Struct SegmentHeader 

#[repr(C)]
pub struct SegmentHeader {

    pub magic: [u8; 8],
    pub version: u32,
    pub flags: SegmentFlags,
    pub n_vec: u32,
    pub dim: u32,
    pub bps_block: u16,
    pub bps_proj: u16,
    pub rdf_t: u16,
    pub rdf_stripe_shift: u8,
    pub num_outliers: u8,
    pub off_bps: u64,
    pub off_i8: u64,
    pub off_scales: u64,
    pub off_outliers: u64,
    pub off_tombstone: u64,
    pub off_rdf_dir: u64,
    pub off_rdf_data: u64,
    pub off_dim_weights: u64,
    pub off_fp32: u64,
    pub off_bps_qparams: u64,
    pub file_len: u64,
    pub _reserved1: [u8; 128],
    pub _reserved2: [u8; 8],
}

Segment header - fixed size at file start

Fields

magic: [u8; 8]

Magic bytes: b“SVSEGM\0\0“

version: u32

Format version

flags: SegmentFlags

Feature flags

n_vec: u32

Number of vectors in segment

dim: u32

Vector dimension

bps_block: u16

BPS block size (e.g., 16)

bps_proj: u16

BPS projections per block (1 or 2)

rdf_t: u16

RDF top-t dimensions per vector

rdf_stripe_shift: u8

RDF stripe shift (log2 of stripe size)

num_outliers: u8

Number of outliers per vector

off_bps: u64

BPS SoA array

off_i8: u64

int8 embeddings (blocked SoA)

off_scales: u64

Quantization scales per block

off_outliers: u64

Outlier entries

off_tombstone: u64

Tombstone bitset

off_rdf_dir: u64

RDF posting list directory

off_rdf_data: u64

RDF posting list data

off_dim_weights: u64

Dimension weights for RDF

off_fp32: u64

Original fp32 vectors (optional, for verification)

off_bps_qparams: u64

BPS quantization parameters (min, inv_range per slot)

file_len: u64

Total file length

_reserved1: [u8; 128]

Padding for alignment (to 256 bytes total) 8 + 4 + 4 + 4 + 4 + 2 + 2 + 2 + 1 + 1 + (10 * 8) + 8 = 120, so we need 136 reserved

_reserved2: [u8; 8]

Implementations

impl SegmentHeader

pub const SIZE: usize

pub fn new(n_vec: u32, dim: u32) -> Self

Create a new header with magic and version

pub fn validate(&self) -> Result<()>

Validate header

pub fn num_bps_blocks(&self) -> u32

Number of BPS blocks

pub fn bps_size(&self) -> usize

Size of BPS data in bytes

pub fn i8_size(&self) -> usize

Size of int8 embedding data in bytes

pub fn stripe_size(&self) -> usize

Stripe size (number of vids per stripe)

Trait Implementations

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 Copy for SegmentHeader

impl Debug for SegmentHeader

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

Formats the value using the given formatter.

impl Pod for SegmentHeader

impl Zeroable for SegmentHeader

fn zeroed() -> Self

Calls zeroed.