Struct MapReadRef 

pub struct MapReadRef<'rh, K, V, M = (), S = RandomState>
where
    K: Hash + Eq,
    V: Eq + Hash,
    S: BuildHasher,
{ /* private fields */ }

A live reference into the read half of an evmap.

As long as this lives, changes to the map being read cannot be published. If a writer attempts to call WriteHandle::publish, that call will block until this is dropped.

Since the map remains immutable while this lives, the methods on this type all give you unguarded references to types contained in the map.

Implementations

impl<'rh, K, V, M, S> MapReadRef<'rh, K, V, M, S>

where K: Hash + Eq, V: Eq + Hash, S: BuildHasher,

pub fn iter(&self) -> ReadGuardIter<'_, K, V, S>

Iterate over all key + valuesets in the map.

Be careful with this function! While the iteration is ongoing, any writer that tries to publish changes will block waiting on this reader to finish.

pub fn keys(&self) -> KeysIter<'_, K, V, S>

Iterate over all keys in the map.

Be careful with this function! While the iteration is ongoing, any writer that tries to publish changes will block waiting on this reader to finish.

pub fn values(&self) -> ValuesIter<'_, K, V, S>

Iterate over all value sets in the map.

Be careful with this function! While the iteration is ongoing, any writer that tries to publish changes will block waiting on this reader to finish.

pub fn len(&self) -> usize

Returns the number of non-empty keys present in the map.

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

pub fn meta(&self) -> &M

Get the current meta value.

pub fn get<'a, Q>(&'a self, key: &Q) -> Option<&'a Values<V, S>>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Returns a reference to the values corresponding to the key.

The key may be any borrowed form of the map’s key type, but Hash and Eq on the borrowed form must match those for the key type.

Note that not all writes will be included with this read – only those that have been published by the writer. If no publish has happened, or the map has been destroyed, this function returns None.

pub fn get_one<'a, Q>(&'a self, key: &Q) -> Option<&'a V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Returns a guarded reference to one value corresponding to the key.

This is mostly intended for use when you are working with no more than one value per key. If there are multiple values stored for this key, there are no guarantees to which element is returned.

The key may be any borrowed form of the map’s key type, but Hash and Eq on the borrowed form must match those for the key type.

Note that not all writes will be included with this read – only those that have been published by the writer. If no publish has happened, or the map has been destroyed, this function returns None.

pub fn contains_key<Q>(&self, key: &Q) -> bool

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Returns true if the map contains any values for the specified key.

The key may be any borrowed form of the map’s key type, but Hash and Eq on the borrowed form must match those for the key type.

pub fn contains_value<Q, W>(&self, key: &Q, value: &W) -> bool

where K: Borrow<Q>, Aliased<V, NoDrop>: Borrow<W>, Q: Hash + Eq + ?Sized, W: Hash + Eq + ?Sized,

Returns true if the map contains the specified value for the specified key.

The key and value may be any borrowed form of the map’s respective types, but Hash and Eq on the borrowed form must match.

Trait Implementations

impl<'rh, K, V, M, S> Debug for MapReadRef<'rh, K, V, M, S>

where K: Hash + Eq + Debug, V: Eq + Hash + Debug, S: BuildHasher, M: Debug,

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

Formats the value using the given formatter.

impl<'rh, K, Q, V, M, S> Index<&Q> for MapReadRef<'rh, K, V, M, S>

where K: Eq + Hash + Borrow<Q>, V: Eq + Hash, Q: Eq + Hash + ?Sized, S: BuildHasher,

type Output = Values<V, S>

The returned type after indexing.

fn index(&self, key: &Q) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<'rg, 'rh, K, V, M, S> IntoIterator for &'rg MapReadRef<'rh, K, V, M, S>

where K: Eq + Hash, V: Eq + Hash, S: BuildHasher,

type Item = (&'rg K, &'rg Values<V, S>)

The type of the elements being iterated over.

type IntoIter = ReadGuardIter<'rg, K, V, S>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.