Trait ShardStore

pub trait ShardStore {
    type H;
    type CheckpointId;
    type Error: Error;

    // Required methods
    fn get_shard(
        &self,
        shard_root: Address,
    ) -> Result<Option<LocatedPrunableTree<Self::H>>, Self::Error>;
    fn last_shard(
        &self,
    ) -> Result<Option<LocatedPrunableTree<Self::H>>, Self::Error>;
    fn put_shard(
        &mut self,
        subtree: LocatedPrunableTree<Self::H>,
    ) -> Result<(), Self::Error>;
    fn get_shard_roots(&self) -> Result<Vec<Address>, Self::Error>;
    fn truncate_shards(&mut self, shard_index: u64) -> Result<(), Self::Error>;
    fn get_cap(&self) -> Result<PrunableTree<Self::H>, Self::Error>;
    fn put_cap(&mut self, cap: PrunableTree<Self::H>) -> Result<(), Self::Error>;
    fn min_checkpoint_id(
        &self,
    ) -> Result<Option<Self::CheckpointId>, Self::Error>;
    fn max_checkpoint_id(
        &self,
    ) -> Result<Option<Self::CheckpointId>, Self::Error>;
    fn add_checkpoint(
        &mut self,
        checkpoint_id: Self::CheckpointId,
        checkpoint: Checkpoint,
    ) -> Result<(), Self::Error>;
    fn checkpoint_count(&self) -> Result<usize, Self::Error>;
    fn get_checkpoint_at_depth(
        &self,
        checkpoint_depth: usize,
    ) -> Result<Option<(Self::CheckpointId, Checkpoint)>, Self::Error>;
    fn get_checkpoint(
        &self,
        checkpoint_id: &Self::CheckpointId,
    ) -> Result<Option<Checkpoint>, Self::Error>;
    fn with_checkpoints<F>(
        &mut self,
        limit: usize,
        callback: F,
    ) -> Result<(), Self::Error>
       where F: FnMut(&Self::CheckpointId, &Checkpoint) -> Result<(), Self::Error>;
    fn for_each_checkpoint<F>(
        &self,
        limit: usize,
        callback: F,
    ) -> Result<(), Self::Error>
       where F: FnMut(&Self::CheckpointId, &Checkpoint) -> Result<(), Self::Error>;
    fn update_checkpoint_with<F>(
        &mut self,
        checkpoint_id: &Self::CheckpointId,
        update: F,
    ) -> Result<bool, Self::Error>
       where F: Fn(&mut Checkpoint) -> Result<(), Self::Error>;
    fn remove_checkpoint(
        &mut self,
        checkpoint_id: &Self::CheckpointId,
    ) -> Result<(), Self::Error>;
    fn truncate_checkpoints_retaining(
        &mut self,
        checkpoint_id: &Self::CheckpointId,
    ) -> Result<(), Self::Error>;
}

A capability for storage of fragment subtrees of the ShardTree type.

All fragment subtrees must have roots at level SHARD_HEIGHT.

Required Associated Types

type H

The type used for leaves and nodes in the tree.

type CheckpointId

The type used to identify checkpointed positions in the tree.

type Error: Error

The error type for operations on this store.

Required Methods

fn get_shard( &self, shard_root: Address, ) -> Result<Option<LocatedPrunableTree<Self::H>>, Self::Error>

Returns the subtree at the given root address, if any such subtree exists.

fn last_shard( &self, ) -> Result<Option<LocatedPrunableTree<Self::H>>, Self::Error>

Returns the subtree containing the maximum inserted leaf position.

fn put_shard( &mut self, subtree: LocatedPrunableTree<Self::H>, ) -> Result<(), Self::Error>

Inserts or replaces the subtree having the same root address as the provided tree.

Implementations of this method MUST enforce the constraint that the root address of the provided subtree has level SHARD_HEIGHT.

fn get_shard_roots(&self) -> Result<Vec<Address>, Self::Error>

Returns the vector of addresses corresponding to the roots of subtrees stored in this store.

fn truncate_shards(&mut self, shard_index: u64) -> Result<(), Self::Error>

Removes subtrees from the underlying store having root addresses at indices greater than or equal to that of the specified index.

fn get_cap(&self) -> Result<PrunableTree<Self::H>, Self::Error>

A tree that is used to cache the known roots of subtrees in the “cap” - the top part of the tree, which contains parent nodes produced by hashing the roots of the individual shards. Nodes in the cap have levels in the range SHARD_HEIGHT..DEPTH. Note that the cap may be sparse, in the same way that individual shards may be sparse.

fn put_cap(&mut self, cap: PrunableTree<Self::H>) -> Result<(), Self::Error>

Persists the provided cap to the data store.

fn min_checkpoint_id(&self) -> Result<Option<Self::CheckpointId>, Self::Error>

Returns the identifier for the checkpoint with the lowest associated position value.

fn max_checkpoint_id(&self) -> Result<Option<Self::CheckpointId>, Self::Error>

Returns the identifier for the checkpoint with the highest associated position value.

fn add_checkpoint( &mut self, checkpoint_id: Self::CheckpointId, checkpoint: Checkpoint, ) -> Result<(), Self::Error>

Adds a checkpoint to the data store.

fn checkpoint_count(&self) -> Result<usize, Self::Error>

Returns the number of checkpoints maintained by the data store

fn get_checkpoint_at_depth( &self, checkpoint_depth: usize, ) -> Result<Option<(Self::CheckpointId, Checkpoint)>, Self::Error>

Returns the id and position of the checkpoint at the specified depth, if it exists.

