Struct CheckpointIndex 

pub struct CheckpointIndex { /* private fields */ }

In-memory sparse index of checkpoint offsets.

This index is rebuilt on startup by scanning for checkpoint records. It provides O(log n) lookup for the nearest checkpoint.

Invariants

• Offsets are stored in ascending order
• Each offset corresponds to a valid checkpoint record in the log

Implementations

impl CheckpointIndex

pub fn new() -> Self

Creates an empty checkpoint index.

pub fn add(&mut self, offset: Offset)

Adds a checkpoint offset to the index.

Panics

Panics if the offset is not greater than the last offset (checkpoints must be added in order).

pub fn find_nearest(&self, offset: Offset) -> Option<Offset>

Finds the nearest checkpoint at or before the given offset.

Returns None if there are no checkpoints before the offset.

pub fn len(&self) -> usize

Returns the number of checkpoints in the index.

pub fn is_empty(&self) -> bool

Returns true if the index is empty.

pub fn last(&self) -> Option<Offset>

Returns the last checkpoint offset, if any.

pub fn iter(&self) -> impl Iterator<Item = &Offset>

Returns an iterator over checkpoint offsets.

Trait Implementations

impl Clone for CheckpointIndex

fn clone(&self) -> CheckpointIndex

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CheckpointIndex

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

Formats the value using the given formatter.

impl Default for CheckpointIndex

fn default() -> CheckpointIndex

Returns the “default value” for a type.