Struct garage_table::crdt::Map

pub struct Map<K, V> { /* fields omitted */ }

Simple CRDT Map

This types defines a CRDT for a map from keys to values. Values are CRDT types which can have their own updating logic.

Internally, the map is stored as a vector of keys and values, sorted by ascending key order. This is why the key type K must implement Ord (and also to ensure a unique serialization, such that two values can be compared for equality based on their hashes). As a consequence, insertions take O(n) time. This means that Map should be used for reasonably small maps. However, note that even if we were using a more efficient data structure such as a BTreeMap, the serialization cost O(n) would still have to be paid at each modification, so we are actually not losing anything here.

Implementations

impl<K, V> Map<K, V> where
    K: Clone + Ord,
    V: Clone + Crdt, 

pub fn new() -> Map<K, V>

Create a new empty map CRDT

pub fn put_mutator(k: K, v: V) -> Map<K, V>

Returns a map that contains a single mapping from the specified key to the specified value. This can be used to build a delta-mutator: when merged with another map, the value will be added or CRDT-merged if a previous value already exists.

pub fn put(&mut self, k: K, v: V)

Add a value to the map

pub fn clear(&mut self)

Removes all values from the map

pub fn get(&self, k: &K) -> Option<&V>

Get a reference to the value assigned to a key

pub fn items(&self) -> &[(K, V)]

Gets a reference to all of the items, as a slice. Usefull to iterate on all map values.

pub fn len(&self) -> usize

Returns the number of items in the map

pub fn is_empty(&self) -> bool

Returns true if the map is empty

Trait Implementations

impl<K, V> Clone for Map<K, V> where
    K: Clone,
    V: Clone, 

pub fn clone(&self) -> Map<K, V>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K, V> Crdt for Map<K, V> where
    K: Clone + Ord,
    V: Clone + Crdt, 

pub fn merge(&mut self, other: &Map<K, V>)

Merge the two datastructures according to the CRDT rules. self is modified to contain the merged CRDT value. other is not modified.

impl<K, V> Debug for Map<K, V> where
    K: Debug,
    V: Debug, 

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<K, V> Default for Map<K, V> where
    K: Clone + Ord,
    V: Clone + Crdt, 

pub fn default() -> Map<K, V>

Returns the “default value” for a type.

impl<'de, K, V> Deserialize<'de> for Map<K, V> where
    K: Deserialize<'de>,
    V: Deserialize<'de>, 

pub fn deserialize<__D>(
    __deserializer: __D
) -> Result<Map<K, V>, <__D as Deserializer<'de>>::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<K, V> PartialEq<Map<K, V>> for Map<K, V> where
    K: PartialEq<K>,
    V: PartialEq<V>, 

pub fn eq(&self, other: &Map<K, V>) -> bool

This method tests for self and other values to be equal, and is used by ==.

pub fn ne(&self, other: &Map<K, V>) -> bool

This method tests for !=.

impl<K, V> Serialize for Map<K, V> where
    K: Serialize,
    V: Serialize, 

pub fn serialize<__S>(
    &self,
    __serializer: __S
) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl<K, V> StructuralPartialEq for Map<K, V>