932 lines
29 KiB
Python
932 lines
29 KiB
Python
|
# -*- coding: utf-8 -*-
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#
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# python-json-patch - An implementation of the JSON Patch format
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# https://github.com/stefankoegl/python-json-patch
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#
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# Copyright (c) 2011 Stefan Kögl <stefan@skoegl.net>
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# All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions
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# are met:
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#
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# 1. Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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# 3. The name of the author may not be used to endorse or promote products
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# derived from this software without specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#
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""" Apply JSON-Patches (RFC 6902) """
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from __future__ import unicode_literals
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import collections
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import copy
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import functools
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import json
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import sys
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try:
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from collections.abc import Sequence
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except ImportError: # Python 3
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from collections import Sequence
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try:
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from types import MappingProxyType
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except ImportError:
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# Python < 3.3
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MappingProxyType = dict
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from jsonpointer import JsonPointer, JsonPointerException
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_ST_ADD = 0
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_ST_REMOVE = 1
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try:
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from collections.abc import MutableMapping, MutableSequence
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except ImportError:
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from collections import MutableMapping, MutableSequence
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str = unicode
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# Will be parsed by setup.py to determine package metadata
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__author__ = 'Stefan Kögl <stefan@skoegl.net>'
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__version__ = '1.33'
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__website__ = 'https://github.com/stefankoegl/python-json-patch'
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__license__ = 'Modified BSD License'
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# pylint: disable=E0611,W0404
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if sys.version_info >= (3, 0):
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basestring = (bytes, str) # pylint: disable=C0103,W0622
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class JsonPatchException(Exception):
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"""Base Json Patch exception"""
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class InvalidJsonPatch(JsonPatchException):
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""" Raised if an invalid JSON Patch is created """
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class JsonPatchConflict(JsonPatchException):
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"""Raised if patch could not be applied due to conflict situation such as:
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- attempt to add object key when it already exists;
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- attempt to operate with nonexistence object key;
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- attempt to insert value to array at position beyond its size;
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- etc.
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"""
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class JsonPatchTestFailed(JsonPatchException, AssertionError):
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""" A Test operation failed """
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def multidict(ordered_pairs):
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"""Convert duplicate keys values to lists."""
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# read all values into lists
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mdict = collections.defaultdict(list)
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for key, value in ordered_pairs:
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mdict[key].append(value)
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return dict(
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# unpack lists that have only 1 item
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(key, values[0] if len(values) == 1 else values)
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for key, values in mdict.items()
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)
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# The "object_pairs_hook" parameter is used to handle duplicate keys when
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# loading a JSON object.
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_jsonloads = functools.partial(json.loads, object_pairs_hook=multidict)
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def apply_patch(doc, patch, in_place=False, pointer_cls=JsonPointer):
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"""Apply list of patches to specified json document.
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:param doc: Document object.
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:type doc: dict
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:param patch: JSON patch as list of dicts or raw JSON-encoded string.
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:type patch: list or str
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:param in_place: While :const:`True` patch will modify target document.
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By default patch will be applied to document copy.
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:type in_place: bool
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:param pointer_cls: JSON pointer class to use.
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:type pointer_cls: Type[JsonPointer]
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:return: Patched document object.
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:rtype: dict
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>>> doc = {'foo': 'bar'}
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>>> patch = [{'op': 'add', 'path': '/baz', 'value': 'qux'}]
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>>> other = apply_patch(doc, patch)
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>>> doc is not other
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True
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>>> other == {'foo': 'bar', 'baz': 'qux'}
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True
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>>> patch = [{'op': 'add', 'path': '/baz', 'value': 'qux'}]
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>>> apply_patch(doc, patch, in_place=True) == {'foo': 'bar', 'baz': 'qux'}
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True
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>>> doc == other
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True
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"""
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if isinstance(patch, basestring):
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patch = JsonPatch.from_string(patch, pointer_cls=pointer_cls)
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else:
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patch = JsonPatch(patch, pointer_cls=pointer_cls)
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return patch.apply(doc, in_place)
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def make_patch(src, dst, pointer_cls=JsonPointer):
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"""Generates patch by comparing two document objects. Actually is
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a proxy to :meth:`JsonPatch.from_diff` method.
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:param src: Data source document object.
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:type src: dict
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:param dst: Data source document object.
