Source code for pytomo.dns.ttl

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"""DNS TTL conversion."""

from __future__ import absolute_import

from . import exception as dns_exception

[docs]class BadTTL(dns_exception.SyntaxError): pass
[docs]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