Struct SegmentReader 

pub struct SegmentReader<'a> { /* private fields */ }

Read-side handle. Borrows the segment bytes (the catalog or test owns the buffer), parses header + bloom + page index up front, and exposes lookup(key) / scan_keys() over the rest.

For an in-RAM cold-tier segment that the catalog holds across many lookups, prefer OwnedSegment — it owns its bytes and reuses the same parsed metadata across calls without any lifetime gymnastics.

Implementations

impl<'a> SegmentReader<'a>

pub fn open(bytes: &'a [u8]) -> Result<Self, SegmentError>

Parse a segment from a contiguous byte slice. Validates magic, CRC32 footer, and structural lengths. v6.6.2: a v2-magic envelope is rejected by the borrowed-slice reader because decompression would need to allocate a fresh Vec — callers with a v2 file must go through OwnedSegment::from_bytes which can own the decompressed bytes.

pub fn meta(&self) -> &SegmentMeta

pub fn codec_version(&self) -> u8

v7.23/v7.27 — the codec version implied by this segment’s inner magic (0 legacy / 46 / 47). Callers thread this into decode_row_body_dense.

pub fn might_contain(&self, key: u64) -> bool

Bloom-only check — false means the key is definitely not in this segment (no false negatives); true means it might be (false-positive rate per the embedded bloom’s target).

pub fn lookup(&self, key: u64) -> Option<Vec<u8>>

Look up key. Returns Some(payload) if found, None if the bloom rejects or the page-internal search misses. Always reads at most one page worth of bytes (4 KiB by default), which is the I/O budget the v5.1 catalog integration relies on.

pub fn scan(&self) -> impl Iterator<Item = (u64, Vec<u8>)> + '_

Iterate all (key, payload) pairs in sorted order. Used by scan-shaped queries and by compaction.

Trait Implementations

impl<'a> Debug for SegmentReader<'a>

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

Formats the value using the given formatter.