Class: ResponseBank::DeferredStore

Inherits:
Object
  • Object
show all
Defined in:
lib/response_bank/deferred_store.rb

Defined Under Namespace

Classes: InvalidContextError, StateError

Constant Summary collapse

ENV_KEY = 
'response_bank.deferred_store'
LOCK_OWNED_ENV_KEY = 
'response_bank.fill_lock_owned'
TERMINAL_STATES = 
%i[aborted completing consumed].freeze
PRIVATE_CACHE_DIRECTIVES = 
%w[private no-store].freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(env, timestamp:) ⇒ DeferredStore

Returns a new instance of DeferredStore.



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# File 'lib/response_bank/deferred_store.rb', line 51

def initialize(env, timestamp:)
  @env = env
  @timestamp = timestamp
  @cache_key = env.fetch('cacheable.key')
  @owns_lock = env.fetch(LOCK_OWNED_ENV_KEY) == true
  @mutex = Mutex.new
  @state = :requested
end

Class Method Details

.arm_from_middleware(env, status:, headers:) ⇒ Object 



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# File 'lib/response_bank/deferred_store.rb', line 28

def arm_from_middleware(env, status:, headers:)
  from_env(env)&.__send__(:arm, status: status, headers: headers)
end

.create(env, timestamp:) ⇒ Object

Raises:



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# File 'lib/response_bank/deferred_store.rb', line 17

def create(env, timestamp:)
  validate_context!(env)
  raise InvalidContextError, 'a deferred store is already registered for this request' if env.key?(ENV_KEY)

  new(env, timestamp: timestamp).tap { |store| env[ENV_KEY] = store }
end

.from_env(env) ⇒ Object 



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# File 'lib/response_bank/deferred_store.rb', line 24

def from_env(env)
  env[ENV_KEY]
end

Instance Method Details

#abort ⇒ Object 



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# File 'lib/response_bank/deferred_store.rb', line 91

def abort
  transitioned, release_lock = @mutex.synchronize do
    if TERMINAL_STATES.include?(@state)
      [false, false]
    else
      @state = :aborted
      [true, @owns_lock]
    end
  end

  release_owned_lock if release_lock
  transitioned
end

#complete(body:, headers: nil) ⇒ Object

body and headers must describe the complete shared cache representation, not a partial response or bytes personalized for the live client.



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# File 'lib/response_bank/deferred_store.rb', line 62

def complete(body:, headers: nil)
  status, cached_headers, release_lock = prepare_completion(headers)

  if release_lock
    release_owned_lock
    return false
  end
  return false unless status

  write_started = false
  completed = false
  begin
    CacheWriter.store(
      @env,
      status: status,
      headers: cached_headers,
      body: body,
      timestamp: @timestamp,
      before_write: -> { write_started = true },
    )
    completed = true
  ensure
    @mutex.synchronize { @state = :consumed }
    @env['cacheable.locked'] = false if @owns_lock
    release_owned_lock if @owns_lock && !completed && !write_started
  end
  true
end