text: # -*- coding: utf-8 -*-
  
  # Copyright © 2012-2015 Roberto Alsina and others.
  
  # Permission is hereby granted, free of charge, to any
  # person obtaining a copy of this software and associated
  # documentation files (the "Software"), to deal in the
  # Software without restriction, including without limitation
  # the rights to use, copy, modify, merge, publish,
  # distribute, sublicense, and/or sell copies of the
  # Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice
  # shall be included in all copies or substantial portions of
  # the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
  # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  # PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
  # OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  # OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  """Create gzipped copies of files."""
  
  import gzip
  import os
  import shlex
  import subprocess
  
  from nikola.plugin_categories import TaskMultiplier
  
  
  class GzipFiles(TaskMultiplier):
      """If appropiate, create tasks to create gzipped versions of files."""
  
      name = "gzip"
      is_default = True
  
      def process(self, task, prefix):
          if not self.site.config['GZIP_FILES']:
              return []
          if task.get('name') is None:
              return []
          gzip_task = {
              'file_dep': [],
              'targets': [],
              'actions': [],
              'basename': '{0}_gzip'.format(prefix),
              'name': task.get('name').split(":", 1)[-1] + '.gz',
              'clean': True,
          }
          targets = task.get('targets', [])
          flag = False
          for target in targets:
              ext = os.path.splitext(target)[1]
              if (ext.lower() in self.site.config['GZIP_EXTENSIONS'] and
                      target.startswith(self.site.config['OUTPUT_FOLDER'])):
                  flag = True
                  gzipped = target + '.gz'
                  gzip_task['file_dep'].append(target)
                  gzip_task['targets'].append(gzipped)
                  gzip_task['actions'].append((create_gzipped_copy, (target, gzipped, self.site.config['GZIP_COMMAND'])))
          if not flag:
              return []
          return [gzip_task]
  
  
  def create_gzipped_copy(in_path, out_path, command=None):
      if command:
          subprocess.check_call(shlex.split(command.format(filename=in_path)))
      else:
          with gzip.GzipFile(out_path, 'wb+') as outf:
              with open(in_path, 'rb') as inf:
                  outf.write(inf.read())
  