Source code for pyrocko.squirrel.environment

# - GPLv3
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------

Manage separate databases and caches for different user projects.

Squirrel based applications can either use the user's global database which
lives in Pyrocko's global cache directory (by default under
``'$HOME/.pyrocko/cache/squirrel'``) or a project specific local database which
can be conveniently created in the top level directory of a user's project
under ``'.squirrel'`` or ``'squirrel'``. The choice of database and associated
cache directory locations is referred to here as the Squirrel environment. This
module provides functions to create local environments and to look for a usable
environment in the hierarchy of a user's project directory.

import os
import logging

from pyrocko.guts import String, load
from pyrocko import config
from pyrocko.has_paths import HasPaths, Path

from . import error
from .database import close_database

logger = logging.getLogger('psq.environment')

guts_prefix = 'squirrel'

g_db_filename = 'nuts.sqlite'
g_cache_dirname = 'cache'
g_config_filename = 'config.yaml'

def get_config_path(squirrel_path):
    return os.path.join(squirrel_path, g_config_filename)

def get_squirrel_path(path=None):
    if path is None:
        path = os.curdir

    path = os.path.abspath(path)
    if os.path.isdir(path) and os.path.exists(
            os.path.join(path, g_db_filename)):
        return path

    while True:
        for entry in ['squirrel', '.squirrel']:
            candidate = os.path.join(path, entry)
            if os.path.isdir(candidate) \
                    and os.path.exists(os.path.join(candidate, g_db_filename)):

                return candidate

        path_new = os.path.dirname(path)
        if path_new == path:

        path = path_new

    return os.path.join(config.config().cache_dir, 'squirrel')

[docs]def get_environment(path=None): ''' Get default Squirrel environment relevant for a given file system path. :param path: Directory path to use as starting point for detection of the Squirrel environment. By default, the current working directory is used as starting point. When searching for a usable environment the directory ``'.squirrel'`` or ``'squirrel'`` in the current (or starting point) directory is used if it exists, otherwise the parent directories are search upwards for the existence of such a directory. If no such directory is found, the user's global Squirrel environment, usually ``'$HOME/.pyrocko/cache/squirrel'``, is used. :returns: :py:class:`Environment` object containing the detected database and cache directory paths. ''' if path is None: path = os.curdir squirrel_path = get_squirrel_path(path) if os.path.exists(get_config_path(squirrel_path)): return Environment.load(squirrel_path) else: return Environment.make(squirrel_path)
[docs]def init_environment(path=None): ''' Initialize empty Squirrel environment. :param path: Path to the directory where the new environment's ``'.squirrel'`` directory should be created. If set to ``None``, the current working directory is used. If a ``'.squirrel'`` directory already exists at the given location, :py:exc:`~pyrocko.squirrel.error.SquirrelError` is raised. ''' if path is None: path = os.curdir squirrel_path = os.path.join(path, '.squirrel') try: 'Creating squirrel environment directory: %s' % os.path.abspath(squirrel_path)) os.mkdir(squirrel_path) except OSError: raise error.SquirrelError( 'Cannot create squirrel directory: %s' % squirrel_path) from .base import Squirrel env = Environment.make(squirrel_path) env.dump(filename=get_config_path(squirrel_path)) sq = Squirrel(env) database = sq.get_database() del sq close_database(database)
[docs]class Environment(HasPaths): ''' Configuration object providing paths to database and cache. ''' database_path = Path.T(optional=True) cache_path = Path.T(optional=True) persistent = String.T(optional=True) @classmethod def make(cls, squirrel_path): env = cls( database_path=g_db_filename, cache_path=g_cache_dirname) env.set_basepath(squirrel_path) return env @classmethod def load(cls, squirrel_path): path = get_config_path(squirrel_path) try: env = load(filename=path) except OSError: raise error.SquirrelError( 'Cannot read environment config file: %s' % path) if not isinstance(env, Environment): raise error.SquirrelError( 'Invalid environment config file "%s".' % path) env.set_basepath(squirrel_path) return env
__all__ = [ 'get_squirrel_path', 'get_environment', 'init_environment', 'Environment']