Class: Rack::Deflater

Inherits:
Object show all
Defined in:
lib/gems/rack-0.4.0/lib/rack/deflater.rb

Constant Summary collapse

DEFLATE_ARGS = 
[
  Zlib::DEFAULT_COMPRESSION,
  # drop the zlib header which causes both Safari and IE to choke
 -Zlib::MAX_WBITS,
  Zlib::DEF_MEM_LEVEL,
  Zlib::DEFAULT_STRATEGY
]

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Deflater

Returns a new instance of Deflater.



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# File 'lib/gems/rack-0.4.0/lib/rack/deflater.rb', line 7

def initialize(app)
  @app = app
end

Class Method Details

.deflate(body) ⇒ Object

Loosely based on Mongrel’s Deflate handler



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# File 'lib/gems/rack-0.4.0/lib/rack/deflater.rb', line 53

def self.deflate(body)
  deflater = Zlib::Deflate.new(*DEFLATE_ARGS)

  # TODO: Add streaming
  body.each { |part| deflater << part }

  return deflater.finish
end

.gzip(body, mtime) ⇒ Object 



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# File 'lib/gems/rack-0.4.0/lib/rack/deflater.rb', line 32

def self.gzip(body, mtime)
  io = StringIO.new
  gzip = Zlib::GzipWriter.new(io)
  gzip.mtime = mtime

  # TODO: Add streaming
  body.each { |part| gzip << part }

  gzip.close
  return io.string
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/gems/rack-0.4.0/lib/rack/deflater.rb', line 11

def call(env)
  status, headers, body = @app.call(env)

  request = Request.new(env)

  encoding = Utils.select_best_encoding(%w(gzip deflate identity), request.accept_encoding)

  case encoding
  when "gzip"
    mtime = headers["Last-Modified"] || Time.now
    [status, headers.merge("Content-Encoding" => "gzip"), self.class.gzip(body, mtime)]
  when "deflate"
    [status, headers.merge("Content-Encoding" => "deflate"), self.class.deflate(body)]
  when "identity"
    [status, headers, body]
  when nil
    message = "An acceptable encoding for the requested resource #{request.fullpath} could not be found."
    [406, {"Content-Type" => "text/plain"}, message]
  end
end