Class: Igniter::Store::ReadCache

Inherits:
Object
  • Object
show all
Includes:
MonitorMixin
Defined in:
lib/igniter/store/read_cache.rb

Constant Summary collapse

DEFAULT_LRU_CAP = 
1_000

Instance Method Summary collapse

Constructor Details

#initialize(lru_cap: DEFAULT_LRU_CAP) ⇒ ReadCache

Returns a new instance of ReadCache.



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# File 'lib/igniter/store/read_cache.rb', line 12

def initialize(lru_cap: DEFAULT_LRU_CAP)
  super()
  @entries         = {}
  @consumers       = Hash.new { |hash, key| hash[key] = [] }
  @scope_consumers = Hash.new { |hash, key| hash[key] = [] }
  @lru_cap         = lru_cap
  # Tracks insertion/access order for time-travel cache entries only.
  # Current-state entries (as_of: nil) live until explicit invalidation.
  # Ruby Hash preserves insertion order; delete+reinsert = move to MRU.
  @lru_order = {}
end

Instance Method Details

#get(store:, key:, as_of: nil, ttl: nil) ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 32

def get(store:, key:, as_of: nil, ttl: nil)
  cache_key = [store, key, as_of]
  entry = synchronize do
    e = @entries[cache_key]
    if e && as_of
      @lru_order.delete(cache_key)
      @lru_order[cache_key] = true
    end
    e
  end
  return nil unless entry

  if ttl
    age = Process.clock_gettime(Process::CLOCK_REALTIME) - entry.fetch(:cached_at)
    return nil if age > ttl
  end

  entry.fetch(:fact)
end

#get_scope(store:, scope:, as_of: nil, ttl: nil) ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 66

def get_scope(store:, scope:, as_of: nil, ttl: nil)
  cache_key = [:scope, store, scope, as_of]
  entry = synchronize do
    e = @entries[cache_key]
    if e && as_of
      @lru_order.delete(cache_key)
      @lru_order[cache_key] = true
    end
    e
  end
  return nil unless entry

  if ttl
    age = Process.clock_gettime(Process::CLOCK_REALTIME) - entry.fetch(:cached_at)
    return nil if age > ttl
  end

  entry.fetch(:facts)
end

#invalidate(store:, key: nil, scope_changes: {}) ⇒ Object

scope_changes is a Hash of { scope_name => :changed | :unchanged | :unknown } produced by IgniterStore#update_scope_indices. Scope consumers are only notified for scopes that are :changed or :unknown (conservative). Scopes marked :unchanged are skipped — their membership did not change and firing their consumers would be a false-positive thundering herd.



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# File 'lib/igniter/store/read_cache.rb', line 105

def invalidate(store:, key: nil, scope_changes: {})
  point_targets, scope_notifications = synchronize do
    affected_scopes = []
    @entries.delete_if do |cache_key, _entry|
      should_delete = if cache_key[0] == :scope && cache_key[1] == store
        affected_scopes << cache_key[2]
        true
      else
        cache_key[0] == store && (key.nil? || cache_key[1] == key)
      end
      @lru_order.delete(cache_key) if should_delete
      should_delete
    end

    notify_scopes = affected_scopes.uniq.reject do |scope|
      scope_changes[scope] == :unchanged
    end

    scope_notifs = notify_scopes.map do |scope|
      [scope, @scope_consumers[[store, scope]].dup]
    end

    [@consumers[store].dup, scope_notifs]
  end

  point_targets.each { |t| notify(t, store, key) }
  scope_notifications.each do |scope, targets|
    targets.each { |t| notify_scope(t, store, scope) }
  end
end

#lru_size ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 136

def lru_size
  synchronize { @lru_order.size }
end

#put(store:, key:, fact:, as_of: nil) ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 52

def put(store:, key:, fact:, as_of: nil)
  cache_key = [store, key, as_of]
  synchronize do
    @entries[cache_key] = {
      fact:      fact,
      cached_at: Process.clock_gettime(Process::CLOCK_REALTIME)
    }
    if as_of
      @lru_order[cache_key] = true
      evict_lru_if_needed
    end
  end
end

#put_scope(store:, scope:, facts:, as_of: nil) ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 86

def put_scope(store:, scope:, facts:, as_of: nil)
  cache_key = [:scope, store, scope, as_of]
  synchronize do
    @entries[cache_key] = {
      facts:     facts,
      cached_at: Process.clock_gettime(Process::CLOCK_REALTIME)
    }
    if as_of
      @lru_order[cache_key] = true
      evict_lru_if_needed
    end
  end
end

#register_consumer(store, callable) ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 24

def register_consumer(store, callable)
  synchronize { @consumers[store] << callable }
end

#register_scope_consumer(store, scope, callable) ⇒ Object 



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# File 'lib/igniter/store/read_cache.rb', line 28

def register_scope_consumer(store, scope, callable)
  synchronize { @scope_consumers[[store, scope]] << callable }
end