# Τεκμηρίωση του Django - 1.10.7

# Πηγαίος κώδικας για το django.contrib.gis.geoip.base

    import os
    import re
    import warnings
    from ctypes import c_char_p

    from django.contrib.gis.geoip.libgeoip import GEOIP_SETTINGS
    from django.contrib.gis.geoip.prototypes import (
        GeoIP_country_code_by_addr, GeoIP_country_code_by_name,
        GeoIP_country_name_by_addr, GeoIP_country_name_by_name,
        GeoIP_database_info, GeoIP_delete, GeoIP_lib_version, GeoIP_open,
        GeoIP_record_by_addr, GeoIP_record_by_name,
    )
    from django.core.validators import ipv4_re
    from django.utils import six
    from django.utils.deprecation import RemovedInDjango20Warning
    from django.utils.encoding import force_bytes, force_text

    # Regular expressions for recognizing the GeoIP free database editions.
    free_regex = re.compile(r'^GEO-\d{3}FREE')
    lite_regex = re.compile(r'^GEO-\d{3}LITE')

    class GeoIPException(Exception):
        pass

    class GeoIP(object):
        # The flags for GeoIP memory caching.
        # GEOIP_STANDARD - read database from filesystem, uses least memory.
        #
        # GEOIP_MEMORY_CACHE - load database into memory, faster performance
        #        but uses more memory
        #
        # GEOIP_CHECK_CACHE - check for updated database.  If database has been
        #        updated, reload filehandle and/or memory cache.  This option
        #        is not thread safe.
        #
        # GEOIP_INDEX_CACHE - just cache the most frequently accessed index
        #        portion of the database, resulting in faster lookups than
        #        GEOIP_STANDARD, but less memory usage than GEOIP_MEMORY_CACHE -
        #        useful for larger databases such as GeoIP Organization and
        #        GeoIP City.  Note, for GeoIP Country, Region and Netspeed
        #        databases, GEOIP_INDEX_CACHE is equivalent to GEOIP_MEMORY_CACHE
        #
        # GEOIP_MMAP_CACHE - load database into mmap shared memory ( not available
        #       on Windows).
        GEOIP_STANDARD = 0
        GEOIP_MEMORY_CACHE = 1
        GEOIP_CHECK_CACHE = 2
        GEOIP_INDEX_CACHE = 4
        GEOIP_MMAP_CACHE = 8
        cache_options = {opt: None for opt in (0, 1, 2, 4, 8)}

        # Paths to the city & country binary databases.
        _city_file = ''
        _country_file = ''

        # Initially, pointers to GeoIP file references are NULL.
        _city = None
        _country = None

        def __init__(self, path=None, cache=0, country=None, city=None):
            """
            Initializes the GeoIP object, no parameters are required to use default
            settings.  Keyword arguments may be passed in to customize the locations
            of the GeoIP data sets.

            * path: Base directory to where GeoIP data is located or the full path
                to where the city or country data files (*.dat) are located.
                Assumes that both the city and country data sets are located in
                this directory; overrides the GEOIP_PATH settings attribute.

            * cache: The cache settings when opening up the GeoIP datasets,
                and may be an integer in (0, 1, 2, 4, 8) corresponding to
                the GEOIP_STANDARD, GEOIP_MEMORY_CACHE, GEOIP_CHECK_CACHE,
                GEOIP_INDEX_CACHE, and GEOIP_MMAP_CACHE, `GeoIPOptions` C API
                settings,  respectively.  Defaults to 0, meaning that the data is read
                from the disk.

            * country: The name of the GeoIP country data file.  Defaults to
                'GeoIP.dat'; overrides the GEOIP_COUNTRY settings attribute.

            * city: The name of the GeoIP city data file.  Defaults to
                'GeoLiteCity.dat'; overrides the GEOIP_CITY settings attribute.
            """

            warnings.warn(
                "django.contrib.gis.geoip is deprecated in favor of "
                "django.contrib.gis.geoip2 and the MaxMind GeoLite2 database "
                "format.", RemovedInDjango20Warning, 2
            )

            # Checking the given cache option.
            if cache in self.cache_options:
                self._cache = cache
            else:
                raise GeoIPException('Invalid GeoIP caching option: %s' % cache)

            # Getting the GeoIP data path.
            if not path:
                path = GEOIP_SETTINGS.get('GEOIP_PATH')
                if not path:
                    raise GeoIPException('GeoIP path must be provided via parameter or the GEOIP_PATH setting.')
            if not isinstance(path, six.string_types):
                raise TypeError('Invalid path type: %s' % type(path).__name__)

            if os.path.isdir(path):
                # Constructing the GeoIP database filenames using the settings
                # dictionary.  If the database files for the GeoLite country
                # and/or city datasets exist, then try and open them.
                country_db = os.path.join(path, country or GEOIP_SETTINGS.get('GEOIP_COUNTRY', 'GeoIP.dat'))
                if os.path.isfile(country_db):
                    self._country = GeoIP_open(force_bytes(country_db), cache)
                    self._country_file = country_db

                city_db = os.path.join(path, city or GEOIP_SETTINGS.get('GEOIP_CITY', 'GeoLiteCity.dat'))
                if os.path.isfile(city_db):
                    self._city = GeoIP_open(force_bytes(city_db), cache)
                    self._city_file = city_db
            elif os.path.isfile(path):
                # Otherwise, some detective work will be needed to figure
                # out whether the given database path is for the GeoIP country
                # or city databases.
                ptr = GeoIP_open(force_bytes(path), cache)
                info = GeoIP_database_info(ptr)
                if lite_regex.match(info):
                    # GeoLite City database detected.
                    self._city = ptr
                    self._city_file = path
                elif free_regex.match(info):
                    # GeoIP Country database detected.
                    self._country = ptr
                    self._country_file = path
                else:
                    raise GeoIPException('Unable to recognize database edition: %s' % info)
            else:
                raise GeoIPException('GeoIP path must be a valid file or directory.')

