Struct Chunk

#[repr(C, packed(1))]
pub struct Chunk {
    pub length: U64,
    pub owner: U64,
    pub stripe_len: U64,
    pub chunk_type: U64,
    pub io_align: U32,
    pub io_width: U32,
    pub sector_size: U32,
    pub num_stripes: U16,
    pub sub_stripes: U16,
}

This structure contains the mapping from a virtualized usable byte range within the backing storage to a set of one or more stripes on individual backing devices. In addition to the mapping, hints on optimal I/O parameters for this chunk. It is associated with CHUNK_ITEM.

Although the structure definition only contains one stripe member, CHUNK_ITEM contain as many struct Stripe structures as specified in the num_stripes and sub_stripes fields.

For the dynamically-sized version of this type with the stripes following, see ChunkDynamic.

Fields

length: U64

The size of this chunk, in bytes.

owner: U64

The object ID of the root referencing this chunk. This is always the ID of an extent root.

stripe_len: U64

The replication stripe length.

chunk_type: U64

Flags indicating allocation type and replication policy.

io_align: U32

The optimal I/O alignment for this chunk.

io_width: U32

The optimal I/O width for this chunk.

sector_size: U32

The minimal I/O size for this chunk.

num_stripes: U16

The number of replication stripes.

sub_stripes: U16

The number of sub-stripes. This is only used for RAID-10.

This is 2 for RAID-10, and 1 for all other chunk types.

Implementations

impl Chunk

pub unsafe fn into_dynamic( &self, num_stripes: usize, ) -> Result<&ChunkDynamic, CastError<&[u8], ChunkDynamic>>

A convenience method for converting a Chunk into a ChunkDynamic.

For a safe version, use ChunkDynamic::ref_from_prefix_with_elems.

Safety

This function is unsafe because it assumes that the bytes following the Chunk structure are valid and contain the expected number of Stripe structures as specified by num_stripes. If this assumption is violated, it may lead to undefined behavior.

Trait Implementations

impl Clone for Chunk

fn clone(&self) -> Chunk

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Chunk

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

Formats the value using the given formatter.

impl FromBytes for Chunk

where U64: FromBytes, U32: FromBytes, U16: FromBytes,

fn ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout + Immutable,

Interprets the given source as a &Self.

fn ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout + Immutable,

Interprets the prefix of the given source as a &Self without copying.

fn ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: Immutable + KnownLayout,

Interprets the suffix of the given bytes as a &Self.

fn mut_from_bytes( source: &mut [u8], ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout,

Interprets the given source as a &mut Self.

fn mut_from_prefix( source: &mut [u8], ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout,

Interprets the prefix of the given source as a &mut Self without copying.

fn mut_from_suffix( source: &mut [u8], ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout,

Interprets the suffix of the given source as a &mut Self without copying.

fn ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &Self with a DST length equal to count.

fn ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the prefix of the given source as a DST &Self with length equal to count.

fn ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the suffix of the given source as a DST &Self with length equal to count.

fn mut_from_bytes_with_elems( source: &mut [u8], count: usize, ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &mut Self with a DST length equal to count.

fn mut_from_prefix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize>,

Interprets the prefix of the given source as a &mut Self with DST length equal to count.

fn mut_from_suffix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize>,

Interprets the suffix of the given source as a &mut Self with DST length equal to count.

fn read_from_bytes(source: &[u8]) -> Result<Self, SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the given source.

fn read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the prefix of the given source.

fn read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the suffix of the given source.

impl FromZeros for Chunk

where U64: FromZeros, U32: FromZeros, U16: FromZeros,

fn zero(&mut self)

Overwrites self with zeros.

fn new_zeroed() -> Self

where Self: Sized,

Creates an instance of Self from zeroed bytes.

impl Hash for Chunk

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 IntoBytes for Chunk

where U64: IntoBytes, U32: IntoBytes, U16: IntoBytes,

fn as_bytes(&self) -> &[u8]

where Self: Immutable,

Gets the bytes of this value.

fn as_mut_bytes(&mut self) -> &mut [u8]

where Self: FromBytes,

Gets the bytes of this value mutably.

fn write_to(&self, dst: &mut [u8]) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to dst.

fn write_to_prefix( &self, dst: &mut [u8], ) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to the prefix of dst.

fn write_to_suffix( &self, dst: &mut [u8], ) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to the suffix of dst.

impl KnownLayout for Chunk

where U16LE: KnownLayout,

type PointerMetadata = <U16<LittleEndian> as KnownLayout>::PointerMetadata

The type of metadata stored in a pointer to Self.

impl TryFromBytes for Chunk

where U64: TryFromBytes, U32: TryFromBytes, U16: TryFromBytes,

fn try_ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the given source as a &Self.

fn try_ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the prefix of the given source as a &Self.

fn try_ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the suffix of the given source as a &Self.

fn try_mut_from_bytes( bytes: &mut [u8], ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the given source as a &mut Self without copying.

fn try_mut_from_prefix( source: &mut [u8], ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the prefix of the given source as a &mut Self.

fn try_mut_from_suffix( source: &mut [u8], ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the suffix of the given source as a &mut Self.

fn try_ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the given source as a &Self with a DST length equal to count.

fn try_ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the prefix of the given source as a &Self with a DST length equal to count.

fn try_ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the suffix of the given source as a &Self with a DST length equal to count.

fn try_mut_from_bytes_with_elems( source: &mut [u8], count: usize, ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the given source as a &mut Self with a DST length equal to count.

fn try_mut_from_prefix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the prefix of the given source as a &mut Self with a DST length equal to count.

fn try_mut_from_suffix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the suffix of the given source as a &mut Self with a DST length equal to count.

fn try_read_from_bytes( source: &[u8], ) -> Result<Self, ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read the given source as a Self.

fn try_read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the prefix of the given source.

fn try_read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the suffix of the given source.

impl Copy for Chunk

impl Immutable for Chunk

where U64: Immutable, U32: Immutable, U16: Immutable,

impl Unaligned for Chunk