Struct exonum_merkledb::access::Prefixed

pub struct Prefixed<T> { /* fields omitted */ }

Access that prepends the specified prefix to each created view. The prefix is separated from user-provided names with a dot char '.'.

Since the prefix itself cannot contain a dot, Prefixed accesses provide namespace separation. A set of indexes to which Prefixed provides access does not intersect with a set of indexes accessed by a Prefixed instance with another prefix. Additionally, index in Prefixed accesses do not intersect with indexes in special-purpose Access implementations (Migrations and Scratchpads).

Examples

use exonum_merkledb::{access::{AccessExt, CopyAccessExt, Prefixed}, Database, TemporaryDB};

let db = TemporaryDB::new();
let fork = db.fork();
let prefixed = Prefixed::new("prefixed", &fork);
prefixed.get_list("list").extend(vec![1_u32, 2, 3]);
let same_list = fork.get_list::<_, u32>("prefixed.list");
assert_eq!(same_list.len(), 3);

Methods

impl<T: RawAccess> Prefixed<T>

pub fn new(prefix: impl Into<String>, access: T) -> Self

Creates a new prefixed access.

Panics

• Will panic if the prefix is not a valid prefix name.

Trait Implementations

impl<T: RawAccess> Access for Prefixed<T>

type Base = T

Raw access serving as the basis for created indexes.

fn get_index_metadata(
    self,
    addr: IndexAddress
) -> Result<Option<IndexMetadata>, AccessError>

Gets index metadata at the specified address, or None if there is no index.

fn get_or_create_view(
    self,
    addr: IndexAddress,
    index_type: IndexType
) -> Result<ViewWithMetadata<Self::Base>, AccessError>

Gets or creates a generic view with the specified address.

fn group_keys<K: ?Sized>(
    self,
    base_addr: IndexAddress
) -> GroupKeys<Self::Base, K> where
    K: BinaryKey,
    Self::Base: AsReadonly<Readonly = Self::Base>, 

Returns an iterator over keys in a group with the specified address.

impl<T: Clone> Clone for Prefixed<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Prefixed<T>

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

Formats the value using the given formatter.

impl<T: RawAccess> From<Prefixed<T>> for GenericAccess<T>

fn from(access: Prefixed<T>) -> Self

Performs the conversion.

impl<'a, T> IntoErased<'a> for Prefixed<T> where
    T: Into<GenericRawAccess<'a>>, 

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

Performs the conversion.