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:type dst: dict
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:param pointer_cls: JSON pointer class to use.
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:type pointer_cls: Type[JsonPointer]
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>>> src = {'foo': 'bar', 'numbers': [1, 3, 4, 8]}
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>>> dst = {'baz': 'qux', 'numbers': [1, 4, 7]}
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>>> patch = make_patch(src, dst)
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>>> new = patch.apply(src)
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>>> new == dst
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True
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"""
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return JsonPatch.from_diff(src, dst, pointer_cls=pointer_cls)
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class PatchOperation(object):
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"""A single operation inside a JSON Patch."""
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def __init__(self, operation, pointer_cls=JsonPointer):
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self.pointer_cls = pointer_cls
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if not operation.__contains__('path'):
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raise InvalidJsonPatch("Operation must have a 'path' member")
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if isinstance(operation['path'], self.pointer_cls):
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self.location = operation['path'].path
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self.pointer = operation['path']
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else:
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self.location = operation['path']
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try:
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self.pointer = self.pointer_cls(self.location)
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except TypeError as ex:
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raise InvalidJsonPatch("Invalid 'path'")
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self.operation = operation
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def apply(self, obj):
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"""Abstract method that applies a patch operation to the specified object."""
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raise NotImplementedError('should implement the patch operation.')
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def __hash__(self):
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return hash(frozenset(self.operation.items()))
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def __eq__(self, other):
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if not isinstance(other, PatchOperation):
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return False
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return self.operation == other.operation
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def __ne__(self, other):
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return not(self == other)
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@property
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def path(self):
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return '/'.join(self.pointer.parts[:-1])
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@property
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def key(self):
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try:
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return int(self.pointer.parts[-1])
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except ValueError:
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return self.pointer.parts[-1]
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@key.setter
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def key(self, value):
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self.pointer.parts[-1] = str(value)
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self.location = self.pointer.path
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self.operation['path'] = self.location
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class RemoveOperation(PatchOperation):
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"""Removes an object property or an array element."""
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def apply(self, obj):
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subobj, part = self.pointer.to_last(obj)
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if isinstance(subobj, Sequence) and not isinstance(part, int):
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raise JsonPointerException("invalid array index '{0}'".format(part))
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try:
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del subobj[part]
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except (KeyError, IndexError) as ex:
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msg = "can't remove a non-existent object '{0}'".format(part)
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raise JsonPatchConflict(msg)
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return obj
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def _on_undo_remove(self, path, key):
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if self.path == path:
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if self.key >= key:
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self.key += 1
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else:
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key -= 1
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return key
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|
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def _on_undo_add(self, path, key):
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|
if self.path == path:
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if self.key > key:
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self.key -= 1
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else:
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key -= 1
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return key
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|
|
||
|
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||
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class AddOperation(PatchOperation):
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"""Adds an object property or an array element."""
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|
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def apply(self, obj):
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try:
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|
value = self.operation["value"]
|
||
|
except KeyError as ex:
|
||
|
raise InvalidJsonPatch(
|
||
|
"The operation does not contain a 'value' member")
|
||
|
|
||
|
subobj, part = self.pointer.to_last(obj)
|
||
|
|
||
|
if isinstance(subobj, MutableSequence):
|
||
|
if part == '-':
|
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|
subobj.append(value) # pylint: disable=E1103
|
||
|
|
||
|
elif part > len(subobj) or part < 0:
|
||
|
raise JsonPatchConflict("can't insert outside of list")
|
||
|
|
||
|
else:
|
||
|
subobj.insert(part, value) # pylint: disable=E1103
|
||
|
|
||
|
elif isinstance(subobj, MutableMapping):
|
||
|
if part is None:
|
||
|
obj = value # we're replacing the root
|
||
|
else:
|
||
|
subobj[part] = value
|
||
|
|
||
|
else:
|
||
|
if part is None:
|
||
|
raise TypeError("invalid document type {0}".format(type(subobj)))
|
||
|
else:
|
||
|
raise JsonPatchConflict("unable to fully resolve json pointer {0}, part {1}".format(self.location, part))
|
||
|
return obj
|
||
|
|
||
|
def _on_undo_remove(self, path, key):
|
||
|
if self.path == path:
|
||
|
if self.key > key:
|
||
|
self.key += 1
|
||
|
else:
|
||
|
key += 1
|
||
|
return key
|
||
|
|
||
|
def _on_undo_add(self, path, key):
|
||
|
if self.path == path:
|
||
|
if self.key > key:
|
||
|
self.key -= 1
|
||
|
else:
|
||
|
key += 1
|
||
|
return key
|
||
|
|
||
|
|
||
|
class ReplaceOperation(PatchOperation):
|
||
|
"""Replaces an object property or an array element by a new value."""
