88 lines
2.2 KiB
Ruby
88 lines
2.2 KiB
Ruby
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require "zlib"
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require "stringio"
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require "time" # for Time.httpdate
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module Rack
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class Deflater
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def initialize(app)
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@app = app
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end
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def call(env)
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status, headers, body = @app.call(env)
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headers = Utils::HeaderHash.new(headers)
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# Skip compressing empty entity body responses and responses with
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# no-transform set.
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if Utils::STATUS_WITH_NO_ENTITY_BODY.include?(status) ||
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headers['Cache-Control'].to_s =~ /\bno-transform\b/
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return [status, headers, body]
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end
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request = Request.new(env)
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encoding = Utils.select_best_encoding(%w(gzip deflate identity),
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request.accept_encoding)
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# Set the Vary HTTP header.
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vary = headers["Vary"].to_s.split(",").map { |v| v.strip }
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unless vary.include?("*") || vary.include?("Accept-Encoding")
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headers["Vary"] = vary.push("Accept-Encoding").join(",")
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end
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case encoding
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when "gzip"
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mtime = if headers.key?("Last-Modified")
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Time.httpdate(headers["Last-Modified"])
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else
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Time.now
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end
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[status,
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headers.merge("Content-Encoding" => "gzip"),
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self.class.gzip(body, mtime)]
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when "deflate"
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[status,
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headers.merge("Content-Encoding" => "deflate"),
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self.class.deflate(body)]
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when "identity"
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[status, headers, body]
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when nil
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message = ["An acceptable encoding for the requested resource #{request.fullpath} could not be found."]
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[406, {"Content-Type" => "text/plain"}, message]
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end
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end
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def self.gzip(body, mtime)
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io = StringIO.new
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gzip = Zlib::GzipWriter.new(io)
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gzip.mtime = mtime
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# TODO: Add streaming
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body.each { |part| gzip << part }
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gzip.close
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return io.string
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end
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DEFLATE_ARGS = [
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Zlib::DEFAULT_COMPRESSION,
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# drop the zlib header which causes both Safari and IE to choke
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-Zlib::MAX_WBITS,
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Zlib::DEF_MEM_LEVEL,
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Zlib::DEFAULT_STRATEGY
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]
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# Loosely based on Mongrel's Deflate handler
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def self.deflate(body)
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deflater = Zlib::Deflate.new(*DEFLATE_ARGS)
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# TODO: Add streaming
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body.each { |part| deflater << part }
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return deflater.finish
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end
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end
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end
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