Struct SegmentHeader

#[repr(C)]
pub struct SegmentHeader {

    pub magic: U64,
    pub version: U16,
    pub start_frame_no: U64,
    pub last_commited_frame_no: U64,
    pub frame_count: U64,
    pub size_after: U32,
    pub index_offset: U64,
    pub index_size: U64,
    pub flags: U32,
    pub salt: U32,
    pub page_size: U16,
    pub log_id: U128,
    pub sealed_at_timestamp: U64,
    pub header_cheksum: U32,
}

Fields

magic: U64

Set to LIBSQL_MAGIC

version: U16

header version

start_frame_no: U64

last_commited_frame_no: U64

frame_count: U64

number of frames in the segment

size_after: U32

size of the database in pages, after applying the segment.

index_offset: U64

byte offset of the index. If 0, then the index wasn’t written, and must be recovered. If non-0, the segment is sealed, and must not be written to anymore the index is followed by its checksum

index_size: U64

flags: U32

salt: U32

salt for the segment checksum

page_size: U16

right now we only support 4096, but if se decided to support other sizes, we could do it without changing the header

log_id: U128

sealed_at_timestamp: U64

ms, from unix epoch

header_cheksum: U32

checksum of the header fields, excluding the checksum itself. This field must be the last

Implementations

impl SegmentHeader

pub fn flags(&self) -> SegmentFlags

pub fn last_commited_frame_no(&self) -> u64

pub fn size_after(&self) -> u32

size fo the db after applying this segment

pub fn frame_count(&self) -> usize

pub fn last_committed(&self) -> u64

Trait Implementations

impl AsBytes for SegmentHeader

where U64: AsBytes, U16: AsBytes, U32: AsBytes, U128: AsBytes, HasPadding<SegmentHeader, { _ }>: ShouldBe<false>,

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

Gets the bytes of this value.

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

where Self: FromBytes,

Gets the bytes of this value mutably.

fn write_to(&self, bytes: &mut [u8]) -> Option<()>

Writes a copy of self to bytes.

fn write_to_prefix(&self, bytes: &mut [u8]) -> Option<()>

Writes a copy of self to the prefix of bytes.

fn write_to_suffix(&self, bytes: &mut [u8]) -> Option<()>

Writes a copy of self to the suffix of bytes.

impl Clone for SegmentHeader

fn clone(&self) -> SegmentHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SegmentHeader

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

Formats the value using the given formatter.

impl FromBytes for SegmentHeader

where U64: FromBytes, U16: FromBytes, U32: FromBytes, U128: FromBytes,

fn ref_from(bytes: &[u8]) -> Option<&Self>

where Self: Sized,

Interprets the given bytes as a &Self without copying.

fn ref_from_prefix(bytes: &[u8]) -> Option<&Self>

where Self: Sized,

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

fn ref_from_suffix(bytes: &[u8]) -> Option<&Self>

where Self: Sized,

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

fn mut_from(bytes: &mut [u8]) -> Option<&mut Self>

where Self: Sized + AsBytes,

Interprets the given bytes as a &mut Self without copying.

fn mut_from_prefix(bytes: &mut [u8]) -> Option<&mut Self>

where Self: Sized + AsBytes,

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

fn mut_from_suffix(bytes: &mut [u8]) -> Option<&mut Self>

where Self: Sized + AsBytes,

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

fn slice_from(bytes: &[u8]) -> Option<&[Self]>

where Self: Sized,

Interprets the given bytes as a &[Self] without copying.

fn slice_from_prefix(bytes: &[u8], count: usize) -> Option<(&[Self], &[u8])>

where Self: Sized,

Interprets the prefix of the given bytes as a &[Self] with length equal to count without copying.

fn slice_from_suffix(bytes: &[u8], count: usize) -> Option<(&[u8], &[Self])>

where Self: Sized,

Interprets the suffix of the given bytes as a &[Self] with length equal to count without copying.

fn mut_slice_from(bytes: &mut [u8]) -> Option<&mut [Self]>

where Self: Sized + AsBytes,

Interprets the given bytes as a &mut [Self] without copying.

fn mut_slice_from_prefix( bytes: &mut [u8], count: usize, ) -> Option<(&mut [Self], &mut [u8])>

where Self: Sized + AsBytes,

Interprets the prefix of the given bytes as a &mut [Self] with length equal to count without copying.

fn mut_slice_from_suffix( bytes: &mut [u8], count: usize, ) -> Option<(&mut [u8], &mut [Self])>

where Self: Sized + AsBytes,

Interprets the suffix of the given bytes as a &mut [Self] with length equal to count without copying.

fn read_from(bytes: &[u8]) -> Option<Self>

where Self: Sized,

Reads a copy of Self from bytes.

fn read_from_prefix(bytes: &[u8]) -> Option<Self>

where Self: Sized,

Reads a copy of Self from the prefix of bytes.

fn read_from_suffix(bytes: &[u8]) -> Option<Self>

where Self: Sized,

Reads a copy of Self from the suffix of bytes.

impl FromZeroes for SegmentHeader

where U64: FromZeroes, U16: FromZeroes, U32: FromZeroes, U128: FromZeroes,

fn zero(&mut self)

Overwrites self with zeroes.

fn new_zeroed() -> Self

where Self: Sized,

Creates an instance of Self from zeroed bytes.

fn new_box_zeroed() -> Box<Self>

where Self: Sized,

Creates a Box<Self> from zeroed bytes.

fn new_box_slice_zeroed(len: usize) -> Box<[Self]>

where Self: Sized,

Creates a Box<[Self]> (a boxed slice) from zeroed bytes.

fn new_vec_zeroed(len: usize) -> Vec<Self>

where Self: Sized,

Creates a Vec<Self> from zeroed bytes.

impl Copy for SegmentHeader