Struct fbnc::mapxnk::Mapxnk

pub struct Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug,  { /* fields omitted */ }

To solve the problem of unlimited memory usage, use this to replace the original in-memory BTreeMap<_, _>.

Implementations

impl<K, V> Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

pub fn new(path: &str) -> Result<Self>

Create an instance.

pub fn get_path(&self) -> &str

Get the database storage path

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

Imitate the behavior of ‘BTreeMap<_>.get(…)’

Any faster/better choice other than JSON ?

pub fn get_closest_smaller(&self, key: &K) -> Option<(K, V)>

Get the closest smaller value

pub fn get_closest_larger(&self, key: &K) -> Option<(K, V)>

Get the closest larger value

pub fn get_mut(&mut self, key: &K) -> Option<ValueMut<'_, K, V>>

Imitate the behavior of ‘BTreeMap<_>.get_mut(…)’

pub fn len(&self) -> usize

Imitate the behavior of ‘BTreeMap<_>.len()’.

pub fn is_empty(&self) -> bool

A helper func

pub fn insert(&mut self, key: K, value: V) -> Option<V>

Imitate the behavior of ‘BTreeMap<_>.insert(…)’.

pub fn set_value(&mut self, key: K, value: V)

Similar with insert, but ignore the old value.

pub fn entry(&mut self, key: K) -> Entry<'_, K, V>

Imitate the behavior of ‘.entry(…).or_insert(…)’

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

Imitate the behavior of ‘.iter()’

pub fn range<R: RangeBounds<K>>(&self, range: R) -> MapxnkIter<'_, K, V>

range(start..end)

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

Check if a key is exists.

pub fn remove(&mut self, key: &K) -> Option<V>

Remove a <K, V> from mem and disk.

pub fn unset_value(&mut self, key: &K)

Remove a <K, V> from mem and disk.

Trait Implementations

impl<K: Clone, V: Clone> Clone for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K: Debug, V: Debug> Debug for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

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

Formats the value using the given formatter.

impl<'de, K, V> Deserialize<'de> for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<K: PartialEq, V: PartialEq> PartialEq<Mapxnk<K, V>> for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

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

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

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

This method tests for !=.

impl<K, V> Serialize for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<K, V> Eq for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug, 

impl<K, V> StructuralPartialEq for Mapxnk<K, V> where
    K: NumKey,
    V: Clone + PartialEq + Serialize + DeserializeOwned + Debug,