Struct dharitri_wasm::storage::mappers::QueueMapper

pub struct QueueMapper<SA, T>
where
    SA: StorageMapperApi,
    T: TopEncode + TopDecode + 'static,
{ /* private fields */ }

A queue with owned nodes.

The QueueMapper allows pushing and popping elements at either end in constant time.

Implementations

impl<SA, T> QueueMapper<SA, T>

where SA: StorageMapperApi, T: TopEncode + TopDecode,

pub fn is_empty(&self) -> bool

Returns true if the Queue is empty.

This operation should compute in O(1) time.

pub fn len(&self) -> usize

Returns the length of the Queue.

This operation should compute in O(1) time.

pub fn push_back(&mut self, elt: T)

Appends an element to the back of a queue.

This operation should compute in O(1) time.

pub fn push_front(&mut self, elt: T)

Adds an element first in the queue.

This operation should compute in O(1) time.

pub fn front(&self) -> Option<T>

Provides a copy to the front element, or None if the queue is empty.

pub fn back(&self) -> Option<T>

Provides a copy to the back element, or None if the queue is empty.

pub fn pop_back(&mut self) -> Option<T>

Removes the last element from a queue and returns it, or None if it is empty.

This operation should compute in O(1) time.

pub fn pop_front(&mut self) -> Option<T>

Removes the first element and returns it, or None if the queue is empty.

This operation should compute in O(1) time.

pub fn iter(&self) -> Iter<'_, SA, T>

Provides a forward iterator.

pub fn check_internal_consistency(&self) -> bool

Runs several checks in order to verify that both forwards and backwards iteration yields the same node entries and that the number of items in the queue is correct. Used for unit testing.

This operation should compute in O(n) time.

Trait Implementations

impl<SA, T> StorageClearable for QueueMapper<SA, T>

where SA: StorageMapperApi, T: TopEncode + TopDecode,

fn clear(&mut self)

Clears all the entries owned by the storage.

impl<SA, T> StorageMapper<SA> for QueueMapper<SA, T>

where SA: StorageMapperApi, T: TopEncode + TopDecode,

fn new(base_key: StorageKey<SA>) -> Self

Will be called automatically by the #[storage_mapper] annotation generated code.

impl<SA, T> TopEncodeMulti for QueueMapper<SA, T>

where SA: StorageMapperApi, T: TopEncode + TopDecode,

Behaves like a MultiResultVec when an endpoint result.

fn multi_encode_or_handle_err<O, H>( &self, output: &mut O, h: H ) -> Result<(), H::HandledErr>

where O: TopEncodeMultiOutput, H: EncodeErrorHandler,

Version of top_encode that can handle errors as soon as they occur. For instance in can exit immediately and make sure that if it returns, it is a success. By not deferring error handling, this can lead to somewhat smaller bytecode.

fn multi_encode<O>(&self, output: &mut O) -> Result<(), EncodeError>

where O: TopEncodeMultiOutput,

Attempt to serialize the value to ouput.

impl<SA, T> TypeAbi for QueueMapper<SA, T>

where SA: StorageMapperApi, T: TopEncode + TopDecode + TypeAbi,

Behaves like a MultiResultVec when an endpoint result.

fn type_name() -> TypeName

fn provide_type_descriptions<TDC: TypeDescriptionContainer>( accumulator: &mut TDC )

A type can provide more than its own description. For instance, a struct can also provide the descriptions of the type of its fields. TypeAbi doesn’t care for the exact accumulator type, which is abstracted by the TypeDescriptionContainer trait.

impl<SA, T> CodecFrom<QueueMapper<SA, T>> for MultiValueEncoded<SA, T>

where SA: StorageMapperApi, T: TopEncode + TopDecode,