hat.json

18def equals(a: Data,
19           b: Data
20           ) -> bool:
21    """Equality comparison of json serializable data.
22
23    Tests for equality of data according to JSON format. Notably, ``bool``
24    values are not considered equal to numeric values in any case. This is
25    different from default equality comparison, which considers `False`
26    equal to `0` and `0.0`; and `True` equal to `1` and `1.0`.
27
28    Example::
29
30        assert equals(0, 0.0) is True
31        assert equals({'a': 1, 'b': 2}, {'b': 2, 'a': 1}) is True
32        assert equals(1, True) is False
33
34    """
35    if a is None:
36        return b is None
37
38    if isinstance(a, bool):
39        return isinstance(b, bool) and a == b
40
41    if isinstance(a, (int, float)):
42        return (isinstance(b, (int, float)) and
43                not isinstance(b, bool) and
44                a == b)
45
46    if isinstance(a, str):
47        return isinstance(b, str) and a == b
48
49    if isinstance(a, list):
50        return (isinstance(b, list) and
51                len(a) == len(b) and
52                all(equals(i, j) for i, j in zip(a, b)))
53
54    if isinstance(a, dict):
55        return (isinstance(b, dict) and
56                len(a) == len(b) and
57                all(equals(a[key], b[key]) for key in a.keys()))
58
59    raise TypeError('invalid json type')

62def clone(data: Data) -> Data:
63    """Deep clone data
64
65    This function recursively creates new instances of array and object data
66    based on input data. Resulting json data is equal to provided data.
67
68    Example::
69
70        x = {'a': [1, 2, 3]}
71        y = clone(x)
72        assert x is not y
73        assert x['a'] is not y['a']
74        assert equals(x, y)
75
76    """
77    if isinstance(data, list):
78        return [clone(i) for i in data]
79
80    if isinstance(data, dict):
81        return {k: clone(v) for k, v in data.items()}
82
83    return data

 86def flatten(data: Data) -> Iterable[Data]:
 87    """Flatten JSON data
 88
 89    If `data` is array, this generator recursively yields result of `flatten`
 90    call with each element of input list. For other `Data` types, input data is
 91    yielded.
 92
 93    Example::
 94
 95        data = [1, [], [2], {'a': [3]}]
 96        result = [1, 2, {'a': [3]}]
 97        assert list(flatten(data)) == result
 98
 99    """
100    if isinstance(data, list):
101        for i in data:
102            yield from flatten(i)
103
104    else:
105        yield data

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

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

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

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

21class Format(enum.Enum):
22    """Encoding format"""
23    JSON = 'json'
24    YAML = 'yaml'
25    TOML = 'toml'

28def encode(data: Data,
29           format: Format = Format.JSON,
30           indent: int | None = None,
31           sort_keys: bool = False
32           ) -> str:
33    """Encode JSON data.
34
35    In case of TOML format, data must be JSON Object.
36
37    In case of TOML format, `indent` is ignored.
38
39    In case of YAML or TOML format, `sort_keys` is ignored.
40
41    Args:
42        data: JSON data
43        format: encoding format
44        indent: indentation size
45        sort_keys: sort object keys
46
47    """
48    if format == Format.JSON:
49        return json.dumps(data,
50                          indent=indent,
51                          sort_keys=sort_keys,
52                          allow_nan=False)
53
54    if format == Format.YAML:
55        dumper = (yaml.CSafeDumper if hasattr(yaml, 'CSafeDumper')
56                  else yaml.SafeDumper)
57        return str(yaml.dump(data, indent=indent, Dumper=dumper))
58
59    if format == Format.TOML:
60        return tomli_w.dumps(data)
61
62    raise ValueError('unsupported format')

65def decode(data_str: str,
66           format: Format = Format.JSON
67           ) -> Data:
68    """Decode JSON data.
69
70    Args:
71        data_str: encoded JSON data
72        format: encoding format
73
74    """
75    if format == Format.JSON:
76        return json.loads(data_str)
77
78    if format == Format.YAML:
79        loader = (yaml.CSafeLoader if hasattr(yaml, 'CSafeLoader')
80                  else yaml.SafeLoader)
81        return yaml.load(io.StringIO(data_str), Loader=loader)
82
83    if format == Format.TOML:
84        return toml.loads(data_str)
85
86    raise ValueError('unsupported format')

 89def get_file_format(path: pathlib.PurePath) -> Format:
 90    """Detect file format based on path suffix"""
 91    if path.suffix == '.json':
 92        return Format.JSON
 93
 94    if path.suffix in ('.yaml', '.yml'):
 95        return Format.YAML
 96
 97    if path.suffix == '.toml':
 98        return Format.TOML
 99
100    raise ValueError('can not determine format from path suffix')

103def encode_file(data: Data,
104                path: pathlib.PurePath,
105                format: Format | None = None,
106                indent: int | None = 4,
107                sort_keys: bool = False):
108    """Encode JSON data to file.
109
110    If `format` is ``None``, encoding format is derived from path suffix.
111
112    In case of TOML format, data must be JSON Object.
113
114    In case of TOML format, `indent` is ignored.
115
116    In case of YAML or TOML format, `sort_keys` is ignored.
117
118    Args:
119        data: JSON data
120        path: file path
121        format: encoding format
122        indent: indentation size
123        sort_keys: sort object keys
124
125    """
126    if format is None:
127        format = get_file_format(path)
128
129    flags = 'w' if format != Format.TOML else 'wb'
130    encoding = 'utf-8' if format != Format.TOML else None
131
132    with open(path, flags, encoding=encoding) as f:
133        encode_stream(data=data,
134                      stream=f,
135                      format=format,
136                      indent=indent,
137                      sort_keys=sort_keys)

