Struct fdb::tuple::Tuple

pub struct Tuple { /* private fields */ }

Represents a set of elements that make up a sortable, typed key.

Tuple is comparable with other Tuples and will sort in Rust in the same order in which they would sort in FDB. Tuples sort first by the first element, then by the second, etc., This make tuple layer ideal for building a variety of higher-level data models.

For general guidance on tuple usage, see this link.

Tuple can contain Null, Bytes, String, another Tuple, BigInt, i64, i32, i16, i8, f32, f64, bool, Uuid, Versionstamp values.

Implementations

impl Tuple

pub fn new() -> Tuple

Create a new empty Tuple.

pub fn get<'a, T>(&'a self, index: usize) -> Option<T>where T: TupleElementGet<'a> + 'a,

Provides the Tuple element at the given index.

If you want to return a FdbResult, use FdbError with TUPLE_GET.

pub fn pop_back<T>(&mut self) -> Option<T>where T: TupleElementPop,

Removes the last element from the Tuple and returns it, or None if it is empty.

If there is a value of a different type other than type T, the Tuple is not mutated and None is returned.

pub fn pop_front<T>(&mut self) -> Option<T>where T: TupleElementPop,

Removes the first element from the Tuple and returns it, or None if it is empty.

If there is a value of a different type other than type T, the Tuple is not mutated and None is returned.

pub fn push_back<T>(&mut self, value: T)where T: TupleElementPush,

Appends a Tuple element.

pub fn push_front<T>(&mut self, value: T)where T: TupleElementPush,

Prepends a Tuple element.

pub fn append(&mut self, other: &mut Tuple)

Moves all the elements of the Tuple other into Tuple self, leaving the Tuple other empty.

Panics

Panics if the new number of elements in self overflows a usize.

pub fn has_incomplete_versionstamp(&self) -> bool

Determines if there is a Versionstamp included in this Tuple that has not had its transaction version set.

pub fn is_empty(&self) -> bool

Returns true if the Tuple is empty.

pub fn len(&self) -> usize

Returns the number of elements in the Tuple.

pub fn pack(&self) -> Bytes

Get an encoded representation of this Tuple.

pub fn pack_with_versionstamp(&self, prefix: Bytes) -> FdbResult<Bytes>

Get an encoded representation of this Tuple for use with SetVersionstampedKey.

Panic

The index where incomplete versionstamp is located is a 32-bit little-endian integer. If the generated index overflows u32, then this function panics.

pub fn range(&self, prefix: Bytes) -> Range

Returns a range representing all keys that encode Tuples strictly starting with this Tuple.

Panic

Panics if the tuple contains an incomplete Versionstamp.

Trait Implementations

impl Clone for Tuple

fn clone(&self) -> Tuple

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Tuple

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

Formats the value using the given formatter.

impl Default for Tuple

fn default() -> Tuple

Returns the “default value” for a type.

impl From<Mapper> for Tuple

fn from(m: Mapper) -> Tuple

Converts to this type from the input type.

impl From<Tuple> for Mapper

fn from(t: Tuple) -> Mapper

Converts to this type from the input type.

impl Ord for Tuple

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<Tuple> for Tuple

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd<Tuple> for Tuple

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<Bytes> for Tuple

fn try_from(b: Bytes) -> FdbResult<Tuple>

Construct a new Tuple with elements decoded from a supplied Bytes.

type Error = FdbError

The type returned in the event of a conversion error.

impl TryFrom<Key> for Tuple

fn try_from(k: Key) -> FdbResult<Tuple>

Construct a new Tuple with elements decoded from a supplied Key.

type Error = FdbError

The type returned in the event of a conversion error.

impl TryFrom<Value> for Tuple

fn try_from(v: Value) -> FdbResult<Tuple>

Construct a new Tuple with elements decoded from a supplied Value.

type Error = FdbError

The type returned in the event of a conversion error.

impl Eq for Tuple

impl<'a> TupleElementGet<'a> for &'a Tuple

impl TupleElementPop for Tuple

impl TupleElementPush for Tuple