class Rack::ETag

defaults to nil, while the second defaults to “max-age=0, private, must-revalidate”
used when Etag is absent and a directive when it is present. The first
On initialization, you can pass two parameters: a Cache-Control directive
should be handled by apache/nginx).
a sendfile body (body.responds_to :to_path) is given (since such cases
The ETag header is skipped if ETag or Last-Modified headers are sent or if
Automatically sets the ETag header on all String bodies.

def call(env)

def call(env)
  status, headers, body = @app.call(env)
  headers = Utils::HeaderHash[headers]
  if etag_status?(status) && etag_body?(body) && !skip_caching?(headers)
    original_body = body
    digest, new_body = digest_body(body)
    body = Rack::BodyProxy.new(new_body) do
      original_body.close if original_body.respond_to?(:close)
    end
    headers[ETAG_STRING] = %(W/"#{digest}") if digest
  end
  unless headers[CACHE_CONTROL]
    if digest
      headers[CACHE_CONTROL] = @cache_control if @cache_control
    else
      headers[CACHE_CONTROL] = @no_cache_control if @no_cache_control
    end
  end
  [status, headers, body]
end

def digest_body(body)

def digest_body(body)
  parts = []
  digest = nil
  body.each do |part|
    parts << part
    (digest ||= Digest::SHA256.new) << part unless part.empty?
  end
  [digest && digest.hexdigest.byteslice(0, 32), parts]
end

def etag_body?(body)

def etag_body?(body)
  !body.respond_to?(:to_path)
end

def etag_status?(status)

def etag_status?(status)
  status == 200 || status == 201
end

def initialize(app, no_cache_control = nil, cache_control = DEFAULT_CACHE_CONTROL)

def initialize(app, no_cache_control = nil, cache_control = DEFAULT_CACHE_CONTROL)
  @app = app
  @cache_control = cache_control
  @no_cache_control = no_cache_control
end

def skip_caching?(headers)

def skip_caching?(headers)
  headers.key?(ETAG_STRING) || headers.key?('Last-Modified')
end

Modules

Classes