Struct Arena 

pub struct Arena<T: ?Sized, Storage = T> { /* private fields */ }

Interning arena for values of type T, storing them with the given Storage type (that needs to be Sized).

For Sized values, Storage = T is a good default that incurs no overhead. For non-Sized values such as dyn Trait, you need to specify a Sized storage type, such as Box<dyn Trait>.

Implementations

impl<T, Storage> Arena<T, Storage>

where T: Ord + ?Sized, Storage: Borrow<T>,

pub fn sort(&self) -> Mapping

Returns a sorted mapping of the items in this arena.

impl<T, Storage> Arena<T, Storage>

where T: Eq + Hash + ?Sized, Storage: Borrow<T> + Clone,

pub fn map(&self, mapping: &ReverseMapping) -> Self

Returns a re-ordered version of this arena based on the given mapping.

impl<T: ?Sized, Storage> Arena<T, Storage>

pub fn with_capacity(len: usize) -> Self

Creates a new arena with pre-allocated space to store at least len values of type T.

pub fn len(&self) -> usize

Returns the number of values in this arena.

Note that because Arena is a concurrent data structure, this is only a snapshot as viewed by this thread, and the result may change if other threads are inserting values.

pub fn is_empty(&self) -> bool

Checks if this arena is empty.

Note that because Arena is a concurrent data structure, this is only a snapshot as viewed by this thread, and the result may change if other threads are inserting values.

impl<T, Storage> Arena<T, Storage>

where T: Eq + Hash + ?Sized, Storage: Borrow<T>,

pub fn find(&self, value: &T) -> Option<Interned<T, Storage>>

Returns the given value’s Interned handle if it is already interned.

Otherwise, this simply returns None without adding the value to this arena.

impl<T, Storage> Arena<T, Storage>

where T: Eq + Hash + ?Sized, Storage: Borrow<T>,

pub fn push_mut(&mut self, value: Storage) -> u32

Available on crate feature raw only.

Unconditionally push a value, without validating that it’s already interned.

impl<T: ?Sized, Storage> Arena<T, Storage>

where Storage: GetSize,

pub fn print_summary(&self, prefix: &str, title: &str, total_bytes: usize)

Available on crate feature debug only.

Prints a summary of the storage used by this arena to stdout.

impl<T, Storage> Arena<T, Storage>

where T: Eq + Hash + ?Sized, Storage: Borrow<T>,

pub fn intern( &self, value: impl Borrow<T> + Into<Storage>, ) -> Interned<T, Storage>

Interns the given value in this arena.

If the value was already interned in this arena, it will simply be borrowed to retrieve its interning index. Otherwise it will then be converted to store it into the arena.

See also intern_mut(), which is more efficient if you hold a mutable reference to this arena as it avoids acquiring locks.

pub fn intern_mut( &mut self, value: impl Borrow<T> + Into<Storage>, ) -> Interned<T, Storage>

Interns the given value in this arena.

If the value was already interned in this arena, it will simply be borrowed to retrieve its interning index. Otherwise it will then be converted to store it into the arena.

Contrary to intern(), no locks are held internally because this function already takes an exclusive mutable reference to this arena.

impl<T: ?Sized, Storage> Arena<T, Storage>

where Storage: Clone,

pub fn lookup(&self, interned: Interned<T, Storage>) -> Storage

Retrieves the given Interned value from this arena.

The caller is responsible for ensuring that the same arena was used to intern this value, otherwise an arbitrary value will be returned or a panic will happen.

See also lookup_ref() if you only need a reference.

impl<T: ?Sized, Storage> Arena<T, Storage>

where Storage: Borrow<T>,

pub fn lookup_ref(&self, interned: Interned<T, Storage>) -> &T

Retrieves a reference to the given Interned value from this arena.

The caller is responsible for ensuring that the same arena was used to intern this value, otherwise an arbitrary value will be returned or a panic will happen.

See also lookup() if you need an owned value.

Trait Implementations

impl<T, Storage> Clone for Arena<T, Storage>

where T: Eq + Hash + ?Sized, Storage: Borrow<T> + Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, Storage> Debug for Arena<T, Storage>

where T: Debug + ?Sized, Storage: Borrow<T>,

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

Formats the value using the given formatter.

impl<T: ?Sized, Storage> Default for Arena<T, Storage>

fn default() -> Self

Returns the “default value” for a type.

impl<'de, T, Storage> Deserialize<'de> for Arena<T, Storage>

where T: Eq + Hash + ?Sized, Storage: Borrow<T> + Deserialize<'de>,

Available on crate feature serde only.

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T: ?Sized, Storage> GetSize for Arena<T, Storage>

where Storage: GetSize,

Available on crate feature get-size2 only.

fn get_heap_size_with_tracker<Tr: GetSizeTracker>( &self, tracker: Tr, ) -> (usize, Tr)

Determines how many bytes this object occupies inside the heap while using a tracker.

fn get_stack_size() -> usize

Determines how may bytes this object occupies inside the stack.

fn get_heap_size(&self) -> usize

Determines how many bytes this object occupies inside the heap.

fn get_size(&self) -> usize

Determines the total size of the object.

fn get_size_with_tracker<T>(&self, tracker: T) -> (usize, T)

where T: GetSizeTracker,

Determines the total size of the object while using a tracker.

impl<T, Storage> PartialEq for Arena<T, Storage>

where T: Eq + ?Sized, Storage: Borrow<T>,

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T, Storage> Serialize for Arena<T, Storage>

where T: Serialize + ?Sized, Storage: Borrow<T>,

Available on crate feature serde only.

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

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<T, Storage> Eq for Arena<T, Storage>

where T: Eq + ?Sized, Storage: Borrow<T>,