Class: ReactOnRailsPro::Cache

Inherits:
Object
  • Object
show all
Defined in:
lib/react_on_rails_pro/cache.rb,
lib/react_on_rails_pro/cache/tag_index.rb,
lib/react_on_rails_pro/cache/revalidates.rb

Defined Under Namespace

Modules: Revalidates Classes: TagIndex

Constant Summary collapse

ACTIVE_SUPPORT_EXPIRES_AT_VERSION = 
Gem::Version.new("7.0.0")
EXPIRED_CACHE_WRITE_TTL =

seconds; minimum positive TTL for race-expired writes

1

Class Method Summary collapse

Class Method Details

.base_cache_key(type, prerender: nil) ⇒ Object

Cache keys by React on Rails Pro should build upon this base Provide prerender: true in order to include bundle hash in the list of keys. The bundle hash is necessary so that any changes to the bundle fault the cache.



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# File 'lib/react_on_rails_pro/cache.rb', line 181

def base_cache_key(type, prerender: nil)
  keys = [
    type,
    ReactOnRails::VERSION,
    ReactOnRailsPro::VERSION
  ]

  # TODO: Move comment over to test
  # We only care about the bundle hash if prerendering because we're not caching anything
  # that would be generated by the bundle.
  keys.push(ReactOnRailsPro::Utils.bundle_hash) if prerender
  keys
end

.cache_supports_expires_at? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/react_on_rails_pro/cache.rb', line 108

def cache_supports_expires_at?
  ActiveSupport.gem_version >= ACTIVE_SUPPORT_EXPIRES_AT_VERSION
end

.cache_write_expired?(cache_options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/react_on_rails_pro/cache.rb', line 99

def cache_write_expired?(cache_options)
  return false unless cache_options&.key?(:expires_at)

  expires_at = cache_options[:expires_at]
  return false if expires_at && unsupported_expires_at_with_explicit_expires_in?(cache_options)

  expires_at && expires_at.to_time.to_f <= Time.now.to_f
end

.cache_write_options(cache_options) ⇒ Object 



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# File 'lib/react_on_rails_pro/cache.rb', line 81

def cache_write_options(cache_options)
  return cache_options unless cache_options&.key?(:expires_at)

  expires_at = cache_options[:expires_at]
  return cache_options unless expires_at

  return cache_options.except(:expires_at) if unsupported_expires_at_with_explicit_expires_in?(cache_options)

  expires_in = expires_at.to_time.to_f - Time.now.to_f
  return cache_options.merge(expires_in: EXPIRED_CACHE_WRITE_TTL).except(:expires_at) if expires_in <= 0

  return supported_expires_at_write_options(cache_options) if cache_supports_expires_at?

  return cache_options.except(:expires_at) unless cache_options[:expires_in].nil?

  cache_options.merge(expires_in:).except(:expires_at)
end

.dependencies_cache_key ⇒ Object 



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# File 'lib/react_on_rails_pro/cache.rb', line 195

def dependencies_cache_key
  # https://github.com/shakacode/react_on_rails_pro/issues/32
  # https://github.com/shakacode/react_on_rails/issues/39#issuecomment-143472325
  return @dependency_checksum if @dependency_checksum.present? && !Rails.env.development?
  return nil unless ReactOnRailsPro.configuration.dependency_globs.present?

  @dependency_checksum =
    ReactOnRailsPro::Utils.digest_of_globs(
      ReactOnRailsPro.configuration.dependency_globs
    ).hexdigest
end

.fetch_react_component(component_name, options) ⇒ Object

options can include :compress, :expires_in, :race_condition_ttl and other options



