Struct StreamGcOutcome 

pub struct StreamGcOutcome {
    pub dry_run: bool,
    pub live_base_snapshot_keys: Vec<String>,
    pub collected_snapshots: Vec<String>,
    pub collected_frame_objects: Vec<String>,
    pub collected_bytes: u64,
    pub retained_snapshots: usize,
    pub base_snapshots_skipped: bool,
    pub retained_frame_objects: usize,
    pub spared_by_grace: usize,
}

What a gc_stream pass found — and, when dry_run was false, deleted.

The collected keys are listed rather than counted because the primary consumer is a human reading a dry run before authorizing the real one.

Fields

dry_run: bool

Echo of StreamGcConfig::dry_run. true means nothing was deleted and collected_* is a proposal.

live_base_snapshot_keys: Vec<String>

Every snapshot key a restore could still reach, sorted. See gc_stream’s “Liveness” section for how this is derived.

collected_snapshots: Vec<String>

Superseded base snapshots, sorted.

collected_frame_objects: Vec<String>

Orphaned frame objects (batch or legacy per-frame), sorted.

collected_bytes: u64

Total bytes across collected_snapshots + collected_frame_objects.

retained_snapshots: usize

Snapshot objects kept — because they are live, or because the whole snapshot half was skipped (see base_snapshots_skipped).

base_snapshots_skipped: bool

true when the prefix held no generation manifests, so this is not provably a tier-2 sink and no base snapshot was collected.

A snapshots/ prefix with no chain over it is indistinguishable from a plain tier-1a sink, whose older snapshots are history rather than garbage — crate::snapshot::restore_latest takes the newest, but an operator restoring a point in time names an older key by hand. Pruning those is crate::dedup::gc_dedup’s keep_n decision to make, not this sweep’s. A live tier-2 sink always has a chain, so in the steady state this is false and the superseded bases are collected; the one way to see it true on a real stream is a GC that lands inside crate::tail::rebase’s manifests-deleted-frames-not-yet-written window, where skipping one pass costs nothing.

retained_frame_objects: usize

Frame objects kept because a generation manifest still names them.

spared_by_grace: usize

Objects that were unreachable but too young to touch — the grace window did its job. A number that never falls to zero across consecutive runs means the grace is longer than the churn interval, not that the sweep is broken.

Trait Implementations

impl Clone for StreamGcOutcome

fn clone(&self) -> StreamGcOutcome

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StreamGcOutcome

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

Formats the value using the given formatter.

impl Default for StreamGcOutcome

fn default() -> StreamGcOutcome

Returns the “default value” for a type.

impl Eq for StreamGcOutcome

impl PartialEq for StreamGcOutcome

fn eq(&self, other: &StreamGcOutcome) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for StreamGcOutcome