| # Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc. |
| # |
| # Permission to use, copy, modify, and distribute this software and its |
| # documentation for any purpose with or without fee is hereby granted, |
| # provided that the above copyright notice and this permission notice |
| # appear in all copies. |
| # |
| # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES |
| # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR |
| # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
| # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| """DNS TTL conversion.""" |
| |
| import dns.exception |
| |
| class BadTTL(dns.exception.SyntaxError): |
| pass |
| |
| def from_text(text): |
| """Convert the text form of a TTL to an integer. |
| |
| The BIND 8 units syntax for TTLs (e.g. '1w6d4h3m10s') is supported. |
| |
| @param text: the textual TTL |
| @type text: string |
| @raises dns.ttl.BadTTL: the TTL is not well-formed |
| @rtype: int |
| """ |
| |
| if text.isdigit(): |
| total = long(text) |
| else: |
| if not text[0].isdigit(): |
| raise BadTTL |
| total = 0L |
| current = 0L |
| for c in text: |
| if c.isdigit(): |
| current *= 10 |
| current += long(c) |
| else: |
| c = c.lower() |
| if c == 'w': |
| total += current * 604800L |
| elif c == 'd': |
| total += current * 86400L |
| elif c == 'h': |
| total += current * 3600L |
| elif c == 'm': |
| total += current * 60L |
| elif c == 's': |
| total += current |
| else: |
| raise BadTTL("unknown unit '%s'" % c) |
| current = 0 |
| if not current == 0: |
| raise BadTTL("trailing integer") |
| if total < 0L or total > 2147483647L: |
| raise BadTTL("TTL should be between 0 and 2^31 - 1 (inclusive)") |
| return total |