improvements for extended json serializer

rhodecode/lib/compat.py

@@ -1,448 +1,476
 # -*- coding: utf-8 -*-
 """
     rhodecode.lib.compat
     ~~~~~~~~~~~~~~~~~~~~
 
     Python backward compatibility functions and common libs
 
 
     :created_on: Oct 7, 2011
     :author: marcink
     :copyright: (C) 2010-2010 Marcin Kuzminski <[e-mail]>
     :license: GPLv3, see COPYING for more details.
 """
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
 import datetime
 import functools
+import decimal
 from rhodecode import __platform__, PLATFORM_WIN
 
 #==============================================================================
 # json
 #==============================================================================
 
 
+def _is_aware(value):
+    """
+    Determines if a given datetime.time is aware.
+
+    The logic is described in Python's docs:
+    http://docs.python.org/library/datetime.html#datetime.tzinfo
+    """
+    return (value.tzinfo is not None
+            and value.tzinfo.utcoffset(value) is not None)
+
+
 def _obj_dump(obj):
     """
-    Custom function for dumping objects to JSON
+    Custom function for dumping objects to JSON, if obj has __json__ attribute
+    or method defined it will be used for serialization
 
     :param obj:
     """
-    DATETIME_FORMAT = "%Y-%m-%dT%H:%M:%S"
-    DATE_FORMAT = "%Y-%m-%d"
+
     if isinstance(obj, complex):
         return [obj.real, obj.imag]
+    # See "Date Time String Format" in the ECMA-262 specification.
+    # some code borrowed from django 1.4
     elif isinstance(obj, datetime.datetime):
-        return obj.strftime(DATETIME_FORMAT)
+        r = obj.isoformat()
+        if obj.microsecond:
+            r = r[:23] + r[26:]
+        if r.endswith('+00:00'):
+            r = r[:-6] + 'Z'
+        return r
     elif isinstance(obj, datetime.date):
-        return obj.strftime(DATE_FORMAT)
+        return obj.isoformat()
+    elif isinstance(obj, decimal.Decimal):
+        return str(obj)
+    elif isinstance(obj, datetime.time):
+        if _is_aware(obj):
+            raise ValueError("JSON can't represent timezone-aware times.")
+        r = obj.isoformat()
+        if obj.microsecond:
+            r = r[:12]
+        return r
     elif isinstance(obj, set):
         return list(obj)
     elif isinstance(obj, OrderedDict):
         return obj.as_dict()
     elif hasattr(obj, '__json__'):
         if callable(obj.__json__):
             return obj.__json__()
         else:
             return obj.__json__
     else:
         raise NotImplementedError
 
 try:
     import json
 
     # extended JSON encoder for json
     class ExtendedEncoder(json.JSONEncoder):
         def default(self, obj):
             try:
                 return _obj_dump(obj)
             except NotImplementedError:
                 pass
             return json.JSONEncoder.default(self, obj)
     # monkey-patch JSON encoder to use extended version
     json.dumps = functools.partial(json.dumps, cls=ExtendedEncoder)
 except ImportError:
     import simplejson as json
 
     def extended_encode(obj):
         try:
             return _obj_dump(obj)
         except NotImplementedError:
             pass
         raise TypeError("%r is not JSON serializable" % (obj,))
     json.dumps = functools.partial(json.dumps, default=extended_encode)
 
 
 #==============================================================================
 # izip_longest
 #==============================================================================
 try:
     from itertools import izip_longest
 except ImportError:
     import itertools
 
     def izip_longest(*args, **kwds):
         fillvalue = kwds.get("fillvalue")
 
         def sentinel(counter=([fillvalue] * (len(args) - 1)).pop):
             yield counter()  # yields the fillvalue, or raises IndexError
 
         fillers = itertools.repeat(fillvalue)
         iters = [itertools.chain(it, sentinel(), fillers)
                     for it in args]
         try:
             for tup in itertools.izip(*iters):
                 yield tup
         except IndexError:
             pass
 
 
 #==============================================================================
 # OrderedDict
 #==============================================================================
 
 # Python Software Foundation License
 
 # XXX: it feels like using the class with "is" and "is not" instead of "==" and
 # "!=" should be faster.
 class _Nil(object):
 
     def __repr__(self):
         return "nil"
 
     def __eq__(self, other):
         if (isinstance(other, _Nil)):
             return True
         else:
             return NotImplemented
 
     def __ne__(self, other):
         if (isinstance(other, _Nil)):
             return False
         else:
             return NotImplemented
 
 _nil = _Nil()
 
 
 class _odict(object):
     """Ordered dict data structure, with O(1) complexity for dict operations
     that modify one element.
 
