Enum git_odb::data::entry::Header

pub enum Header {
    Commit,
    Tree,
    Blob,
    Tag,
    RefDelta {
        base_id: ObjectId,
    },
    OfsDelta {
        base_distance: u64,
    },
}

The header portion of a pack data entry, identifying the kind of stored object.

Variants

Commit

The object is a commit

Tree

The object is a tree

Blob

The object is a blob

Tag

The object is a tag

RefDelta

Describes a delta-object which needs to be applied to a base. The base object is identified by the base_id field which is found within the parent repository. Most commonly used for thin-packs when receiving pack files from the server to refer to objects that are not part of the pack but expected to be present in the receivers repository.

Note

This could also be an object within this pack if the LSB encoded offset would be larger than 20 bytes, which is unlikely to happen.

The naming is exactly the same as the canonical implementation uses, namely REF_DELTA.

Fields of RefDelta

base_id: ObjectId

OfsDelta

Describes a delta-object present in this pack which acts as base for this object. The base object is measured as a distance from this objects pack offset, so that base_pack_offset = this_objects_pack_offset - base_distance

Note

The naming is exactly the same as the canonical implementation uses, namely OFS_DELTA.

Fields of OfsDelta

base_distance: u64

Implementations

impl Header

pub fn verified_base_pack_offset(pack_offset: u64, distance: u64) -> Option<u64>

Subtract distance from pack_offset safely without the chance for overflow or no-ops if distance is 0.

pub fn as_kind(&self) -> Option<Kind>

Convert the header’s object kind into git_object::Kind if possible

pub fn as_type_id(&self) -> u8

Convert this header’s object kind into the packs internal representation

pub fn is_delta(&self) -> bool

Return’s true if this is a delta object, i.e. not a full object.

pub fn is_base(&self) -> bool

Return’s true if this is a base object, i.e. not a delta object.

impl Header

pub fn write_to(
    &self,
    decompressed_size_in_bytes: u64,
    out: impl Write
) -> Result<usize, Error>

Encode this header along the given decompressed_size_in_bytes into the out write stream for use within a data pack.

Returns the amount of bytes written to out. decompressed_size_in_bytes is the full size in bytes of the object that this header represents

pub fn size(&self, decompressed_size: u64) -> usize

The size of the header in bytes when serialized

Trait Implementations

impl Clone for Header

pub fn clone(&self) -> Header

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.

impl Hash for Header

pub 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, 

Feeds a slice of this type into the given Hasher.

impl Ord for Header

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

Restrict a value to a certain interval.

impl PartialEq<Header> for Header

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

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

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

This method tests for !=.

impl PartialOrd<Header> for Header

pub fn partial_cmp(&self, other: &Header) -> 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 Copy for Header

impl Eq for Header

impl StructuralEq for Header

impl StructuralPartialEq for Header