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# File 'lib/react_on_rails_pro/cache.rb', line 27

def fetch_react_component(component_name, options)
  if use_cache?(options)
    cache_key = react_component_cache_key(component_name, options)
    Rails.logger.debug { "React on Rails Pro cache_key is #{cache_key.inspect}" }
    cache_options = cache_write_options(options[:cache_options])
    if cache_write_expired?(options[:cache_options])
      result = yield
      if result.is_a?(Hash)
        result[:RORP_CACHE_KEY] = cache_key
        result[:RORP_CACHE_HIT] = false
      end
      return result
    end

    cache_hit = true
    normalized_cache_tags = []
    result = Rails.cache.fetch(cache_key, cache_options) do
      cache_hit = false
      normalized_cache_tags = normalize_tags(options[:cache_tags])
      yield
    end
    register_normalized_tags(normalized_cache_tags, cache_key, cache_options) unless cache_hit
    # Pass back the cache key in the results only if the result is a Hash
    if result.is_a?(Hash)
      result[:RORP_CACHE_KEY] = cache_key
      result[:RORP_CACHE_HIT] = cache_hit
    end
    result
  else
    yield
  end
end

.normalize_tags(tags) ⇒ Object 



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# File 'lib/react_on_rails_pro/cache.rb', line 75

def normalize_tags(tags)
  return [] if tags.nil? || (tags.is_a?(Array) && tags.empty?)

  TagIndex.normalize_tags(tags)
end

.react_component_cache_key(component_name, options) ⇒ Object 



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# File 'lib/react_on_rails_pro/cache.rb', line 207

def react_component_cache_key(component_name, options)
  cache_key_option = options[:cache_key]
  cache_key_value = if cache_key_option.respond_to?(:call)
                      cache_key_option.call
                    else
                      cache_key_option
                    end

  # NOTE: Rails seems to do this automatically: ActiveSupport::Cache.expand_cache_key(keys)
  [
    *base_cache_key("ror_component", prerender: options[:prerender]),
    dependencies_cache_key,
    component_name,
    cache_key_value
  ].compact
end

.register_normalized_tags(normalized_tags, cache_key, cache_options) ⇒ Object 



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# File 'lib/react_on_rails_pro/cache.rb', line 69

def register_normalized_tags(normalized_tags, cache_key, cache_options)
  return if normalized_tags.blank?

  TagIndex.register_normalized(normalized_tags, cache_key, cache_options || {})
end

.register_tags(tags, cache_key, cache_options) ⇒ Object

Registers cache tags for an already-written cache entry so a later ReactOnRailsPro.revalidate_tag can delete it. Call after a successful cache write (never on a cache hit). No-op when tags are nil or []. See ReactOnRailsPro::Cache::TagIndex for the v1 index semantics (best-effort, lossy-OK; correctness bounded by :expires_in).



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# File 'lib/react_on_rails_pro/cache.rb', line 65

def register_tags(tags, cache_key, cache_options)
  register_normalized_tags(normalize_tags(tags), cache_key, cache_options)
end

.revalidate_tags(*tags) ⇒ Object

Deletes every cached component entry registered under the given tags and clears the tag index entries. Tags accept the same forms as the ‘cache_tags:` helper option. Blank tags (nil/empty/whitespace) are silently ignored at the revalidation boundary (unlike registration, which raises on blank tags). Missing/evicted index entries are a no-op. Returns the number of cache entries deleted.



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# File 'lib/react_on_rails_pro/cache.rb', line 128

def revalidate_tags(*tags)
  meaningful_tags = meaningful_revalidation_tags(tags)
  return 0 if meaningful_tags.empty?

  TagIndex.revalidate(*meaningful_tags)
end

.supported_expires_at_write_options(cache_options) ⇒ Object 



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# File 'lib/react_on_rails_pro/cache.rb', line 112

def supported_expires_at_write_options(cache_options)
  return cache_options.except(:expires_in) if cache_options.key?(:expires_in)

  cache_options
end

.unsupported_expires_at_with_explicit_expires_in?(cache_options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/react_on_rails_pro/cache.rb', line 118

def unsupported_expires_at_with_explicit_expires_in?(cache_options)
  !cache_supports_expires_at? && cache_options.key?(:expires_in) && !cache_options[:expires_in].nil?
end

.use_cache?(options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/react_on_rails_pro/cache.rb', line 168

def use_cache?(options)
  if options.key?(:if)
    options[:if]
  elsif options.key?(:unless)
    !options[:unless]
  else
    true
  end
end