Source code for gammapy.catalog.registry

# Licensed under a 3-clause BSD style license - see LICENSE.rst
from __future__ import absolute_import, division, print_function, unicode_literals
import sys
from collections import OrderedDict
from astropy.table import Table

__all__ = [
    'source_catalogs',
    'SourceCatalogRegistry',
]


class SourceCatalogRegistry(object):
    """Source catalog registry.

    Provides simple and efficient access to source catalogs
    by lazy-loading and caching catalog objects.

    You should use these catalogs read-only, if you modify
    them you can get non-reproducible results if you access
    the modified version later on.
    """

    def __init__(self):
        self._available_catalogs = OrderedDict()
        self._loaded_catalogs = OrderedDict()

    @classmethod
    def builtins(cls):
        """Factory function that make a catalog registry and
        registers the built-in catalogs.
        """
        source_catalogs = cls()

        import os
        if 'HGPS_ANALYSIS' in os.environ:
            from .hess import SourceCatalogHGPS
            source_catalogs.register('hgps', SourceCatalogHGPS)

        if 'GAMMA_CAT' in os.environ:
            from .gammacat import SourceCatalogGammaCat
            source_catalogs.register('gamma-cat', SourceCatalogGammaCat)

        from .fermi import SourceCatalog3FGL
        source_catalogs.register('3fgl', SourceCatalog3FGL)

        from .fermi import SourceCatalog1FHL
        source_catalogs.register('1fhl', SourceCatalog1FHL)

        from .fermi import SourceCatalog2FHL
        source_catalogs.register('2fhl', SourceCatalog2FHL)

        from .fermi import SourceCatalog3FHL
        source_catalogs.register('3fhl', SourceCatalog3FHL)

        from .hawc import SourceCatalog2HWC
        source_catalogs.register('2hwc', SourceCatalog2HWC)

        return source_catalogs

    @property
    def catalog_names(self):
        """Catalog names (`list`)."""
        return list(self._available_catalogs.keys())

    def register(self, name, cls, args=()):
        """Register a source catalog.

        It must be possible to load it via ``cls(*args)``.
        """
        self._available_catalogs[name] = dict(cls=cls, args=args)

    def __getitem__(self, name):
        if name not in self._available_catalogs:
            msg = 'Unknown catalog: "{}". '.format(name)
            msg += 'Available catalogs: {}'.format(self.catalog_names)
            raise KeyError(msg)

        if name not in self._loaded_catalogs:
            cat = self._available_catalogs[name]
            self._loaded_catalogs[name] = cat['cls'](*cat['args'])

        return self._loaded_catalogs[name]

    def info(self):
        """Print summary info about catalogs."""
        print('Source catalog registry:')
        self.info_table.pprint()

    @property
    def info_table(self):
        """Summary info table on catalogs.

        Loads all catalogs.
        """
        rows = []
        for name in self._available_catalogs.keys():
            cat = self[name]
            rows.append(dict(
                name=name,
                description=cat.description,
                sources=len(cat.table),
            ))

        return Table(rows=rows, names=['name', 'description', 'sources'])


source_catalogs = SourceCatalogRegistry.builtins()
"""Registry of built-in catalogs in Gammapy.

The main point of the registry is to have one point that
knows about all available catalogs and there's an easy way
to load them.
"""