gzip static files options dir listing and etags

format

src/kemal/config.cr

@@ -11,13 +11,13 @@ module Kemal
     @ssl : OpenSSL::SSL::Context::Server?
 
     property host_binding, ssl, port, env, public_folder, logging,
-      always_rescue, serve_static, server, extra_options
+      always_rescue, serve_static : (Bool | Hash(String, Bool)), server, extra_options
 
     def initialize
       @host_binding = "0.0.0.0"
       @port = 3000
       @env = "development"
-      @serve_static = true
+      @serve_static = {"dir_listing" => false, "gzip" => true}
       @public_folder = "./public"
       @logging = true
       @logger = nil
@@ -89,7 +89,7 @@ module Kemal
     end
 
     private def setup_static_file_handler
-      HANDLERS.insert(3, Kemal::StaticFileHandler.new(@public_folder)) if @serve_static
+      HANDLERS.insert(3, Kemal::StaticFileHandler.new(@public_folder)) if @serve_static.is_a?(Hash)
     end
   end
 

src/kemal/helpers/helpers.cr

@@ -32,7 +32,7 @@ def logger(logger)
 end
 
 # Enables / Disables static file serving.
-def serve_static(status)
+def serve_static(status : (Bool | Hash))
   Kemal.config.serve_static = status
 end
 

src/kemal/static_file_handler.cr

@@ -1,13 +1,92 @@
+{% if !flag?(:without_zlib) %}
+  require "zlib"
+{% end %}
+
 module Kemal
-  # Kemal::StaticFileHandler is used to serve static files(.js/.css/.png e.g).
-  # This handler is on by default and you can disable it like.
-  #
-  #   serve_static false
-  #
   class StaticFileHandler < HTTP::StaticFileHandler
     def call(context)
       return call_next(context) if context.request.path.not_nil! == "/"
-      super
+
+      unless context.request.method == "GET" || context.request.method == "HEAD"
+        if @fallthrough
+          call_next(context)
+        else
+          context.response.status_code = 405
+          context.response.headers.add("Allow", "GET, HEAD")
+        end
+        return
+      end
+
+      config = Kemal.config.serve_static
+      original_path = context.request.path.not_nil!
+      is_dir_path = original_path.ends_with? "/"
+      request_path = URI.unescape(original_path)
+
+      # File path cannot contains '\0' (NUL) because all filesystem I know
+      # don't accept '\0' character as file name.
+      if request_path.includes? '\0'
+        context.response.status_code = 400
+        return
+      end
+
+      expanded_path = File.expand_path(request_path, "/")
+      if is_dir_path && !expanded_path.ends_with? "/"
+        expanded_path = "#{expanded_path}/"
+      end
+      is_dir_path = expanded_path.ends_with? "/"
+
+      file_path = File.join(@public_dir, expanded_path)
+      is_dir = Dir.exists? file_path
+
+      if request_path != expanded_path || is_dir && !is_dir_path
+        redirect_to context, "#{expanded_path}#{is_dir && !is_dir_path ? "/" : ""}"
+      end
+
+      if Dir.exists?(file_path)
+        if config.is_a?(Hash) && config["dir_listing"] == true
+          context.response.content_type = "text/html"
+          directory_listing(context.response, request_path, file_path)
+        else
+          return call_next(context)
+        end
+      elsif File.exists?(file_path)
+        return if self.etag(context, file_path)
+        minsize = 860 # http://webmasters.stackexchange.com/questions/31750/what-is-recommended-minimum-object-size-for-gzip-performance-benefits ??
+        context.response.content_type = mime_type(file_path)
+        request_headers = context.request.headers
+        filesize = File.size(file_path)
+        File.open(file_path) do |file|
+          if request_headers.includes_word?("Accept-Encoding", "gzip") && config.is_a?(Hash) && config["gzip"] == true && filesize > minsize && self.zip_types(file_path)
+            context.response.headers["Content-Encoding"] = "gzip"
+            Zlib::Deflate.gzip(context.response) do |deflate|
+              IO.copy(file, deflate)
+            end
+          elsif request_headers.includes_word?("Accept-Encoding", "deflate") && config.is_a?(Hash) && config["gzip"]? == true && filesize > minsize && self.zip_types(file_path)
+            context.response.headers["Content-Encoding"] = "deflate"
+            Zlib::Deflate.new(context.response) do |deflate|
+              IO.copy(file, deflate)
+            end
+          else
+            context.response.content_length = filesize
+            IO.copy(file, context.response)
+          end
+        end
+      else
+        call_next(context)
+      end
+    end
+
+    def etag(context, file_path)
+      etag = %{W/"#{File.lstat(file_path).mtime.epoch.to_s}"}
+      context.response.headers["ETag"] = etag
+      return false if !context.request.headers["If-None-Match"]? || context.request.headers["If-None-Match"] != etag
+      context.response.content_length = 0
+      context.response.status_code = 304 # not modified
+      return true
+    end
+
+    def zip_types(path) # https://github.com/h5bp/server-configs-nginx/blob/master/nginx.conf
+      [".htm", ".html", ".txt", ".css", ".js", ".svg", ".json", ".xml", ".otf", ".ttf", ".woff", ".woff2"].includes? File.extname(path)
     end
 
     def mime_type(path)
@@ -20,6 +99,11 @@ module Kemal
       when ".jpg", ".jpeg" then "image/jpeg"
       when ".gif"          then "image/gif"
       when ".svg"          then "image/svg+xml"
+      when ".xml"          then "application/xml"
+      when ".json"         then "application/json"
+      when ".otf", ".ttf"  then "application/font-sfnt"
+      when ".woff"         then "application/font-woff"
+      when ".woff2"        then "font/woff2"
       else                      "application/octet-stream"
       end
     end