     Overwriting values doesn't change their original sequential order.
     """
 
     def _dict_impl(self):
         return None
 
     def __init__(self, data=(), **kwds):
         """This doesn't accept keyword initialization as normal dicts to avoid
         a trap - inside a function or method the keyword args are accessible
         only as a dict, without a defined order, so their original order is
         lost.
         """
         if kwds:
             raise TypeError("__init__() of ordered dict takes no keyword "
                             "arguments to avoid an ordering trap.")
         self._dict_impl().__init__(self)
         # If you give a normal dict, then the order of elements is undefined
         if hasattr(data, "iteritems"):
             for key, val in data.iteritems():
                 self[key] = val
         else:
             for key, val in data:
                 self[key] = val
 
     # Double-linked list header
     def _get_lh(self):
         dict_impl = self._dict_impl()
         if not hasattr(self, '_lh'):
             dict_impl.__setattr__(self, '_lh', _nil)
         return dict_impl.__getattribute__(self, '_lh')
 
     def _set_lh(self, val):
         self._dict_impl().__setattr__(self, '_lh', val)
 
     lh = property(_get_lh, _set_lh)
 
     # Double-linked list tail
     def _get_lt(self):
         dict_impl = self._dict_impl()
         if not hasattr(self, '_lt'):
             dict_impl.__setattr__(self, '_lt', _nil)
         return dict_impl.__getattribute__(self, '_lt')
 
     def _set_lt(self, val):
         self._dict_impl().__setattr__(self, '_lt', val)
 
     lt = property(_get_lt, _set_lt)
 
     def __getitem__(self, key):
         return self._dict_impl().__getitem__(self, key)[1]
 
     def __setitem__(self, key, val):
         dict_impl = self._dict_impl()
         try:
             dict_impl.__getitem__(self, key)[1] = val
         except KeyError:
             new = [dict_impl.__getattribute__(self, 'lt'), val, _nil]
             dict_impl.__setitem__(self, key, new)
             if dict_impl.__getattribute__(self, 'lt') == _nil:
                 dict_impl.__setattr__(self, 'lh', key)
             else:
                 dict_impl.__getitem__(
                     self, dict_impl.__getattribute__(self, 'lt'))[2] = key
             dict_impl.__setattr__(self, 'lt', key)
 
     def __delitem__(self, key):
         dict_impl = self._dict_impl()
         pred, _, succ = self._dict_impl().__getitem__(self, key)
         if pred == _nil:
             dict_impl.__setattr__(self, 'lh', succ)
         else:
             dict_impl.__getitem__(self, pred)[2] = succ
         if succ == _nil:
             dict_impl.__setattr__(self, 'lt', pred)
         else:
             dict_impl.__getitem__(self, succ)[0] = pred
         dict_impl.__delitem__(self, key)
 
     def __contains__(self, key):
         return key in self.keys()
 
     def __len__(self):
         return len(self.keys())
 
     def __str__(self):
         pairs = ("%r: %r" % (k, v) for k, v in self.iteritems())
         return "{%s}" % ", ".join(pairs)
 
     def __repr__(self):
         if self:
             pairs = ("(%r, %r)" % (k, v) for k, v in self.iteritems())
             return "odict([%s])" % ", ".join(pairs)
         else:
             return "odict()"
 
     def get(self, k, x=None):
         if k in self:
             return self._dict_impl().__getitem__(self, k)[1]
         else:
             return x
 
     def __iter__(self):
         dict_impl = self._dict_impl()
         curr_key = dict_impl.__getattribute__(self, 'lh')
         while curr_key != _nil:
             yield curr_key
             curr_key = dict_impl.__getitem__(self, curr_key)[2]
 
     iterkeys = __iter__
 
     def keys(self):
         return list(self.iterkeys())
 
     def itervalues(self):
         dict_impl = self._dict_impl()
         curr_key = dict_impl.__getattribute__(self, 'lh')
         while curr_key != _nil:
             _, val, curr_key = dict_impl.__getitem__(self, curr_key)
             yield val
 
     def values(self):
         return list(self.itervalues())
 
     def iteritems(self):
         dict_impl = self._dict_impl()
         curr_key = dict_impl.__getattribute__(self, 'lh')
         while curr_key != _nil:
             _, val, next_key = dict_impl.__getitem__(self, curr_key)
             yield curr_key, val
             curr_key = next_key
 
     def items(self):
         return list(self.iteritems())
 
