Enum BlockType 

pub enum BlockType {
    Data,
    Index,
    Filter,
    Meta,
    RangeTombstone,
    Manifest,
    ManifestFooter,
    BlockLayout,
    Locator,
    SeqnoBounds,
    ZoneMap,
    Columnar,
    DeleteBitmap,
}

The mutually-exclusive ROLE of a block within a table file.

BlockType answers “what is this block and which parser decodes its logical structure” — not “how was its payload post-processed”. Orthogonal, composable transform layers (compression, encryption, Reed-Solomon ECC, per-KV checksum footer) are NOT roles: they stack on top of a block of any role and are recorded in the block header’s block_flags bitfield, not here. A compressed, encrypted, per-KV-checked data block is still BlockType::Data with three transform bits set.

Variants

Data

User key/value entries (the SST data payload).

Index

Block handles (offset/size/key/seqno) pointing at data blocks.

Filter

Bloom / Ribbon filter bit arrays.

Meta

Sorted key/value table properties (the SST metadata section).

RangeTombstone

Range tombstone entries, written as a separate block.

Manifest

One section of the Blocks-based manifest (e.g. tables, blob_files, format_version). Payload is the raw section bytes that the manifest writer puts there. All Block-level protections (XXH3, optional ECC, optional AEAD) apply, so the section gains bit-rot defence + (optional) encryption / recovery automatically.

ManifestFooter

Footer Block of the Blocks-based manifest. Payload carries manifest_layout_version, flags, section count, and the table of contents (TOC) for the surrounding Manifest section Blocks. Written last (primary read target) and mirrored at file offset 0 in a 4 KiB padded region for partial-write recovery.

BlockLayout

Optional per-table index of inner zstd-block layouts: for each data block that compressed into >= 2 inner zstd blocks, its file offset and the cumulative decompressed END offsets of those inner blocks. Lets a range query partial-decode only the inner blocks covering a key range. Absent unless the table has at least one such multi-inner-block block.

Locator

Optional per-table retrieval-ribbon locator section: maps each key to a packed (block_id, slot) for O(1) point reads. Present by default (block precision); absent when the level’s locator policy is disabled or the per-SST ribbon could not be built.

SeqnoBounds

Optional per-table seqno-bounds section: maps each data block’s file offset to its [seqno_min, seqno_max], powering the scan_since_seqno block-skip without bloating the index entries. Absent unless seqno_in_index is on.

ZoneMap

Optional per-table zone-map section: maps each data block’s file offset to per-column (min, max, null_count, row_count) statistics, letting a range / analytical scan skip a block whose stats prove no predicate match without decoding it. Kept parallel to the index (like Self::SeqnoBounds) so point reads never load it. Off by default; absent unless the zone-map policy is enabled.

Columnar

A PAX / rowgroup columnar block: a row-group laid out as per-column chunks rather than row-major key/value entries. Each chunk is a typed, codec-tagged opaque byte array plus a validity bitmap. Produced by the transpose on flush / major-compaction for a columnar tree / CF and read as a ColumnBatch. The wire tag is reserved unconditionally; the codec framework that fills these blocks is built only with the columnar feature.

DeleteBitmap

Optional per-table positional delete-bitmap section: marks, by row position, which rows of the table’s columnar segment are deleted. A pure membership set (MVCC reconciled at materialization via the compaction watermark), applied as a mask at scan time. Kept parallel to the data (like Self::ZoneMap) so a read without deletes pays nothing. Absent unless the segment has materialized deletes.

Trait Implementations

impl Clone for BlockType

fn clone(&self) -> BlockType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BlockType

impl Debug for BlockType

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

Formats the value using the given formatter.

impl Eq for BlockType

impl From<BlockType> for u8

fn from(val: BlockType) -> Self

Converts to this type from the input type.

impl PartialEq for BlockType

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for BlockType

impl TryFrom<u8> for BlockType

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: u8) -> Result<Self, Self::Error>

Performs the conversion.