src.heuristics.HeuristicsRegistry.load_heuristics() - Code Metrics - mattboyer/sqbrite - Measure and Improve Code Quality continuously with Scrutinizer

HeuristicsRegistry.load_heuristics() B
last analyzed 2022-03-20 10:13 UTC

↳ Parent: src.heuristics

Complexity

Conditions

Size

Total Lines	14
Code Lines	13

Duplication

Lines	14
Ratio	100 %

Importance

Changes

Metric	Value
cc	6
eloc	13
nop	1
dl	14
loc	14
rs	8.6666
c	0
b	0
f	0

# MIT License
#
# Copyright (c) 2017 Matt Boyer
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import os
from pkg_resources import resource_stream
import re
import yaml

from . import _LOGGER
from . import PROJECT_NAME, USER_YAML_PATH, BUILTIN_YAML


class Heuristic(object):

    def __init__(self, magic, offset, grouping, table, name_regex=None):
        self._offset = offset
        self._table_name = table
        self._grouping = grouping
        self._magic_re = re.compile(magic)

        self._table_name_regex = None
        if name_regex is not None:
            self._table_name_regex = re.compile(name_regex)

    def __repr__(self):
        return "<Record heuristic for table \"{0}\"({1})>".format(
            self._table_name, self._grouping
        )

    def __call__(self, freeblock_bytes):
        # We need to unwind the full set of matches so we can traverse it
        # in reverse
        all_matches = [
            match for match in self._magic_re.finditer(freeblock_bytes)
        ]
        for magic_match in all_matches[::-1]:
            header_start = magic_match.start() - self._offset
            if header_start < 0:
                _LOGGER.debug("Header start outside of freeblock!")
                break
            yield header_start

    def match(self, table):
        if self._table_name_regex is not None:
            return bool(self._table_name_regex.match(table.name))
        else:
            return self._table_name == table.name


class HeuristicsRegistry(dict):


    def __init__(self):
        super().__init__(self)

    @staticmethod
    def check_heuristic(magic, offset):
        assert(isinstance(magic, bytes))
        assert(isinstance(offset, int))
        assert(offset >= 0)

    def _load_from_yaml(self, yaml_string):
        if isinstance(yaml_string, bytes):
            yaml_string = yaml_string.decode('utf-8')

        raw_yaml = yaml.load(yaml_string, Loader=yaml.CLoader)
        # TODO Find a more descriptive term than "table grouping"
        for table_grouping, tables in raw_yaml.items():
            _LOGGER.debug(
                "Loading YAML data for table grouping \"%s\"",
                table_grouping
            )
            grouping_tables = {}
            for table_name, table_props in tables.items():
                self.check_heuristic(
                    table_props['magic'], table_props['offset']
                )
                grouping_tables[table_name] = Heuristic(
                    table_props['magic'], table_props['offset'],
                    table_grouping, table_name,
                    name_regex=table_props.get('name_regex')
                )
                _LOGGER.debug("Loaded heuristics for \"%s\"", table_name)
            self[table_grouping] = grouping_tables

    def load_heuristics(self):
        with resource_stream(PROJECT_NAME, BUILTIN_YAML) as builtin:
            try:
                self._load_from_yaml(builtin.read())
            except KeyError as ex:
                raise SystemError("Malformed builtin magic file") from ex

        if not os.path.exists(USER_YAML_PATH):
            return
        with open(USER_YAML_PATH, 'r', encoding='UTF8') as user_yaml:
            try:
                self._load_from_yaml(user_yaml.read())
            except KeyError as ex:
                raise SystemError("Malformed user magic file") from ex

    @property
    def groupings(self):
        for db_name in sorted(self.keys()):
            yield db_name

    @property
    def all_tables(self):
        for db in self.groupings:
            for table in self[db].keys():
                yield (db, table)

    def _get_heuristic_in_grouping(self, db_table, grouping):
        heuristic_name = None
        if grouping in self:
            for heuristic_name in self[grouping]:
                if self[grouping][heuristic_name].match(db_table):
                    break
            else:
                # We haven't found a match within the grouping... what
                # shall we do?
                raise ValueError("No heuristic found")

            return self[grouping][heuristic_name]

        else:
            raise ValueError(
                "No heuristic defined for table \"%s\" in grouping \"%s\"" %
                (db_table.name, grouping)
            )

    def _get_heuristic_in_all_groupings(self, db_table):
        grouping = None
        heuristic_name = None
        for grouping, heuristic_name in self.all_tables:
            if self[grouping][heuristic_name].match(db_table):
                break
        else:
            raise ValueError(
                "No heuristic defined for table \"%s\" in any grouping" %
                (db_table.name,)
            )

        return self[grouping][heuristic_name]

    def get_heuristic(self, db_table, grouping):
        if grouping is not None:
            return self._get_heuristic_in_grouping(db_table, grouping)
        else:
            return self._get_heuristic_in_all_groupings(db_table)


