Trait sp_blockchain::Backend

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

    // Provided methods
    fn longest_containing(
        &self,
        base_hash: Block::Hash,
        import_lock: &RwLock<()>
    ) -> Result<Option<Block::Hash>> { ... }
    fn has_indexed_transaction(&self, hash: Block::Hash) -> Result<bool> { ... }
}

Blockchain database backend. Does not perform any validation.

Required Methods

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

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

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

Get block justifications. Returns None if no justification exists.

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

Get last finalized block hash.

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

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 displaced_leaves_after_finalizing( &self, block_number: NumberFor<Block> ) -> Result<Vec<Block::Hash>>

Returns displaced leaves after the given block would be finalized.

The returned leaves do not contain the leaves from the same height as block_number.

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

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

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

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::Hash) -> Result<Option<Vec<Vec<u8>>>>

Provided Methods

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

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 descendents of it.

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

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

Check if indexed transaction exists.

Implementors