Struct Ledger

pub struct Ledger<Context, Value>(pub BTreeMap<ValueHash, Observation<Context, Value>>)
where
    Context: Config,
    Value: Encode + Decode + Clone;

Persistent observation ledger used by Finalized storage.

A Ledger maps a stable ValueHash to its corresponding Observation record.

Within the Finalized storage model:

• The ledger is stored in persistent offchain storage.
• Entries are fork-independent and survive chain re-organizations.
• Each entry accumulates observation history across OCW executions.

The ledger acts as the authoritative source of truth for:

• value identity (via ValueHash),
• temporal stability,
• and block-scoped confirmation counts.

It is consulted to derive confidence levels (see Confidence) and to detect and clean up fork-aware inconsistencies.

Tuple Fields

0: BTreeMap<ValueHash, Observation<Context, Value>>

Trait Implementations

impl<Context, Value> Clone for Ledger<Context, Value>

where Context: Config + Clone, Value: Encode + Decode + Clone + Clone,

fn clone(&self) -> Ledger<Context, Value>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Context, Value> Debug for Ledger<Context, Value>

where Context: Config + Debug, Value: Encode + Decode + Clone + Debug,

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

Formats the value using the given formatter.

impl<Context, Value> Decode for Ledger<Context, Value>

where Context: Config, Value: Encode + Decode + Clone, BTreeMap<ValueHash, Observation<Context, Value>>: Decode,

fn decode<__CodecInputEdqy: Input>( __codec_input_edqy: &mut __CodecInputEdqy, ) -> Result<Self, Error>

Attempt to deserialise the value from input.

fn decode_into<I>( input: &mut I, dst: &mut MaybeUninit<Self>, ) -> Result<DecodeFinished, Error>

where I: Input,

Attempt to deserialize the value from input into a pre-allocated piece of memory.

fn skip<I>(input: &mut I) -> Result<(), Error>

where I: Input,

Attempt to skip the encoded value from input.

fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type.

impl<Context, Value> Encode for Ledger<Context, Value>

where Context: Config, Value: Encode + Decode + Clone, BTreeMap<ValueHash, Observation<Context, Value>>: Encode,

fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding.

fn encode_to<__CodecOutputEdqy: Output + ?Sized>( &self, __codec_dest_edqy: &mut __CodecOutputEdqy, )

Convert self to a slice and append it to the destination.

fn encode(&self) -> Vec<u8>

Convert self to an owned vector.

fn using_encoded<__CodecOutputReturn, __CodecUsingEncodedCallback: FnOnce(&[u8]) -> __CodecOutputReturn>( &self, f: __CodecUsingEncodedCallback, ) -> __CodecOutputReturn

Convert self to a slice and then invoke the given closure with it.

fn encoded_size(&self) -> usize

Calculates the encoded size.

impl<Context, Value> EncodeLike for Ledger<Context, Value>

where Context: Config, Value: Encode + Decode + Clone, BTreeMap<ValueHash, Observation<Context, Value>>: Encode,