Struct Key

pub struct Key(/* private fields */);

The key part of a key/value pair.

In TiKV, keys are an ordered sequence of bytes. This has an advantage over choosing String as valid UTF-8 is not required. This means that the user is permitted to store any data they wish, as long as it can be represented by bytes. (Which is to say, pretty much anything!)

This type wraps around an owned value, so it should be treated it like String or Vec<u8>.

Examples

use tikv_client::Key;

let static_str: &'static str = "TiKV";
let from_static_str = Key::from(static_str.to_owned());

let string: String = String::from(static_str);
let from_string = Key::from(string);
assert_eq!(from_static_str, from_string);

let vec: Vec<u8> = static_str.as_bytes().to_vec();
let from_vec = Key::from(vec);
assert_eq!(from_static_str, from_vec);

let bytes = static_str.as_bytes().to_vec();
let from_bytes = Key::from(bytes);
assert_eq!(from_static_str, from_bytes);

While .into() is usually sufficient for obtaining the buffer itself, sometimes type inference isn’t able to determine the correct type. Notably in the assert_eq!() and == cases. In these cases using the fully-qualified-syntax is useful:

Examples

use tikv_client::Key;

let buf = "TiKV".as_bytes().to_owned();
let key = Key::from(buf.clone());
assert_eq!(Into::<Vec<u8>>::into(key), buf);

Many functions which accept a Key accept an Into<Key>, which means all of the above types can be passed directly to those functions.

Implementations

impl Key

pub const EMPTY: Self

The empty key.

pub fn is_empty(&self) -> bool

Return whether the key is empty.

pub fn to_encoded(&self) -> Key

Return the MVCC-encoded representation of the key.

pub fn len(&self) -> usize

Trait Implementations

impl AsRef<Key> for Key

fn as_ref(&self) -> &Key

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<Key> for KvPair

fn as_ref(&self) -> &Key

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<Key> for Vec<u8>

fn as_ref(&self) -> &Key

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for Key

fn clone(&self) -> Key

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Key

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

Formats the value using the given formatter.

impl Default for Key

fn default() -> Key

Returns the “default value” for a type.

impl EncodeKeyspace for Key

fn encode_keyspace(self, keyspace: Keyspace, key_mode: KeyMode) -> Self

impl<'a> From<&'a Key> for &'a [u8]

fn from(key: &'a Key) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Vec<u8>> for &'a Key

fn from(key: &'a Vec<u8>) -> Self

Converts to this type from the input type.

impl From<Key> for Vec<u8>

fn from(key: Key) -> Self

Converts to this type from the input type.

impl From<KvPair> for Key

fn from(pair: KvPair) -> Self

Converts to this type from the input type.

impl From<String> for Key

fn from(v: String) -> Key

Converts to this type from the input type.

impl From<Vec<u8>> for Key

fn from(v: Vec<u8>) -> Self

Converts to this type from the input type.

impl Hash for Key

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

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 Ord for Key

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

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Key

fn eq(&self, other: &Key) -> 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 PartialOrd for Key

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl PessimisticLock for Key

fn key(self) -> Key

fn assertion(&self) -> Assertion

impl RangeBounds<Key> for BoundRange

fn start_bound(&self) -> Bound<&Key>

Start index bound.

fn end_bound(&self) -> Bound<&Key>

End index bound.

fn contains<U>(&self, item: &U) -> bool

where T: PartialOrd<U>, U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range.

impl TruncateKeyspace for Key

fn truncate_keyspace(self, keyspace: Keyspace) -> Self

impl Eq for Key

impl StructuralPartialEq for Key