add route to dump bytes

app.rb

@@ -375,6 +375,12 @@ get "/cookies" do
   jsonify response.headers
 end
 
+get "/config", provides: "json" do
+  pretty = params.key? :pretty
+
+  jsonify config.as_json, pretty:
+end
+
 get "/_cat/headers" do
   stream do |out|
     req_headers.each do |k, v|
@@ -399,6 +405,21 @@ get "/_cat/cookies" do
   end
 end
 
+get "/_cat/config" do
+  stream do |out|
+    config.instance_variables.each do |k|
+      k = k.to_s.delete_prefix "@"
+      begin
+        v = config.send(k)
+      rescue NoMethodError
+        next
+      end
+
+      out << "#{k}(#{v.to_s.length})=#{v}\n"
+    end
+  end
+end
+
 route :delete, :get, :patch, :post, :put, "/status/:code" do
   # hello
   code = Integer(params[:code])
@@ -425,3 +446,48 @@ route :delete, :get, :patch, :post, :put, "/auth/basic", provides: "json" do
 
   jsonify({authenticated: true, user: @auth.username}, pretty:)
 end
+
+def human_size_to_bytes(size)
+  units = %i[b kb mb gb tb pb eb zb yb rb qb]
+
+  number, unit = size.split(/(?<=\d)(?=[A-Za-z])/)
+
+  raise ArgumentError, "the unit is not recognized" if unit.nil?
+
+  number = Float(number)
+  unit = unit.downcase.to_sym
+
+  exponent = units.find_index(unit)
+
+  number *= (1024**exponent)
+  Integer(number.ceil)
+end
+
+MAX_DOWNLOAD_SIZE = "1GB"
+
+get "/bytes/:size" do
+  size = params[:size]
+  n = [human_size_to_bytes(size), human_size_to_bytes(MAX_DOWNLOAD_SIZE)].min
+
+  headers["content-type"] = "application/octet-stream"
+  headers["content-length"] = n
+
+  headers["content-disposition"] = "attachment; filename=\"#{params[:f]}\"" if params.key? :f
+
+  def generate_bytes(number, byte = "\x00", block_size = 4096)
+    raise ArgumentError, "'byte' must be 1 byte" unless byte.b.length == 1
+
+    bytes_written = 0
+    block = byte * block_size
+    Enumerator.new do |g|
+      while bytes_written < number
+        remaining_bytes = number - bytes_written
+        bytes_to_write = [block_size, remaining_bytes].min
+        g.yield block[0, bytes_to_write]
+        bytes_written += bytes_to_write
+      end
+    end
+  end
+
+  generate_bytes(Integer(n))
+end