|
||
|
|
||
|
def apply(self, obj):
|
||
|
try:
|
||
|
value = self.operation["value"]
|
||
|
except KeyError as ex:
|
||
|
raise InvalidJsonPatch(
|
||
|
"The operation does not contain a 'value' member")
|
||
|
|
||
|
subobj, part = self.pointer.to_last(obj)
|
||
|
|
||
|
if part is None:
|
||
|
return value
|
||
|
|
||
|
if part == "-":
|
||
|
raise InvalidJsonPatch("'path' with '-' can't be applied to 'replace' operation")
|
||
|
|
||
|
if isinstance(subobj, MutableSequence):
|
||
|
if part >= len(subobj) or part < 0:
|
||
|
raise JsonPatchConflict("can't replace outside of list")
|
||
|
|
||
|
elif isinstance(subobj, MutableMapping):
|
||
|
if part not in subobj:
|
||
|
msg = "can't replace a non-existent object '{0}'".format(part)
|
||
|
raise JsonPatchConflict(msg)
|
||
|
else:
|
||
|
if part is None:
|
||
|
raise TypeError("invalid document type {0}".format(type(subobj)))
|
||
|
else:
|
||
|
raise JsonPatchConflict("unable to fully resolve json pointer {0}, part {1}".format(self.location, part))
|
||
|
|
||
|
subobj[part] = value
|
||
|
return obj
|
||
|
|
||
|
def _on_undo_remove(self, path, key):
|
||
|
return key
|
||
|
|
||
|
def _on_undo_add(self, path, key):
|
||
|
return key
|
||
|
|
||
|
|
||
|
class MoveOperation(PatchOperation):
|
||
|
"""Moves an object property or an array element to a new location."""
|
||
|
|
||
|
def apply(self, obj):
|
||
|
try:
|
||
|
if isinstance(self.operation['from'], self.pointer_cls):
|
||
|
from_ptr = self.operation['from']
|
||
|
else:
|
||
|
from_ptr = self.pointer_cls(self.operation['from'])
|
||
|
except KeyError as ex:
|
||
|
raise InvalidJsonPatch(
|
||
|
"The operation does not contain a 'from' member")
|
||
|
|
||
|
subobj, part = from_ptr.to_last(obj)
|
||
|
try:
|
||
|
value = subobj[part]
|
||
|
except (KeyError, IndexError) as ex:
|
||
|
raise JsonPatchConflict(str(ex))
|
||
|
|
||
|
# If source and target are equal, this is a no-op
|
||
|
if self.pointer == from_ptr:
|
||
|
return obj
|
||
|
|
||
|
if isinstance(subobj, MutableMapping) and \
|
||
|
self.pointer.contains(from_ptr):
|
||
|
raise JsonPatchConflict('Cannot move values into their own children')
|
||
|
|
||
|
obj = RemoveOperation({
|
||
|
'op': 'remove',
|
||
|
'path': self.operation['from']
|
||
|
}, pointer_cls=self.pointer_cls).apply(obj)
|
||
|
|
||
|
obj = AddOperation({
|
||
|
'op': 'add',
|
||
|
'path': self.location,
|
||
|
'value': value
|
||
|
}, pointer_cls=self.pointer_cls).apply(obj)
|
||
|
|
||
|
return obj
|
||
|
|
||
|
@property
|
||
|
def from_path(self):
|
||
|
from_ptr = self.pointer_cls(self.operation['from'])
|
||
|
return '/'.join(from_ptr.parts[:-1])
|
||
|
|
||
|
@property
|
||
|
def from_key(self):
|
||
|
from_ptr = self.pointer_cls(self.operation['from'])
|
||
|
try:
|
||
|
return int(from_ptr.parts[-1])
|
||
|
except TypeError:
|
||
|
return from_ptr.parts[-1]
|
||
|
|
||
|
@from_key.setter
|
||
|
def from_key(self, value):
|
||
|
from_ptr = self.pointer_cls(self.operation['from'])
|
||
|
from_ptr.parts[-1] = str(value)
|
||
|
self.operation['from'] = from_ptr.path
|
||
|
|
||
|
def _on_undo_remove(self, path, key):
|
||
|
if self.from_path == path:
|
||
|
if self.from_key >= key:
|
||
|
self.from_key += 1
|
||
|
else:
|
||
|
key -= 1
|
||
|
if self.path == path:
|
||
|
if self.key > key:
|
||
|
self.key += 1
|
||
|
else:
|
||
|
key += 1
|
||
|
return key
|
||
|
|
||
|
def _on_undo_add(self, path, key):
|
||
|
if self.from_path == path:
|
||
|
if self.from_key > key:
|
||
|
self.from_key -= 1
|
||
|
else:
|
||
|
key -= 1
|
||
|
if self.path == path:
|
||
|
if self.key > key:
|
||
|
self.key -= 1
|
||
|
else:
|
||
|
key += 1
|
||
|
return key
|
||
|
|
||
|
|
||
|
class TestOperation(PatchOperation):
|
||
|
"""Test value by specified location."""
