Class: Familia::Features::Housekeeping::EnforceCollectionCaps

Inherits:
Object
  • Object
show all
Defined in:
lib/familia/features/housekeeping/enforce_collection_caps.rb

Overview

A reusable, idempotent chore that trims every capped collection on an instance down to its :max_length via +enforce_max_length!+.

Adding max_length: to a live collection caps future writes but leaves any existing overage in place until the next write. Register this chore and run it (once, or nightly until clean) to trim the backlog. A collection already within its cap trims zero members, so the chore returns the removed count on the first pass and nil on every clean pass after -- the truthy-modified / nil-no-op convention run_chores! aggregates on.

The class itself responds to +call+, so it registers directly:

class Customer < Familia::Horreum feature :housekeeping

sorted_set :events,       max_length: 100
list       :activity_log, max_length: 50

chore :enforce_collection_caps, Familia::Features::Housekeeping::EnforceCollectionCaps

end

It is also a base class. Capped lists have per-end semantics the sweep cannot infer (push-fed lists keep the tail, unshift-fed ones the head), so subclass and override +keep_for+ when a list is unshift-fed; override +collection_names+ to scope the sweep:

class InboxCaps < Familia::Features::Housekeeping::EnforceCollectionCaps def keep_for(name) name == :inbox ? :head : :tail end end

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.call(obj) ⇒ Integer?

Entry point when the class itself is registered as the chore.

Parameters:

Returns:

  • (Integer, nil) —

    members removed, or nil when nothing trimmed



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# File 'lib/familia/features/housekeeping/enforce_collection_caps.rb', line 46

def self.call(obj)
  new.call(obj)
end

Instance Method Details

#call(obj) ⇒ Integer?

Returns members removed, or nil when nothing trimmed.

Parameters:

Returns:

  • (Integer, nil) —

    members removed, or nil when nothing trimmed



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# File 'lib/familia/features/housekeeping/enforce_collection_caps.rb', line 52

def call(obj)
  removed = capped_collections(obj).sum do |name, collection|
    enforce(name, collection)
  end
  removed if removed.positive?
end

#capped_collections(obj) ⇒ Object (protected)

The (name, collection) pairs the sweep trims: every candidate from +collection_names+ that carries a :max_length. Uncapped collections and non-capping types report a nil max_length and drop out here, so the sweep never trips enforce_max_length!'s uncapped guard.



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# File 'lib/familia/features/housekeeping/enforce_collection_caps.rb', line 65

def capped_collections(obj)
  collection_names(obj).filter_map do |name|
    collection = obj.send(name)
    [name, collection] if collection.max_length
  end
end

#collection_names(obj) ⇒ Object (protected)

Candidate collection names; override to scope the sweep.



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# File 'lib/familia/features/housekeeping/enforce_collection_caps.rb', line 73

def collection_names(obj)
  obj.class.related_fields.keys
end

#enforce(name, collection) ⇒ Object (protected) 



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# File 'lib/familia/features/housekeeping/enforce_collection_caps.rb', line 77

def enforce(name, collection)
  case collection
  when Familia::ListKey
    collection.enforce_max_length!(keep: keep_for(name))
  else
    collection.enforce_max_length!
  end
end

#keep_for(_name) ⇒ Object (protected)

Which end of a capped list survives; override per list name for unshift-fed lists. The default matches push-fed lists.



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# File 'lib/familia/features/housekeeping/enforce_collection_caps.rb', line 88

def keep_for(_name)
  :tail
end