luci-py/isolateserver.py: Add support for tar archives when downloading.

client/isolated_format.py

 # Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Understands .isolated files and can do local operations on them."""
 
 import hashlib
 import json
 import logging
 import os
 import re
 import stat
 import sys
 
 from utils import file_path
 from utils import fs
 from utils import tools
 
 
 # Version stored and expected in .isolated files.
-ISOLATED_FILE_VERSION = '1.5'
+ISOLATED_FILE_VERSION = '1.6'
 
 
 # Chunk size to use when doing disk I/O.
 DISK_FILE_CHUNK = 1024 * 1024
 
 
 # Sadly, hashlib uses 'sha1' instead of the standard 'sha-1' so explicitly
 # specify the names here.
 SUPPORTED_ALGOS = {
   'md5': hashlib.md5,
   'sha-1': hashlib.sha1,
   'sha-512': hashlib.sha512,
 }
 
 
 # Used for serialization.
 SUPPORTED_ALGOS_REVERSE = dict((v, k) for k, v in SUPPORTED_ALGOS.iteritems())
 
-SUPPORTED_FILE_TYPES = ['basic', 'ar']
+SUPPORTED_FILE_TYPES = ['basic', 'ar', 'tar']
 
 
 class IsolatedError(ValueError):
   """Generic failure to load a .isolated file."""
   pass
 
 
 class MappingError(OSError):
   """Failed to recreate the tree."""
   pass
@@ skipping 516 matching lines @@
     data['files'] = dict(
         (k.replace(wrong_path_sep, os.path.sep), v)
         for k, v in data['files'].iteritems())
     for v in data['files'].itervalues():
       if 'l' in v:
         v['l'] = v['l'].replace(wrong_path_sep, os.path.sep)
   if 'relative_cwd' in data:
     data['relative_cwd'] = data['relative_cwd'].replace(
         wrong_path_sep, os.path.sep)
   return data