Struct gix::index::hash::Prefix

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. Read more

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

Performs copy-assignment from source. Read more

impl Debug for Prefix

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

Formats the value using the given formatter. Read more

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. Read more

impl Display for Prefix

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

Formats the value using the given formatter. Read more

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. Read more

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

Feeds a slice of this type into the given Hasher. Read more

impl Ord for Prefix

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

This method returns an Ordering between self and other. Read more

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

Compares and returns the maximum of two values. Read more

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

Compares and returns the minimum of two values. Read more

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

Restrict a value to a certain interval. Read more

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 ==.

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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. Read more

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

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

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

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

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

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

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

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

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. Read more

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 StructuralPartialEq for Prefix

Auto Trait Implementations§

impl RefUnwindSafe for Prefix

impl Send for Prefix

impl Sync for Prefix

impl Unpin for Prefix

impl UnwindSafe for Prefix

Blanket Implementations§

impl<T> Any for Twhere T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for Twhere T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for Twhere T: ?Sized,

const: unstable · source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more

impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into for Twhere U: From<T>,

const: unstable · source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<T> Pointable for T

const ALIGN: usize = mem::align_of::<T>()

The alignment of pointer.

type Init = T

The type for initializers.

unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more

impl<T> Same<T> for T

type Output = T

Should always be Self

impl<T> ToOwned for Twhere T: Clone,

type Owned = T

The resulting type after obtaining ownership.

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T> ToString for Twhere T: Display + ?Sized,

default fn to_string(&self) -> String

Converts the given value to a String. Read more

impl<T, U> TryFrom for Twhere U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom>::Error>

Performs the conversion.

impl<T, U> TryInto for Twhere U: TryFrom<T>,

type Error = >::Error

The type returned in the event of a conversion error.

const: unstable · source§

fn try_into(self) -> Result<U, >::Error>

Performs the conversion.