commit 5a202017333cb64f5b9ca7d862e7ef9677761221 Author: Karsten Loesing karsten.loesing@gmx.net Date: Tue Nov 6 10:19:40 2012 -0500
Add simple Python database lookup code (#6471). --- task-6471/python/.gitignore | 3 + task-6471/python/pygeodate.py | 140 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 143 insertions(+), 0 deletions(-)
diff --git a/task-6471/python/.gitignore b/task-6471/python/.gitignore new file mode 100644 index 0000000..4d9663e --- /dev/null +++ b/task-6471/python/.gitignore @@ -0,0 +1,3 @@ +*.csv +*.csv.bz2 + diff --git a/task-6471/python/pygeodate.py b/task-6471/python/pygeodate.py new file mode 100644 index 0000000..6480f20 --- /dev/null +++ b/task-6471/python/pygeodate.py @@ -0,0 +1,140 @@ +import bisect +import socket +import struct +import datetime + +class Range: + def __init__(self, line): + parts = line.split(',') + # TODO Extend to IPv6. The cool thing in Python is that ints have + # variable size, so we can use 48 bit keys for IPv4 (32 bit for the + # IPv4 address and 16 bit for the database date) and 144 bit keys for + # IPv6. + self.start_address = Database.address_ston(parts[0]) + self.end_address = Database.address_ston(parts[1]) + self.code = parts[2] + self.start_date = Database.date_ston(parts[3]) + self.end_date = Database.date_ston(parts[4]) + self.key = Database.create_key(self.start_address, self.start_date) + + def __str__(self): + return "%s,%s,%s,%s,%s" % \ + (Database.address_ntos(self.start_address), + Database.address_ntos(self.end_address), + self.code, + Database.date_ntos(self.start_date), + Database.date_ntos(self.end_date)) + +class Database: + def __init__(self): + # TODO Replace with crit-bit tree if performance becomes a problem + self.data = [] + self.dates = [] + self.keys = [] + + @staticmethod + def address_ston(address_string): + try: + address_struct = socket.inet_pton(socket.AF_INET, address_string) + except socket.error: + raise ValueError + return struct.unpack('!I', address_struct)[0] + + @staticmethod + def address_ntos(address): + return socket.inet_ntop(socket.AF_INET, struct.pack('!I', address)) + + @staticmethod + def date_ston(date_string): + date_datetime = datetime.datetime.strptime(date_string, '%Y%m%d') + return int(date_datetime.strftime('%s')) / 86400 + + @staticmethod + def date_ntos(date): + return datetime.datetime.fromtimestamp(date * 86400).strftime('%Y%m%d') + + @staticmethod + def address_kton(key): + return key >> 16 + + @staticmethod + def date_kton(key): + return key & 0xffff + + @staticmethod + def address_ktos(key): + return Database.address_ntos(Database.address_kton(key)) + + @staticmethod + def date_ktos(key): + return Database.date_ntos(Database.date_kton(key)) + + @staticmethod + def create_key(address, date): + return (address << 16) + date + + def load_combined_databases(self, path): + with open(path) as input_file: + for line in input_file.readlines(): + line = line.strip() + if line.startswith('!'): + self.add_date(line) + continue + else: + self.add_range(line) + self.data.sort() + self.keys = [r[0] for r in self.data] + + def add_date(self, line): + date = line.split("!")[1] + if date not in self.dates: + bisect.insort(self.dates, date) + + def add_range(self, line): + r = Range(line) + self.data.append((r.key, r)) + + def lookup_address_and_date(self, address_string, date_string): + if len(self.data) == 0: + return '??' + dates_pos = max(0, bisect.bisect(self.dates, date_string) - 1) + address = Database.address_ston(address_string) + date = Database.date_ston(self.dates[dates_pos]) + key = Database.create_key(address, date) + pos = bisect.bisect(self.keys, key + 1) + # Look up address and date by iterating backwards over possibly + # matching ranges. + while pos: + pos = pos - 1 + r = self.data[pos][1] + # If either the end address or end date of the range we're looking + # at is smaller than the values we're looking for, we can be sure + # not to find it anymore. + if r.end_address < address or r.end_date < date: + return '??' + # If the range starts at a later date, skip it and look at the next + # one. + if r.start_date > date: + continue + # Both address and date ranges match, so return the assigned + # code. + return r.code + # No ranges (left) to look at. We don't have what we were looking + # for. */ + return '??'; + +if __name__ == "__main__": + db = Database() + db.load_combined_databases('geoip-2007-10-2012-09.csv') + with open('test-cases-2007-10-2012-09.csv') as input_file: + for line in input_file.readlines(): + line = line.strip() + parts = line.split(',') + address_string = parts[0] + date_string = parts[1] + expected = parts[2] + result = db.lookup_address_and_date(address_string, date_string) + if (expected != result): + print "! %s -> %s" % (line, result) + break +