     def sort(self, cmp=None, key=None, reverse=False):
         items = [(k, v) for k, v in self.items()]
         if cmp is not None:
             items = sorted(items, cmp=cmp)
         elif key is not None:
             items = sorted(items, key=key)
         else:
             items = sorted(items, key=lambda x: x[1])
         if reverse:
             items.reverse()
         self.clear()
         self.__init__(items)
 
     def clear(self):
         dict_impl = self._dict_impl()
         dict_impl.clear(self)
         dict_impl.__setattr__(self, 'lh', _nil)
         dict_impl.__setattr__(self, 'lt', _nil)
 
     def copy(self):
         return self.__class__(self)
 
     def update(self, data=(), **kwds):
         if kwds:
             raise TypeError("update() of ordered dict takes no keyword "
                             "arguments to avoid an ordering trap.")
         if hasattr(data, "iteritems"):
             data = data.iteritems()
         for key, val in data:
             self[key] = val
 
     def setdefault(self, k, x=None):
         try:
             return self[k]
         except KeyError:
             self[k] = x
             return x
 
     def pop(self, k, x=_nil):
         try:
             val = self[k]
             del self[k]
             return val
         except KeyError:
             if x == _nil:
                 raise
             return x
 
     def popitem(self):
         try:
             dict_impl = self._dict_impl()
             key = dict_impl.__getattribute__(self, 'lt')
             return key, self.pop(key)
         except KeyError:
             raise KeyError("'popitem(): ordered dictionary is empty'")
 
     def riterkeys(self):
         """To iterate on keys in reversed order.
         """
         dict_impl = self._dict_impl()
         curr_key = dict_impl.__getattribute__(self, 'lt')
         while curr_key != _nil:
             yield curr_key
             curr_key = dict_impl.__getitem__(self, curr_key)[0]
 
     __reversed__ = riterkeys
 
     def rkeys(self):
         """List of the keys in reversed order.
         """
         return list(self.riterkeys())
 
     def ritervalues(self):
         """To iterate on values in reversed order.
         """
         dict_impl = self._dict_impl()
         curr_key = dict_impl.__getattribute__(self, 'lt')
         while curr_key != _nil:
             curr_key, val, _ = dict_impl.__getitem__(self, curr_key)
             yield val
 
     def rvalues(self):
         """List of the values in reversed order.
         """
         return list(self.ritervalues())
 
     def riteritems(self):
         """To iterate on (key, value) in reversed order.
         """
         dict_impl = self._dict_impl()
         curr_key = dict_impl.__getattribute__(self, 'lt')
         while curr_key != _nil:
             pred_key, val, _ = dict_impl.__getitem__(self, curr_key)
             yield curr_key, val
             curr_key = pred_key
 
     def ritems(self):
         """List of the (key, value) in reversed order.
         """
         return list(self.riteritems())
 
     def firstkey(self):
         if self:
             return self._dict_impl().__getattribute__(self, 'lh')
         else:
             raise KeyError("'firstkey(): ordered dictionary is empty'")
 
     def lastkey(self):
         if self:
             return self._dict_impl().__getattribute__(self, 'lt')
         else:
             raise KeyError("'lastkey(): ordered dictionary is empty'")
 
     def as_dict(self):
         return self._dict_impl()(self.items())
 
     def _repr(self):
         """_repr(): low level repr of the whole data contained in the odict.
         Useful for debugging.
         """
         dict_impl = self._dict_impl()
         form = "odict low level repr lh,lt,data: %r, %r, %s"
         return form % (dict_impl.__getattribute__(self, 'lh'),
                        dict_impl.__getattribute__(self, 'lt'),
                        dict_impl.__repr__(self))
 
 
 class OrderedDict(_odict, dict):
 
     def _dict_impl(self):
         return dict
 
 
 #==============================================================================
 # OrderedSet
 #==============================================================================
 from sqlalchemy.util import OrderedSet
 
 
 #==============================================================================
 # kill FUNCTIONS
 #==============================================================================
 if __platform__ in PLATFORM_WIN:
     import ctypes
 
     def kill(pid, sig):
         """kill function for Win32"""
         kernel32 = ctypes.windll.kernel32
         handle = kernel32.OpenProcess(1, 0, pid)
         return (0 != kernel32.TerminateProcess(handle, 0))
 
 else:
     kill = os.kill
 
 
 #==============================================================================
 # itertools.product
 #==============================================================================
 
 try:
     from itertools import product
 except ImportError:
     def product(*args, **kwds):
         # product('ABCD', 'xy') --> Ax Ay Bx By Cx Cy Dx Dy
         # product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111
         pools = map(tuple, args) * kwds.get('repeat', 1)
         result = [[]]
         for pool in pools:
             result = [x + [y] for x in result for y in pool]
         for prod in result:
             yield tuple(prod)