Enum MaybeCompactedCid 

enum MaybeCompactedCid {
    Compact(CidV1DagCborBlake2b256),
    Uncompactable(Uncompactable),
}

The core primitive for saving space in this module.

CIDs contain a significant amount of static data (such as version, codec, hash identifier, hash length).

Nearly all Filecoin CIDs are V1,DagCbor encoded, and hashed with Blake2b256 (which has a hash length of 256 bits (32 bytes)). Naively representing such a CID requires 96 bytes but the non-static portion is only 32 bytes, represented as CidV1DagCborBlake2b256.

In collections, choose to store only 32 bytes where possible.

Note that construction of CIDs should always go through this type, to ensure

• canonicalization
• the contract of Uncompactable

assert_eq!(std::mem::size_of::<cid::Cid>(), 96);

If other types of CID become popular, they should be added to this enum.

Variants

Compact(CidV1DagCborBlake2b256)

Uncompactable(Uncompactable)

MUST NOT overlap with the above.

Trait Implementations

impl Clone for MaybeCompactedCid

fn clone(&self) -> MaybeCompactedCid

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for MaybeCompactedCid

impl Debug for MaybeCompactedCid

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

Formats the value using the given formatter.

impl Eq for MaybeCompactedCid

impl From<Cid<64>> for MaybeCompactedCid

fn from(value: Cid) -> Self

Converts to this type from the input type.

impl From<MaybeCompactedCid> for Cid

fn from(value: MaybeCompactedCid) -> Self

Converts to this type from the input type.

impl Hash for MaybeCompactedCid

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for MaybeCompactedCid

fn cmp(&self, other: &MaybeCompactedCid) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for MaybeCompactedCid

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for MaybeCompactedCid

fn partial_cmp(&self, other: &MaybeCompactedCid) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for MaybeCompactedCid