diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/dns/ttl.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/dns/ttl.py | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/dns/ttl.py b/.venv/lib/python3.12/site-packages/dns/ttl.py new file mode 100644 index 00000000..b9a99fe3 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/dns/ttl.py @@ -0,0 +1,92 @@ +# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license + +# Copyright (C) 2003-2017 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.""" + +from typing import Union + +import dns.exception + +# Technically TTLs are supposed to be between 0 and 2**31 - 1, with values +# greater than that interpreted as 0, but we do not impose this policy here +# as values > 2**31 - 1 occur in real world data. +# +# We leave it to applications to impose tighter bounds if desired. +MAX_TTL = 2**32 - 1 + + +class BadTTL(dns.exception.SyntaxError): + """DNS TTL value is not well-formed.""" + + +def from_text(text: str) -> int: + """Convert the text form of a TTL to an integer. + + The BIND 8 units syntax for TTLs (e.g. '1w6d4h3m10s') is supported. + + *text*, a ``str``, the textual TTL. + + Raises ``dns.ttl.BadTTL`` if the TTL is not well-formed. + + Returns an ``int``. + """ + + if text.isdigit(): + total = int(text) + elif len(text) == 0: + raise BadTTL + else: + total = 0 + current = 0 + need_digit = True + for c in text: + if c.isdigit(): + current *= 10 + current += int(c) + need_digit = False + else: + if need_digit: + raise BadTTL + c = c.lower() + if c == "w": + total += current * 604800 + elif c == "d": + total += current * 86400 + elif c == "h": + total += current * 3600 + elif c == "m": + total += current * 60 + elif c == "s": + total += current + else: + raise BadTTL(f"unknown unit '{c}'") + current = 0 + need_digit = True + if not current == 0: + raise BadTTL("trailing integer") + if total < 0 or total > MAX_TTL: + raise BadTTL("TTL should be between 0 and 2**32 - 1 (inclusive)") + return total + + +def make(value: Union[int, str]) -> int: + if isinstance(value, int): + return value + elif isinstance(value, str): + return dns.ttl.from_text(value) + else: + raise ValueError("cannot convert value to TTL") |