Struct Level0Root 

#[repr(C)]
pub struct Level0Root {

    pub magic: u32,
    pub version: u16,
    pub flags: u16,
    pub l1_manifest_offset: u64,
    pub l1_manifest_length: u64,
    pub total_vector_count: u64,
    pub dimension: u16,
    pub base_dtype: u8,
    pub profile_id: u8,
    pub epoch: u32,
    pub created_ns: u64,
    pub modified_ns: u64,
    pub entrypoint: EntrypointPtr,
    pub toplayer: TopLayerPtr,
    pub centroid: CentroidPtr,
    pub quantdict: QuantDictPtr,
    pub hot_cache: HotCachePtr,
    pub prefetch_map: PrefetchMapPtr,
    pub sig_algo: u16,
    pub sig_length: u16,
    pub signature_buf: [u8; 3684],
    pub reserved: [u8; 252],
    pub root_checksum: u32,
}

The Level 0 root manifest (exactly 4096 bytes).

Always located at the last 4096 bytes of the most recent MANIFEST_SEG. Its fixed size enables instant boot: seek(EOF - 4096).

Binary layout

Offset	Size	Field
0x000	4	magic (0x52564D30 “RVM0”)
0x004	2	version
0x006	2	flags
0x008	8	l1_manifest_offset
0x010	8	l1_manifest_length
0x018	8	total_vector_count
0x020	2	dimension
0x022	1	base_dtype
0x023	1	profile_id
0x024	4	epoch
0x028	8	created_ns
0x030	8	modified_ns
0x038	16	entrypoint_ptr
0x048	16	toplayer_ptr
0x058	16	centroid_ptr
0x068	16	quantdict_ptr
0x078	16	hot_cache_ptr
0x088	16	prefetch_map_ptr (includes 4B padding)
0x098	2	sig_algo
0x09A	2	sig_length
0x09C	3684	signature_buf
0xF00	252	reserved
0xFFC	4	root_checksum

Fields

magic: u32

Magic number: must be 0x52564D30 (“RVM0”).

version: u16

Root manifest version.

flags: u16

Root manifest flags.

l1_manifest_offset: u64

Byte offset to the Level 1 manifest segment.

l1_manifest_length: u64

Byte length of the Level 1 manifest segment.

total_vector_count: u64

Total vectors across all segments.

dimension: u16

Vector dimensionality.

base_dtype: u8

Base data type enum (see DataType).

profile_id: u8

Domain profile id.

epoch: u32

Current overlay epoch number.

created_ns: u64

File creation timestamp (nanoseconds).

modified_ns: u64

Last modification timestamp (nanoseconds).

entrypoint: EntrypointPtr

HNSW entry points.

toplayer: TopLayerPtr

Top-layer adjacency.

centroid: CentroidPtr

Cluster centroids / pivots.

quantdict: QuantDictPtr

Quantization dictionary.

hot_cache: HotCachePtr

Hot vector cache (HOT_SEG).

prefetch_map: PrefetchMapPtr

Prefetch hint table.

sig_algo: u16

Manifest signature algorithm.

sig_length: u16

Signature byte length.

signature_buf: [u8; 3684]

Signature bytes (up to 3688 bytes; only first sig_length are meaningful).

reserved: [u8; 252]

Reserved / zero-padded area.

root_checksum: u32

CRC32C of bytes 0x000 through 0xFFB.

Implementations

impl Level0Root

pub const SIG_BUF_SIZE: usize = 3684

Size of the signature buffer within the root manifest. From offset 0x09C to 0xEFF inclusive = 3684 bytes.

pub const fn zeroed() -> Self

Create a zeroed root manifest with only the magic set.

pub const fn is_valid_magic(&self) -> bool

Check whether the magic field matches the expected value.

Trait Implementations

impl Clone for Level0Root

fn clone(&self) -> Level0Root

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Level0Root

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

Formats the value using the given formatter.

impl Copy for Level0Root