Struct mmids_core::workflows::metadata::MediaPayloadMetadataCollection

pub struct MediaPayloadMetadataCollection { /* private fields */ }

Allows storing arbitrary attributes and value pairs that can are relevant to an individual media payload/packet. These are stored in a relatively efficient way to make it cheap to clone and attempt to minimize per-packet heap allocations. Once a metadata collection has been created it cannot be modified.

The metadata currently relies on being passed in a BytesMut buffer that it will use for storage. This allows for the creator of media payloads to maintain an arena style memory buffer that persists across media payloads, which should eventually cause each media payload to no longer require its own heap allocation and efficiently re-use unreserved parts of the memory buffer.

The trade off for cloning and allocation efficiency is that iterating through metadata is an O(N) operation, which means if you need to look for a specific type of metadata you may have to iterate through all other metadata items first. This tradeoff was deemed acceptable for now with the idea that each payload would only have a small amount of metadata attached to it.

Implementations

impl MediaPayloadMetadataCollection

pub fn new(
    entries: impl Iterator<Item = MetadataEntry>,
    buffer: &mut BytesMut
) -> Self

Creates a new collection of metadata based on the provided entries. A buffer is passed in which can allow the creators of the collection to maintain an arena to reduce allocations for each new metadata collection that is created.

pub fn iter(&self) -> impl Iterator<Item = MetadataEntry>

Provides a non-consuming iterator that allows reading of entries within the collection

Trait Implementations

impl Clone for MediaPayloadMetadataCollection

fn clone(&self) -> MediaPayloadMetadataCollection

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MediaPayloadMetadataCollection

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

Formats the value using the given formatter.

impl PartialEq<MediaPayloadMetadataCollection> for MediaPayloadMetadataCollection

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

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

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

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

impl Eq for MediaPayloadMetadataCollection

impl StructuralEq for MediaPayloadMetadataCollection

impl StructuralPartialEq for MediaPayloadMetadataCollection