|
||
|
|
||
|
def apply(self, obj):
|
||
|
try:
|
||
|
subobj, part = self.pointer.to_last(obj)
|
||
|
if part is None:
|
||
|
val = subobj
|
||
|
else:
|
||
|
val = self.pointer.walk(subobj, part)
|
||
|
except JsonPointerException as ex:
|
||
|
raise JsonPatchTestFailed(str(ex))
|
||
|
|
||
|
try:
|
||
|
value = self.operation['value']
|
||
|
except KeyError as ex:
|
||
|
raise InvalidJsonPatch(
|
||
|
"The operation does not contain a 'value' member")
|
||
|
|
||
|
if val != value:
|
||
|
msg = '{0} ({1}) is not equal to tested value {2} ({3})'
|
||
|
raise JsonPatchTestFailed(msg.format(val, type(val),
|
||
|
value, type(value)))
|
||
|
|
||
|
return obj
|
||
|
|
||
|
|
||
|
class CopyOperation(PatchOperation):
|
||
|
""" Copies an object property or an array element to a new location """
|
||
|
|
||
|
def apply(self, obj):
|
||
|
try:
|
||
|
from_ptr = self.pointer_cls(self.operation['from'])
|
||
|
except KeyError as ex:
|
||
|
raise InvalidJsonPatch(
|
||
|
"The operation does not contain a 'from' member")
|
||
|
|
||
|
subobj, part = from_ptr.to_last(obj)
|
||
|
try:
|
||
|
value = copy.deepcopy(subobj[part])
|
||
|
except (KeyError, IndexError) as ex:
|
||
|
raise JsonPatchConflict(str(ex))
|
||
|
|
||
|
obj = AddOperation({
|
||
|
'op': 'add',
|
||
|
'path': self.location,
|
||
|
'value': value
|
||
|
}, pointer_cls=self.pointer_cls).apply(obj)
|
||
|
|
||
|
return obj
|
||
|
|
||
|
|
||
|
class JsonPatch(object):
|
||
|
json_dumper = staticmethod(json.dumps)
|
||
|
json_loader = staticmethod(_jsonloads)
|
||
|
|
||
|
operations = MappingProxyType({
|
||
|
'remove': RemoveOperation,
|
||
|
'add': AddOperation,
|
||
|
'replace': ReplaceOperation,
|
||
|
'move': MoveOperation,
|
||
|
'test': TestOperation,
|
||
|
'copy': CopyOperation,
|
||
|
})
|
||
|
|
||
|
"""A JSON Patch is a list of Patch Operations.
