hat.json

17def equals(a: Data,
18           b: Data
19           ) -> bool:
20    """Equality comparison of json serializable data.
21
22    Tests for equality of data according to JSON format. Notably, ``bool``
23    values are not considered equal to numeric values in any case. This is
24    different from default equality comparison, which considers `False`
25    equal to `0` and `0.0`; and `True` equal to `1` and `1.0`.
26
27    Example::
28
29        assert equals(0, 0.0) is True
30        assert equals({'a': 1, 'b': 2}, {'b': 2, 'a': 1}) is True
31        assert equals(1, True) is False
32
33    """
34    if isinstance(a, bool) != isinstance(b, bool):
35        return False
36    if a != b:
37        return False
38
39    if isinstance(a, dict):
40        return all(equals(a[key], b[key]) for key in a)
41    elif isinstance(a, list):
42        return all(equals(i, j) for i, j in zip(a, b))
43    else:
44        return True

47def clone(data: Data) -> Data:
48    """Deep clone data
49
50    This function recursively creates new instances of array and object data
51    based on input data. Resulting json data is equal to provided data.
52
53    Example::
54
55        x = {'a': [1, 2, 3]}
56        y = clone(x)
57        assert x is not y
58        assert x['a'] is not y['a']
59        assert equals(x, y)
60
61    """
62    if isinstance(data, list):
63        return [clone(i) for i in data]
64
65    if isinstance(data, dict):
66        return {k: clone(v) for k, v in data.items()}
67
68    return data

71def flatten(data: Data
72            ) -> typing.Iterable[Data]:
73    """Flatten JSON data
74
75    If `data` is array, this generator recursively yields result of `flatten`
76    call with each element of input list. For other `Data` types, input data is
77    yielded.
78
79    Example::
80
81        data = [1, [], [2], {'a': [3]}]
82        result = [1, 2, {'a': [3]}]
83        assert list(flatten(data)) == result
84
85    """
86    if isinstance(data, list):
87        for i in data:
88            yield from flatten(i)
89    else:
90        yield data

16def get(data: Data,
17        path: Path,
18        default: Data | None = None
19        ) -> Data:
20    """Get data element referenced by path
21
22    Example::
23
24        data = {'a': [1, 2, [3, 4]]}
25        path = ['a', 2, 0]
26        assert get(data, path) == 3
27
28        data = [1, 2, 3]
29        assert get(data, 0) == 1
30        assert get(data, 5) is None
31        assert get(data, 5, default=123) == 123
32
33    """
34    for i in flatten(path):
35        if isinstance(i, str):
36            if not isinstance(data, dict) or i not in data:
37                return default
38            data = data[i]
39
40        elif isinstance(i, int) and not isinstance(i, bool):
41            if not isinstance(data, list):
42                return default
43            try:
44                data = data[i]
45            except IndexError:
46                return default
47
48        else:
49            raise ValueError('invalid path')
50
51    return data

 54def set_(data: Data,
 55         path: Path,
 56         value: Data
 57         ) -> Data:
 58    """Create new data by setting data path element value
 59
 60    Example::
 61
 62        data = [1, {'a': 2, 'b': 3}, 4]
 63        path = [1, 'b']
 64        result = set_(data, path, 5)
 65        assert result == [1, {'a': 2, 'b': 5}, 4]
 66        assert result is not data
 67
 68        data = [1, 2, 3]
 69        result = set_(data, 4, 4)
 70        assert result == [1, 2, 3, None, 4]
 71
 72    """
 73    parents = collections.deque()
 74
 75    for i in flatten(path):
 76        parent = data
 77
 78        if isinstance(i, str):
 79            data = data.get(i) if isinstance(data, dict) else None
 80
 81        elif isinstance(i, int) and not isinstance(i, bool):
 82            try:
 83                data = data[i] if isinstance(data, list) else None
 84            except IndexError:
 85                data = None
 86
 87        else:
 88            raise ValueError('invalid path')
 89
 90        parents.append((parent, i))
 91
 92    while parents:
 93        parent, i = parents.pop()
 94
 95        if isinstance(i, str):
 96            parent = dict(parent) if isinstance(parent, dict) else {}
 97            parent[i] = value
 98
 99        elif isinstance(i, int) and not isinstance(i, bool):
100            if not isinstance(parent, list):
101                parent = []
102
103            if i >= len(parent):
104                parent = [*parent,
105                          *itertools.repeat(None, i - len(parent) + 1)]
106
107            elif i < 0 and (-i) > len(parent):
108                parent = [*itertools.repeat(None, (-i) - len(parent)),
109                          *parent]
110
111            else:
112                parent = list(parent)
113
114            parent[i] = value
115
116        else:
117            raise ValueError('invalid path')
118
119        value = parent
120
121    return value

