ScriptHost.python_chdir() - Code Metrics - Inspection of "Correctly change the working directory in python" - neovim/python-client - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#296)

by Justin M.

created 2018-04-12 23:33 UTC

ScriptHost.python_chdir() A

↳ Parent: ScriptHost

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	1
CRAP Score	1.2963

Importance

Changes

Metric	Value
cc	1
c	0
b	0
f	0
dl	0
loc	4
ccs	1
cts	3
cp	0.3333
crap	1.2963
rs	10

"""Legacy python/python3-vim emulation."""
import imp
import io
import logging
import os
import sys

from .decorators import plugin, rpc_export
from ..api import Nvim, walk
from ..msgpack_rpc import ErrorResponse
from ..util import format_exc_skip

__all__ = ('ScriptHost',)


logger = logging.getLogger(__name__)
debug, info, warn = (logger.debug, logger.info, logger.warn,)

IS_PYTHON3 = sys.version_info >= (3, 0)

if IS_PYTHON3:
    basestring = str

    if sys.version_info >= (3, 4):
        from importlib.machinery import PathFinder

    PYTHON_SUBDIR = 'python3'
else:
    PYTHON_SUBDIR = 'python2'


@plugin
class ScriptHost(object):

    """Provides an environment for running python plugins created for Vim."""

    def __init__(self, nvim):
        """Initialize the legacy python-vim environment."""
        self.setup(nvim)
        # context where all code will run
        self.module = imp.new_module('__main__')
        nvim.script_context = self.module
        # it seems some plugins assume 'sys' is already imported, so do it now
        exec('import sys', self.module.__dict__)

        self.legacy_vim = LegacyVim.from_nvim(nvim)
        sys.modules['vim'] = self.legacy_vim

        # Handle DirChanged. #296
        nvim.command(
            'autocmd DirChanged * call rpcrequest({}, "python_chdir", v:event)'
            .format(nvim.channel_id), async=True)
        os.chdir(nvim.eval('getcwd()', async=False))

    def setup(self, nvim):
        """Setup import hooks and global streams.

        This will add import hooks for importing modules from runtime
        directories and patch the sys module so 'print' calls will be
        forwarded to Nvim.
        """
        self.nvim = nvim
        info('install import hook/path')
        self.hook = path_hook(nvim)
        sys.path_hooks.append(self.hook)
        nvim.VIM_SPECIAL_PATH = '_vim_path_'
        sys.path.append(nvim.VIM_SPECIAL_PATH)
        info('redirect sys.stdout and sys.stderr')
        self.saved_stdout = sys.stdout
        self.saved_stderr = sys.stderr
        sys.stdout = RedirectStream(lambda data: nvim.out_write(data))

        sys.stderr = RedirectStream(lambda data: nvim.err_write(data))


    def teardown(self):
        """Restore state modified from the `setup` call."""
        nvim = self.nvim
        info('uninstall import hook/path')
        sys.path.remove(nvim.VIM_SPECIAL_PATH)
        sys.path_hooks.remove(self.hook)
        info('restore sys.stdout and sys.stderr')
        sys.stdout = self.saved_stdout
        sys.stderr = self.saved_stderr

    @rpc_export('python_execute', sync=True)
    def python_execute(self, script, range_start, range_stop):
        """Handle the `python` ex command."""
        self._set_current_range(range_start, range_stop)
        try:
            exec(script, self.module.__dict__)

        except Exception:
            raise ErrorResponse(format_exc_skip(1))

    @rpc_export('python_execute_file', sync=True)
    def python_execute_file(self, file_path, range_start, range_stop):
        """Handle the `pyfile` ex command."""
        self._set_current_range(range_start, range_stop)
        with open(file_path) as f:
            script = compile(f.read(), file_path, 'exec')
            try:
                exec(script, self.module.__dict__)

            except Exception:
                raise ErrorResponse(format_exc_skip(1))

    @rpc_export('python_do_range', sync=True)
    def python_do_range(self, start, stop, code):
        """Handle the `pydo` ex command."""
        self._set_current_range(start, stop)
        nvim = self.nvim
        start -= 1
        fname = '_vim_pydo'

