RIPDPI: Skill for Claude Code

Compose Performance -- RIPDPI

1. Stability system

The Compose compiler decides at compile time whether each class is stable (safe to skip recomposition when equal) or unstable (must always recompose). Classes from non-Compose modules (protobuf, java.time, Room entities) are unstable by default unless declared in the stability config.

@Immutable -- all public properties never change after construction. Use for sealed-class hierarchies and pure value types (DiagnosticsUiModels, HistoryUiModels, theme tokens like Color, Spacing, Shape, Surface, Motion).

@Stable -- property reads return equal values between recompositions, or the runtime is notified on change. Use for state holders with callbacks or MutableState (SettingsUiModels: DesyncCoreUiState, ProxyNetworkUiState, etc.).

Project conventions

• ui/screens/diagnostics/state/DiagnosticsUiModels.kt -- 60+ annotations, @Immutable for data, @Stable for models with callbacks.
• ui/screens/settings/SettingsUiModels.kt -- @Stable on all section state holders.
• ui/screens/history/HistoryUiModels.kt -- @Immutable on all models (pure data).
• activities/MainViewModel.kt -- @Immutable on sealed states.
• ui/theme/ -- @Immutable on all token classes.

Rule: every new class passed to a @Composable MUST be annotated. Explicit annotation prevents regressions when a field type changes.

Stability configuration file

app/compose-stability.conf marks external types as stable:

• com.poyka.ripdpi.proto.*, com.google.protobuf.GeneratedMessageLite
• java.time.{Instant,Duration,LocalDate,LocalDateTime,ZonedDateTime,ZoneId}
• kotlin.time.Duration, kotlinx.collections.immutable.*
• com.poyka.ripdpi.data.{TcpChainStepModel,UdpChainStepModel,ActivationFilterModel,NumericRangeModel}

Add new non-Compose-module types here rather than wrapping in UI models.

2. Compiler metrics

Convention plugin ripdpi.android.compose.gradle.kts enables reports when CI=true or -Pripdpi.composeReports=true: