Enum Tier 

pub enum Tier {
    Short,
    Mid,
    Long,
}

Memory-lifecycle tier — short (6h TTL) / mid (7d TTL) / long (permanent). Drives the create-time backstop, the touch-time sliding window, the auto-promotion at 5 accesses (mid → long), the GC sweep, and the recall ranker’s per-tier bonus.

Disambiguation (issue #970)

The codebase has three enums whose names end in Tier. They are orthogonal — same descriptive substring, distinct domains:

• Tier (this enum) — memory-lifecycle TTL bucket.
• ConfidenceTier — confidence-value bucket (Confirmed / Likely / Ambiguous) derived from Memory.confidence thresholds. Operator dashboards / human-review queues filter on it.
• crate::config::FeatureTier — host capability tier (Keyword / Semantic / Smart / Autonomous) that gates which AI features the host can fit in RAM.

They do not share variants, do not share wire strings, and are never substitutable. See docs/internal/enum-proliferation-audit-970.md.

Variants

Short

Mid

Long

Implementations

impl Tier

pub fn as_str(&self) -> &'static str

pub fn from_str(s: &str) -> Option<Self>

Parse a tier wire string into the typed enum.

The string literals in the match arms below are the canonical deserializer for the Tier wire form. They are the one place in the codebase where raw "short" / "mid" / "long" literals legitimately appear, because this is the boundary where a caller-supplied &str (HTTP body field, MCP JSON param, CLI flag value, TOML config field) gets dispatched into the typed enum. They are intentionally byte-equal to Tier::as_str’s outputs so the round-trip is identity. Anywhere else that constructs a tier wire value MUST route through Tier::<X>.as_str() instead of restamping a fresh literal. See pm-v3.1 PR6 (#1174) for the sweep that pinned this invariant.

pub fn default_ttl_secs(&self) -> Option<i64>

Trait Implementations

impl Clone for Tier

fn clone(&self) -> Tier

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Tier

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Tier

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Tier

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

Formats the value using the given formatter.

impl PartialEq for Tier

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Tier

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Tier