Class: ResponseBank::Middleware

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

Constant Summary collapse

CACHEABLE_HEADERS = 
ResponseBank::CACHEABLE_HEADERS
CACHEABLE_STATUSES = 
ResponseBank::CACHEABLE_STATUSES
REQUESTED_WITH = 
"HTTP_X_REQUESTED_WITH"
ACCEPT = 
"HTTP_ACCEPT"
USER_AGENT = 
"HTTP_USER_AGENT"

Instance Method Summary collapse

Constructor Details

#initialize(app, brotli_splice_injector = nil) ⇒ Middleware

Returns a new instance of Middleware.



16
17
18
19
 
# File 'lib/response_bank/middleware.rb', line 16

def initialize(app, brotli_splice_injector = nil)
  @app = app
  @brotli_splice_injector = brotli_splice_injector
end

Instance Method Details

#call(env) ⇒ Object 



21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
 
# File 'lib/response_bank/middleware.rb', line 21

def call(env)
  env['cacheable.cache'] = false
  install_brotli_splice_injector(env)

  content_encoding = env['response_bank.server_cache_encoding'] = ResponseBank.check_encoding(env)

  status, headers, body = begin
    @app.call(env)
  rescue StandardError
    ResponseBank::DeferredStore.from_env(env)&.abort
    raise
  end
  deferred_store = ResponseBank::DeferredStore.from_env(env)
  ResponseBank::DeferredStore.arm_from_middleware(env, status: status, headers: headers)

  if env['cacheable.cache']
    if [200, 404, 301, 304].include?(status) && !deferred_store
      headers['ETag'] = %{"#{env['cacheable.key']}"}
    end

    if CACHEABLE_STATUSES.include?(status) && env['cacheable.miss'] && !deferred_store
      body_string = CacheWriter.flatten(body)
      stored = nil
      begin
        stored = CacheWriter.store(
          env,
          status: status,
          headers: headers,
          body: body_string,
          timestamp: -> { timestamp },
          content_encoding: content_encoding,
        )

        if stored.compressed_body
          if env['HTTP_ACCEPT_ENCODING'].to_s.include?(content_encoding)
            headers['Content-Encoding'] = content_encoding
            if content_encoding == 'br'
              body = [ResponseBank::BrotliSpliceSlot.replace_compressed_secret(env, stored.compressed_body, stored.metadata)]
            else
              body = [stored.compressed_body]
            end
          else
            headers.delete('Content-Encoding')
            body = [ResponseBank::BrotliSpliceSlot.replace_plain_body(env, stored.body, stored.metadata)] if stored.metadata
          end
        end
      rescue => exception
        headers.delete('Content-Encoding') if stored&.compressed_body
        ResponseBank.log("Failed to write to cache: #{exception.class} - #{exception.message}")
        if env['response_bank.on_exception']
          begin
            env['response_bank.on_exception'].call(exception)
          rescue => handler_exception
            ResponseBank.log("Exception handler failed: #{handler_exception.class} - #{handler_exception.message}")
          end
        end
      end
    end

    # Add X-Cache header
    miss = env['cacheable.miss']
    x_cache = miss ? 'miss' : 'hit'
    x_cache += ", #{env['cacheable.store']}" unless miss
    headers['X-Cache'] = x_cache
  end

  [status, headers, body]
end