Struct Keyless 

pub struct Keyless<E: Storage + Clock + Metrics, V: Codec, H: CHasher> { /* private fields */ }

A keyless ADB for variable length data.

Implementations

impl<E: Storage + Clock + Metrics, V: Codec, H: CHasher> Keyless<E, V, H>

pub async fn init(context: E, cfg: Config<V::Cfg>) -> Result<Self, Error>

Returns a Keyless adb initialized from cfg. Any uncommitted operations will be discarded and the state of the db will be as of the last committed operation.

pub async fn get(&self, loc: u64) -> Result<Option<V>, Error>

Get the value at location loc in the database.

pub fn op_count(&self) -> u64

Get the number of operations (appends + commits) that have been applied to the db since inception.

pub fn last_commit_loc(&self) -> Option<u64>

Returns the location of the last commit, if any.

pub async fn oldest_retained_loc(&self) -> Result<Option<u64>, Error>

Return the oldest location that remains retrievable.

pub async fn prune(&mut self, loc: u64) -> Result<(), Error>

Prunes the db of up to all operations that have location less than loc. The actual number pruned may be fewer than requested due to blob boundaries in the underlying journals.

Panics

Panics if loc is beyond the last commit point.

pub async fn append(&mut self, value: V) -> Result<u64, Error>

Append a value to the db, returning its location which can be used to retrieve it.

pub async fn commit(&mut self, metadata: Option<V>) -> Result<u64, Error>

Commit any pending operations to the database, ensuring their durability upon return from this function. Caller can associate an arbitrary metadata value with the commit.

Failures after commit (but before sync or close) may still require reprocessing to recover the database on restart.

pub async fn sync(&mut self) -> Result<(), Error>

Sync all database state to disk. While this isn’t necessary to ensure durability of committed operations, periodic invocation may reduce memory usage and the time required to recover the database on restart.

pub async fn get_metadata(&self) -> Result<Option<(u64, Option<V>)>, Error>

Get the location and metadata associated with the last commit, or None if no commit has been made.

pub fn root(&self, hasher: &mut Standard<H>) -> H::Digest

Return the root of the db.

Warning

Panics if there are uncommitted operations.

pub async fn proof( &self, start_loc: u64, max_ops: NonZeroU64, ) -> Result<(Proof<H::Digest>, Vec<Operation<V>>), Error>

Generate and return:

1. a proof of all operations applied to the db in the range starting at (and including) location start_loc, and ending at the first of either:
   • the last operation performed, or
   • the operation max_ops from the start.
2. the operations corresponding to the leaves in this range.

Warning

Panics if there are uncommitted operations.

pub async fn historical_proof( &self, size: u64, start_loc: u64, max_ops: NonZeroU64, ) -> Result<(Proof<H::Digest>, Vec<Operation<V>>), Error>

Analogous to proof, but with respect to the state of the MMR when it had size elements.

pub async fn close(self) -> Result<(), Error>

Close the db. Operations that have not been committed will be lost.

pub async fn destroy(self) -> Result<(), Error>

Destroy the db, removing all data from disk.