 +45,74 @@ impl<K, V> NodeStorage<K, V> {
fn len(&self) -> usize {
self.0.len()
}
fn insert_new(
&mut self,
key: K,
value: V,
hash: HashType,
number_of_elements: usize,
max_distance_to_initial_bucket: u32,
) -> u32 {
debug_assert!(
self.len() * 85 / 100 > number_of_elements,
"Do not have space to insert into len {} with {number_of_elements}",
self.len()
);
let mut new_node = Node {
hash,
distance_to_initial_bucket: 0,
key,
value,
};
let mut max_distance_to_initial_bucket = max_distance_to_initial_bucket;
loop {
let location = fast_mod(self.len(), hash + new_node.distance_to_initial_bucket);
let current_node = self.0[location].as_mut();
if let Some(current_node) = current_node {
if current_node.distance_to_initial_bucket <= new_node.distance_to_initial_bucket {
max_distance_to_initial_bucket = new_node
.distance_to_initial_bucket
.max(max_distance_to_initial_bucket);
mem::swap(&mut new_node, current_node);
}
} else {
self.0[location] = Some(new_node);
break;
}
new_node.distance_to_initial_bucket += 1;
}
max_distance_to_initial_bucket
}
fn remove_from_location(&mut self, location: usize) -> V {
let mut current_location = location;
let result = loop {
let next_location = fast_mod(self.len(), (current_location + 1) as HashType);
// if the next node is empty, then we can clear the current node
if self.0[next_location].is_none() {
break self.0[current_location].take().unwrap();
}
self.0.swap(current_location, next_location);
self.0[current_location]
.as_mut()
.unwrap()
.distance_to_initial_bucket -= 1;
current_location = next_location;
};
result.value
}
}
pub struct HashMap<K, V> {
@ -125,7 +193,14 @@ where
return Some(old_value);
}
self.insert_new(key, value, hash);
self.max_distance_to_initial_bucket = self.nodes.insert_new(
key,
value,
hash,
self.number_of_elements,
self.max_distance_to_initial_bucket,
);
self.number_of_elements += 1;
None
}
@ -140,7 +215,11 @@ where
let hash = self.hash(key);
self.get_location(key, hash)
.map(|location| self.remove_from_location(location))
.map(|location| self.nodes.remove_from_location(location))
.map(|value| {
self.number_of_elements -= 1;
value
})
}
}
@ -155,66 +234,7 @@ where
}
}
impl<K, V> HashMap<K, V> {
fn insert_new(&mut self, key: K, value: V, hash: HashType) {
// if we need to resize
if self.nodes.len() * 85 / 100 < self.number_of_elements {
todo!("resize not implemented yet");
}
let mut new_node = Node {
hash,
distance_to_initial_bucket: 0,
key,
value,
};
loop {
let location = fast_mod(self.nodes.len(), hash + new_node.distance_to_initial_bucket);
let current_node = self.nodes.0[location].as_mut();
if let Some(current_node) = current_node {
if current_node.distance_to_initial_bucket <= new_node.distance_to_initial_bucket {
self.max_distance_to_initial_bucket = new_node
.distance_to_initial_bucket
.max(self.max_distance_to_initial_bucket);
mem::swap(&mut new_node, current_node);
}
} else {
self.nodes.0[location] = Some(new_node);
break;
}
new_node.distance_to_initial_bucket += 1;
}
self.number_of_elements += 1;
}
fn remove_from_location(&mut self, location: usize) -> V {
let mut current_location = location;
let result = loop {
let next_location = fast_mod(self.nodes.len(), (current_location + 1) as HashType);
// if the next node is empty, then we can clear the current node
if self.nodes.0[next_location].is_none() {
break self.nodes.0[current_location].take().unwrap();
}
self.nodes.0.swap(current_location, next_location);
self.nodes.0[current_location]
.as_mut()
.unwrap()
.distance_to_initial_bucket -= 1;
current_location = next_location;
};
self.number_of_elements -= 1;
result.value
}
}
impl<K, V> HashMap<K, V> {}
pub struct Iter<'a, K: 'a, V: 'a> {
map: &'a HashMap<K, V>,