        # define the function
        function_def = 'def %s(line, linenr):\n %s' % (fname, code,)
        exec(function_def, self.module.__dict__)

        # get the function
        function = self.module.__dict__[fname]
        while start < stop:
            # Process batches of 5000 to avoid the overhead of making multiple
            # API calls for every line. Assuming an average line length of 100
            # bytes, approximately 488 kilobytes will be transferred per batch,
            # which can be done very quickly in a single API call.
            sstart = start
            sstop = min(start + 5000, stop)
            lines = nvim.current.buffer.api.get_lines(sstart, sstop, True)

            exception = None
            newlines = []
            linenr = sstart + 1
            for i, line in enumerate(lines):

                result = function(line, linenr)
                if result is None:
                    # Update earlier lines, and skip to the next
                    if newlines:
                        end = sstart + len(newlines) - 1
                        nvim.current.buffer.api.set_lines(sstart, end,
                                                          True, newlines)
                    sstart += len(newlines) + 1
                    newlines = []
                    pass

                elif isinstance(result, basestring):
                    newlines.append(result)
                else:
                    exception = TypeError('pydo should return a string ' +
                                          'or None, found %s instead'
                                          % result.__class__.__name__)
                    break
                linenr += 1

            start = sstop
            if newlines:
                end = sstart + len(newlines)
                nvim.current.buffer.api.set_lines(sstart, end, True, newlines)
            if exception:
                raise exception

        # delete the function
        del self.module.__dict__[fname]

    @rpc_export('python_eval', sync=True)
    def python_eval(self, expr):
        """Handle the `pyeval` vim function."""
        return eval(expr, self.module.__dict__)


    @rpc_export('python_chdir', sync=True)
    def python_chdir(self, args):
class Foo:
    def some_method(self, x, y):
        return x + y;
        """Handle working directory changes."""
        os.chdir(args['cwd'])

    def _set_current_range(self, start, stop):
        current = self.legacy_vim.current
        current.range = current.buffer.range(start, stop)


class RedirectStream(io.IOBase):
    def __init__(self, redirect_handler):
        self.redirect_handler = redirect_handler

    def write(self, data):
        self.redirect_handler(data)

    def writelines(self, seq):
        self.redirect_handler('\n'.join(seq))


if IS_PYTHON3:
    num_types = (int, float)
else:
    num_types = (int, long, float)  # noqa: F821



def num_to_str(obj):
    if isinstance(obj, num_types):
        return str(obj)
    else:
        return obj


class LegacyVim(Nvim):
    def eval(self, expr):
        obj = self.request("vim_eval", expr)
        return walk(num_to_str, obj)


# This was copied/adapted from nvim-python help
def path_hook(nvim):
    def _get_paths():
        return discover_runtime_directories(nvim)

    def _find_module(fullname, oldtail, path):
        idx = oldtail.find('.')
        if idx > 0:
            name = oldtail[:idx]
            tail = oldtail[idx + 1:]
            fmr = imp.find_module(name, path)
            module = imp.find_module(fullname[:-len(oldtail)] + name, *fmr)
            return _find_module(fullname, tail, module.__path__)

        else:
            return imp.find_module(fullname, path)

    class VimModuleLoader(object):
        def __init__(self, module):
            self.module = module

        def load_module(self, fullname, path=None):

            # Check sys.modules, required for reload (see PEP302).
            if fullname in sys.modules:
                return sys.modules[fullname]
            return imp.load_module(fullname, *self.module)

    class VimPathFinder(object):
        @staticmethod
        def find_module(fullname, path=None):
            """Method for Python 2.7 and 3.3."""
            try:
                return VimModuleLoader(
                    _find_module(fullname, fullname, path or _get_paths()))
            except ImportError:
                return None

