1 files changed, 38 insertions, 0 deletions
diff --git a/lib/metropolis/gzip.rb b/lib/metropolis/gzip.rb
new file mode 100644
index 0000000..50d71ef
--- /dev/null
+++ b/lib/metropolis/gzip.rb
@@ -0,0 +1,38 @@
+# -*- encoding: binary -*-
+require "zlib"
+
+# allows storing pre-gzipped data on disk and serving it
+# as-is for clients that accept that gzip encoding
+module Metropolis::Gzip
+  def get(key, env)
+    status, headers, body = r = super
+    if 200 == status && /\bgzip\b/ !~ env['HTTP_ACCEPT_ENCODING']
+      body[0] = Zlib::GzipReader.new(StringIO.new(body[0])).read
+      headers['Content-Length'] = body[0].size.to_s
+      headers.delete('Content-Encoding')
+      headers.delete('Vary')
+    end
+    r
+  end
+
+  def put(key, env)
+    Wrapper.new(env)
+    super(key, env)
+  end
+
+  def self.extended(obj)
+    obj.instance_eval do
+      @headers['Content-Encoding'] = 'gzip'
+      @headers['Vary'] = 'Accept-Encoding'
+    end
+  end
+
+  class Wrapper < Metropolis::InputWrapper
+
+    def read_all
+      zipped = StringIO.new("")
+      Zlib::GzipWriter.wrap(zipped) { |io| io.write(@input.read) }
+      zipped.string
+    end
+  end
+end