@type t() :: %Indexed.Managed.State{
  index: Indexed.t() | nil,
  module: module(),
  repo: module(),
  tmp: tmp() | nil,
  tracking: tracking()
}

• :index - Indexed struct. Static after created via Indexed.warm/1.
• :module - Module which has use Indexed.Managed.
• :repo - Ecto Repo module to use for loading data.
• :tmp - Data structure used internally during a call to manage/5. Otherwise nil.
• :tracking - Data about how many :one refs there are to a certain entity.

@type tmp() :: %{
  done_ids: %{required(atom()) => %{required(phase()) => [id()]}},
  many_added: %{required(atom()) => %{required(id()) => [atom()]}},
  one_rm_queue: %{required(atom()) => %{required(id()) => {list(), record()}}},
  records: %{required(atom()) => %{required(id()) => record()}},
  rm_ids: %{
    required(atom()) => %{required(id()) => %{required(atom()) => [id()]}}
  },
  top_rm_ids: [id()],
  tracking: tracking()
}

Data structure used to hold temporary data while running manage/5.

• :done_ids - Entity name-keyed map with lists of record IDs which have been processed during the :add or :remove phases because another entity has :one of them. This allows us to skip processing it next time(s) if it appears elsewhere.
• :many_added - For each %{entity_name => id}, a list of :many assoc fields. A field is added here when processing it during the :add phase, and it's used to know whether to skip the field in drop_rm_ids.
• :one_rm_queue - When a :one association is handled in the :rm phase, a tuple is put here under the parent name and parent id containing the sub path and the record to remove. Removals will occur either immediately preceeding the same parent being processed during the :add phase OR during the finishing step. (But only if no other record has a :many relationship to it still.)
• :records - Records which may be committed to ETS at the end of the operation. Outer map is keyed by entity name. Inner map is keyed by id.
• :rm_ids - Record IDs queued for removal with respect to their parent. Outer map is keyed by entity name. Inner map is keyed by parent ID. Inner-most map is keyed by parent field containing the children.
• :top_rm_ids - Top-level record IDs queued for removal.
• :tracking - For record ids relevant to the operation, initial values are copied from State and manipulated as needed within this structure.

@type tracking() :: %{required(atom()) => tracking_status()}

A set of tracked entity statuses.

An entity is tracked if another entity refers to it with a :one relationship.

@type tracking_status() :: %{required(id()) => non_neg_integer()}

Map of tracked record IDs to occurrences throughout the records held. Used to manage subscriptions and garbage collection.