Struct Reader 

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

Zero-copy reader for a .nxb buffer; supports row, columnar, and PAX layouts.

When opened with Self::with_options, prefetch state is protected by internal mutexes so the reader remains Send + Sync.

Implementations

impl<'a> Reader<'a>

pub fn new(data: &'a [u8]) -> Result<Self>

Validate the file header, detect layout, and build the schema index.

pub fn with_options(data: &'a [u8], options: OpenOptions) -> Result<Self>

Open with prefetch options (row-layout viewport cache; phase 1+2).

pub fn warmup(&self)

Wait for in-progress eager / background prefetch (§8).

pub fn pause_prefetch(&self)

Stop scheduling speculative and eager prefetch (§8.1).

pub fn resume_prefetch(&self)

Resume speculative prefetch after Self::pause_prefetch.

pub fn prefetch_column(&self, key: &str) -> Result<()>

Prefetch a single column buffer (columnar layout only; §7.4).

pub fn prefetch_viewport( &self, start_index: usize, end_index: usize, ) -> Result<()>

Prefetch pages covering records [start_index, end_index] (row layout only).

pub fn cache_stats(&self) -> CacheStats

Page-cache statistics. Row prefetch counters are zero when opened via Self::new; columnar readers may still report CacheStats::column_fetches_issued.

pub fn layout(&self) -> Layout

Row, columnar, or PAX layout.

pub fn col_sum_f64(&self, key: &str) -> Option<f64>

Sum key as f64 across all records (uses column buffers when columnar/PAX).

pub fn col_buffer(&self, key: &str) -> Option<&[u8]>

Zero-copy slice of a column’s dense numeric value buffer (columnar only).

pub fn col_var_buffer(&self, key: &str) -> Result<VarColumnView<'_>>

Zero-copy string/binary column (offsets + values); columnar only.

pub fn col_field_var_parts(&self, slot: usize) -> Result<(&[u8], &[u8], &[u8])>

Variable-length column parts (null bitmap, u32 offsets, values) for columnar layout.

pub fn record_count(&self) -> usize

Number of top-level records in the file.

pub fn keys(&self) -> &[String]

Schema key names.

pub fn key_sigils(&self) -> &[u8]

Schema sigil bytes, parallel to keys().

pub fn slot(&self, key: &str) -> Option<usize>

Resolve a key name to its slot index. O(1) via HashMap.

pub fn record(&self, i: usize) -> Option<Record<'a, '_>>

Access a single record by zero-based index. O(1) via tail-index.

pub fn all(&'a self) -> Records<'a, 'a, AlwaysTrue>

Return an iterator over all records.

pub fn where_pred<P: Predicate>(&'a self, pred: P) -> Records<'a, 'a, P>

Return a lazy iterator over records matching pred.