Completed
Pull Request — master (#199)
by Björn
03:00
created

start_host()   F

Complexity

Conditions 10

Size

Total Lines 42

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 1
CRAP Score 96.3889

Importance

Changes 1
Bugs 0 Features 0
Metric Value
cc 10
dl 0
loc 42
ccs 1
cts 21
cp 0.0476
crap 96.3889
rs 3.1304
c 1
b 0
f 0

How to fix   Complexity   

Complexity

Complex classes like start_host() often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

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"""Python client for Nvim.
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Client library for talking with Nvim processes via it's msgpack-rpc API.
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"""
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import logging
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import os
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import sys
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from .api import Nvim
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from .compat import IS_PYTHON3
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from .msgpack_rpc import (ErrorResponse, child_session, socket_session,
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                          stdio_session, tcp_session)
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from .plugin import (Host, autocmd, command, decode, encoding, function,
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                     plugin, rpc_export, shutdown_hook)
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__all__ = ('tcp_session', 'socket_session', 'stdio_session', 'child_session',
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           'start_host', 'autocmd', 'command', 'encoding', 'decode',
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           'function', 'plugin', 'rpc_export', 'Host', 'Nvim',
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           'shutdown_hook', 'attach', 'setup_logging', 'ErrorResponse')
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def start_host(session=None):
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    """Promote the current process into python plugin host for Nvim.
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    Start msgpack-rpc event loop for `session`, listening for Nvim requests
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    and notifications. It registers Nvim commands for loading/unloading
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    python plugins.
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    The sys.stdout and sys.stderr streams are redirected to Nvim through
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    `session`. That means print statements probably won't work as expected
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    while this function doesn't return.
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    This function is normally called at program startup and could have been
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    defined as a separate executable. It is exposed as a library function for
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    testing purposes only.
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    """
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    plugins = []
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    for arg in sys.argv:
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        _, ext = os.path.splitext(arg)
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        if ext == '.py':
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            plugins.append(arg)
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        elif os.path.isdir(arg):
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            init = os.path.join(arg, '__init__.py')
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            if os.path.isfile(init):
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                plugins.append(arg)
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    # This is a special case to support the old workaround of
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    # adding an empty .py file to make a package directory
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    # visible, and it should be removed soon.
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    for path in list(plugins):
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        dup = path + ".py"
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        if os.path.isdir(path) and dup in plugins:
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            plugins.remove(dup)
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    if not plugins:
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        sys.exit('must specify at least one plugin as argument')
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    setup_logging()
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    if not session:
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        session = stdio_session()
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    host = Host(Nvim.from_session(session))
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    host.start(plugins)
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def attach(session_type, address=None, port=None,
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           path=None, argv=None, decode=None):
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    """Provide a nicer interface to create python api sessions.
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    Previous machinery to create python api sessions is still there. This only
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    creates a facade function to make things easier for the most usual cases.
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    Thus, instead of:
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        from neovim import socket_session, Nvim
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        session = tcp_session(address=<address>, port=<port>)
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        nvim = Nvim.from_session(session)
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    You can now do:
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        from neovim import attach
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        nvim = attach('tcp', address=<address>, port=<port>)
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    And also:
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        nvim = attach('socket', path=<path>)
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        nvim = attach('child', argv=<argv>)
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        nvim = attach('stdio')
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    """
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    session = (tcp_session(address, port) if session_type == 'tcp' else
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               socket_session(path) if session_type == 'socket' else
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               stdio_session() if session_type == 'stdio' else
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               child_session(argv) if session_type == 'child' else
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               None)
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    if not session:
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        raise Exception('Unknown session type "%s"' % session_type)
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    if decode is None:
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        decode = IS_PYTHON3
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    return Nvim.from_session(session).with_decode(decode)
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def setup_logging():
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    """Setup logging according to environment variables."""
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    logger = logging.getLogger(__name__)
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    if 'NVIM_PYTHON_LOG_FILE' in os.environ:
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        logfile = (os.environ['NVIM_PYTHON_LOG_FILE'].strip() +
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                   '_' + str(os.getpid()))
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        handler = logging.FileHandler(logfile, 'w')
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        handler.formatter = logging.Formatter(
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            '%(asctime)s [%(levelname)s @ '
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            '%(filename)s:%(funcName)s:%(lineno)s] %(process)s - %(message)s')
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        logging.root.addHandler(handler)
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        level = logging.INFO
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        if 'NVIM_PYTHON_LOG_LEVEL' in os.environ:
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            l = getattr(logging,
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                        os.environ['NVIM_PYTHON_LOG_LEVEL'].strip(),
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                        level)
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            if isinstance(l, int):
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                level = l
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        logger.setLevel(level)
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# Required for python 2.6
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class NullHandler(logging.Handler):
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    def emit(self, record):
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        pass
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if not logging.root.handlers:
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    logging.root.addHandler(NullHandler())
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