        @staticmethod
        def find_spec(fullname, path=None, target=None):
            """Method for Python 3.4+."""
            return PathFinder.find_spec(fullname, path or _get_paths(), target)

    def hook(path):
        if path == nvim.VIM_SPECIAL_PATH:
            return VimPathFinder
        else:
            raise ImportError

    return hook


def discover_runtime_directories(nvim):
    rv = []
    for rtp in nvim.list_runtime_paths():
        if not os.path.exists(rtp):
            continue
        for subdir in ['pythonx', PYTHON_SUBDIR]:
            path = os.path.join(rtp, subdir)
            if os.path.exists(path):
                rv.append(path)
    return rv


1		"""Legacy python/python3-vim emulation."""
2	5	import imp
3	5	import io
4	5	import logging
5	5	import os
6	5	import sys
7
8	5	from .decorators import plugin, rpc_export
9	5	from ..api import Nvim, walk
10	5	from ..msgpack_rpc import ErrorResponse
11	5	from ..util import format_exc_skip
12
13	5	__all__ = ('ScriptHost',)
14
15
16	5	logger = logging.getLogger(__name__)
17	5	debug, info, warn = (logger.debug, logger.info, logger.warn,)
18
19	5	IS_PYTHON3 = sys.version_info >= (3, 0)
20
21	5	if IS_PYTHON3:
22	3	basestring = str
23
24	3	if sys.version_info >= (3, 4):
25	2	from importlib.machinery import PathFinder
26
27		PYTHON_SUBDIR = 'python3'
28	5	else:
29	5	PYTHON_SUBDIR = 'python2'
30
31
32		@plugin
33	5	class ScriptHost(object):
34
35		"""Provides an environment for running python plugins created for Vim."""
36
37		def __init__(self, nvim):
38		"""Initialize the legacy python-vim environment."""
39		self.setup(nvim)
40		# context where all code will run
41		self.module = imp.new_module('__main__')
42		nvim.script_context = self.module
43		# it seems some plugins assume 'sys' is already imported, so do it now
44	5	exec('import sys', self.module.__dict__)
		0 ignored issues – show Coding Style Security introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report The use of `exec` is discouraged. Execution of dynamic code might introduce security vulnerabilities. It is generally recommended to use this feature with care and only when necessary. Loading history...
45		self.legacy_vim = LegacyVim.from_nvim(nvim)
46		sys.modules['vim'] = self.legacy_vim
47
48		# Handle DirChanged. #296
49		nvim.command(
50		'autocmd DirChanged * call rpcrequest({}, "python_chdir", v:event)'
51		.format(nvim.channel_id), async=True)
52		os.chdir(nvim.eval('getcwd()', async=False))
53
54		def setup(self, nvim):
55		"""Setup import hooks and global streams.
56
57		This will add import hooks for importing modules from runtime
58		directories and patch the sys module so 'print' calls will be
59		forwarded to Nvim.
60		"""
61		self.nvim = nvim
62		info('install import hook/path')
63	5	self.hook = path_hook(nvim)
64		sys.path_hooks.append(self.hook)
65		nvim.VIM_SPECIAL_PATH = '_vim_path_'
66		sys.path.append(nvim.VIM_SPECIAL_PATH)
67		info('redirect sys.stdout and sys.stderr')
68		self.saved_stdout = sys.stdout
69		self.saved_stderr = sys.stderr
70		sys.stdout = RedirectStream(lambda data: nvim.out_write(data))
		0 ignored issues – show Unused Code introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report This lambda might be unnecessary. Loading history...
71		sys.stderr = RedirectStream(lambda data: nvim.err_write(data))
		0 ignored issues – show Unused Code introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report This lambda might be unnecessary. Loading history...
72
73	5	def teardown(self):
74		"""Restore state modified from the `setup` call."""
75		nvim = self.nvim
76		info('uninstall import hook/path')
77		sys.path.remove(nvim.VIM_SPECIAL_PATH)
78		sys.path_hooks.remove(self.hook)
79		info('restore sys.stdout and sys.stderr')
80		sys.stdout = self.saved_stdout
81		sys.stderr = self.saved_stderr
82	5
83		@rpc_export('python_execute', sync=True)
84		def python_execute(self, script, range_start, range_stop):
85		"""Handle the `python` ex command."""
86		self._set_current_range(range_start, range_stop)
87		try:
88		exec(script, self.module.__dict__)
