Class: Chef::Util::Diff

Inherits:
Object
  • Object
show all
Defined in:
lib/chef/util/diff.rb

Instance Method Summary collapse

Instance Method Details

#diff(old_file, new_file) ⇒ Object 



75
76
77
78
79
80
81
 
# File 'lib/chef/util/diff.rb', line 75

def diff(old_file, new_file)
  use_tempfile_if_missing(old_file) do |old_file|
    use_tempfile_if_missing(new_file) do |new_file|
      @error = do_diff(old_file, new_file)
    end
  end
end

#for_output ⇒ Object

@todo: to_a, to_s, to_json, inspect defs, accessors for @diff and @error @todo: move coercion to UTF-8 into to_json



49
50
51
52
 
# File 'lib/chef/util/diff.rb', line 49

def for_output
  # formatted output to a terminal uses arrays of strings and returns error strings
  @diff.nil? ? [ @error ] : @diff
end

#for_reporting ⇒ Object 



54
55
56
57
58
59
 
# File 'lib/chef/util/diff.rb', line 54

def for_reporting
  # caller needs to ensure that new files aren't posted to resource reporting
  return nil if @diff.nil?

  @diff.join("\\n")
end

#udiff(old_file, new_file) ⇒ Object

produces a unified-output-format diff with 3 lines of context ChefFS uses udiff() directly



85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
 
# File 'lib/chef/util/diff.rb', line 85

def udiff(old_file, new_file)
  require "diff/lcs"
  require "diff/lcs/hunk"

  diff_str = ""
  file_length_difference = 0

  old_data = IO.readlines(old_file).map(&:chomp)
  new_data = IO.readlines(new_file).map(&:chomp)
  diff_data = ::Diff::LCS.diff(old_data, new_data)

  return diff_str if old_data.empty? && new_data.empty?
  return "No differences encountered\n" if diff_data.empty?

  # write diff header (standard unified format)
  ft = File.stat(old_file).mtime.localtime.strftime("%Y-%m-%d %H:%M:%S.%N %z")
  diff_str << "--- #{old_file}\t#{ft}\n"
  ft = File.stat(new_file).mtime.localtime.strftime("%Y-%m-%d %H:%M:%S.%N %z")
  diff_str << "+++ #{new_file}\t#{ft}\n"

  # loop over diff hunks. if a hunk overlaps with the last hunk,
  # join them. otherwise, print out the old one.
  old_hunk = hunk = nil
  diff_data.each do |piece|

    hunk = ::Diff::LCS::Hunk.new(old_data, new_data, piece, 3, file_length_difference)
    file_length_difference = hunk.file_length_difference
    next unless old_hunk
    next if hunk.merge(old_hunk)

    diff_str << old_hunk.diff(:unified) << "\n"
  ensure
    old_hunk = hunk

  end
  diff_str << old_hunk.diff(:unified) << "\n"
  diff_str
end

#use_tempfile_if_missing(file) {|file| ... } ⇒ Object

Yields:

  • (file) 


61
62
63
64
65
66
67
68
69
70
71
72
73
 
# File 'lib/chef/util/diff.rb', line 61

def use_tempfile_if_missing(file)
  tempfile = nil
  unless File.exist?(file)
    Chef::Log.trace("File #{file} does not exist to diff against, using empty tempfile")
    tempfile = Tempfile.new("chef-diff")
    file = tempfile.path
  end
  yield file
  unless tempfile.nil?
    tempfile.close
    tempfile.unlink
  end
end