https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/Recent content in Snapshots and observable state on Staticvar LearnHugo -- gohugo.ioen-ushttps://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/01-a-state-object-is-a-record-chain/Mon, 01 Jan 0001 00:00:00 +0000https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/01-a-state-object-is-a-record-chain/Status: A state object owning versioned records is Durable . The linked-list fields, snapshot-ID algorithm, and record-reuse helpers are Version-specific at the pinned revision. Outcome Given a MutableState, you should be able to explain why the same object can return different values in different snapshots without copying every object it references. The object owns versions, not a copied object graph StateObject is the snapshot module’s interface for an object with state records.https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/02-snapshots-isolate-values/Mon, 01 Jan 0001 00:00:00 +0000https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/02-snapshots-isolate-values/Status: A snapshot is an isolated view of snapshot-aware state, not a lock or a copied application graph. That model is Durable . The GlobalSnapshot, MutableSnapshot, and nested-snapshot classes are Version-specific at the pinned revision. Outcome Given a state write inside a snapshot, you should be able to say who can see it now, who can see it after a child apply, and who can see it after the parent applies.https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/03-apply-is-a-commit-attempt/Mon, 01 Jan 0001 00:00:00 +0000https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/03-apply-is-a-commit-attempt/Status: Apply is a visibility and conflict boundary, not a recomposition command. That separation is Durable . The previous/current/applied comparison and SnapshotApplyResult classes are Version-specific at the pinned revision. Outcome Given two mutable snapshots that write the same state object, you should be able to predict whether the second apply succeeds, fails, or asks a mutation policy to merge values. Apply closes an isolation interval A mutable snapshot accumulates modified StateObjects.https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/04-mutation-policies-decide-equivalence/Mon, 01 Jan 0001 00:00:00 +0000https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/04-mutation-policies-decide-equivalence/Status: A mutation policy defines the state layer’s notion of equivalence and optional conflict merge. That role is Durable . The stock implementations and exact merge path are Version-specific at the pinned revision. Outcome Given two assignments or two competing snapshot writes, you should be able to predict when a policy treats them as equivalent and when it permits a merge. Equivalence is a state decision SnapshotMutationPolicy<T> has two operations.https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/05-reads-become-observation-edges/Mon, 01 Jan 0001 00:00:00 +0000https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/05-reads-become-observation-edges/Status: Turning a read into an observation edge is Durable . The composition maps, reader flags, apply queue, and executor behavior are Version-specific at the pinned revision. Outcome After a state read, you should be able to identify the recorded edge and distinguish it from the later work that a scheduler may perform. A read has an owner SnapshotMutableState documents the central boundary: reading value during a composable subscribes the current RecomposeScope to that value, while writes are transacted through snapshots (SnapshotMutableState.https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/06-derived-state-tracks-dependencies-and-values/Mon, 01 Jan 0001 00:00:00 +0000https://learn.staticvar.dev/courses/jetpack-compose-internals/05-snapshots-and-observable-state/06-derived-state-tracks-dependencies-and-values/Status: Derived state as cached state plus dependency tracking is Durable . ResultRecord, nested read levels, readable hashes, and observer maps are Version-specific at the pinned revision. Outcome Given a derivedStateOf calculation, you should be able to explain what is cached, which state objects are dependencies, and why an unchanged derived result can avoid a downstream observation change. It is a state object with a calculation record derivedStateOf { .