Struct TwoLevelIndex 

pub struct TwoLevelIndex {
    pub fence_pointers: Vec<FencePointer>,
    pub total_blocks: u32,
    pub block_index_offset: u64,
    pub block_index_length: u64,
}

Two-level index for efficient lookups with minimal memory usage

The top-level fence pointers are always in memory (~1KB per GB of data). Block index entries are loaded on-demand.

Fields

fence_pointers: Vec<FencePointer>

Top-level fence pointers (always in memory)

total_blocks: u32

Total number of blocks in the SSTable

block_index_offset: u64

Offset of the block index section in the file

block_index_length: u64

Length of the block index section

Implementations

impl TwoLevelIndex

pub fn build(blocks: &[BlockIndexEntry], block_index_offset: u64) -> Self

Create a new two-level index from block entries

This is called during SSTable creation to build the index structure.

pub fn find_fence_range(&self, key: &TemporalKey) -> (u64, u64)

Find the fence pointer range that may contain the target key

Returns (start_offset, end_offset) within the block index section.

pub fn find_fence_range_for_timestamps( &self, start_ts: u64, end_ts: u64, ) -> (u64, u64)

Find fence pointer range for a timestamp range query

Returns (start_offset, end_offset) within the block index section.

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

Serialize the fence pointers to bytes (stored in footer)

pub fn fence_pointers_from_bytes( bytes: &[u8], block_index_offset: u64, block_index_length: u64, ) -> Result<Self>

Deserialize fence pointers from bytes

pub fn memory_usage(&self) -> usize

Estimate memory usage of this index in bytes

pub fn fence_count(&self) -> usize

Get the number of fence pointers

Trait Implementations

impl Debug for TwoLevelIndex

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

Formats the value using the given formatter.