Struct grin_core::core::pmmr::VecBackend

pub struct VecBackend<T: PMMRable> {
    pub data: Option<Vec<T>>,
    pub hashes: Vec<Hash>,
    pub removed: HashSet<u64>,
}

Simple/minimal/naive MMR backend implementation backed by Vec and Vec. Removed pos are maintained in a HashSet.

Fields

data: Option<Vec<T>>

Backend elements (optional, possible to just store hashes).

hashes: Vec<Hash>

Vec of hashes for the PMMR (both leaves and parents).

removed: HashSet<u64>

Positions of removed elements (is this applicable if we do not store data?)

Implementations

impl<T: PMMRable> VecBackend<T>

pub fn new() -> VecBackend<T>

Instantiates a new empty vec backend.

pub fn new_hash_only() -> VecBackend<T>

Instantiate a new empty “hash only” vec backend.

pub fn size(&self) -> u64

Size of this vec backend in hashes.

Trait Implementations

impl<T: PMMRable> Backend<T> for VecBackend<T>

fn n_unpruned_leaves(&self) -> u64

Number of leaves in the MMR

fn leaf_idx_iter(&self, from_idx: u64) -> Box<dyn Iterator<Item = u64> + '_>

NOTE this function is needlessly inefficient with repeated calls to n_leaves()

fn append(&mut self, elmt: &T, hashes: &[Hash]) -> Result<(), String>

Append the provided Hashes to the backend storage, and optionally an associated data element to flatfile storage (for leaf nodes only). The position of the first element of the Vec in the MMR is provided to help the implementation.

fn append_pruned_subtree( &mut self, _hash: Hash, _pos0: u64 ) -> Result<(), String>

Rebuilding a PMMR locally from PIBD segments requires pruned subtree support. This allows us to append an existing pruned subtree directly without the underlying leaf nodes.

fn append_hash(&mut self, _hash: Hash) -> Result<(), String>

Append a single hash to the pmmr

fn get_hash(&self, pos0: u64) -> Option<Hash>

Get a Hash by insertion position.

fn get_data(&self, pos0: u64) -> Option<T::E>

Get underlying data by insertion position.

fn get_from_file(&self, pos0: u64) -> Option<Hash>

Get a Hash by original insertion position (ignoring the remove log).

fn get_peak_from_file(&self, pos0: u64) -> Option<Hash>

Get hash for peak pos. Optimized for reading peak hashes rather than arbitrary pos hashes. Peaks can be assumed to not be compacted.

fn get_data_from_file(&self, pos0: u64) -> Option<T::E>

Get a Data Element by original insertion position (ignoring the remove log).

fn n_unpruned_leaves_to_index(&self, _to_index: u64) -> u64

Number of leaves up to the given leaf index

fn leaf_pos_iter(&self) -> Box<dyn Iterator<Item = u64> + '_>

Iterator over current (unpruned, unremoved) leaf positions.

fn remove(&mut self, pos0: u64) -> Result<(), String>

Remove Hash by insertion position. An index is also provided so the underlying backend can implement some rollback of positions up to a given index (practically the index is the height of a block that triggered removal).

fn remove_from_leaf_set(&mut self, _pos0: u64)

Remove a leaf from the leaf set

fn reset_prune_list(&mut self)

Reset prune list, used when PIBD is reset

fn rewind( &mut self, position: u64, _rewind_rm_pos: &Bitmap ) -> Result<(), String>

Rewind the backend state to a previous position, as if all append operations after that had been canceled. Expects a position in the PMMR to rewind to as well as bitmaps representing the positions added and removed since the rewind position. These are what we will “undo” during the rewind.

fn snapshot(&self, _header: &BlockHeader) -> Result<(), String>

Saves a snapshot of the rewound utxo file with the block hash as filename suffix. We need this when sending a txhashset zip file to a node for fast sync.

fn release_files(&mut self)

Release underlying datafiles and locks

fn dump_stats(&self)

For debugging purposes so we can see how compaction is doing.

impl<T: Clone + PMMRable> Clone for VecBackend<T>

fn clone(&self) -> VecBackend<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + PMMRable> Debug for VecBackend<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.