        def __del__(self):
            # Cleaning any GeoIP file handles lying around.
            if GeoIP_delete is None:
                return
            if self._country:
                GeoIP_delete(self._country)
            if self._city:
                GeoIP_delete(self._city)

        def __repr__(self):
            version = ''
            if GeoIP_lib_version is not None:
                version += ' [v%s]' % force_text(GeoIP_lib_version())
            return '<%(cls)s%(version)s _country_file="%(country)s", _city_file="%(city)s">' % {
                'cls': self.__class__.__name__,
                'version': version,
                'country': self._country_file,
                'city': self._city_file,
            }

        def _check_query(self, query, country=False, city=False, city_or_country=False):
            "Helper routine for checking the query and database availability."
            # Making sure a string was passed in for the query.
            if not isinstance(query, six.string_types):
                raise TypeError('GeoIP query must be a string, not type %s' % type(query).__name__)

            # Extra checks for the existence of country and city databases.
            if city_or_country and not (self._country or self._city):
                raise GeoIPException('Invalid GeoIP country and city data files.')
            elif country and not self._country:
                raise GeoIPException('Invalid GeoIP country data file: %s' % self._country_file)
            elif city and not self._city:
                raise GeoIPException('Invalid GeoIP city data file: %s' % self._city_file)

            # Return the query string back to the caller. GeoIP only takes bytestrings.
            return force_bytes(query)

        def city(self, query):
            """
            Returns a dictionary of city information for the given IP address or
            Fully Qualified Domain Name (FQDN).  Some information in the dictionary
            may be undefined (None).
            """
            enc_query = self._check_query(query, city=True)
            if ipv4_re.match(query):
                # If an IP address was passed in
                return GeoIP_record_by_addr(self._city, c_char_p(enc_query))
            else:
                # If a FQDN was passed in.
                return GeoIP_record_by_name(self._city, c_char_p(enc_query))

        def country_code(self, query):
            "Returns the country code for the given IP Address or FQDN."
            enc_query = self._check_query(query, city_or_country=True)
            if self._country:
                if ipv4_re.match(query):
                    return GeoIP_country_code_by_addr(self._country, enc_query)
                else:
                    return GeoIP_country_code_by_name(self._country, enc_query)
            else:
                return self.city(query)['country_code']

        def country_name(self, query):
            "Returns the country name for the given IP Address or FQDN."
            enc_query = self._check_query(query, city_or_country=True)
            if self._country:
                if ipv4_re.match(query):
                    return GeoIP_country_name_by_addr(self._country, enc_query)
                else:
                    return GeoIP_country_name_by_name(self._country, enc_query)
            else:
                return self.city(query)['country_name']

        def country(self, query):
            """
            Returns a dictionary with the country code and name when given an
            IP address or a Fully Qualified Domain Name (FQDN).  For example, both
            '24.124.1.80' and 'djangoproject.com' are valid parameters.
            """
            # Returning the country code and name
            return {'country_code': self.country_code(query),
                    'country_name': self.country_name(query),
                    }

        # #### Coordinate retrieval routines ####
        def coords(self, query, ordering=('longitude', 'latitude')):
            cdict = self.city(query)
            if cdict is None:
                return None
            else:
                return tuple(cdict[o] for o in ordering)

        def lon_lat(self, query):
            "Returns a tuple of the (longitude, latitude) for the given query."
            return self.coords(query)

        def lat_lon(self, query):
            "Returns a tuple of the (latitude, longitude) for the given query."
            return self.coords(query, ('latitude', 'longitude'))

        def geos(self, query):
            "Returns a GEOS Point object for the given query."
            ll = self.lon_lat(query)
            if ll:
                from django.contrib.gis.geos import Point
                return Point(ll, srid=4326)
            else:
                return None

        # #### GeoIP Database Information Routines ####
        @property
        def country_info(self):
            "Returns information about the GeoIP country database."
            if self._country is None:
                ci = 'No GeoIP Country data in "%s"' % self._country_file
            else:
                ci = GeoIP_database_info(self._country)
            return ci

        @property
        def city_info(self):
            "Returns information about the GeoIP city database."
            if self._city is None:
                ci = 'No GeoIP City data in "%s"' % self._city_file
            else:
                ci = GeoIP_database_info(self._city)
            return ci

        @property
        def info(self):
            "Returns information about the GeoIP library and databases in use."
            info = ''
            if GeoIP_lib_version:
                info += 'GeoIP Library:\n\t%s\n' % GeoIP_lib_version()
            return info + 'Country:\n\t%s\nCity:\n\t%s' % (self.country_info, self.city_info)

        # #### Methods for compatibility w/the GeoIP-Python API. ####
        @classmethod
        def open(cls, full_path, cache):
            return GeoIP(full_path, cache)

        def _rec_by_arg(self, arg):
            if self._city:
                return self.city(arg)
            else:
                return self.country(arg)
        region_by_addr = city
        region_by_name = city
        record_by_addr = _rec_by_arg
        record_by_name = _rec_by_arg
        country_code_by_addr = country_code
        country_code_by_name = country_code
        country_name_by_addr = country_name
        country_name_by_name = country_name