Struct infinitree::fields::VersionedMap

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pub struct VersionedMap<K, V> where
    K: Key + 'static,
    V: Value + 'static,  { /* private fields */ }

Expand description

HashMap that tracks incremental changes between commits

Calling clone() will create a reference to the same instance, and can be easily shared between threads.

To write to disk the entire content of a hash map on every commit, see Map

Implementations

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impl<K, V> VersionedMap<K, V> where
K: Key + Clone,
V: Value,

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pub fn insert(&self, key: K, value: impl Into<Arc<V>>) -> Arc<V>

Set key to value.

insert never overwrites existing values.

Returns either the existing value, or the newly inserted value.

It is equivalent to calling map.insert_with(key, move || value).

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();
assert_eq!(m.insert(1, "first".to_owned()), "first".to_owned().into());
assert_eq!(m.insert(1, "second".to_owned()), "first".to_owned().into());

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pub fn insert_with<T: Into<Arc<V>>, F: FnOnce() -> T>(
 &self,
 key: K,
 new: F
) -> Arc<V>

Set key to the value returned by new.

insert never overwrites existing values.

Returns either the existing value, or the newly inserted value.

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();
assert_eq!(m.insert_with(1, || "first".to_owned()), "first".to_owned().into());
assert_eq!(m.insert_with(1, || "second".to_owned()), "first".to_owned().into());

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pub fn update_with(
 &self,
 key: K,
 update: impl FnOnce(Arc<V>) -> V
) -> Option<Arc<V>>

Update the value in key to the one returned by the update closure.

update_with will never insert a new value to the map.

Returns the update value, or None if key does not exist in the map.

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();

assert_eq!(m.update_with(1, |_| "first".to_owned()), None);

m.insert(1, "first".to_owned());

assert_eq!(m.update_with(1, |_| "second".to_owned()), Some("second".to_owned().into()));

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pub fn get<Q>(&self, key: &Q) -> Option<Arc<V>> where
K: Borrow<Q>,
Q: Hash + Eq + ?Sized,

Returns the stored value for a key, or None

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();

assert_eq!(m.get(&1), None);

m.insert(1, "first".to_owned());
assert_eq!(m.get(&1), Some("first".to_owned().into()));

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pub fn remove(&self, key: K)

Sets the key as removed in the map

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();

m.insert(1, "first".to_owned());
assert_eq!(m.get(&1), Some("first".to_owned().into()));

m.remove(1);
assert_eq!(m.get(&1), None);

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pub fn contains(&self, key: &K) -> bool

Returns true if there’s an addition for the specified key

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();

assert_eq!(m.contains(&1), false);
m.insert(1, "first".to_owned());

assert_eq!(m.contains(&1), true);

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pub fn for_each(&self, callback: impl FnMut(&K, &V))

Call the function for all additive keys

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();

m.insert(1, "first".to_owned());

m.for_each(|k, v| {
    assert_eq!(v, &"first".to_owned());
});

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pub fn retain(&self, callback: impl FnMut(&K, &V) -> bool)

Mark values as deleted where callback returns false

Examples

use infinitree::fields::VersionedMap;

let m = VersionedMap::<usize, String>::default();

m.insert(1, "first".to_owned());

m.retain(|k, v| false);
assert_eq!(m.contains(&1), false);

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pub fn commit(&self)

Clear out the current changeset, and commit all changes to history.

This operation potentially helps free some memory, but more importantly any subsequent Store calls are going to be empty until further additions or removals.

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pub fn len(&self) -> usize

Returns the number of additive keys

See VersionedMap::clear for example use.

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pub fn size(&self) -> usize

Returns the number of all keys, including deletions

See VersionedMap::clear for example use.

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pub fn capacity(&self) -> usize

Return the size of all allocated items

See VersionedMap::clear for example use.

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pub fn clear(&self) -> usize

Free all items in the VersionedMap, without tracking changes

Returns the number of elements freed.

Examples

use infinitree::fields::VersionedMap;

let value = "first".to_owned();
let m = VersionedMap::<usize, String>::default();

assert_eq!(m.is_empty(), true);

let _ = m.insert(1, value.clone());

assert_eq!(m.len(), 1);
assert_eq!(m.size(), 1);
assert_eq!(m.is_empty(), false);

m.commit();

assert_eq!(m.contains(&1), true);

assert_eq!(m.len(), 1);
assert_eq!(m.size(), 1);
assert_eq!(m.is_empty(), false);

m.remove(1);

assert_eq!(m.contains(&1), false);

assert_eq!(m.len(), 0);
assert_eq!(m.size(), 2);
assert_eq!(m.is_empty(), true);

// Call `clear()`
assert_eq!(m.clear(), 2);

assert_eq!(m.len(), 0);
assert_eq!(m.size(), 0);
assert_eq!(m.is_empty(), true);

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pub fn rollback(&self) -> usize

Roll back all modification since the last commit

Calling rollback also frees up memory dynamically.

Examples

use infinitree::fields::VersionedMap;

let value = "first".to_owned();
let m = VersionedMap::<usize, String>::default();

assert_eq!(m.is_empty(), true);

let _ = m.insert(1, value.clone());

assert_eq!(m.len(), 1);
assert_eq!(m.size(), 1);
assert_eq!(m.is_empty(), false);

m.commit();

assert_eq!(m.contains(&1), true);

assert_eq!(m.len(), 1);
assert_eq!(m.size(), 1);
assert_eq!(m.is_empty(), false);

m.remove(1);

assert_eq!(m.contains(&1), false);

assert_eq!(m.len(), 0);
assert_eq!(m.size(), 2);
assert_eq!(m.is_empty(), true);

// Call `rollback()`
assert_eq!(m.rollback(), 1);

assert_eq!(m.len(), 1);
assert_eq!(m.size(), 1);
assert_eq!(m.is_empty(), false);