Struct StorageProofChecker

pub struct StorageProofChecker<H>
where
    H: Hasher,
{ /* private fields */ }

This struct is used to read storage values from a subset of a Merklized database. The “proof” is a subset of the nodes in the Merkle structure of the database, so that it provides authentication against a known Merkle root as well as the values in the database themselves.

Implementations

impl<H> StorageProofChecker<H>

where H: Hasher,

pub fn new( root: H::Out, proof: RawStorageProof, ) -> Result<Self, StorageProofError>

Constructs a new storage proof checker.

This returns an error if the given proof is invalid with respect to the given root.

pub fn ensure_no_unused_nodes(self) -> Result<(), StorageProofError>

Returns error if the proof has some nodes that are left intact by previous read_value calls.

pub fn read_value( &mut self, key: &[u8], ) -> Result<Option<Vec<u8>>, StorageProofError>

Reads a value from the available subset of storage. If the value cannot be read due to an incomplete or otherwise invalid proof, this function returns an error.

pub fn read_and_decode_value<T: Decode>( &mut self, key: &[u8], ) -> Result<Option<T>, StorageProofError>

Reads and decodes a value from the available subset of storage. If the value cannot be read due to an incomplete or otherwise invalid proof, this function returns an error. If value is read, but decoding fails, this function returns an error.

pub fn read_and_decode_mandatory_value<T: Decode>( &mut self, key: &[u8], ) -> Result<T, StorageProofError>

Reads and decodes a value from the available subset of storage. If the value cannot be read due to an incomplete or otherwise invalid proof, or if the value is None, this function returns an error. If value is read, but decoding fails, this function returns an error.

pub fn read_and_decode_opt_value<T: Decode>( &mut self, key: &[u8], ) -> Result<Option<T>, StorageProofError>

Reads and decodes a value from the available subset of storage. If the value cannot be read due to an incomplete or otherwise invalid proof, this function returns Ok(None). If value is read, but decoding fails, this function returns an error.