Struct SlotRow 

pub struct SlotRow { /* private fields */ }

Slot-based row format with O(1) field access

Memory Layout

┌───────────────────────────────────────────────────────┐
│ Header (28 bytes)                                      │
│  row_id: u64           (8 bytes)                       │
│  null_bitmap: u16      (2 bytes)                       │
│  slot_count: u8        (1 byte)                        │
│  flags: u8             (1 byte)                        │
│  txn_start: u64        (8 bytes) MVCC                  │
│  txn_end: u64          (8 bytes) MVCC                  │
├───────────────────────────────────────────────────────┤
│ Slots: [offset: u16, len: u16] × slot_count           │
├───────────────────────────────────────────────────────┤
│ Data: contiguous column values                         │
└───────────────────────────────────────────────────────┘

Implementations

impl SlotRow

pub fn new(row_id: u64, slot_count: u8) -> Self

Create a new slot row with specified column count

pub fn from_values(row_id: u64, values: &[Option<&[u8]>]) -> Self

Create from raw values

pub fn row_id(&self) -> u64

Get row ID

pub fn column_count(&self) -> usize

Get column count

pub fn is_null(&self, column_idx: usize) -> bool

Check if column is NULL - O(1)

pub fn get_bytes(&self, column_idx: usize) -> Option<&[u8]>

Get column value as bytes - O(1)

This is the key performance advantage: direct offset arithmetic instead of HashMap lookup (~50ns → ~2ns)

pub fn get_i64(&self, column_idx: usize) -> Option<i64>

Get column as i64 - O(1)

pub fn get_u64(&self, column_idx: usize) -> Option<u64>

Get column as u64 - O(1)

pub fn get_f64(&self, column_idx: usize) -> Option<f64>

Get column as f64 - O(1)

pub fn get_bool(&self, column_idx: usize) -> Option<bool>

Get column as bool - O(1)

pub fn get_str(&self, column_idx: usize) -> Option<&str>

Get column as string - O(1)

pub fn set_mvcc(&mut self, txn_start: u64, txn_end: u64)

Set MVCC timestamps

pub fn txn_start(&self) -> u64

Get MVCC start timestamp

pub fn txn_end(&self) -> u64

Get MVCC end timestamp

pub fn is_visible_at(&self, snapshot_ts: u64) -> bool

Check if visible at snapshot

pub fn set_deleted(&mut self)

Set deleted flag

pub fn is_deleted(&self) -> bool

Check if deleted

pub fn memory_size(&self) -> usize

Get total memory size

pub fn to_bytes(&self) -> Vec<u8>

Serialize to bytes

pub fn from_bytes(data: &[u8]) -> Option<Self>

Deserialize from bytes

Trait Implementations

impl Debug for SlotRow

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

Formats the value using the given formatter.