Bear.download_cached_file() - Code Metrics - Inspection of "Sils/down" - coala-analyzer/coala - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#2147)

by Lasse

created 2016-05-15 13:55 UTC

Bear.download_cached_file() B

↳ Parent: Bear

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	3
c	1
b	0
f	0
dl	0
loc	37
rs	8.8571

import traceback
from os import makedirs
from os.path import join, abspath, isdir, exists
from shutil import copyfileobj
from urllib.request import urlopen

from appdirs import user_data_dir

from pyprint.Printer import Printer

from coalib.misc.Decorators import enforce_signature, classproperty
from coalib.output.printers.LogPrinter import LogPrinter
from coalib.settings.FunctionMetadata import FunctionMetadata
from coalib.settings.Section import Section
from coalib.settings.ConfigurationGathering import get_config_directory


class Bear(Printer, LogPrinter):
    """
    A bear contains the actual subroutine that is responsible for checking
    source code for certain specifications. However it can actually do
    whatever it wants with the files it gets. If you are missing some Result
    type, feel free to contact us and/or help us extending the coalib.

    This is the base class for every bear. If you want to write an bear, you
    will probably want to look at the GlobalBear and LocalBear classes that
    inherit from this class. In any case you'll want to overwrite at least the
    run method. You can send debug/warning/error messages through the
    debug(), warn(), err() functions. These will send the
    appropriate messages so that they are outputted. Be aware that if you use
    err(), you are expected to also terminate the bear run-through
    immediately.

    If you need some setup or teardown for your bear, feel free to overwrite
    the set_up() and tear_down() functions. They will be invoked
    before/after every run invocation.

    Settings are available at all times through self.section.

    To indicate which languages your bear supports, just give it the
    ``LANGUAGES`` value which can either be a string (if the bear supports
    only 1 language) or a tuple of strings:

    >>> class SomeBear(Bear):
    ...     LANGUAGES = ('C', 'CPP','C#', 'D')

    >>> class SomeBear(Bear):
    ...     LANGUAGES = "Java"

    Every bear has a data directory which is unique to that particular bear:

    >>> class SomeBear(Bear): pass
    >>> class SomeOtherBear(Bear): pass
    >>> SomeBear.data_dir == SomeOtherBear.data_dir
    False
    """

    LANGUAGES = ()

    @classproperty
    def name(cls):
        """
        :return: The name of the bear
        """
        return cls.__name__

    @classproperty
    def supported_languages(cls):
        """
        :return: The languages supported by the bear.
        """
        return (cls.LANGUAGES if isinstance(
            cls.LANGUAGES, tuple) else (cls.LANGUAGES,))

    @enforce_signature
    def __init__(self,
                 section: Section,
                 message_queue,
                 timeout=0):
        """
        Constructs a new bear.

        :param section:       The section object where bear settings are
                              contained.
        :param message_queue: The queue object for messages. Can be ``None``.
        :param timeout:       The time the bear is allowed to run. To set no
                              time limit, use 0.
        :raises TypeError:    Raised when ``message_queue`` is no queue.
        :raises RuntimeError: Raised when bear requirements are not fulfilled.
        """
        Printer.__init__(self)
        LogPrinter.__init__(self, self)

        if message_queue is not None and not hasattr(message_queue, "put"):
            raise TypeError("message_queue has to be a Queue or None.")

        self.section = section
        self.message_queue = message_queue
        self.timeout = timeout

        self.setup_dependencies()
        cp = type(self).check_prerequisites()
        if cp is not True:
            error_string = ("The bear " + self.name +
                            " does not fulfill all requirements.")
            if cp is not False:
                error_string += " " + cp

            self.warn(error_string)
            raise RuntimeError(error_string)

    def _print(self, output, **kwargs):
        self.debug(output)

    def log_message(self, log_message, timestamp=None, **kwargs):
        if self.message_queue is not None:
            self.message_queue.put(log_message)

    def run(self, *args, dependency_results=None, **kwargs):
        raise NotImplementedError

    def run_bear_from_section(self, args, kwargs):
        try:
            kwargs.update(
                self.get_metadata().create_params_from_section(self.section))
        except ValueError as err:
            self.warn("The bear {} cannot be executed.".format(
                self.name), str(err))
            return

        return self.run(*args, **kwargs)

    def execute(self, *args, **kwargs):
        name = self.name
        try:
            self.debug("Running bear {}...".format(name))
            # If it's already a list it won't change it
            return list(self.run_bear_from_section(args, kwargs) or [])
        except:
            self.warn(
                "Bear {} failed to run. Take a look at debug messages for "
                "further information.".format(name))
            self.debug(
                "The bear {bear} raised an exception. If you are the writer "
                "of this bear, please make sure to catch all exceptions. If "
                "not and this error annoys you, you might want to get in "
                "contact with the writer of this bear.\n\nTraceback "
                "information is provided below:\n\n{traceback}"
                "\n".format(bear=name, traceback=traceback.format_exc()))

