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Diffstat (limited to 'lib/dnspython/dns/ttl.py')
-rw-r--r-- | lib/dnspython/dns/ttl.py | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/lib/dnspython/dns/ttl.py b/lib/dnspython/dns/ttl.py new file mode 100644 index 0000000000..f295300517 --- /dev/null +++ b/lib/dnspython/dns/ttl.py @@ -0,0 +1,64 @@ +# 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 |