[PLUG] new plugin, acts_as_modified

Rails
1

Nothing special, just my first plugin. it came out of a request I saw
on
the list from someone who wanted to be able to tell if a model’s
attributes
had changed prior to being saved. Well, this plugin does just that (at
least I hope it does).

http://rubyforge.org/projects/actsasmodified/

Please see the README for details. Constructive comments and criticisms
are
appreciated.

Chris

2

Looks good!

It is probably also useful to be able to ask if a specific attribute
has been modified. Perhaps by appending _modified? to the attribute
name. Eg:

person.name_modified?

Could be equivalent to:

person.modified.include?(‘name’)

Also, you should note that the plugin has quite a large impact on
performance because of the use of after_find and after_initialize.
http://dev.rubyonrails.org/browser/trunk/activerecord/lib/active_record/callbacks.rb#L154

-Jonathan.

3

Regarding the performance hit, this patch in the tracker might be
helpful: http://dev.rubyonrails.org/ticket/5436

Chris, perhaps you’d take a look at including that code in your plugin?

–
Benjamin C.
http://www.bencurtis.com/
http://www.tesly.com/ – Collaborative test case management
http://www.agilewebdevelopment.com/ – Resources for the Rails community

4

Jonathan, Ben,

Thanks for the input. Since I’ve read your comments, I made a minor
change and removed the after_initialization code. This resulted in a
bit of a performance increase over the previous version. I’ll be
updating the project page later today.

Here are some benchmark results.

setup: 500 “things”, 5000 “widgets” (10 “widgets” associated with 1
“thing”)

                                        user     system      total
   real

find all things 0.083333 0.000000 0.083333
( 0.044024)
find all things (aam) 0.300000 0.016667 0.316667
( 0.192542)

                                        user     system      total
   real

find all things include widgets 1.166667 0.000000 1.166667
( 3.941230)
find all things include widgets (aam) 5.233333 0.000000 5.233333
( 6.412996)

                                        user     system      total
   real

find all widgets 0.216667 0.000000 0.216667
( 0.138359)
find all widgets (aam) 3.183333 0.000000 3.183333
( 1.937386)

                                        user     system      total
   real

find all widgets include thing 0.983333 0.000000 0.983333
( 0.620862)
find all widgets include thing (aam) 4.783333 0.033333 4.816667
( 2.909969)

so there is definitely a performance penalty where finding large
numbers of records and including associations. keep in mind that in
the aam tests, ALL models are aam. In a realworld scenario you may
not need to aam EVERY model.

these are the test results from finding only the first record:

                                        user     system      total
   real

find first thing 0.033333 0.000000 0.033333
( 0.019966)
find first thing (aam) 0.016667 0.000000 0.016667
( 0.005061)

                                       user     system      total
  real

find first thing include widgets 1.616667 0.000000 1.616667
( 4.267549)
find first thing include widgets (aam) 5.416667 0.066667 5.483333
( 6.631500)

                                        user     system      total
   real

find first widget 0.000000 0.000000 0.000000
( 0.000801)
find first widget (aam) 0.000000 0.000000 0.000000
( 0.001166)

                                        user     system      total
   real

find first widget include thing 1.433333 0.000000 1.433333
( 0.973662)
find first widget include thing (aam) 5.100000 0.033333 5.133333
( 3.545063)

again, forgive me if the formatting goes all screwy.

Chris