|
||
|
|
||
|
>>> patch = JsonPatch([
|
||
|
... {'op': 'add', 'path': '/foo', 'value': 'bar'},
|
||
|
... {'op': 'add', 'path': '/baz', 'value': [1, 2, 3]},
|
||
|
... {'op': 'remove', 'path': '/baz/1'},
|
||
|
... {'op': 'test', 'path': '/baz', 'value': [1, 3]},
|
||
|
... {'op': 'replace', 'path': '/baz/0', 'value': 42},
|
||
|
... {'op': 'remove', 'path': '/baz/1'},
|
||
|
... ])
|
||
|
>>> doc = {}
|
||
|
>>> result = patch.apply(doc)
|
||
|
>>> expected = {'foo': 'bar', 'baz': [42]}
|
||
|
>>> result == expected
|
||
|
True
|
||
|
|
||
|
JsonPatch object is iterable, so you can easily access each patch
|
||
|
statement in a loop:
|
||
|
|
||
|
>>> lpatch = list(patch)
|
||
|
>>> expected = {'op': 'add', 'path': '/foo', 'value': 'bar'}
|
||
|
>>> lpatch[0] == expected
|
||
|
True
|
||
|
>>> lpatch == patch.patch
|
||
|
True
|
||
|
|
||
|
Also JsonPatch could be converted directly to :class:`bool` if it contains
|
||
|
any operation statements:
|
||
|
|
||
|
>>> bool(patch)
|
||
|
True
|
||
|
>>> bool(JsonPatch([]))
|
||
|
False
|
||
|
|
||
|
This behavior is very handy with :func:`make_patch` to write more readable
|
||
|
code:
|
||
|
|
||
|
>>> old = {'foo': 'bar', 'numbers': [1, 3, 4, 8]}
|
||
|
>>> new = {'baz': 'qux', 'numbers': [1, 4, 7]}
|
||
|
>>> patch = make_patch(old, new)
|
||
|
>>> if patch:
|
||
|
... # document have changed, do something useful
|
||
|
... patch.apply(old) #doctest: +ELLIPSIS
|
||
|
{...}
|
||
|
"""
|
||
|
def __init__(self, patch, pointer_cls=JsonPointer):
|
||
|
self.patch = patch
|
||
|
self.pointer_cls = pointer_cls
|
||
|
|
||
|
# Verify that the structure of the patch document
|
||
|
# is correct by retrieving each patch element.
|
||
|
# Much of the validation is done in the initializer
|
||
|
# though some is delayed until the patch is applied.
|
||
|
for op in self.patch:
|
||
|
# We're only checking for basestring in the following check
|
||
|
# for two reasons:
|
||
|
#
|
||
|
# - It should come from JSON, which only allows strings as
|
||
|
# dictionary keys, so having a string here unambiguously means
|
||
|
# someone used: {"op": ..., ...} instead of [{"op": ..., ...}].
|
||
|
#
|
||
|
# - There's no possible false positive: if someone give a sequence
|
||
|
# of mappings, this won't raise.
|
||
|
if isinstance(op, basestring):
|
||
|
raise InvalidJsonPatch("Document is expected to be sequence of "
|
||
|
"operations, got a sequence of strings.")
|
||
|
|
||
|
self._get_operation(op)
|
||
|
|
||
|
def __str__(self):
|
||
|
"""str(self) -> self.to_string()"""
|
||
|
return self.to_string()
|
||
|
|
||
|
def __bool__(self):
|
||
|
return bool(self.patch)
|
||
|
|
||
|
__nonzero__ = __bool__
|
||
|
|
||
|
def __iter__(self):
|
||
|
return iter(self.patch)
|
||
|
|
||
|
def __hash__(self):
|
||
|
return hash(tuple(self._ops))
|
||
|
|
||
|
def __eq__(self, other):
|
||
|
if not isinstance(other, JsonPatch):
|
||
|
return False
|
||
|
return self._ops == other._ops
|
||
|
|
||
|
def __ne__(self, other):
|
||
|
return not(self == other)
|
||
|
|
||
|
@classmethod
|
||
|
def from_string(cls, patch_str, loads=None, pointer_cls=JsonPointer):
|
||
|
"""Creates JsonPatch instance from string source.
|
||
|
|
||
|
:param patch_str: JSON patch as raw string.
|
||
|
:type patch_str: str
|
||
|
|
||
|
:param loads: A function of one argument that loads a serialized
|
||
|
JSON string.
|
||
|
:type loads: function
|
||
|
|
||
|
:param pointer_cls: JSON pointer class to use.
|
||
|
:type pointer_cls: Type[JsonPointer]
|
||
|
|
||
|
:return: :class:`JsonPatch` instance.