1		# MIT License
2		#
3		# Copyright (c) 2017 Matt Boyer
4		#
5		# Permission is hereby granted, free of charge, to any person obtaining a copy
6		# of this software and associated documentation files (the "Software"), to deal
7		# in the Software without restriction, including without limitation the rights
8		# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9		# copies of the Software, and to permit persons to whom the Software is
10		# furnished to do so, subject to the following conditions:
11		#
12		# The above copyright notice and this permission notice shall be included in
13		# all copies or substantial portions of the Software.
14		#
15		# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16		# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17		# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18		# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19		# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20		# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21		# SOFTWARE.
22
23		import os
24		from pkg_resources import resource_stream
25		import re
26		import yaml
27
28		from . import _LOGGER
29		from . import PROJECT_NAME, USER_YAML_PATH, BUILTIN_YAML
30
31
32	View Code Duplication	class Heuristic(object):
		0 ignored issues – show Duplication introduced 2022-03-20 09:42 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
33		def __init__(self, magic, offset, grouping, table, name_regex=None):
34		self._offset = offset
35		self._table_name = table
36		self._grouping = grouping
37		self._magic_re = re.compile(magic)
38
39		self._table_name_regex = None
40		if name_regex is not None:
41		self._table_name_regex = re.compile(name_regex)
42
43		def __repr__(self):
44		return "<Record heuristic for table \"{0}\"({1})>".format(
45		self._table_name, self._grouping
46		)
47
48		def __call__(self, freeblock_bytes):
49		# We need to unwind the full set of matches so we can traverse it
50		# in reverse
51		all_matches = [
52		match for match in self._magic_re.finditer(freeblock_bytes)
53		]
54		for magic_match in all_matches[::-1]:
55		header_start = magic_match.start() - self._offset
56		if header_start < 0:
57		_LOGGER.debug("Header start outside of freeblock!")
58		break
59		yield header_start
60
61		def match(self, table):
62		if self._table_name_regex is not None:
63		return bool(self._table_name_regex.match(table.name))
64		else:
65		return self._table_name == table.name
66
67
68	View Code Duplication	class HeuristicsRegistry(dict):
		0 ignored issues – show Duplication introduced 2022-03-20 09:42 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
69
70		def __init__(self):
71		super().__init__(self)
72
73		@staticmethod
74		def check_heuristic(magic, offset):
75		assert(isinstance(magic, bytes))
76		assert(isinstance(offset, int))
77		assert(offset >= 0)
78
79		def _load_from_yaml(self, yaml_string):
80		if isinstance(yaml_string, bytes):
81		yaml_string = yaml_string.decode('utf-8')
82
83		raw_yaml = yaml.load(yaml_string, Loader=yaml.CLoader)
84		# TODO Find a more descriptive term than "table grouping"
85		for table_grouping, tables in raw_yaml.items():
86		_LOGGER.debug(
87		"Loading YAML data for table grouping \"%s\"",
88		table_grouping
89		)
90		grouping_tables = {}
91		for table_name, table_props in tables.items():
92		self.check_heuristic(
93		table_props['magic'], table_props['offset']
94		)
95		grouping_tables[table_name] = Heuristic(
96		table_props['magic'], table_props['offset'],
97		table_grouping, table_name,
98		name_regex=table_props.get('name_regex')
99		)
100		_LOGGER.debug("Loaded heuristics for \"%s\"", table_name)
101		self[table_grouping] = grouping_tables
102
103		def load_heuristics(self):
104		with resource_stream(PROJECT_NAME, BUILTIN_YAML) as builtin:
105		try:
106		self._load_from_yaml(builtin.read())
107		except KeyError as ex:
108		raise SystemError("Malformed builtin magic file") from ex
109
110		if not os.path.exists(USER_YAML_PATH):
111		return
112		with open(USER_YAML_PATH, 'r', encoding='UTF8') as user_yaml:
113		try:
114		self._load_from_yaml(user_yaml.read())
115		except KeyError as ex:
116		raise SystemError("Malformed user magic file") from ex
117
118		@property
119		def groupings(self):
120		for db_name in sorted(self.keys()):
121		yield db_name
122
123		@property
124		def all_tables(self):
125		for db in self.groupings:
126		for table in self[db].keys():
127		yield (db, table)
128
129		def _get_heuristic_in_grouping(self, db_table, grouping):
130		heuristic_name = None
131		if grouping in self:
132		for heuristic_name in self[grouping]:
133		if self[grouping][heuristic_name].match(db_table):
134		break
135		else:
136		# We haven't found a match within the grouping... what
137		# shall we do?
138		raise ValueError("No heuristic found")
139
140		return self[grouping][heuristic_name]
141
142		else:
143		raise ValueError(
144		"No heuristic defined for table \"%s\" in grouping \"%s\"" %
145		(db_table.name, grouping)
146		)
147
148		def _get_heuristic_in_all_groupings(self, db_table):
149		grouping = None
150		heuristic_name = None
151		for grouping, heuristic_name in self.all_tables:
152		if self[grouping][heuristic_name].match(db_table):
153		break
154		else:
155		raise ValueError(
156		"No heuristic defined for table \"%s\" in any grouping" %
157		(db_table.name,)
158		)
159
160		return self[grouping][heuristic_name]
161
162		def get_heuristic(self, db_table, grouping):
163		if grouping is not None:
164		return self._get_heuristic_in_grouping(db_table, grouping)
165		else:
166		return self._get_heuristic_in_all_groupings(db_table)
167

mattboyer / sqbrite

HeuristicsRegistry.load_heuristics() B last analyzed 2022-03-20 10:13 UTC

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HeuristicsRegistry.load_heuristics() B
last analyzed 2022-03-20 10:13 UTC