    @staticmethod
    def kind():
        """
        :return: The kind of the bear
        """
        raise NotImplementedError

    @classmethod
    def get_metadata(cls):
        """
        :return: Metadata for the run function. However parameters like
                 ``self`` or parameters implicitly used by coala (e.g.
                 filename for local bears) are already removed.
        """
        return FunctionMetadata.from_function(
            cls.run,
            omit={"self", "dependency_results"})

    @classmethod
    def missing_dependencies(cls, lst):
        """
        Checks if the given list contains all dependencies.

        :param lst: A list of all already resolved bear classes (not
                    instances).
        :return:    A list of missing dependencies.
        """
        dep_classes = cls.get_dependencies()

        for item in lst:
            if item in dep_classes:
                dep_classes.remove(item)

        return dep_classes

    @staticmethod
    def get_dependencies():
        """
        Retrieves bear classes that are to be executed before this bear gets
        executed. The results of these bears will then be passed to the
        run method as a dict via the dependency_results argument. The dict
        will have the name of the Bear as key and the list of its results as
        results.

        :return: A list of bear classes.
        """
        return []

    @classmethod
    def get_non_optional_settings(cls):
        """
        This method has to determine which settings are needed by this bear.
        The user will be prompted for needed settings that are not available
        in the settings file so don't include settings where a default value
        would do.

        :return: A dictionary of needed settings as keys and a tuple of help
                 text and annotation as values
        """
        return cls.get_metadata().non_optional_params

    @staticmethod
    def setup_dependencies():
        """
        This is a user defined function that can download and set up
        dependencies (via download_cached_file or arbitary other means) in an OS
        independent way.
        """
        pass

    @classmethod
    def check_prerequisites(cls):
        """
        Checks whether needed runtime prerequisites of the bear are satisfied.

        This function gets executed at construction and returns True by
        default.

        Section value requirements shall be checked inside the ``run`` method.

        :return: True if prerequisites are satisfied, else False or a string
                 that serves a more detailed description of what's missing.
        """
        return True

    def get_config_dir(self):
        """
        Gives the directory where the configuration file is

        :return: Directory of the config file
        """
        return get_config_directory(self.section)

    def download_cached_file(self, url, filename):
        """
        Downloads the file if needed and caches it for the next time. If a
        download happens, the user will be informed.

        Take a sane simple bear:

        >>> from queue import Queue
        >>> bear = Bear(Section("a section"), Queue())

        We can now carelessly query for a neat file that doesn't exist yet:

        >>> from os import remove
        >>> if exists(join(bear.data_dir, "a_file")):
        ...     remove(join(bear.data_dir, "a_file"))
        >>> file = bear.download_cached_file("http://gitmate.com/", "a_file")

        If we download it again, it'll be much faster as no download occurs:

        >>> newfile = bear.download_cached_file("http://gitmate.com/", "a_file")
        >>> newfile == file
        True

        :param url: The URL to download the file from.
        :param filename: The filename it should get, e.g. "test.txt".
        :return: A full path to the file ready for you to use!
        """
        filename = join(self.data_dir, filename)
        if exists(filename):
            return filename

        self.info("Downloading {filename!r} for bear {bearname} from {url}."
                  .format(filename=filename, bearname=self.name, url=url))

        with urlopen(url) as response, open(filename, 'wb') as out_file:
            copyfileobj(response, out_file)
        return filename

    @classproperty
    def data_dir(cls):
        """
        Returns a directory that may be used by the bear to store stuff. Every
        bear has an own directory dependent on his name.
        """
        data_dir = abspath(join(user_data_dir('coala-bears'), cls.name))

        if not isdir(data_dir):  # pragma: no cover
            makedirs(data_dir)
        return data_dir


