openstreetmap-website/lib/output_compression/output_compression.rb
2015-02-20 19:47:26 +00:00

68 lines
1.7 KiB
Ruby

# OutputCompression
# Rails output compression filters
#
# Adds two classmethods to ActionController that can be used as after-filters:
# strip_whitespace and compress_output.
# If you use page-caching, you MUST specify the compress_output filter AFTER
# caches_page, otherwise the compressed data will be cached instead of the HTML
#
# class MyController < ApplicationController
# after_filter :strip_whitespace
# caches_page :index
# after_filter :compress_output
# end
begin
require "zlib"
require "stringio"
GZIP_SUPPORTED = true
rescue
GZIP_SUPPORTED = false
end
module CompressionSystem
def compress_output
return unless accepts_gzip?
output = StringIO.new
def output.close
# Zlib does a close. Bad Zlib...
rewind
end
gz = Zlib::GzipWriter.new(output)
gz.write(response.body)
gz.close
if output.length < response.body.length
@old_response_body = response.body
response.body = output.string
response.headers["Content-encoding"] = @compression_encoding
end
end
def accepts_gzip?
return false unless GZIP_SUPPORTED
accepts = request.env["HTTP_ACCEPT_ENCODING"]
return false unless accepts && accepts =~ /(x-gzip|gzip)/
@compression_encoding = $1
true
end
def strip_whitespace
response.body.gsub!(/()|(.*?<\/script>)|()|()|\s+/m) do |m|
if m =~ /^()(.*?)<\/script>$/m
$1 + $2.strip.gsub(/\s+/, " ").gsub("", "\n-->") + ""
elsif m =~ /^$/m
""
elsif m =~ /^<(textarea|pre)/
m
else " "
end
end
response.body.gsub! /\s+\s+/, ">"
end
end
module ActionController
class Base
include CompressionSystem
end
end