git.oblomov.eu Git - ohcount/blob - lib/ohcount/scratch_dir.rb

   1 require 'fileutils'
   2 require 'tmpdir'
   3
   4 # A utility class to manage the creation and automatic cleanup of temporary directories.
   5 class ScratchDir
   6         attr_reader :path
   7
   8         # Creates a uniquely named directory in the system tmp directory.
   9         #
  10         # If a block is passed to the constructor, the path to the created directory
  11         # will be yielded to the block. The directory will then be deleted
  12         # when this block returns.
  13         #
  14         # Sample usage:
  15         #
  16         #   ScratchDir.new do |path|
  17         #     # Do some work in the new directory
  18         #     File.new( path + '/foobaz', 'w' ) do
  19         #       # ...
  20         #     end
  21         #   end # Scratch directory is deleted here
  22         #
  23         def initialize
  24                 until @path
  25                         @path = File.join(Dir.tmpdir, Time.now.utc.strftime("ohloh_%Y%H%m%S#{rand(900) + 100}"))
  26                         begin
  27                                 Dir.mkdir(@path)
  28                         rescue Errno::EEXIST
  29                                 @path = nil
  30                         end
  31                 end
  32                 if block_given?
  33                         begin
  34                                 yield @path
  35                         ensure
  36                                 FileUtils.rm_rf(@path)
  37                         end
  38                 end
  39         end
  40 end
  41
  42 if $0 == __FILE__
  43         path = nil
  44
  45         ScratchDir.new do |d|
  46                 path = d
  47                 STDOUT.puts "Created scratch direcory #{d}"
  48                 File.open(File.join(d, "test"), "w") do |io|
  49                         io.write "test"
  50                 end
  51         end
  52         raise RuntimeError.new("Directory wasn't cleaned up") if FileTest.directory?(path)
  53
  54         begin
  55                 ScratchDir.new do |d|
  56                         path = d
  57                         STDOUT.puts "Created scratch direcory #{d}"
  58                         raise RuntimeError.new("This error should not prevent cleanup")
  59                 end
  60         rescue
  61         end
  62         raise RuntimeError.new("Directory wasn't cleaned up") if FileTest.directory?(path)
  63
  64         STDOUT.puts "Tests passed."
  65 end