Returns None if if insufficient checkpoints exist to seek back to the requested depth. Depth 0 refers to the most recent checkpoint in the tree; depth 1 refers to the previous checkpoint, and so forth.

fn get_checkpoint( &self, checkpoint_id: &Self::CheckpointId, ) -> Result<Option<Checkpoint>, Self::Error>

Returns the checkpoint corresponding to the specified checkpoint identifier.

fn with_checkpoints<F>( &mut self, limit: usize, callback: F, ) -> Result<(), Self::Error>

where F: FnMut(&Self::CheckpointId, &Checkpoint) -> Result<(), Self::Error>,

Iterates in checkpoint ID order over the first limit checkpoints, applying the given callback to each.

fn for_each_checkpoint<F>( &self, limit: usize, callback: F, ) -> Result<(), Self::Error>

where F: FnMut(&Self::CheckpointId, &Checkpoint) -> Result<(), Self::Error>,

Calls the given callback for each checkpoint in CheckpointId order. This is essentially the immutable version of with_checkpoints.

fn update_checkpoint_with<F>( &mut self, checkpoint_id: &Self::CheckpointId, update: F, ) -> Result<bool, Self::Error>

where F: Fn(&mut Checkpoint) -> Result<(), Self::Error>,

Update the checkpoint having the given identifier by mutating it with the provided function, and persist the updated checkpoint to the data store.

Returns Ok(true) if the checkpoint was found, Ok(false) if no checkpoint with the provided identifier exists in the data store, or an error if a storage error occurred.

fn remove_checkpoint( &mut self, checkpoint_id: &Self::CheckpointId, ) -> Result<(), Self::Error>

Removes a checkpoint from the data store.

If no checkpoint exists with the given ID, this does nothing.

fn truncate_checkpoints_retaining( &mut self, checkpoint_id: &Self::CheckpointId, ) -> Result<(), Self::Error>

Removes checkpoints with identifiers greater than to the given identifier, and removes mark removal metadata from the specified checkpoint.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<S: ShardStore> ShardStore for &mut S

type H = <S as ShardStore>::H

type CheckpointId = <S as ShardStore>::CheckpointId

type Error = <S as ShardStore>::Error

fn get_shard( &self, shard_root: Address, ) -> Result<Option<LocatedPrunableTree<Self::H>>, Self::Error>

fn last_shard( &self, ) -> Result<Option<LocatedPrunableTree<Self::H>>, Self::Error>

fn put_shard( &mut self, subtree: LocatedPrunableTree<Self::H>, ) -> Result<(), Self::Error>

fn get_shard_roots(&self) -> Result<Vec<Address>, Self::Error>

fn get_cap(&self) -> Result<PrunableTree<Self::H>, Self::Error>

fn put_cap(&mut self, cap: PrunableTree<Self::H>) -> Result<(), Self::Error>

fn truncate_shards(&mut self, shard_index: u64) -> Result<(), Self::Error>

fn min_checkpoint_id(&self) -> Result<Option<Self::CheckpointId>, Self::Error>

fn max_checkpoint_id(&self) -> Result<Option<Self::CheckpointId>, Self::Error>

fn add_checkpoint( &mut self, checkpoint_id: Self::CheckpointId, checkpoint: Checkpoint, ) -> Result<(), Self::Error>

fn checkpoint_count(&self) -> Result<usize, Self::Error>

fn get_checkpoint_at_depth( &self, checkpoint_depth: usize, ) -> Result<Option<(Self::CheckpointId, Checkpoint)>, Self::Error>

fn get_checkpoint( &self, checkpoint_id: &Self::CheckpointId, ) -> Result<Option<Checkpoint>, Self::Error>

fn with_checkpoints<F>( &mut self, limit: usize, callback: F, ) -> Result<(), Self::Error>

where F: FnMut(&Self::CheckpointId, &Checkpoint) -> Result<(), Self::Error>,

fn for_each_checkpoint<F>( &self, limit: usize, callback: F, ) -> Result<(), Self::Error>

where F: FnMut(&Self::CheckpointId, &Checkpoint) -> Result<(), Self::Error>,

fn update_checkpoint_with<F>( &mut self, checkpoint_id: &Self::CheckpointId, update: F, ) -> Result<bool, Self::Error>

where F: Fn(&mut Checkpoint) -> Result<(), Self::Error>,

fn remove_checkpoint( &mut self, checkpoint_id: &Self::CheckpointId, ) -> Result<(), Self::Error>

fn truncate_checkpoints_retaining( &mut self, checkpoint_id: &Self::CheckpointId, ) -> Result<(), Self::Error>

Implementors

impl<H: Clone, C: Clone + Ord> ShardStore for MemoryShardStore<H, C>

type H = H

type CheckpointId = C

type Error = Infallible

impl<S> ShardStore for CachingShardStore<S>

where S: ShardStore, S::H: Clone, S::CheckpointId: Clone + Ord,

type H = <S as ShardStore>::H

type CheckpointId = <S as ShardStore>::CheckpointId

type Error = Infallible