Skuld.Effects.EffectLogger.EnvStateSnapshot (skuld v0.1.15)

A serializable snapshot of env.state for cold resume.

The env.state map uses tuple keys like {Module, key} which aren't JSON-serializable. This struct captures a snapshot with string keys for serialization, and can restore the original format on deserialization.

Key Format

Tuple keys {Elixir.Module, :key} are encoded as "Elixir.Module::key".

Filtering

EffectLogger's internal state keys are filtered out when capturing:

Log state key: would create circular reference (log contains snapshot)
Resume value key: only needed during active resume, not for persistence
State keys filter: internal config that doesn't survive JSON round-trip

Example

env_state = %{
  {Skuld.Effects.State, Skuld.Effects.State} => 42,
  {Skuld.Effects.EffectLogger, :log} => %Log{...}
}

snapshot = EnvStateSnapshot.capture(env_state)
# => %EnvStateSnapshot{entries: %{"Elixir.Skuld.Effects.State::Elixir.Skuld.Effects.State" => 42}}

restored = EnvStateSnapshot.restore(snapshot)
# => %{{Skuld.Effects.State, Skuld.Effects.State} => 42}

Summary

Types

t()

Functions

capture(env_state, opts \\ [])

Capture a snapshot of env.state for serialization.

from_json(map)

Reconstruct from decoded JSON map.

restore(env_state_snapshot)

Restore env.state from a snapshot.

Types

t()

@type t() :: %Skuld.Effects.EffectLogger.EnvStateSnapshot{
  entries: %{required(String.t()) => term()}
}

Functions

capture(env_state, opts \\ [])

@spec capture(
  map(),
  keyword()
) :: t()

Capture a snapshot of env.state for serialization.

Filters out EffectLogger's internal state and converts tuple keys to strings.

Options

:state_keys - List of state keys to include. Default :all captures everything. Keys should be in the format {Module, tag} as used in env.state.

Examples

# Capture all state
EnvStateSnapshot.capture(env_state)

# Capture only specific State effect keys
EnvStateSnapshot.capture(env_state, state_keys: [
  {Skuld.Effects.State, MyApp.Counter}
])

from_json(map)

@spec from_json(map()) :: t()

Reconstruct from decoded JSON map.

restore(env_state_snapshot)

@spec restore(t()) :: map()

Restore env.state from a snapshot.

Converts string keys back to tuple format.