| """Convert times to and from HTTP-date serialisations. |
| |
| Reference: https://www.rfc-editor.org/rfc/rfc7231#section-7.1.1.1 |
| """ |
| |
| import time |
| import warnings |
| from email.utils import formatdate, parsedate_tz |
| |
| from sphinx.deprecation import RemovedInSphinx90Warning |
| |
| _GMT_OFFSET = float(time.localtime().tm_gmtoff) |
| |
| |
| def epoch_to_rfc1123(epoch: float) -> str: |
| """Return HTTP-date string from epoch offset.""" |
| return formatdate(epoch, usegmt=True) |
| |
| |
| def rfc1123_to_epoch(rfc1123: str) -> float: |
| """Return epoch offset from HTTP-date string.""" |
| t = parsedate_tz(rfc1123) |
| if t is None: |
| raise ValueError |
| if not rfc1123.endswith(" GMT"): |
| warnings.warn( |
| "HTTP-date string does not meet RFC 7231 requirements " |
| f"(must end with 'GMT'): {rfc1123!r}", |
| RemovedInSphinx90Warning, stacklevel=3, |
| ) |
| epoch_secs = time.mktime(time.struct_time(t[:9])) + _GMT_OFFSET |
| if (gmt_offset := t[9]) != 0: |
| warnings.warn( |
| "HTTP-date string does not meet RFC 7231 requirements " |
| f"(must be GMT time): {rfc1123!r}", |
| RemovedInSphinx90Warning, stacklevel=3, |
| ) |
| return epoch_secs - (gmt_offset or 0) |
| return epoch_secs |
