Struct Entry 

pub struct Entry {
    pub header: Header,
    pub decompressed_size: u64,
    pub data_offset: Offset,
    pub encoded_header_size: u16,
}

An representing an full- or delta-object within a pack

Fields

header: Header

The entry’s header

decompressed_size: u64

The decompressed size of the entry in bytes.

Note that for non-delta entries this will be the size of the object itself.

data_offset: Offset

absolute offset to compressed object data in the pack, just behind the entry’s header

encoded_header_size: u16

The amount of bytes used to encode the entry header in the pack.

Git accepts non-canonical size encodings in pack entry headers. These are encodings that continue the variable-length size field even though the remaining size bits are zero, for example b3 00 for a blob of size 3 instead of the canonical single-byte 33.

Git does not usually write such headers itself, but they can appear when pack data is reused verbatim, for example when a server constructs fetch or clone responses from already stored pack entries. Readers have to preserve the byte length that was actually consumed: recomputing the canonical length from the decoded size would shift Entry::pack_offset() backwards and make ofs-delta base-offset calculations refer to the wrong entry.

A value of 0 means the actual length is unknown, causing Entry::header_size() to recompute the canonical length from the decoded size. This is useful for deserializing data produced by older versions.

Implementations

impl Entry

Decoding

pub fn from_bytes( d: &[u8], pack_offset: Offset, object_hash: Kind, ) -> Result<Entry, Error>

Decode an entry from the given entry data d, providing the pack_offset to allow tracking the start of the entry data section.

pub fn from_read( r: &mut dyn Read, pack_offset: Offset, hash_len: usize, ) -> Result<Entry>

Instantiate an Entry from the reader r, providing the pack_offset to allow tracking the start of the entry data section.

impl Entry

Access

pub fn checked_base_pack_offset(&self, distance: u64) -> Option<Offset>

Compute the pack offset to the base entry of the object represented by this entry, or return None if the distance would underflow or is invalid.

pub fn base_pack_offset(&self, distance: u64) -> Offset

Compute the pack offset to the base entry of the object represented by this entry.

Panics

Panics if the distance will cause an underflow or is invalid.

pub fn pack_offset(&self) -> Offset

The pack offset at which this entry starts

pub fn header_size(&self) -> usize

The amount of bytes used to describe this entry in the pack.

For entries decoded from pack data this returns the actual encoded header length, including non-canonical overlong size encodings accepted by Git. This is the length to use for offset reconstruction because the header starts at Self::pack_offset() and the compressed data starts at Entry::data_offset.

If Entry::encoded_header_size is 0, the actual encoded length is unknown and this falls back to Header::size(), which computes the canonical serialized length from the decoded header and decompressed size.

Trait Implementations

impl Clone for Entry

fn clone(&self) -> Entry

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Entry

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Entry

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Entry

impl Hash for Entry

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 Entry

fn cmp(&self, other: &Entry) -> 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 Entry

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Entry

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

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Entry