124def remove(data: Data,
125           path: Path
126           ) -> Data:
127    """Create new data by removing part of data referenced by path
128
129    Example::
130
131        data = [1, {'a': 2, 'b': 3}, 4]
132        path = [1, 'b']
133        result = remove(data, path)
134        assert result == [1, {'a': 2}, 4]
135        assert result is not data
136
137        data = [1, 2, 3]
138        result = remove(data, 4)
139        assert result == [1, 2, 3]
140
141    """
142    result = data
143    parents = collections.deque()
144
145    for i in flatten(path):
146        parent = data
147
148        if isinstance(i, str):
149            if not isinstance(data, dict) or i not in data:
150                return result
151            data = data[i]
152
153        elif isinstance(i, int) and not isinstance(i, bool):
154            if not isinstance(data, list):
155                return result
156            try:
157                data = data[i]
158            except IndexError:
159                return result
160
161        else:
162            raise ValueError('invalid path')
163
164        parents.append((parent, i))
165
166    result = None
167
168    while parents:
169        parent, i = parents.pop()
170
171        if isinstance(i, str):
172            parent = dict(parent)
173
174        elif isinstance(i, int) and not isinstance(i, bool):
175            parent = list(parent)
176
177        else:
178            raise ValueError('invalid path')
179
180        if result is None:
181            del parent[i]
182
183        else:
184            parent[i] = result
185
186        result = parent
187
188    return result

191class Storage:
192    """JSON data storage
193
194    Helper class representing observable JSON data state manipulated with
195    path based get/set/remove functions.
196
197    """
198
199    def __init__(self, data: Data = None):
200        self._data = data
201        self._change_cbs = util.CallbackRegistry()
202
203    @property
204    def data(self) -> Data:
205        """Data"""
206        return self._data
207
208    def register_change_cb(self,
209                           cb: typing.Callable[[Data], None]
210                           ) -> util.RegisterCallbackHandle:
211        """Register data change callback"""
212        return self._change_cbs.register(cb)
213
214    def get(self, path: Path, default: Data | None = None):
215        """Get data"""
216        return get(self._data, path, default)
217
218    def set(self, path: Path, value: Data):
219        """Set data"""
220        self._data = set_(self._data, path, value)
221        self._change_cbs.notify(self._data)
222
223    def remove(self, path: Path):
224        """Remove data"""
225        self._data = remove(self._data, path)
226        self._change_cbs.notify(self._data)

16class Format(enum.Enum):
17    """Encoding format"""
18    JSON = 'json'
19    YAML = 'yaml'
20    TOML = 'toml'

23def encode(data: Data,
24           format: Format = Format.JSON,
25           indent: int | None = None
26           ) -> str:
27    """Encode JSON data.
28
29    In case of TOML format, data must be JSON Object.
30
31    Args:
32        data: JSON data
33        format: encoding format
34        indent: indentation size
35
36    """
37    if format == Format.JSON:
38        return json.dumps(data, indent=indent, allow_nan=False)
39
40    if format == Format.YAML:
41        dumper = (yaml.CSafeDumper if hasattr(yaml, 'CSafeDumper')
42                  else yaml.SafeDumper)
43        return str(yaml.dump(data, indent=indent, Dumper=dumper))
44
45    if format == Format.TOML:
46        return tomli_w.dumps(data)
47
48    raise ValueError('unsupported format')

51def decode(data_str: str,
52           format: Format = Format.JSON
53           ) -> Data:
54    """Decode JSON data.
55
56    Args:
57        data_str: encoded JSON data
58        format: encoding format
59
60    """
61    if format == Format.JSON:
62        return json.loads(data_str)
63
64    if format == Format.YAML:
65        loader = (yaml.CSafeLoader if hasattr(yaml, 'CSafeLoader')
66                  else yaml.SafeLoader)
67        return yaml.load(io.StringIO(data_str), Loader=loader)
68
69    if format == Format.TOML:
70        return tomli.loads(data_str)
71
72    raise ValueError('unsupported format')

75def get_file_format(path: pathlib.PurePath) -> Format:
76    """Detect file format based on path suffix"""
77    if path.suffix == '.json':
78        return Format.JSON
79
80    if path.suffix in ('.yaml', '.yml'):
81        return Format.YAML
82
83    if path.suffix == '.toml':
84        return Format.TOML
85
86    raise ValueError('can not determine format from path suffix')

