Trait Backend 

pub trait Backend<Block>: HeaderBackend<Block> + HeaderMetadata<Block, Error = Error>
where
    Block: Block,
{
    // Required methods
    fn body(
        &self,
        hash: <Block as Block>::Hash,
    ) -> Result<Option<Vec<<Block as Block>::Extrinsic>>, Error>;
    fn justifications(
        &self,
        hash: <Block as Block>::Hash,
    ) -> Result<Option<Justifications>, Error>;
    fn last_finalized(&self) -> Result<<Block as Block>::Hash, Error>;
    fn leaves(&self) -> Result<Vec<<Block as Block>::Hash>, Error>;
    fn children(
        &self,
        parent_hash: <Block as Block>::Hash,
    ) -> Result<Vec<<Block as Block>::Hash>, Error>;
    fn indexed_transaction(
        &self,
        hash: <Block as Block>::Hash,
    ) -> Result<Option<Vec<u8>>, Error>;
    fn block_indexed_body(
        &self,
        hash: <Block as Block>::Hash,
    ) -> Result<Option<Vec<Vec<u8>>>, Error>;

    // Provided methods
    fn longest_containing(
        &self,
        base_hash: <Block as Block>::Hash,
        import_lock: &RwLock<RawRwLock, ()>,
    ) -> Result<Option<<Block as Block>::Hash>, Error> { ... }
    fn has_indexed_transaction(
        &self,
        hash: <Block as Block>::Hash,
    ) -> Result<bool, Error> { ... }
    fn displaced_leaves_after_finalizing(
        &self,
        finalized_block_hash: <Block as Block>::Hash,
        finalized_block_number: <<Block as Block>::Header as Header>::Number,
        finalized_block_parent_hash: <Block as Block>::Hash,
    ) -> Result<DisplacedLeavesAfterFinalization<Block>, Error> { ... }
}

Blockchain database backend. Does not perform any validation.

Required Methods

fn body( &self, hash: <Block as Block>::Hash, ) -> Result<Option<Vec<<Block as Block>::Extrinsic>>, Error>

Get block body. Returns None if block is not found.

fn justifications( &self, hash: <Block as Block>::Hash, ) -> Result<Option<Justifications>, Error>

Get block justifications. Returns None if no justification exists.

fn last_finalized(&self) -> Result<<Block as Block>::Hash, Error>

Get last finalized block hash.

fn leaves(&self) -> Result<Vec<<Block as Block>::Hash>, Error>

Returns hashes of all blocks that are leaves of the block tree. in other words, that have no children, are chain heads. Results must be ordered best (longest, highest) chain first.

fn children( &self, parent_hash: <Block as Block>::Hash, ) -> Result<Vec<<Block as Block>::Hash>, Error>

Return hashes of all blocks that are children of the block with parent_hash.

fn indexed_transaction( &self, hash: <Block as Block>::Hash, ) -> Result<Option<Vec<u8>>, Error>

Get single indexed transaction by content hash. Note that this will only fetch transactions that are indexed by the runtime with storage_index_transaction.

fn block_indexed_body( &self, hash: <Block as Block>::Hash, ) -> Result<Option<Vec<Vec<u8>>>, Error>

Provided Methods

fn longest_containing( &self, base_hash: <Block as Block>::Hash, import_lock: &RwLock<RawRwLock, ()>, ) -> Result<Option<<Block as Block>::Hash>, Error>

Get the most recent block hash of the longest chain that contains a block with the given base_hash.

The search space is always limited to blocks which are in the finalized chain or descendants of it.

Returns Ok(None) if base_hash is not found in search space.

fn has_indexed_transaction( &self, hash: <Block as Block>::Hash, ) -> Result<bool, Error>

Check if indexed transaction exists.

fn displaced_leaves_after_finalizing( &self, finalized_block_hash: <Block as Block>::Hash, finalized_block_number: <<Block as Block>::Header as Header>::Number, finalized_block_parent_hash: <Block as Block>::Hash, ) -> Result<DisplacedLeavesAfterFinalization<Block>, Error>

Returns all leaves that will be displaced after the block finalization.

Implementors

impl<Block> Backend<Block> for Blockchain<Block>

where Block: Block,

impl<Block> Backend<Block> for BlockchainDb<Block>

where Block: Block,