class RuboCop::ResultCache

Provides functionality for caching rubocop runs.

Constants

NON_CHANGING

Attributes

inhibit_cleanup[RW]
source_checksum[RW]

Public Class Methods

cache_root(config_store) click to toggle source
# File lib/rubocop/result_cache.rb, line 52
def self.cache_root(config_store)
  root = config_store.for('.').for_all_cops['CacheRootDirectory']
  if root == '/tmp'
    tmpdir = File.realpath(Dir.tmpdir)
    # Include user ID in the path to make sure the user has write access.
    root = File.join(tmpdir, Process.uid.to_s)
  end
  File.join(root, 'rubocop_cache')
end
cleanup(config_store, verbose, cache_root = nil) click to toggle source

Remove old files so that the cache doesn't grow too big. When the threshold MaxFilesInCache has been exceeded, the oldest 50% of all the files in the cache are removed. The reason for removing so much is that cleaning should be done relatively seldom, since there is a slight risk that some other RuboCop process was just about to read the file, when there's parallel execution and the cache is shared.

# File lib/rubocop/result_cache.rb, line 20
def self.cleanup(config_store, verbose, cache_root = nil)
  return if inhibit_cleanup # OPTIMIZE: For faster testing
  cache_root ||= cache_root(config_store)
  return unless File.exist?(cache_root)

  files, dirs = Find.find(cache_root).partition { |path| File.file?(path) }
  if files.length > config_store.for('.').for_all_cops['MaxFilesInCache'] &&
     files.length > 1
    # Add 1 to half the number of files, so that we remove the file if
    # there's only 1 left.
    remove_count = 1 + files.length / 2
    if verbose
      puts "Removing the #{remove_count} oldest files from #{cache_root}"
    end
    sorted = files.sort_by { |path| File.mtime(path) }
    remove_files(sorted, dirs, remove_count, verbose)
  end
end
new(file, options, config_store, cache_root = nil) click to toggle source
# File lib/rubocop/result_cache.rb, line 62
def initialize(file, options, config_store, cache_root = nil)
  cache_root ||= ResultCache.cache_root(config_store)
  @path = File.join(cache_root, rubocop_checksum,
                    relevant_options_digest(options),
                    file_checksum(file, config_store))
  @cached_data = CachedData.new(file)
end

Private Class Methods

remove_files(files, dirs, remove_count, verbose) click to toggle source
# File lib/rubocop/result_cache.rb, line 42
def remove_files(files, dirs, remove_count, verbose)
  File.delete(*files[0, remove_count])
  dirs.each { |dir| Dir.rmdir(dir) if Dir["#{dir}/*"].empty? }
rescue Errno::ENOENT
  # This can happen if parallel RuboCop invocations try to remove the
  # same files. No problem.
  puts $ERROR_INFO if verbose
end

Public Instance Methods

load() click to toggle source
# File lib/rubocop/result_cache.rb, line 74
def load
  @cached_data.from_json(IO.binread(@path))
end
save(offenses) click to toggle source
# File lib/rubocop/result_cache.rb, line 78
def save(offenses)
  dir = File.dirname(@path)
  FileUtils.mkdir_p(dir)
  preliminary_path = "#{@path}_#{rand(1_000_000_000)}"
  # RuboCop must be in control of where its cached data is stored. A
  # symbolic link anywhere in the cache directory tree is an indication
  # that a symlink attack is being waged.
  return if any_symlink?(dir)

  File.open(preliminary_path, 'wb') do |f|
    f.write(@cached_data.to_json(offenses))
  end
  # The preliminary path is used so that if there are multiple RuboCop
  # processes trying to save data for the same inspected file
  # simultaneously, the only problem we run in to is a competition who gets
  # to write to the final file. The contents are the same, so no corruption
  # of data should occur.
  FileUtils.mv(preliminary_path, @path)
end
valid?() click to toggle source
# File lib/rubocop/result_cache.rb, line 70
def valid?
  File.exist?(@path)
end

Private Instance Methods

file_checksum(file, config_store) click to toggle source
# File lib/rubocop/result_cache.rb, line 111
def file_checksum(file, config_store)
  Digest::MD5.hexdigest(Dir.pwd + file + IO.read(file) +
                        config_store.for(file).to_s)
rescue Errno::ENOENT
  # Spurious files that come and go should not cause a crash, at least not
  # here.
  '_'
end
relevant_options_digest(options) click to toggle source

Return a hash of the options given at invocation, minus the ones that have no effect on which offenses and disabled line ranges are found, and thus don't affect caching.

# File lib/rubocop/result_cache.rb, line 140
def relevant_options_digest(options)
  options = options.reject { |key, _| NON_CHANGING.include?(key) }
  options = options.to_s.gsub(/[^a-z]+/i, '_')
  # We must avoid making file names too long for some filesystems to handle
  # If they are short, we can leave them human-readable
  options.length <= 32 ? options : Digest::MD5.hexdigest(options)
end
rubocop_checksum() click to toggle source

The checksum of the rubocop program running the inspection.

# File lib/rubocop/result_cache.rb, line 125
def rubocop_checksum
  ResultCache.source_checksum ||=
    begin
      lib_root = File.join(File.dirname(__FILE__), '..')
      bin_root = File.join(lib_root, '..', 'bin')
      source = Find.find(lib_root, bin_root).sort.map do |path|
        IO.read(path) if File.file?(path)
      end
      Digest::MD5.hexdigest(source.join)
    end
end