 89def encode_file(data: Data,
 90                path: pathlib.PurePath,
 91                format: Format | None = None,
 92                indent: int | None = 4):
 93    """Encode JSON data to file.
 94
 95    If `format` is ``None``, encoding format is derived from path suffix.
 96
 97    In case of TOML format, data must be JSON Object.
 98
 99    Args:
100        data: JSON data
101        path: file path
102        format: encoding format
103        indent: indentation size
104
105    """
106    if format is None:
107        format = get_file_format(path)
108
109    flags = 'w' if format != Format.TOML else 'wb'
110    encoding = 'utf-8' if format != Format.TOML else None
111
112    with open(path, flags, encoding=encoding) as f:
113        encode_stream(data, f, format, indent)

116def decode_file(path: pathlib.PurePath,
117                format: Format | None = None
118                ) -> Data:
119    """Decode JSON data from file.
120
121    If `format` is ``None``, encoding format is derived from path suffix.
122
123    Args:
124        path: file path
125        format: encoding format
126
127    """
128    if format is None:
129        format = get_file_format(path)
130
131    flags = 'r' if format != Format.TOML else 'rb'
132    encoding = 'utf-8' if format != Format.TOML else None
133
134    with open(path, flags, encoding=encoding) as f:
135        return decode_stream(f, format)

138def encode_stream(data: Data,
139                  stream: io.TextIOBase | io.RawIOBase,
140                  format: Format = Format.JSON,
141                  indent: int | None = 4):
142    """Encode JSON data to stream.
143
144    In case of TOML format, data must be JSON Object.
145
146    In case of TOML format, `stream` should be `io.RawIOBase`. For
147    other formats, `io.TextIOBase` is expected.
148
149    Args:
150        data: JSON data
151        stream: output stream
152        format: encoding format
153        indent: indentation size
154
155    """
156    if format == Format.JSON:
157        json.dump(data, stream, indent=indent, allow_nan=False)
158
159    elif format == Format.YAML:
160        dumper = (yaml.CSafeDumper if hasattr(yaml, 'CSafeDumper')
161                  else yaml.SafeDumper)
162        yaml.dump(data, stream, indent=indent, Dumper=dumper,
163                  explicit_start=True, explicit_end=True)
164
165    elif format == Format.TOML:
166        tomli_w.dump(data, stream)
167
168    else:
169        raise ValueError('unsupported format')

172def decode_stream(stream: io.TextIOBase | io.RawIOBase,
173                  format: Format = Format.JSON
174                  ) -> Data:
175    """Decode JSON data from stream.
176
177    In case of TOML format, `stream` should be `io.RawIOBase`. For
178    other formats, `io.TextIOBase` is expected.
179
180    Args:
181        stream: input stream
182        format: encoding format
183
184    """
185    if format == Format.JSON:
186        return json.load(stream)
187
188    if format == Format.YAML:
189        loader = (yaml.CSafeLoader if hasattr(yaml, 'CSafeLoader')
190                  else yaml.SafeLoader)
191        return yaml.load(stream, Loader=loader)
192
193    if format == Format.TOML:
194        return tomli.load(stream)
195
196    raise ValueError('unsupported format')

 9def diff(src: Data,
10         dst: Data
11         ) -> Data:
12    """Generate JSON Patch diff.
13
14    Example::
15
16        src = [1, {'a': 2}, 3]
17        dst = [1, {'a': 4}, 3]
18        result = diff(src, dst)
19        assert result == [{'op': 'replace', 'path': '/1/a', 'value': 4}]
20
21    """
22    return jsonpatch.JsonPatch.from_diff(src, dst).patch

25def patch(data: Data,
26          diff: Data
27          ) -> Data:
28    """Apply JSON Patch diff.
29
30    Example::
31
32        data = [1, {'a': 2}, 3]
33        d = [{'op': 'replace', 'path': '/1/a', 'value': 4}]
34        result = patch(data, d)
35        assert result == [1, {'a': 4}, 3]
36
37    """
38    return jsonpatch.apply_patch(data, diff)

