git.cworth.org Git - apitrace/blob - scripts/jsondiff.py

   1 #!/usr/bin/env python
   2 ##########################################################################
   3 #
   4 # Copyright 2011 Jose Fonseca
   5 # All Rights Reserved.
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the "Software"), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23 # THE SOFTWARE.
  24 #
  25 ##########################################################################/
  26
  27
  28 import json
  29 import sys
  30
  31
  32 def strip_object_hook(obj):
  33     if '__class__' in obj:
  34         return None
  35     for name in obj.keys():
  36         if name.startswith('__') and name.endswith('__'):
  37             del obj[name]
  38     return obj
  39
  40
  41 class Visitor:
  42
  43     def visit(self, node, *args, **kwargs):
  44         if isinstance(node, dict):
  45             return self.visit_object(node, *args, **kwargs)
  46         elif isinstance(node, list):
  47             return self.visit_array(node, *args, **kwargs)
  48         else:
  49             return self.visit_value(node, *args, **kwargs)
  50
  51     def visit_object(self, node, *args, **kwargs):
  52         pass
  53
  54     def visit_array(self, node, *args, **kwargs):
  55         pass
  56
  57     def visit_value(self, node, *args, **kwargs):
  58         pass
  59
  60
  61 class Dumper(Visitor):
  62
  63     def __init__(self, stream = sys.stdout):
  64         self.stream = stream
  65         self.level = 0
  66
  67     def _write(self, s):
  68         self.stream.write(s)
  69
  70     def _indent(self):
  71         self._write('  '*self.level)
  72
  73     def _newline(self):
  74         self._write('\n')
  75
  76     def visit_object(self, node):
  77         self.enter_object()
  78
  79         members = node.keys()
  80         members.sort()
  81         for i in range(len(members)):
  82             name = members[i]
  83             value = node[name]
  84             self.enter_member(name)
  85             self.visit(value)
  86             self.leave_member(i == len(members) - 1)
  87         self.leave_object()
  88
  89     def enter_object(self):
  90         self._write('{')
  91         self._newline()
  92         self.level += 1
  93
  94     def enter_member(self, name):
  95         self._indent()
  96         self._write('%s: ' % name)
  97
  98     def leave_member(self, last):
  99         if not last:
 100             self._write(',')
 101         self._newline()
 102
 103     def leave_object(self):
 104         self.level -= 1
 105         self._indent()
 106         self._write('}')
 107         if self.level <= 0:
 108             self._newline()
 109
 110     def visit_array(self, node):
 111         self.enter_array()
 112         for i in range(len(node)):
 113             value = node[i]
 114             self._indent()
 115             self.visit(value)
 116             if i != len(node) - 1:
 117                 self._write(',')
 118             self._newline()
 119         self.leave_array()
 120
 121     def enter_array(self):
 122         self._write('[')
 123         self._newline()
 124         self.level += 1
 125
 126     def leave_array(self):
 127         self.level -= 1
 128         self._indent()
 129         self._write(']')
 130
 131     def visit_value(self, node):
 132         self._write(json.dumps(node))
 133
 134
 135
 136 class Comparer(Visitor):
 137
 138     def __init__(self, ignore_added = False):
 139         self.ignore_added = ignore_added
 140
 141     def visit_object(self, a, b):
 142         if not isinstance(b, dict):
 143             return False
 144         if len(a) != len(b) and not self.ignore_added:
 145             return False
 146         ak = a.keys()
 147         bk = b.keys()
 148         ak.sort()
 149         bk.sort()
 150         if ak != bk and not self.ignore_added:
 151             return False
 152         for k in ak:
 153             ae = a[k]
 154             try:
 155                 be = b[k]
 156             except KeyError:
 157                 return False
 158             if not self.visit(ae, be):
 159                 return False
 160         return True
 161
 162     def visit_array(self, a, b):
 163         if not isinstance(b, list):
 164             return False
 165         if len(a) != len(b):
 166             return False
 167         for ae, be in zip(a, b):
 168             if not self.visit(ae, be):
 169                 return False
 170         return True
 171
 172     def visit_value(self, a, b):
 173         return a == b
 174
 175
 176
 177 class Differ(Visitor):
 178
 179     def __init__(self, stream = sys.stdout, ignore_added = False):
 180         self.dumper = Dumper(stream)
 181         self.comparer = Comparer(ignore_added = ignore_added)
 182
 183     def visit(self, a, b):
 184         if self.comparer.visit(a, b):
 185             return
 186         Visitor.visit(self, a, b)
 187
 188     def visit_object(self, a, b):
 189         if not isinstance(b, dict):
 190             self.replace(a, b)
 191         else:
 192             self.dumper.enter_object()
 193             names = set(a.keys())
 194             if not self.comparer.ignore_added:
 195                 names.update(b.keys())
 196             names = list(names)
 197             names.sort()
 198
 199             for i in range(len(names)):
 200                 name = names[i]
 201                 ae = a.get(name, None)
 202                 be = b.get(name, None)
 203                 if not self.comparer.visit(ae, be):
 204                     self.dumper.enter_member(name)
 205                     self.visit(ae, be)
 206                     self.dumper.leave_member(i == len(names) - 1)
 207
 208             self.dumper.leave_object()
 209
 210     def visit_array(self, a, b):
 211         if not isinstance(b, list):
 212             self.replace(a, b)
 213         else:
 214             self.dumper.enter_array()
 215             max_len = max(len(a), len(b))
 216             for i in range(max_len):
 217                 try:
 218                     ae = a[i]
 219                 except IndexError:
 220                     ae = None
 221                 try:
 222                     be = b[i]
 223                 except IndexError:
 224                     be = None
 225                 self.dumper._indent()
 226                 if self.comparer.visit(ae, be):
 227                     self.dumper.visit(ae)
 228                 else:
 229                     self.visit(ae, be)
 230                 if i != max_len - 1:
 231                     self.dumper._write(',')
 232                 self.dumper._newline()
 233
 234             self.dumper.leave_array()
 235
 236     def visit_value(self, a, b):
 237         if a != b:
 238             self.replace(a, b)
 239
 240     def replace(self, a, b):
 241         self.dumper.visit(a)
 242         self.dumper._write(' -> ')
 243         self.dumper.visit(b)
 244
 245
 246 def load(stream, strip = True):
 247     if strip:
 248         object_hook = strip_object_hook
 249     else:
 250         object_hook = None
 251     return json.load(stream, strict=False, object_hook = object_hook)
 252
 253
 254 def main():
 255     a = load(open(sys.argv[1], 'rt'))
 256     b = load(open(sys.argv[2], 'rt'))
 257
 258     if False:
 259         dumper = Dumper()
 260         dumper.visit(a)
 261
 262     differ = Differ()
 263     differ.visit(a, b)
 264
 265
 266 if __name__ == '__main__':
 267     main()