Enum SegmentRole 

#[repr(u8)]
pub enum SegmentRole {
    Core = 0,
    Extension = 1,
    Journal = 2,
    Index = 3,
    Cache = 4,
    Audit = 5,
    Shard = 6,
    Unclassified = 7,
}

Segment role classification.

Encoded as a 4-bit value (0-15). Currently 8 roles defined.

Variants

Core = 0

Primary fixed-layout state. Must be preserved across migrations.

Extension = 1

Optional extension fields added in later versions.

Journal = 2

Append-only audit trail (Journal<T>). Can be cleared on migration.

Index = 3

Lookup index (SortedVec, SlotMap). Rebuildable from core data.

Cache = 4

Derived/computed cache. Safe to drop and rebuild.

Audit = 5

Immutable audit log. Locked after initialization.

Shard = 6

Part of a sharded collection. May be redistributed on rebalance.

Unclassified = 7

Unclassified segment (legacy compatibility).

Implementations

impl SegmentRole

pub const fn from_flags(flags: u16) -> Self

Decode role from segment flags (upper 4 bits).

pub const fn into_flags(self, existing_flags: u16) -> u16

Encode role into segment flags (preserving lower 12 bits).

pub const fn must_preserve(&self) -> bool

Whether this segment must be preserved during migration.

pub const fn clearable_on_migration(&self) -> bool

Whether this segment can safely be cleared on migration.

pub const fn rebuildable(&self) -> bool

Whether this segment can be rebuilt from other data.

pub const fn is_append_only(&self) -> bool

Whether this segment should be append-only at runtime.

pub const fn is_immutable_after_init(&self) -> bool

Whether writes to this segment should be rejected after init.

pub const fn requires_migration_copy(&self) -> bool

Whether this segment’s data must be copied during migration.

Core and Audit segments contain irreplaceable state that cannot be rebuilt or cleared, their bytes must survive migration intact.

pub const fn is_safe_to_drop(&self) -> bool

Whether this segment can be safely dropped (zeroed) without data loss.

Cache segments hold derived/computed values that can be rebuilt from other on-chain state. Dropping them is always safe.

pub const fn should_emit_receipt(&self) -> bool

Whether mutations to this segment should generate a receipt entry.

Core, Extension, and Shard mutations are always receipt-worthy. Journal and Audit appends are also receipt-worthy. Cache and Index rebuilds typically are not.

pub const fn is_operator_relevant(&self) -> bool

Whether this segment is relevant to operator dashboards and Manager output.

Core, Audit, and Journal segments carry meaningful business state. Cache and Index are derived and typically hidden from operators.

pub const fn may_hold_financial_state(&self) -> bool

Whether this segment potentially holds financial state.

Core and Extension segments may contain balance/treasury fields. Other segments (Journal, Cache, Index) typically hold derived data.

pub const fn name(&self) -> &'static str

Human-readable role name (for schema export and tooling).

Trait Implementations

impl Clone for SegmentRole

fn clone(&self) -> SegmentRole

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SegmentRole

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

Formats the value using the given formatter.

impl PartialEq for SegmentRole

fn eq(&self, other: &SegmentRole) -> 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 Copy for SegmentRole

impl Eq for SegmentRole

impl StructuralPartialEq for SegmentRole