class Rack::Cache::Context

Implements Rack’s middleware interface and provides the context for all cache logic, including the core logic engine.

Attributes

backend[R]

The Rack application object immediately downstream.

trace[R]

Array of trace Symbols

Public Instance Methods

call(env) click to toggle source

The Rack call interface. The receiver acts as a prototype and runs each request in a dup object unless the rack.run_once variable is set in the environment.

# File lib/rack/cache/context.rb, line 46
def call(env)
  if env['rack.run_once']
    call! env
  else
    clone.call! env
  end
end

call!(env) click to toggle source

The real Rack call interface. The caching logic is performed within the context of the receiver.

# File lib/rack/cache/context.rb, line 56
def call!(env)
  @trace = []
  @default_options.each { |k,v| env[k] ||= v }
  @env = env
  @request = Request.new(@env.dup.freeze)

  response =
    if @request.get? || @request.head?
      if !@env['HTTP_EXPECT'] && !@env['rack-cache.force-pass']
        lookup
      else
        pass
      end
    else
      invalidate
    end

  # log trace and set X-Rack-Cache tracing header
  trace = @trace.join(', ')
  response.headers['X-Rack-Cache'] = trace

  # write log message to rack.errors
  if verbose?
    message = "cache: [%s %s] %s\n" %
      [@request.request_method, @request.fullpath, trace]
    @env['rack.errors'].write(message)
  end

  # tidy up response a bit
  response.not_modified! if not_modified?(response)
  if @request.head?
    response.body.close if response.body.respond_to?(:close)
    response.body = []
  end
  response.to_a
end

entitystore() click to toggle source

The configured EntityStore instance. Changing the rack-cache.entitystore value effects the result of this method immediately.

# File lib/rack/cache/context.rb, line 38
def entitystore
  uri = options['rack-cache.entitystore']
  storage.resolve_entitystore_uri(uri)
end

metastore() click to toggle source

The configured MetaStore instance. Changing the rack-cache.metastore value effects the result of this method immediately.

# File lib/rack/cache/context.rb, line 31
def metastore
  uri = options['rack-cache.metastore']
  storage.resolve_metastore_uri(uri)
end

Public Class Methods

new(backend, options={}) { |self| ... } click to toggle source

# File lib/rack/cache/context.rb, line 18
def initialize(backend, options={})
  @backend = backend
  @trace = []

  initialize_options options
  yield self if block_given?

  @private_header_keys =
    private_headers.map { |name| "HTTP_#{name.upcase.tr('-', '_')}" }
end