|
||
|
"""
|
||
|
json_loader = loads or cls.json_loader
|
||
|
patch = json_loader(patch_str)
|
||
|
return cls(patch, pointer_cls=pointer_cls)
|
||
|
|
||
|
@classmethod
|
||
|
def from_diff(
|
||
|
cls, src, dst, optimization=True, dumps=None,
|
||
|
pointer_cls=JsonPointer,
|
||
|
):
|
||
|
"""Creates JsonPatch instance based on comparison of two document
|
||
|
objects. Json patch would be created for `src` argument against `dst`
|
||
|
one.
|
||
|
|
||
|
:param src: Data source document object.
|
||
|
:type src: dict
|
||
|
|
||
|
:param dst: Data source document object.
|
||
|
:type dst: dict
|
||
|
|
||
|
:param dumps: A function of one argument that produces a serialized
|
||
|
JSON string.
|
||
|
:type dumps: function
|
||
|
|
||
|
:param pointer_cls: JSON pointer class to use.
|
||
|
:type pointer_cls: Type[JsonPointer]
|
||
|
|
||
|
:return: :class:`JsonPatch` instance.
|
||
|
|
||
|
>>> src = {'foo': 'bar', 'numbers': [1, 3, 4, 8]}
|
||
|
>>> dst = {'baz': 'qux', 'numbers': [1, 4, 7]}
|
||
|
>>> patch = JsonPatch.from_diff(src, dst)
|
||
|
>>> new = patch.apply(src)
|
||
|
>>> new == dst
|
||
|
True
|
||
|
"""
|
||
|
json_dumper = dumps or cls.json_dumper
|
||
|
builder = DiffBuilder(src, dst, json_dumper, pointer_cls=pointer_cls)
|
||
|
builder._compare_values('', None, src, dst)
|
||
|
ops = list(builder.execute())
|
||
|
return cls(ops, pointer_cls=pointer_cls)
|
||
|
|
||
|
def to_string(self, dumps=None):
|
||
|
"""Returns patch set as JSON string."""
|
||
|
json_dumper = dumps or self.json_dumper
|
||
|
return json_dumper(self.patch)
|
||
|
|
||
|
@property
|
||
|
def _ops(self):
|
||
|
return tuple(map(self._get_operation, self.patch))
|
||
|
|
||
|
def apply(self, obj, in_place=False):
|
||
|
"""Applies the patch to a given object.
|
||
|
|
||
|
:param obj: Document object.
|
||
|
:type obj: dict
|
||
|
|
||
|
:param in_place: Tweaks the way how patch would be applied - directly to
|
||
|
specified `obj` or to its copy.
|
||
|
:type in_place: bool
|
||
|
|
||
|
:return: Modified `obj`.
|
||
|
"""
|
||
|
|
||
|
if not in_place:
|
||
|
obj = copy.deepcopy(obj)
|
||
|
|
||
|
for operation in self._ops:
|
||
|
obj = operation.apply(obj)
|
||
|
|
||
|
return obj
|
||
|
|
||
|
def _get_operation(self, operation):
|
||
|
if 'op' not in operation:
|
||
|
raise InvalidJsonPatch("Operation does not contain 'op' member")
|
||
|
|
||
|
op = operation['op']
|
||
|
|
||
|
if not isinstance(op, basestring):
|
||
|
raise InvalidJsonPatch("Operation's op must be a string")
|
||
|
|
||
|
if op not in self.operations:
|
||
|
raise InvalidJsonPatch("Unknown operation {0!r}".format(op))
|
||
|
|
||
|
cls = self.operations[op]
|
||
|
return cls(operation, pointer_cls=self.pointer_cls)
|
||
|
|
||
|
|
||
|
class DiffBuilder(object):
|
||
|
|
||
|
def __init__(self, src_doc, dst_doc, dumps=json.dumps, pointer_cls=JsonPointer):
|
||
|
self.dumps = dumps
|
||
|
self.pointer_cls = pointer_cls
|
||
|
self.index_storage = [{}, {}]
|
||
|
self.index_storage2 = [[], []]
|
||
|
self.__root = root = []
|
||
|
self.src_doc = src_doc
|
||
|
self.dst_doc = dst_doc
|
||
|
root[:] = [root, root, None]
|
||
|
|
||
|