140def decode_file(path: pathlib.PurePath,
141                format: Format | None = None
142                ) -> Data:
143    """Decode JSON data from file.
144
145    If `format` is ``None``, encoding format is derived from path suffix.
146
147    Args:
148        path: file path
149        format: encoding format
150
151    """
152    if format is None:
153        format = get_file_format(path)
154
155    flags = 'r' if format != Format.TOML else 'rb'
156    encoding = 'utf-8' if format != Format.TOML else None
157
158    with open(path, flags, encoding=encoding) as f:
159        return decode_stream(f, format)

162def encode_stream(data: Data,
163                  stream: io.TextIOBase | io.RawIOBase,
164                  format: Format = Format.JSON,
165                  indent: int | None = 4,
166                  sort_keys: bool = False):
167    """Encode JSON data to stream.
168
169    In case of TOML format, data must be JSON Object.
170
171    In case of TOML format, `stream` should be `io.RawIOBase`. For
172    other formats, `io.TextIOBase` is expected.
173
174    In case of TOML format, `indent` is ignored.
175
176    In case of YAML or TOML format, `sort_keys` is ignored.
177
178    Args:
179        data: JSON data
180        stream: output stream
181        format: encoding format
182        indent: indentation size
183        sort_keys: sort object keys
184
185    """
186    if format == Format.JSON:
187        json.dump(data, stream,
188                  indent=indent,
189                  sort_keys=sort_keys,
190                  allow_nan=False)
191
192    elif format == Format.YAML:
193        dumper = (yaml.CSafeDumper if hasattr(yaml, 'CSafeDumper')
194                  else yaml.SafeDumper)
195        yaml.dump(data, stream,
196                  indent=indent,
197                  Dumper=dumper,
198                  explicit_start=True,
199                  explicit_end=True)
200
201    elif format == Format.TOML:
202        tomli_w.dump(data, stream)
203
204    else:
205        raise ValueError('unsupported format')

208def decode_stream(stream: io.TextIOBase | io.RawIOBase,
209                  format: Format = Format.JSON
210                  ) -> Data:
211    """Decode JSON data from stream.
212
213    In case of TOML format, `stream` should be `io.RawIOBase`. For
214    other formats, `io.TextIOBase` is expected.
215
216    Args:
217        stream: input stream
218        format: encoding format
219
220    """
221    if format == Format.JSON:
222        return json.load(stream)
223
224    if format == Format.YAML:
225        loader = (yaml.CSafeLoader if hasattr(yaml, 'CSafeLoader')
226                  else yaml.SafeLoader)
227        return yaml.load(stream, Loader=loader)
228
229    if format == Format.TOML:
230        return toml.load(stream)
231
232    raise ValueError('unsupported format')

235def read_conf(path: pathlib.Path | None,
236              default_path: pathlib.Path | None = None,
237              default_suffixes: list[str] = ['.yaml', '.yml', '.toml', '.json'],  # NOQA
238              stdio_path: pathlib.Path | None = pathlib.Path('-')
239              ) -> Data:
240    """Read configuration formated as JSON data"""
241    if stdio_path and path == stdio_path:
242        return decode_stream(sys.stdin)
243
244    if path:
245        return decode_file(path)
246
247    if not default_path:
248        raise Exception('invalid configuration path')
249
250    for suffix in default_suffixes:
251        path = default_path.with_suffix(suffix)
252        if path.exists():
253            break
254
255    return decode_file(path)

 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)

34def create_schema_repository(*args: pathlib.PurePath | Schema
35                             ) -> SchemaRepository:
36    """Create JSON Schema repository.
37
38    Repository can be initialized with multiple arguments, which can be
39    instances of ``pathlib.PurePath`` or ``Schema``.
40
41    If an argument is of type ``pathlib.PurePath``, and path points to file
42    with a suffix '.json', '.yml' or '.yaml', json serializable data is decoded
43    from the file. Otherwise, it is assumed that path points to a directory,
44    which is recursively searched for json and yaml files. All decoded schemas
45    are added to the repository. If a schema with the same `id` was previously
46    added, an exception is raised.
47
48    If an argument is of type ``Schema``, it should be a json serializable data
49    representation of a JSON schema. If a schema with the same `id` was
50    previously added, an exception is raised.
51
52    """
53    repo = {}
54
55    for arg in args:
56        if isinstance(arg, pathlib.PurePath):
57            if arg.suffix in _schema_path_suffixes:
58                paths = [arg]
59
60            else:
61                paths = itertools.chain.from_iterable(
62                    arg.rglob(f'*{i}') for i in _schema_path_suffixes)
63
64            schemas = (decode_file(path) for path in paths)
65
66        elif isinstance(arg, dict):
67            schemas = [arg]
68
69        else:
70            raise TypeError('invalid argument type')
71
72        for schema in schemas:
73            if '$schema' in schema:
74                meta_schema_id = urllib.parse.urldefrag(schema['$schema']).url
75                if meta_schema_id not in _meta_schema_ids:
76                    raise Exception(
77                        f"unsupported meta schema id {meta_schema_id}")
78
79            else:
80                schema = {'$schema': _default_meta_schema_id,
81                          **schema}
82
83            schema_id = schema.get('$id')
84            if not schema_id:
85                schema_id = schema.get('id')
86            if not schema_id:
87                raise Exception('invalid schema id')
88
89            sanitized_schema_id = urllib.parse.urldefrag(schema_id).url
90            if sanitized_schema_id in repo:
91                raise Exception(f"duplicate schema id {sanitized_schema_id}")
92
93            repo[sanitized_schema_id] = schema
94
95    return repo