Struct ppom::mdb::OMap

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

Partially persistent ordered-map type using left-leaning-red-black tree.

OMap type allow concurrent read and write access at API level, while behind the scenes, all write-operations are serialized into single thread, but the key difference is that OMap map allow concurrent-reads without using locks. To serialize concurrent writes OMap uses a spin-lock implementation.

Implementations

impl<K, V> OMap<K, V>

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

impl<K, V> OMap<K, V>

pub fn len(&self) -> usize

Return number of entries in this instance.

pub fn is_empty(&self) -> bool

Return whether index is empty.

pub fn to_seqno(&self) -> u64

Return current sequence-no for index.

pub fn set_seqno(&self, seqno: u64) -> u64 where
    K: Clone,
    V: Clone, 

Update index to a new sequence-no, future mutations shall start from this value.

impl<K, V> OMap<K, V>

pub fn set(&self, key: K, value: V) -> Result<Option<V>> where
    K: Clone + Ord,
    V: Clone, 

Set key, value into index. If an older entry exist with same key, it shall be overwritten.

pub fn set_cas(&self, key: K, value: V, cas: u64) -> Result<Option<V>> where
    K: Clone + Ord,
    V: Clone, 

Set key, value into index. If already an entry in present with key, cas should match entry’s sequence-number. If index don’t have an entry with key, cas must be ZERO.

pub fn remove<Q>(&self, key: &Q) -> Result<Option<V>> where
    K: Clone + Ord + Borrow<Q>,
    Q: Ord + ToOwned<Owned = K> + ?Sized,
    V: Clone, 

Remove the entry, matching the key, from the index.

pub fn remove_cas<Q>(&self, key: &Q, cas: u64) -> Result<Option<V>> where
    K: Clone + Ord + Borrow<Q>,
    Q: Ord + ToOwned<Owned = K> + ?Sized,
    V: Clone, 

Remove the entry, with matching key and matching entry’s sequencey-number with cas.

impl<K, V> OMap<K, V>

pub fn get<Q>(&self, key: &Q) -> Result<(V, u64)> where
    K: Clone + Borrow<Q>,
    V: Clone,
    Q: Ord + ?Sized, 

Get entry from index for key. An entry is returned as (value, seqno). If key is not found return Error::KeyNotFound

pub fn iter(&self) -> Result<Iter<K, V>>

For full table scan.

pub fn range<R, Q>(&self, range: R) -> Result<Range<K, V, R, Q>> where
    K: Borrow<Q>,
    R: RangeBounds<Q>,
    Q: Ord + ?Sized, 

Iterate over entries within the specifed range.

pub fn reverse<R, Q>(&self, range: R) -> Result<Reverse<K, V, R, Q>> where
    K: Borrow<Q>,
    R: RangeBounds<Q>,
    Q: Ord + ?Sized, 

Reverse iterate over entries withing specified range. While range method iterate entries from start_bound to end_bound reverse method iterate entries from end_bound to start_bound.

pub fn validate(&self) -> Result<()> where
    K: Ord + Debug, 

Validate OMap tree with following rules:

• Root node is always black in color.
• Verify the sort order between a node and its left/right child.
• No node has RIGHT RED child and LEFT BLACK child (or NULL child).
• Make sure there are no consecutive reds.
• Make sure number of blacks are same on both left and right arm.
• Make sure that the maximum depth do not exceed MAX_TREE_DEPTH.

Trait Implementations

impl<K: Clone, V: Clone> Clone for OMap<K, V>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K, V> Default for OMap<K, V>

fn default() -> Self

Returns the “default value” for a type.