 16class SchemaRepository:
 17    """JSON Schema repository.
 18
 19    A repository that holds json schemas and enables validation against them.
 20
 21    Repository can be initialized with multiple arguments, which can be
 22    instances of ``pathlib.PurePath``, ``Data`` or ``SchemaRepository``.
 23
 24    If an argument is of type ``pathlib.PurePath``, and path points to file
 25    with a suffix '.json', '.yml' or '.yaml', json serializable data is decoded
 26    from the file. Otherwise, it is assumed that path points to a directory,
 27    which is recursively searched for json and yaml files. All decoded schemas
 28    are added to the repository. If a schema with the same `id` was previously
 29    added, an exception is raised.
 30
 31    If an argument is of type ``Data``, it should be a json serializable data
 32    representation of a JSON schema. If a schema with the same `id` was
 33    previously added, an exception is raised.
 34
 35    If an argument is of type ``SchemaRepository``, its schemas are added to
 36    the new repository. Previously added schemas with the same `id` are
 37    replaced.
 38
 39    """
 40
 41    def __init__(self, *args: typing.Union[pathlib.PurePath,
 42                                           Data,
 43                                           'SchemaRepository']):
 44        self._validators = weakref.WeakValueDictionary()
 45        self._data = {}
 46        for arg in args:
 47            if isinstance(arg, pathlib.PurePath):
 48                self._load_path(arg)
 49            elif isinstance(arg, SchemaRepository):
 50                self._load_repository(arg)
 51            else:
 52                self._load_schema(arg)
 53
 54    def get_uri_schemes(self) -> typing.Iterable[str]:
 55        """Get URI schemes stored in repository"""
 56        return self._data.keys()
 57
 58    def get_schema_ids(self,
 59                       uri_schemes: typing.Iterable[str] | None = None
 60                       ) -> typing.Iterable[str]:
 61        """Get schema ids stored in repository
 62
 63        If `uri_schemes` is ``None``, all schema ids are returned. Otherwise,
 64        only schema ids that have one of provided URI scheme are returned.
 65
 66        """
 67        if uri_schemes is None:
 68            uri_schemes = self._data.keys()
 69
 70        for uri_scheme in uri_schemes:
 71            schemas = self._data.get(uri_scheme)
 72            if not schemas:
 73                continue
 74
 75            for path in schemas.keys():
 76                yield f'{uri_scheme}://{path}'
 77
 78    def get_schema(self, schema_id: str) -> Data:
 79        """Get stored schema based on schema id"""
 80        uri = urllib.parse.urlparse(schema_id)
 81        path = uri.netloc + uri.path
 82        return self._data[uri.scheme][path]
 83
 84    def validate(self,
 85                 schema_id: str,
 86                 data: Data,
 87                 validator_cls: typing.Type[Validator] = DefaultValidator):
 88        """Validate data against JSON schema.
 89
 90        Args:
 91            schema_id: JSON schema identifier
 92            data: data to be validated
 93            validator_cls: validator implementation
 94
 95        Raises:
 96            Exception
 97
 98        """
 99        validator = self._validators.get(validator_cls)
100        if validator is None:
101            validator = validator_cls(self)
102            self._validators[validator_cls] = validator
103
104        validator.validate(schema_id, data)
105
106    def to_json(self) -> Data:
107        """Export repository content as json serializable data.
108
109        Entire repository content is exported as json serializable data.
110        New repository can be created from the exported content by using
111        :meth:`SchemaRepository.from_json`.
112
113        """
114        return self._data
115
116    @staticmethod
117    def from_json(data: pathlib.PurePath | Data
118                  ) -> 'SchemaRepository':
119        """Create new repository from content exported as json serializable
120        data.
121
122        Creates a new repository from content of another repository that was
123        exported by using :meth:`SchemaRepository.to_json`.
124
125        Args:
126            data: repository data
127
128        """
129        if isinstance(data, pathlib.PurePath):
130            data = decode_file(data)
131        repo = SchemaRepository()
132        repo._data = data
133        return repo
134
135    def _load_path(self, path):
136        json_suffixes = {'.json', '.yaml', '.yml'}
137        paths = ([path] if path.suffix in json_suffixes
138                 else list(itertools.chain.from_iterable(
139                    path.rglob(f'*{i}') for i in json_suffixes)))
140        for path in paths:
141            schema = decode_file(path)
142            self._load_schema(schema)
143
144    def _load_schema(self, schema):
145        if '$schema' in schema:
146            meta_schema_id = urllib.parse.urldefrag(schema['$schema']).url
147            if meta_schema_id not in _meta_schema_ids:
148                schema = dict(schema)
149                del schema['$schema']
150
151        uri = urllib.parse.urlparse(schema['id'])
152        path = uri.netloc + uri.path
153        if uri.scheme not in self._data:
154            self._data[uri.scheme] = {}
155        if path in self._data[uri.scheme]:
156            raise Exception(f"duplicate schema id {uri.scheme}://{path}")
157        self._data[uri.scheme][path] = schema
158
159    def _load_repository(self, repo):
160        for k, v in repo._data.items():
161            if k not in self._data:
162                self._data[k] = v
163            else:
164                self._data[k].update(v)