Struct PackedMap 

pub struct PackedMap<'a, K: Pod + FixedLayout + PartialEq, V: Pod + FixedLayout> { /* private fields */ }

Packed key->value map overlaid on a byte slice.

Supports O(n) lookup, O(1) insert (append), O(1) remove (swap-last). No heap allocation.

Implementations

impl<'a, K: Pod + FixedLayout + PartialEq, V: Pod + FixedLayout> PackedMap<'a, K, V>

pub fn from_bytes(data: &'a mut [u8]) -> Result<Self, ProgramError>

Overlay a PackedMap on a mutable byte slice.

pub fn len(&self) -> usize

Current number of entries.

pub fn capacity(&self) -> usize

Maximum capacity.

pub fn is_empty(&self) -> bool

Is the map empty?

pub fn is_full(&self) -> bool

Is the map full?

pub fn find(&self, key: &K) -> Option<usize>

Find the index of a key, or None.

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

Get the value for a key, or error if not found.

pub fn get_value_offset(&self, key: &K) -> Result<usize, ProgramError>

Get a mutable reference to the value bytes for a key. Returns the byte offset of the value within data for direct manipulation.

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

Insert or update a key-value pair.

If the key already exists, updates the value and returns true. If the key is new, appends and returns false. Returns error if full and key doesn’t exist.

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

Remove a key-value pair by swapping with the last entry. O(1).

Returns the removed value, or error if key not found.

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

Check if the map contains a key.

pub fn clear(&mut self)

Clear all entries.

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

Iterate over all entries (key, value) by index.

Returns an iterator that yields (K, V) copies.