Changeset - 3754ee8ab3ad
[Not reviewed]
beta
0 1 0
Marcin Kuzminski - 14 years ago 2012-03-23 20:36:36
marcin@python-works.com
improvements for extended json serializer
1 file changed with 33 insertions and 5 deletions:
0 comments (0 inline, 0 general)
rhodecode/lib/compat.py
Show inline comments
 
# -*- 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 <marcin@python-works.com>
 
    :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:
0 comments (0 inline, 0 general)