		0 ignored issues – show Coding Style Security introduced 2017-04-16 08:05 UTC by Report Bug Copy Issue Report The use of `exec` is discouraged. Execution of dynamic code might introduce security vulnerabilities. It is generally recommended to use this feature with care and only when necessary. Loading history...
89		except Exception:
90		raise ErrorResponse(format_exc_skip(1))
91
92		@rpc_export('python_execute_file', sync=True)
93	5	def python_execute_file(self, file_path, range_start, range_stop):
94		"""Handle the `pyfile` ex command."""
95		self._set_current_range(range_start, range_stop)
96		with open(file_path) as f:
97		script = compile(f.read(), file_path, 'exec')
98		try:
99		exec(script, self.module.__dict__)
		0 ignored issues – show Coding Style Security introduced 2016-06-08 19:50 UTC by Report Bug Copy Issue Report The use of `exec` is discouraged. Execution of dynamic code might introduce security vulnerabilities. It is generally recommended to use this feature with care and only when necessary. Loading history...
100		except Exception:
101		raise ErrorResponse(format_exc_skip(1))
102
103		@rpc_export('python_do_range', sync=True)
104		def python_do_range(self, start, stop, code):
105		"""Handle the `pydo` ex command."""
106		self._set_current_range(start, stop)
107		nvim = self.nvim
108		start -= 1
109		fname = '_vim_pydo'
110
111		# define the function
112		function_def = 'def %s(line, linenr):\n %s' % (fname, code,)
113		exec(function_def, self.module.__dict__)
		0 ignored issues – show Coding Style Security introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report The use of `exec` is discouraged. Execution of dynamic code might introduce security vulnerabilities. It is generally recommended to use this feature with care and only when necessary. Loading history...
114		# get the function
115		function = self.module.__dict__[fname]
116		while start < stop:
117		# Process batches of 5000 to avoid the overhead of making multiple
118		# API calls for every line. Assuming an average line length of 100
119		# bytes, approximately 488 kilobytes will be transferred per batch,
120		# which can be done very quickly in a single API call.
121		sstart = start
122		sstop = min(start + 5000, stop)
123		lines = nvim.current.buffer.api.get_lines(sstart, sstop, True)
124
125		exception = None
126		newlines = []
127		linenr = sstart + 1
128		for i, line in enumerate(lines):
		0 ignored issues – show Unused Code introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report The variable `i` seems to be unused. Loading history...
129		result = function(line, linenr)
130		if result is None:
131		# Update earlier lines, and skip to the next
132		if newlines:
133		end = sstart + len(newlines) - 1
134		nvim.current.buffer.api.set_lines(sstart, end,
135		True, newlines)
136		sstart += len(newlines) + 1
137		newlines = []
138		pass
		0 ignored issues – show Unused Code introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report Unnecessary pass statement Loading history...
139		elif isinstance(result, basestring):
140		newlines.append(result)
141		else:
142		exception = TypeError('pydo should return a string ' +
143		'or None, found %s instead'
144		% result.__class__.__name__)
145		break
146		linenr += 1
147	5
148		start = sstop
149		if newlines:
150		end = sstart + len(newlines)
151		nvim.current.buffer.api.set_lines(sstart, end, True, newlines)
152	5	if exception:
153		raise exception
		0 ignored issues – show Bug introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report Raising NoneType while only classes or instances are allowed Loading history...
154		# delete the function
155		del self.module.__dict__[fname]
156
157	5	@rpc_export('python_eval', sync=True)
158	5	def python_eval(self, expr):
159		"""Handle the `pyeval` vim function."""
160		return eval(expr, self.module.__dict__)
		0 ignored issues – show Security Best Practice introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report `eval` should generally only be used if absolutely necessary. The usage of `eval` might allow for executing arbitrary code if a user manages to inject dynamic input. Please use this language feature with care and only when you are sure of the input. Loading history...
