Struct AppBlockTreeView

pub struct AppBlockTreeView<'a, K: KVStore> {
    pub(super) block_tree: &'a BlockTreeSingleton<K>,
    pub(super) pending_ancestors_app_state_updates: Vec<Option<AppStateUpdates>>,
}

View of the block tree made available to method calls on Apps.

Purpose

The view of the block tree that AppBlockTreeView provides is special in two important ways to the correct implementation of the App trait:

1. AppBlockTreeView presents the App State as it is at a specific “point in time”, that is:
   • Just after parent_block is executed in the case of produce_block.
   • Just before proposed_block is executed in the case of validate_block.
2. AppBlockTreeView does not implement all of the block tree getters available through, e.g., BlockTreeSnapshot. Instead, AppBlockTreeView’s getters are limited to those that get the fields of the block tree that should be consistent across all replicas at a specific point in time. App methods can therefore safely depend on the data in these fields without risking non-determinism.

Constructor

To create an instance of AppBlockTreeView, use [BlockTree::app_view].

Fields

block_tree: &'a BlockTreeSingleton<K>

pending_ancestors_app_state_updates: Vec<Option<AppStateUpdates>>

Implementations

impl<'a, K: KVStore> AppBlockTreeView<'a, K>

pub fn block(&self, block: &CryptoHash) -> Result<Option<Block>, BlockTreeError>

Get block, if it is currently in the block tree.

pub fn block_height( &self, block: &CryptoHash, ) -> Result<Option<BlockHeight>, BlockTreeError>

Get the height of block, if block is currently in the block tree.

pub fn block_justify( &self, block: &CryptoHash, ) -> Result<PhaseCertificate, BlockTreeError>

Get block.justify, if block is currently in the block tree.

pub fn block_data_hash( &self, block: &CryptoHash, ) -> Result<Option<CryptoHash>, BlockTreeError>

Get block.data_hash, if block is currently in the block tree.

pub fn block_data_len( &self, block: &CryptoHash, ) -> Result<Option<DataLen>, BlockTreeError>

Get block.data.len(), if block is currently in the block tree.

pub fn block_data( &self, block: &CryptoHash, ) -> Result<Option<Data>, BlockTreeError>

Get the whole of block.data, if block is currently in the block tree.

pub fn block_datum(&self, block: &CryptoHash, datum_index: u32) -> Option<Datum>

Get one block.data[datum_index], if block is currently in the block tree.

pub fn block_at_height( &self, height: BlockHeight, ) -> Result<Option<CryptoHash>, BlockTreeError>

Get the committed block at height, if it is currently in the block tree.

pub fn app_state(&'a self, key: &[u8]) -> Option<Vec<u8>>

Get the value associated with key in the current app state.

pub fn validator_set(&self) -> Result<ValidatorSet, BlockTreeError>

Get the current committed validator set.