When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.
There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the
| #!/usr/bin/env ruby -wKU | |
| require "test/unit" | |
| class Stock | |
| # To change this template use File | Settings | File Templates. | |
| def self.find_longest_run(prices=[]) | |
| return {:low=>{0.0=>0},:high=>{0.0=>0}} if prices.nil? || prices.size == 0 | |
| result = {} | |
| # start at the end | |
| #find the highest value |
| $> ./linked_list.rb | |
| Run options: | |
| # Running tests: | |
| ...... | |
| Finished tests in 0.000599s, 10016.6945 tests/s, 20033.3890 assertions/s. | |
| 6 tests, 12 assertions, 0 failures, 0 errors, 0 skips |
| def add_1_to_n(n) | |
| return n <= 0 ? 0 : n + add_1_to_n( n - 1 ) | |
| end | |
| puts add_1_to_n(10) #=> 55 |
| BASH_KEYS=$(cat <<EOF | |
| Ctrl + A Go to the beginning of the line you are currently typing on | |
| Ctrl + E Go to the end of the line you are currently typing on | |
| Ctrl + L Clears the Screen, similar to the clear command | |
| Ctrl + U Clears the line before the cursor position. If you are at the end of the line, clears the entire line. | |
| Ctrl + H Same as backspace | |
| Ctrl + R Let’s you search through previously used commands | |
| Ctrl + C Kill whatever you are running | |
| Ctrl + D Exit the current shell |
| # 1) Use VCR.use_cassette in your let block. This will use | |
| # the cassette just for requests made by creating bar, not | |
| # for anything else in your test. | |
| let(:foo) { VCR.use_cassette("foo") { create(:bar) } } | |
| it "uses foo" do | |
| foo | |
| end | |
| # 2) Wrap the it block that uses #foo in VCR.use_cassette. |
Sublime Text 2 ships with a CLI called subl (why not "sublime", go figure). This utility is hidden in the following folder (assuming you installed Sublime in /Applications like normal folk. If this following line opens Sublime Text for you, then bingo, you're ready.
open /Applications/Sublime\ Text\ 2.app/Contents/SharedSupport/bin/subl
You can find more (official) details about subl here: http://www.sublimetext.com/docs/2/osx_command_line.html
| =Navigating= | |
| visit('/projects') | |
| visit(post_comments_path(post)) | |
| =Clicking links and buttons= | |
| click_link('id-of-link') | |
| click_link('Link Text') | |
| click_button('Save') | |
| click('Link Text') # Click either a link or a button | |
| click('Button Value') |
