Struct git_repository::index::hash::Prefix

pub struct Prefix { /* private fields */ }

An partial owned hash possibly identifying an object uniquely, whose non-prefix bytes are zeroed.

Implementations

impl Prefix

pub const MIN_HEX_LEN: usize = 4usize

The smallest allowed prefix length below which chances for collisions are too high even in small repositories.

pub fn new(id: impl AsRef<oid>, hex_len: usize) -> Result<Prefix, Error>

Create a new instance by taking a full id as input and truncating it to hex_len.

For instance, with hex_len of 7 the resulting prefix is 3.5 bytes, or 3 bytes and 4 bits wide, with all other bytes and bits set to zero.

pub fn as_oid(&self) -> &oid

Returns the prefix as object id.

Note that it may be deceptive to use given that it looks like a full object id, even though its post-prefix bytes/bits are set to zero.

pub fn hex_len(&self) -> usize

Return the amount of hexadecimal characters that are set in the prefix.

This gives the prefix a granularity of 4 bits.

pub fn cmp_oid(&self, candidate: &oid) -> Ordering

Provided with candidate id which is a full hash, determine how this prefix compares to it, only looking at the prefix bytes, ignoring everything behind that.

pub fn from_hex(value: &str) -> Result<Prefix, Error>

Create an instance from the given hexadecimal prefix value, e.g. 35e77c16 would yield a Prefix with hex_len() = 8.

Trait Implementations

impl Clone for Prefix

fn clone(&self) -> Prefix

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Prefix

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Prefix

fn deserialize<__D>(
    __deserializer: __D
) -> Result<Prefix, <__D as Deserializer<'de>>::Error>where
    __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Prefix

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

Formats the value using the given formatter.

impl From<ObjectId> for Prefix

fn from(oid: ObjectId) -> Prefix

Converts to this type from the input type.

impl Hash for Prefix

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 Ord for Prefix

fn cmp(&self, other: &Prefix) -> 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<Prefix> for Prefix

fn eq(&self, other: &Prefix) -> 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<Prefix> for Prefix

fn partial_cmp(&self, other: &Prefix) -> 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 Serialize for Prefix

fn serialize<__S>(
    &self,
    __serializer: __S
) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>where
    __S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<&str> for Prefix

Create an instance from the given hexadecimal prefix, e.g. 35e77c16 would yield a Prefix with hex_len() = 8.

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: &str) -> Result<Prefix, <Prefix as TryFrom<&str>>::Error>

Performs the conversion.

impl Copy for Prefix

impl Eq for Prefix

impl StructuralEq for Prefix

impl StructuralPartialEq for Prefix