Trait exonum_merkledb::Snapshot

pub trait Snapshot: Send + Sync + 'static {
    fn get(&self, name: &ResolvedAddress, key: &[u8]) -> Option<Vec<u8>>;
    fn iter(&self, name: &ResolvedAddress, from: &[u8]) -> Iter;

    fn contains(&self, name: &ResolvedAddress, key: &[u8]) -> bool { ... }
}

A read-only snapshot of a storage backend.

A Snapshot instance is an immutable representation of a certain storage state. It provides read isolation, so consistency is guaranteed even if the data in the database changes between reads.

Required methods

fn get(&self, name: &ResolvedAddress, key: &[u8]) -> Option<Vec<u8>>

Returns a value corresponding to the specified address and key as a raw vector of bytes, or None if it does not exist.

fn iter(&self, name: &ResolvedAddress, from: &[u8]) -> Iter

Returns an iterator over the entries of the snapshot in ascending order starting from the specified key. The iterator element type is (&[u8], &[u8]).

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Provided methods

fn contains(&self, name: &ResolvedAddress, key: &[u8]) -> bool

Returns true if the snapshot contains a value for the specified address and key.

The default implementation checks existence of the value using get.

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Trait Implementations

impl<'_> AsReadonly for &'_ dyn Snapshot

type Readonly = Self

Readonly version of the access.

fn as_readonly(&self) -> Self::Readonly

Performs the conversion.

impl AsRef<dyn Snapshot + 'static> for dyn Snapshot

fn as_ref(&self) -> &dyn Snapshot

Performs the conversion.

impl Debug for dyn Snapshot

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

Formats the value using the given formatter.

impl<'a> From<&'a (dyn Snapshot + 'static)> for GenericRawAccess<'a>

fn from(snapshot: &'a dyn Snapshot) -> Self

Performs the conversion.

impl<'a> IntoErased<'a> for &'a dyn Snapshot

fn into_erased(self) -> ErasedAccess<'a>

Performs the conversion.

impl<'_> RawAccess for &'_ dyn Snapshot

type Changes = ()

Type of the changes() that will be applied to the database.

fn snapshot(&self) -> &dyn Snapshot

Reference to a Snapshot. This is the base relative to which the changes are defined.

fn changes(&self, _address: &ResolvedAddress) -> Self::Changes

Returns changes related to specific address compared to the snapshot().

Implementations on Foreign Types

impl Snapshot for Box<dyn Snapshot>

fn get(&self, name: &ResolvedAddress, key: &[u8]) -> Option<Vec<u8>>

fn contains(&self, name: &ResolvedAddress, key: &[u8]) -> bool

fn iter(&self, name: &ResolvedAddress, from: &[u8]) -> Iter

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Implementors

impl Snapshot for Patch

fn get(&self, name: &ResolvedAddress, key: &[u8]) -> Option<Vec<u8>>

fn contains(&self, name: &ResolvedAddress, key: &[u8]) -> bool

fn iter(&self, name: &ResolvedAddress, from: &[u8]) -> Iter

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