161	5
162		@rpc_export('python_chdir', sync=True)
163		def python_chdir(self, args):
		0 ignored issues – show Coding Style introduced 2018-01-19 11:18 UTC by Report Bug Copy Issue Report This method could be written as a function/class method. If a method does not access any attributes of the class, it could also be implemented as a function or static method. This can help improve readability. For example class Foo: def some_method(self, x, y): return x + y; could be written as class Foo: @classmethod def some_method(cls, x, y): return x + y; Loading history...
164	5	"""Handle working directory changes."""
165		os.chdir(args['cwd'])
166
167		def _set_current_range(self, start, stop):
168	5	current = self.legacy_vim.current
169	3	current.range = current.buffer.range(start, stop)
170
171	2
172		class RedirectStream(io.IOBase):
173		def __init__(self, redirect_handler):
174	5	self.redirect_handler = redirect_handler
175
176		def write(self, data):
177		self.redirect_handler(data)
178
179		def writelines(self, seq):
180		self.redirect_handler('\n'.join(seq))
181	5
182	5
183		if IS_PYTHON3:
184		num_types = (int, float)
185		else:
186		num_types = (int, long, float) # noqa: F821
		0 ignored issues – show Comprehensibility Best Practice introduced 2017-12-30 15:38 UTC by Report Bug Copy Issue Report Undefined variable 'long' Loading history...
187
188	5
189		def num_to_str(obj):
190		if isinstance(obj, num_types):
191		return str(obj)
192		else:
193		return obj
194
195
196		class LegacyVim(Nvim):
197		def eval(self, expr):
198		obj = self.request("vim_eval", expr)
199		return walk(num_to_str, obj)
200
201
202		# This was copied/adapted from nvim-python help
203		def path_hook(nvim):
204		def _get_paths():
205		return discover_runtime_directories(nvim)
206
207		def _find_module(fullname, oldtail, path):
208		idx = oldtail.find('.')
209		if idx > 0:
210		name = oldtail[:idx]
211		tail = oldtail[idx + 1:]
212		fmr = imp.find_module(name, path)
213		module = imp.find_module(fullname[:-len(oldtail)] + name, *fmr)
214		return _find_module(fullname, tail, module.__path__)
		0 ignored issues – show Bug introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report The Instance of `tuple` does not seem to have a member named `__path__`. This check looks for calls to members that are non-existent. These calls will fail. The member could have been renamed or removed. Loading history...
215		else:
216		return imp.find_module(fullname, path)
217
218		class VimModuleLoader(object):
219		def __init__(self, module):
220		self.module = module
221
222		def load_module(self, fullname, path=None):
		0 ignored issues – show Unused Code introduced 2016-03-06 13:35 UTC by Report Bug Copy Issue Report The argument `path` seems to be unused. Loading history...
223		# Check sys.modules, required for reload (see PEP302).
224		if fullname in sys.modules:
225		return sys.modules[fullname]
226		return imp.load_module(fullname, *self.module)
227
228		class VimPathFinder(object):
229		@staticmethod
230		def find_module(fullname, path=None):
231		"""Method for Python 2.7 and 3.3."""
232		try:
233		return VimModuleLoader(
234		_find_module(fullname, fullname, path or _get_paths()))
235		except ImportError:
236		return None
237	5
238		@staticmethod
239		def find_spec(fullname, path=None, target=None):
240		"""Method for Python 3.4+."""
241		return PathFinder.find_spec(fullname, path or _get_paths(), target)
242
243		def hook(path):
244		if path == nvim.VIM_SPECIAL_PATH:
245		return VimPathFinder
246		else:
247		raise ImportError
248
249		return hook
250
251
252		def discover_runtime_directories(nvim):
253		rv = []
254		for rtp in nvim.list_runtime_paths():
255		if not os.path.exists(rtp):
256		continue
257		for subdir in ['pythonx', PYTHON_SUBDIR]:
258		path = os.path.join(rtp, subdir)
259		if os.path.exists(path):
260		rv.append(path)
261		return rv
262

neovim / python-client

Pull Request — master (#296)

ScriptHost.python_chdir() A

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