lighthouse/beacon_node/beacon_chain/src/block_graph.rs

45 lines
1.4 KiB
Rust

use parking_lot::{RwLock, RwLockReadGuard};
use std::collections::HashSet;
use types::Hash256;
/// Maintains a view of the block DAG, also known as the "blockchain" (except, it tracks multiple
/// chains eminating from a single root instead of just the head of some canonical chain).
///
/// The BlockGraph does not store the blocks, instead it tracks the block hashes of blocks at the
/// tip of the DAG. It is out of the scope of the object to retrieve blocks.
///
/// Presently, the DAG root (genesis block) is not tracked.
///
/// The BlogGraph is thread-safe due to internal RwLocks.
pub struct BlockGraph {
pub leaves: RwLock<HashSet<Hash256>>,
}
impl BlockGraph {
/// Create a new block graph without any leaves.
pub fn new() -> Self {
Self {
leaves: RwLock::new(HashSet::new()),
}
}
/// Add a new leaf to the block hash graph. Returns `true` if the leaf was built upon another
/// leaf.
pub fn add_leaf(&self, parent: &Hash256, leaf: Hash256) -> bool {
let mut leaves = self.leaves.write();
if leaves.contains(parent) {
leaves.remove(parent);
leaves.insert(leaf);
true
} else {
leaves.insert(leaf);
false
}
}
/// Returns a read-guarded HashSet of all leaf blocks.
pub fn leaves(&self) -> RwLockReadGuard<HashSet<Hash256>> {
self.leaves.read()
}
}