def store_index(self, value, index, st):
|
||
|
typed_key = (value, type(value))
|
||
|
try:
|
||
|
storage = self.index_storage[st]
|
||
|
stored = storage.get(typed_key)
|
||
|
if stored is None:
|
||
|
storage[typed_key] = [index]
|
||
|
else:
|
||
|
storage[typed_key].append(index)
|
||
|
|
||
|
except TypeError:
|
||
|
self.index_storage2[st].append((typed_key, index))
|
||
|
|
||
|
def take_index(self, value, st):
|
||
|
typed_key = (value, type(value))
|
||
|
try:
|
||
|
stored = self.index_storage[st].get(typed_key)
|
||
|
if stored:
|
||
|
return stored.pop()
|
||
|
|
||
|
except TypeError:
|
||
|
storage = self.index_storage2[st]
|
||
|
for i in range(len(storage)-1, -1, -1):
|
||
|
if storage[i][0] == typed_key:
|
||
|
return storage.pop(i)[1]
|
||
|
|
||
|
def insert(self, op):
|
||
|
root = self.__root
|
||
|
last = root[0]
|
||
|
last[1] = root[0] = [last, root, op]
|
||
|
return root[0]
|
||
|
|
||
|
def remove(self, index):
|
||
|
link_prev, link_next, _ = index
|
||
|
link_prev[1] = link_next
|
||
|
link_next[0] = link_prev
|
||
|
index[:] = []
|
||
|
|
||
|
def iter_from(self, start):
|
||
|
root = self.__root
|
||
|
curr = start[1]
|
||
|
while curr is not root:
|
||
|
yield curr[2]
|
||
|
curr = curr[1]
|
||
|
|
||
|
def __iter__(self):
|
||
|
root = self.__root
|
||
|
curr = root[1]
|
||
|
while curr is not root:
|
||
|
yield curr[2]
|
||
|
curr = curr[1]
|
||
|
|
||
|
def execute(self):
|
||
|
root = self.__root
|
||
|
curr = root[1]
|
||
|
while curr is not root:
|
||
|
if curr[1] is not root:
|
||
|
op_first, op_second = curr[2], curr[1][2]
|
||
|
if op_first.location == op_second.location and \
|
||
|
type(op_first) == RemoveOperation and \
|
||
|
type(op_second) == AddOperation:
|
||
|
yield ReplaceOperation({
|
||
|
'op': 'replace',
|
||
|
'path': op_second.location,
|
||
|
'value': op_second.operation['value'],
|
||
|
}, pointer_cls=self.pointer_cls).operation
|
||
|
curr = curr[1][1]
|
||
|
continue
|
||
|
|
||
|
yield curr[2].operation
|
||
|
curr = curr[1]
|
||
|
|
||
|
def _item_added(self, path, key, item):
|
||
|
index = self.take_index(item, _ST_REMOVE)
|
||
|
if index is not None:
|
||
|
op = index[2]
|
||
|
if type(op.key) == int and type(key) == int:
|
||
|
for v in self.iter_from(index):
|
||
|
op.key = v._on_undo_remove(op.path, op.key)
|
||
|
|
||
|
self.remove(index)
|
||
|
if op.location != _path_join(path, key):
|
||
|
new_op = MoveOperation({
|
||
|
'op': 'move',
|
||
|
'from': op.location,
|
||
|
'path': _path_join(path, key),
|
||
|
}, pointer_cls=self.pointer_cls)
|
||
|
self.insert(new_op)
|
||
|
else:
|
||
|
new_op = AddOperation({
|
||
|
'op': 'add',
|
||
|
'path': _path_join(path, key),
|
||
|
'value': item,
|
||
|
}, pointer_cls=self.pointer_cls)
|
||
|
new_index = self.insert(new_op)
|
||
|
self.store_index(item, new_index, _ST_ADD)
|
||
|
|
||
|
def _item_removed(self, path, key, item):
|
||
|
new_op = RemoveOperation({
|
||
|
'op': 'remove',
|
||
|
'path': _path_join(path, key),
|
||
|
}, pointer_cls=self.pointer_cls)
|
||
|
index = self.take_index(item, _ST_ADD)
|
||
|
new_index = self.insert(new_op)
|
||
|
if index is not None:
|
||
|
op = index[2]
