class Bootsnap::LoadPathCache::Path

def entries_and_dirs(store)
  if stable?
    # the cached_mtime field is unused for 'stable' paths, but is
    # set to zero anyway, just in case we change the stability heuristics.
    _, entries, dirs = store.get(path)
    return [entries, dirs] if entries # cache hit
    entries, dirs = scan!
    store.set(path, [0, entries, dirs])
    return [entries, dirs]
  end
  cached_mtime, entries, dirs = store.get(path)
  current_mtime = latest_mtime(path, dirs || [])
  return [[], []]        if current_mtime == -1 # path does not exist
  return [entries, dirs] if cached_mtime == current_mtime
  entries, dirs = scan!
  store.set(path, [current_mtime, entries, dirs])
  [entries, dirs]
end

def initialize(path)
  @path = path.to_s
end

def latest_mtime(path, dirs)
  max = -1
  ["", *dirs].each do |dir|
    curr = begin
      File.mtime("#{path}/#{dir}").to_i
    rescue Errno::ENOENT
      -1
    end
    max = curr if curr > max
  end
  max
end

def non_directory?
  !File.stat(path).directory?
rescue Errno::ENOENT
  false
end

def scan! # (expensive) returns [entries, dirs]
  PathScanner.call(path)
end

def stability
  @stability ||= begin
    if Gem.path.detect { |p| path.start_with?(p.to_s) }
      STABLE
    elsif path.start_with?(RUBY_PREFIX) && !path.start_with?(SITE_DIR)
      STABLE
    else
      VOLATILE
    end
  end
end

def stable?
  stability == STABLE
end

def volatile?
  stability == VOLATILE
end