Struct TreeStats 

pub struct TreeStats {

    pub blob_count: u32,
    pub total_space_used: u64,
    pub total_gap_space: u64,
    pub total_slots: u64,
    pub total_compactions: u64,
    pub total_tombstones: u64,
    pub total_blob_edges: u64,
    pub leaf_blob_count: u32,
    pub max_blob_depth: u32,
    pub total_blob_depth: u64,
    pub max_blob_fill_per_mille: u32,
    pub blobs: Vec<BlobStats>,
    pub bm_dirty_count: usize,
    pub bm_pending_delete_count: usize,
    pub bm_cache_hits: u64,
    pub bm_cache_misses: u64,
    pub bm_optimistic_restarts: u64,
    pub bm_range_restarts: u64,
    pub bm_walker_ops: u64,
    pub bm_walker_blob_hops: u64,
    pub bm_max_blob_hops: u64,
    pub bm_max_cross_blob_depth: u64,
    pub bm_spillovers: u64,
    pub bm_merges: u64,
    pub route_cache: RouteCacheStats,
    pub journal: Option<JournalStats>,
    pub checkpointer: Option<CheckpointerStats>,
}

Tree-wide aggregate counters from Tree::stats.

blobs carries the per-blob breakdown in BFS order from the root; the totals are pre-summed for the common “how big is the tree?” question. All bytes / counts are sums over blobs.

Fields

blob_count: u32

Number of distinct blobs reachable from the tree root.

total_space_used: u64

Sum of space_used over every blob.

total_gap_space: u64

Sum of gap_space over every blob.

total_slots: u64

Sum of num_slots over every blob.

total_compactions: u64

Sum of compact_times over every blob (lifetime compactions across the whole tree).

total_tombstones: u64

Sum of tombstone_leaf_cnt over every blob.

total_blob_edges: u64

Sum of num_ext_blobs over every blob. In a tree-shaped blob graph this is the number of cross-blob edges.

leaf_blob_count: u32

Number of reachable blobs with no installed BlobNode children.

max_blob_depth: u32

Maximum cross-blob depth from the root blob. Root-only trees report 0.

total_blob_depth: u64

Sum of per-blob depths, used to derive Self::avg_blob_depth.

max_blob_fill_per_mille: u32

Highest data-area occupancy among reachable blobs, in per-mille units (1000 = full data area).

blobs: Vec<BlobStats>

Per-blob breakdown in BFS order from the root.

bm_dirty_count: usize

Number of blobs currently dirty in the BufferManager — modified in cache but not yet flushed to store. With the background checkpointer enabled this stays bounded by the checkpoint cadence; without it, it tracks the user’s explicit Tree::checkpoint schedule.

bm_pending_delete_count: usize

Number of blobs queued for deferred store deletion — children unlinked by an erase walker’s SubtreeGone path or by a merge pass, waiting for the next checkpoint round (or Tree::checkpoint) to issue the actual store.delete_blob + manifest re-sync.

bm_cache_hits: u64

Cumulative cache lookups served from BM cache without going to the inner store. Read by external observers to derive a hit rate (bm_cache_hits / (bm_cache_hits + bm_cache_misses)); higher is better.

bm_cache_misses: u64

Cumulative cache lookups that fell through to inner_store.read_blob because the entry was absent or evicted. Tracks cold-start + eviction churn.

bm_optimistic_restarts: u64

Cumulative wait-free read restarts in Tree::get — each one means a concurrent writer lapped an optimistic snapshot and the lookup walked the tree from scratch. Spikes here indicate writer/reader contention.

bm_range_restarts: u64

Cumulative range-iterator cursor restarts. Each one means a range/list cursor detected a rewritten blob on its descent path and rebuilt from its monotonic lower bound.

bm_walker_ops: u64

Cumulative mutation walker invocations (insert_multi / erase_multi). rename and atomic count their inner walker calls separately.

bm_walker_blob_hops: u64

Total blob hops across mutation walker invocations. Divide by Self::bm_walker_ops for the average.

bm_max_blob_hops: u64

Maximum blob hops observed for one mutation walker call.

bm_max_cross_blob_depth: u64

Largest key-depth at which a mutation walker entered a blob. This is a cross-blob boundary-depth signal, not a full per-node ART-depth trace.

bm_spillovers: u64

Successful foreground spillover events.

bm_merges: u64

BlobNode children folded back into parents by manual compact or background merge passes.

route_cache: RouteCacheStats

Root route-cache counters for large path-shaped trees.

journal: Option<JournalStats>

WAL/journal worker counters, or None for memory trees and caller-supplied stores opened without holt’s WAL.

checkpointer: Option<CheckpointerStats>

Background checkpointer telemetry, or None if the bg thread group isn’t running (the default; opt in via crate::CheckpointConfig::enabled).

Implementations

impl TreeStats

pub fn bm_avg_blob_hops(&self) -> f64

Average blob hops per mutation walker invocation.

pub fn avg_blob_depth(&self) -> f64

Average cross-blob graph depth across reachable blobs.

pub fn leaf_blob_ratio(&self) -> f64

Fraction of reachable blobs that are leaves in the blob graph.

pub fn avg_blob_fill_ratio(&self) -> f64

Average data-area occupancy across reachable blobs.

pub fn max_blob_fill_ratio(&self) -> f64

Maximum data-area occupancy among reachable blobs.

Trait Implementations

impl Clone for TreeStats

fn clone(&self) -> TreeStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TreeStats

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

Formats the value using the given formatter.