1			import traceback
2			from os import makedirs
3			from os.path import join, abspath, isdir, exists
4			from shutil import copyfileobj
5			from urllib.request import urlopen
6
7			from appdirs import user_data_dir
8
9			from pyprint.Printer import Printer
10
11			from coalib.misc.Decorators import enforce_signature, classproperty
12			from coalib.output.printers.LogPrinter import LogPrinter
13			from coalib.settings.FunctionMetadata import FunctionMetadata
14			from coalib.settings.Section import Section
15			from coalib.settings.ConfigurationGathering import get_config_directory
16
17
18			class Bear(Printer, LogPrinter):
19			"""
20			A bear contains the actual subroutine that is responsible for checking
21			source code for certain specifications. However it can actually do
22			whatever it wants with the files it gets. If you are missing some Result
23			type, feel free to contact us and/or help us extending the coalib.
24
25			This is the base class for every bear. If you want to write an bear, you
26			will probably want to look at the GlobalBear and LocalBear classes that
27			inherit from this class. In any case you'll want to overwrite at least the
28			run method. You can send debug/warning/error messages through the
29			debug(), warn(), err() functions. These will send the
30			appropriate messages so that they are outputted. Be aware that if you use
31			err(), you are expected to also terminate the bear run-through
32			immediately.
33
34			If you need some setup or teardown for your bear, feel free to overwrite
35			the set_up() and tear_down() functions. They will be invoked
36			before/after every run invocation.
37
38			Settings are available at all times through self.section.
39
40			To indicate which languages your bear supports, just give it the
41			``LANGUAGES`` value which can either be a string (if the bear supports
42			only 1 language) or a tuple of strings:
43
44			>>> class SomeBear(Bear):
45			... LANGUAGES = ('C', 'CPP','C#', 'D')
46
47			>>> class SomeBear(Bear):
48			... LANGUAGES = "Java"
49
50			Every bear has a data directory which is unique to that particular bear:
51
52			>>> class SomeBear(Bear): pass
53			>>> class SomeOtherBear(Bear): pass
54			>>> SomeBear.data_dir == SomeOtherBear.data_dir
55			False
56			"""
57
58			LANGUAGES = ()
59
60			@classproperty
61			def name(cls):
62			"""
63			:return: The name of the bear
64			"""
65			return cls.__name__
66
67			@classproperty
68			def supported_languages(cls):
69			"""
70			:return: The languages supported by the bear.
71			"""
72			return (cls.LANGUAGES if isinstance(
73			cls.LANGUAGES, tuple) else (cls.LANGUAGES,))
74
75			@enforce_signature
76			def __init__(self,
77			section: Section,
78			message_queue,
79			timeout=0):
80			"""
81			Constructs a new bear.
82
83			:param section: The section object where bear settings are
84			contained.
85			:param message_queue: The queue object for messages. Can be ``None``.
86			:param timeout: The time the bear is allowed to run. To set no
87			time limit, use 0.
88			:raises TypeError: Raised when ``message_queue`` is no queue.
89			:raises RuntimeError: Raised when bear requirements are not fulfilled.
90			"""
91			Printer.__init__(self)
92			LogPrinter.__init__(self, self)
93
94			if message_queue is not None and not hasattr(message_queue, "put"):
95			raise TypeError("message_queue has to be a Queue or None.")
96
97			self.section = section
98			self.message_queue = message_queue
99			self.timeout = timeout
100
101			self.setup_dependencies()
102			cp = type(self).check_prerequisites()
103			if cp is not True:
104			error_string = ("The bear " + self.name +
105			" does not fulfill all requirements.")
106			if cp is not False:
107			error_string += " " + cp
108
109			self.warn(error_string)
110			raise RuntimeError(error_string)
111
112			def _print(self, output, **kwargs):
113			self.debug(output)
114
115			def log_message(self, log_message, timestamp=None, **kwargs):
116			if self.message_queue is not None:
117			self.message_queue.put(log_message)
118
119			def run(self, args, dependency_results=None, *kwargs):
120			raise NotImplementedError
121
122			def run_bear_from_section(self, args, kwargs):
123			try:
124			kwargs.update(
125			self.get_metadata().create_params_from_section(self.section))
126			except ValueError as err:
127			self.warn("The bear {} cannot be executed.".format(
128			self.name), str(err))
129			return
130
131			return self.run(args, *kwargs)
132
133			def execute(self, args, *kwargs):
134			name = self.name
135			try:
136			self.debug("Running bear {}...".format(name))
137			# If it's already a list it won't change it
138			return list(self.run_bear_from_section(args, kwargs) or [])
139			except:
140			self.warn(
141			"Bear {} failed to run. Take a look at debug messages for "
142			"further information.".format(name))
143			self.debug(
144			"The bear {bear} raised an exception. If you are the writer "
145			"of this bear, please make sure to catch all exceptions. If "
