Struct Subspace 

pub struct Subspace {
    prefix: Vec<u8>,
    versionstamp_offset: VersionstampOffset,
}

Represents a well-defined region of keyspace in a FoundationDB database

It provides a convenient way to use FoundationDB tuples to define namespaces for different categories of data. The namespace is specified by a prefix tuple which is prepended to all tuples packed by the subspace. When unpacking a key with the subspace, the prefix tuple will be removed from the result.

As a best practice, API clients should use at least one subspace for application data. For general guidance on subspace usage, see the Subspaces section of the Developer Guide.

Fields

prefix: Vec<u8>

versionstamp_offset: VersionstampOffset

Implementations

impl Subspace

pub fn all() -> Subspace

all returns the Subspace corresponding to all keys in a FoundationDB database.

pub fn from_bytes(prefix: impl Into<Vec<u8>>) -> Subspace

Returns a new Subspace from the provided bytes.

pub fn into_bytes(self) -> Vec<u8>

Convert into prefix key bytes

pub fn subspace<T>(&self, t: &T) -> Subspace

where T: TuplePack,

Returns a new Subspace whose prefix extends this Subspace with a given tuple encodable.

pub fn bytes(&self) -> &[u8]

bytes returns the literal bytes of the prefix of this Subspace.

pub fn pack<T>(&self, t: &T) -> Vec<u8>

where T: TuplePack,

Returns the key encoding the specified Tuple with the prefix of this Subspace prepended.

pub fn pack_with_versionstamp<T>(&self, t: &T) -> Vec<u8>

where T: TuplePack,

Returns the key encoding the specified Tuple with the prefix of this Subspace prepended, with a versionstamp.

pub fn unpack<'de, T>(&self, key: &'de [u8]) -> Result<T, PackError>

where T: TupleUnpack<'de>,

unpack returns the Tuple encoded by the given key with the prefix of this Subspace removed. unpack will return an error if the key is not in this Subspace or does not encode a well-formed Tuple.

pub fn is_start_of(&self, key: &[u8]) -> bool

is_start_of returns true if the provided key starts with the prefix of this Subspace, indicating that the Subspace logically contains the key.

pub fn range(&self) -> (Vec<u8>, Vec<u8>)

range returns first and last key of given Subspace

Trait Implementations

impl Clone for Subspace

fn clone(&self) -> Subspace

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Subspace

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Display for Subspace

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<&Subspace> for RangeOption<'static>

fn from(subspace: &Subspace) -> RangeOption<'static>

Converts to this type from the input type.

impl<E> From<E> for Subspace

where E: TuplePack,

fn from(e: E) -> Subspace

Converts to this type from the input type.

impl Hash for Subspace

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Subspace

fn eq(&self, other: &Subspace) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Subspace

impl StructuralPartialEq for Subspace