1# Copyright (c) 2012 The Chromium Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5import copy 6 7import json_parse 8 9 10def DeleteNodes(item, delete_key=None, matcher=None): 11 """Deletes certain nodes in item, recursively. If |delete_key| is set, all 12 dicts with |delete_key| as an attribute are deleted. If a callback is passed 13 as |matcher|, |DeleteNodes| will delete all dicts for which matcher(dict) 14 returns True. 15 """ 16 assert (delete_key is not None) != (matcher is not None) 17 18 def ShouldDelete(thing): 19 return json_parse.IsDict(thing) and ( 20 delete_key is not None and delete_key in thing or 21 matcher is not None and matcher(thing)) 22 23 if json_parse.IsDict(item): 24 toDelete = [] 25 for key, value in item.items(): 26 if ShouldDelete(value): 27 toDelete.append(key) 28 else: 29 DeleteNodes(value, delete_key, matcher) 30 for key in toDelete: 31 del item[key] 32 elif type(item) == list: 33 item[:] = [DeleteNodes(thing, delete_key, matcher) 34 for thing in item if not ShouldDelete(thing)] 35 36 return item 37 38 39def Load(filename): 40 with open(filename, 'r') as handle: 41 schemas = json_parse.Parse(handle.read()) 42 return schemas 43 44 45# A dictionary mapping |filename| to the object resulting from loading the JSON 46# at |filename|. 47_cache = {} 48 49 50def CachedLoad(filename): 51 """Equivalent to Load(filename), but caches results for subsequent calls""" 52 if filename not in _cache: 53 _cache[filename] = Load(filename) 54 # Return a copy of the object so that any changes a caller makes won't affect 55 # the next caller. 56 return copy.deepcopy(_cache[filename]) 57 58