146			"not and this error annoys you, you might want to get in "
147			"contact with the writer of this bear.\n\nTraceback "
148			"information is provided below:\n\n{traceback}"
149			"\n".format(bear=name, traceback=traceback.format_exc()))
150
151			@staticmethod
152			def kind():
153			"""
154			:return: The kind of the bear
155			"""
156			raise NotImplementedError
157
158			@classmethod
159			def get_metadata(cls):
160			"""
161			:return: Metadata for the run function. However parameters like
162			``self`` or parameters implicitly used by coala (e.g.
163			filename for local bears) are already removed.
164			"""
165			return FunctionMetadata.from_function(
166			cls.run,
167			omit={"self", "dependency_results"})
168
169			@classmethod
170			def missing_dependencies(cls, lst):
171			"""
172			Checks if the given list contains all dependencies.
173
174			:param lst: A list of all already resolved bear classes (not
175			instances).
176			:return: A list of missing dependencies.
177			"""
178			dep_classes = cls.get_dependencies()
179
180			for item in lst:
181			if item in dep_classes:
182			dep_classes.remove(item)
183
184			return dep_classes
185
186			@staticmethod
187			def get_dependencies():
188			"""
189			Retrieves bear classes that are to be executed before this bear gets
190			executed. The results of these bears will then be passed to the
191			run method as a dict via the dependency_results argument. The dict
192			will have the name of the Bear as key and the list of its results as
193			results.
194
195			:return: A list of bear classes.
196			"""
197			return []
198
199			@classmethod
200			def get_non_optional_settings(cls):
201			"""
202			This method has to determine which settings are needed by this bear.
203			The user will be prompted for needed settings that are not available
204			in the settings file so don't include settings where a default value
205			would do.
206
207			:return: A dictionary of needed settings as keys and a tuple of help
208			text and annotation as values
209			"""
210			return cls.get_metadata().non_optional_params
211
212			@staticmethod
213			def setup_dependencies():
214			"""
215			This is a user defined function that can download and set up
216			dependencies (via download_cached_file or arbitary other means) in an OS
217			independent way.
218			"""
219			pass
220
221			@classmethod
222			def check_prerequisites(cls):
223			"""
224			Checks whether needed runtime prerequisites of the bear are satisfied.
225
226			This function gets executed at construction and returns True by
227			default.
228
229			Section value requirements shall be checked inside the ``run`` method.
230
231			:return: True if prerequisites are satisfied, else False or a string
232			that serves a more detailed description of what's missing.
233			"""
234			return True
235
236			def get_config_dir(self):
237			"""
238			Gives the directory where the configuration file is
239
240			:return: Directory of the config file
241			"""
242			return get_config_directory(self.section)
243
244			def download_cached_file(self, url, filename):
245			"""
246			Downloads the file if needed and caches it for the next time. If a
247			download happens, the user will be informed.
248
249			Take a sane simple bear:
250
251			>>> from queue import Queue
252			>>> bear = Bear(Section("a section"), Queue())
253
254			We can now carelessly query for a neat file that doesn't exist yet:
255
256			>>> from os import remove
257			>>> if exists(join(bear.data_dir, "a_file")):
258			... remove(join(bear.data_dir, "a_file"))
259			>>> file = bear.download_cached_file("http://gitmate.com/", "a_file")
260
261			If we download it again, it'll be much faster as no download occurs:
262
263			>>> newfile = bear.download_cached_file("http://gitmate.com/", "a_file")
264			>>> newfile == file
265			True
266
267			:param url: The URL to download the file from.
268			:param filename: The filename it should get, e.g. "test.txt".
269			:return: A full path to the file ready for you to use!
270			"""
271			filename = join(self.data_dir, filename)
272			if exists(filename):
273			return filename
274
275			self.info("Downloading {filename!r} for bear {bearname} from {url}."
276			.format(filename=filename, bearname=self.name, url=url))
277
278			with urlopen(url) as response, open(filename, 'wb') as out_file:
279			copyfileobj(response, out_file)
280			return filename
281
282			@classproperty
283			def data_dir(cls):
284			"""
285			Returns a directory that may be used by the bear to store stuff. Every
286			bear has an own directory dependent on his name.
287			"""
288			data_dir = abspath(join(user_data_dir('coala-bears'), cls.name))
289
290			if not isdir(data_dir): # pragma: no cover
291			makedirs(data_dir)
292			return data_dir
293

coala-analyzer / coala

Pull Request — master (#2147)

Bear.download_cached_file() B

Complexity

Size

Duplication

Importance

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