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 append(&mut self, elmt: &T, hashes: Vec<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 get_hash(&self, position: u64) -> Option<Hash>

Get a Hash by insertion position.

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

Get underlying data by insertion position.

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

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

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

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

fn data_as_temp_file(&self) -> Result<File, String>

Creates a temp file containing the contents of the underlying data file from the backend storage. This allows a caller to see a consistent view of the data without needing to lock the backend storage.

fn n_unpruned_leaves(&self) -> u64

Number of leaves in the MMR

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

Iterator over current (unpruned, unremoved) leaf positions.

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

Iterator over current (unpruned, unremoved) leaf insertion index. Note: This differs from underlying MMR pos - [0, 1, 2, 3, 4] vs. [1, 2, 4, 5, 8].

fn remove(&mut self, position: 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 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.