|
||
|
# We can't rely on the op.key type since PatchOperation casts
|
||
|
# the .key property to int and this path wrongly ends up being taken
|
||
|
# for numeric string dict keys while the intention is to only handle lists.
|
||
|
# So we do an explicit check on the item affected by the op instead.
|
||
|
added_item = op.pointer.to_last(self.dst_doc)[0]
|
||
|
if type(added_item) == list:
|
||
|
for v in self.iter_from(index):
|
||
|
op.key = v._on_undo_add(op.path, op.key)
|
||
|
|
||
|
self.remove(index)
|
||
|
if new_op.location != op.location:
|
||
|
new_op = MoveOperation({
|
||
|
'op': 'move',
|
||
|
'from': new_op.location,
|
||
|
'path': op.location,
|
||
|
}, pointer_cls=self.pointer_cls)
|
||
|
new_index[2] = new_op
|
||
|
|
||
|
else:
|
||
|
self.remove(new_index)
|
||
|
|
||
|
else:
|
||
|
self.store_index(item, new_index, _ST_REMOVE)
|
||
|
|
||
|
def _item_replaced(self, path, key, item):
|
||
|
self.insert(ReplaceOperation({
|
||
|
'op': 'replace',
|
||
|
'path': _path_join(path, key),
|
||
|
'value': item,
|
||
|
}, pointer_cls=self.pointer_cls))
|
||
|
|
||
|
def _compare_dicts(self, path, src, dst):
|
||
|
src_keys = set(src.keys())
|
||
|
dst_keys = set(dst.keys())
|
||
|
added_keys = dst_keys - src_keys
|
||
|
removed_keys = src_keys - dst_keys
|
||
|
|
||
|
for key in removed_keys:
|
||
|
self._item_removed(path, str(key), src[key])
|
||
|
|
||
|
for key in added_keys:
|
||
|
self._item_added(path, str(key), dst[key])
|
||
|
|
||
|
for key in src_keys & dst_keys:
|
||
|
self._compare_values(path, key, src[key], dst[key])
|
||
|
|
||
|
def _compare_lists(self, path, src, dst):
|
||
|
len_src, len_dst = len(src), len(dst)
|
||
|
max_len = max(len_src, len_dst)
|
||
|
min_len = min(len_src, len_dst)
|
||
|
for key in range(max_len):
|
||
|
if key < min_len:
|
||
|
old, new = src[key], dst[key]
|
||
|
if old == new:
|
||
|
continue
|
||
|
|
||
|
elif isinstance(old, MutableMapping) and \
|
||
|
isinstance(new, MutableMapping):
|
||
|
self._compare_dicts(_path_join(path, key), old, new)
|
||
|
|
||
|
elif isinstance(old, MutableSequence) and \
|
||
|
isinstance(new, MutableSequence):
|
||
|
self._compare_lists(_path_join(path, key), old, new)
|
||
|
|
||
|
else:
|
||
|
self._item_removed(path, key, old)
|
||
|
self._item_added(path, key, new)
|
||
|
|
||
|
elif len_src > len_dst:
|
||
|
self._item_removed(path, len_dst, src[key])
|
||
|
|
||
|
else:
|
||
|
self._item_added(path, key, dst[key])
|
||
|
|
||
|
def _compare_values(self, path, key, src, dst):
|
||
|
if isinstance(src, MutableMapping) and \
|
||
|
isinstance(dst, MutableMapping):
|
||
|
self._compare_dicts(_path_join(path, key), src, dst)
|
||
|
|
||
|
elif isinstance(src, MutableSequence) and \
|
||
|
isinstance(dst, MutableSequence):
|
||
|
self._compare_lists(_path_join(path, key), src, dst)
|
||
|
|
||
|
# To ensure we catch changes to JSON, we can't rely on a simple
|
||
|
# src == dst, because it would not recognize the difference between
|
||
|
# 1 and True, among other things. Using json.dumps is the most
|
||
|
# fool-proof way to ensure we catch type changes that matter to JSON
|
||
|
# and ignore those that don't. The performance of this could be
|
||
|
# improved by doing more direct type checks, but we'd need to be
|
||
|
# careful to accept type changes that don't matter when JSONified.
|
||
|
elif self.dumps(src) == self.dumps(dst):
|
||
|
return
|
||
|
|
||
|
else:
|
||
|
self._item_replaced(path, key, dst)
|
||
|
|
||
|
|
||
|
def _path_join(path, key):
|
||
|
if key is None:
|
||
|
return path
|
||
|
|
||
|
return path + '/' + str(key).replace('~', '~0').replace('/', '~1')
|