Class: Faraday::Gzip::Middleware

Inherits:
Middleware
  • Object
show all
Defined in:
lib/faraday/gzip/middleware.rb

Overview

Faraday middleware for decompression

Constant Summary collapse

BROTLI_SUPPORTED = 
optional_dependency 'brotli'
ACCEPT_ENCODING = 
'Accept-Encoding'
CONTENT_ENCODING = 
'Content-Encoding'
CONTENT_LENGTH = 
'Content-Length'
SUPPORTED_ENCODINGS = 
supported_encodings.join(',').freeze

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.optional_dependency(lib = nil) ⇒ Object

System method required by Faraday



16
17
18
19
20
21
 
# File 'lib/faraday/gzip/middleware.rb', line 16

def self.optional_dependency(lib = nil)
  lib ? require(lib) : yield
  true
rescue LoadError, NameError
  false
end

.supported_encodings ⇒ Object

Returns supported encodings, adds brotli if the corresponding dependency is present



27
28
29
30
31
 
# File 'lib/faraday/gzip/middleware.rb', line 27

def self.supported_encodings
  encodings = %w[gzip deflate]
  encodings << 'br' if BROTLI_SUPPORTED
  encodings
end

Instance Method Details

#brotli_inflate(body) ⇒ Object

Process brotli



89
90
91
 
# File 'lib/faraday/gzip/middleware.rb', line 89

def brotli_inflate(body)
  Brotli.inflate(body)
end

#call(env) ⇒ Object

Main method to process the response



39
40
41
42
43
44
45
 
# File 'lib/faraday/gzip/middleware.rb', line 39

def call(env)
  env[:request_headers][ACCEPT_ENCODING] ||= SUPPORTED_ENCODINGS

  @app.call(env).on_complete do |response_env|
    reset_body(response_env, find_processor(response_env))
  end
end

#find_processor(response_env) ⇒ Object

Finds a proper processor



48
49
50
51
52
53
54
 
# File 'lib/faraday/gzip/middleware.rb', line 48

def find_processor(response_env)
  if empty_body?(response_env)
    ->(body) { raw_body(body) }
  else
    processors[response_env[:response_headers][CONTENT_ENCODING]]
  end
end

#inflate(body) ⇒ Object

Process deflate



74
75
76
77
78
79
80
81
82
83
84
85
86
 
# File 'lib/faraday/gzip/middleware.rb', line 74

def inflate(body)
  # Inflate as a DEFLATE (RFC 1950+RFC 1951) stream
  Zlib::Inflate.inflate(body)
rescue Zlib::DataError
  # Fall back to inflating as a "raw" deflate stream which
  # Microsoft servers return
  inflate = Zlib::Inflate.new(-Zlib::MAX_WBITS)
  begin
    inflate.inflate(body)
  ensure
    inflate.close
  end
end

#raw_body(body) ⇒ Object

Do not process anything, leave body as is



94
95
96
 
# File 'lib/faraday/gzip/middleware.rb', line 94

def raw_body(body)
  body
end

#reset_body(env, processor) ⇒ Object

Calls the proper processor to decompress body



57
58
59
60
61
62
63
64
 
# File 'lib/faraday/gzip/middleware.rb', line 57

def reset_body(env, processor)
  return if processor.nil?

  env[:body] = processor.call(env[:body])
  env[:response_headers].delete(CONTENT_ENCODING)

  env[:response_headers][CONTENT_LENGTH] = env[:body].nil? ? 0 : env[:body].length
end

#uncompress_gzip(body) ⇒ Object

Process gzip



67
68
69
70
71
 
# File 'lib/faraday/gzip/middleware.rb', line 67

def uncompress_gzip(body)
  io = StringIO.new(body)
  gzip_reader = Zlib::GzipReader.new(io, encoding: 'ASCII-8BIT')
  gzip_reader.read
end