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Diffstat (limited to 'venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py')
| -rw-r--r-- | venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py b/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py new file mode 100644 index 0000000..7011ea4 --- /dev/null +++ b/venv/lib/python3.8/site-packages/werkzeug/datastructures/range.py @@ -0,0 +1,180 @@ +from __future__ import annotations + + +class IfRange: + """Very simple object that represents the `If-Range` header in parsed + form. It will either have neither a etag or date or one of either but + never both. + + .. versionadded:: 0.7 + """ + + def __init__(self, etag=None, date=None): + #: The etag parsed and unquoted. Ranges always operate on strong + #: etags so the weakness information is not necessary. + self.etag = etag + #: The date in parsed format or `None`. + self.date = date + + def to_header(self): + """Converts the object back into an HTTP header.""" + if self.date is not None: + return http.http_date(self.date) + if self.etag is not None: + return http.quote_etag(self.etag) + return "" + + def __str__(self): + return self.to_header() + + def __repr__(self): + return f"<{type(self).__name__} {str(self)!r}>" + + +class Range: + """Represents a ``Range`` header. All methods only support only + bytes as the unit. Stores a list of ranges if given, but the methods + only work if only one range is provided. + + :raise ValueError: If the ranges provided are invalid. + + .. versionchanged:: 0.15 + The ranges passed in are validated. + + .. versionadded:: 0.7 + """ + + def __init__(self, units, ranges): + #: The units of this range. Usually "bytes". + self.units = units + #: A list of ``(begin, end)`` tuples for the range header provided. + #: The ranges are non-inclusive. + self.ranges = ranges + + for start, end in ranges: + if start is None or (end is not None and (start < 0 or start >= end)): + raise ValueError(f"{(start, end)} is not a valid range.") + + def range_for_length(self, length): + """If the range is for bytes, the length is not None and there is + exactly one range and it is satisfiable it returns a ``(start, stop)`` + tuple, otherwise `None`. + """ + if self.units != "bytes" or length is None or len(self.ranges) != 1: + return None + start, end = self.ranges[0] + if end is None: + end = length + if start < 0: + start += length + if http.is_byte_range_valid(start, end, length): + return start, min(end, length) + return None + + def make_content_range(self, length): + """Creates a :class:`~werkzeug.datastructures.ContentRange` object + from the current range and given content length. + """ + rng = self.range_for_length(length) + if rng is not None: + return ContentRange(self.units, rng[0], rng[1], length) + return None + + def to_header(self): + """Converts the object back into an HTTP header.""" + ranges = [] + for begin, end in self.ranges: + if end is None: + ranges.append(f"{begin}-" if begin >= 0 else str(begin)) + else: + ranges.append(f"{begin}-{end - 1}") + return f"{self.units}={','.join(ranges)}" + + def to_content_range_header(self, length): + """Converts the object into `Content-Range` HTTP header, + based on given length + """ + range = self.range_for_length(length) + if range is not None: + return f"{self.units} {range[0]}-{range[1] - 1}/{length}" + return None + + def __str__(self): + return self.to_header() + + def __repr__(self): + return f"<{type(self).__name__} {str(self)!r}>" + + +def _callback_property(name): + def fget(self): + return getattr(self, name) + + def fset(self, value): + setattr(self, name, value) + if self.on_update is not None: + self.on_update(self) + + return property(fget, fset) + + +class ContentRange: + """Represents the content range header. + + .. versionadded:: 0.7 + """ + + def __init__(self, units, start, stop, length=None, on_update=None): + assert http.is_byte_range_valid(start, stop, length), "Bad range provided" + self.on_update = on_update + self.set(start, stop, length, units) + + #: The units to use, usually "bytes" + units = _callback_property("_units") + #: The start point of the range or `None`. + start = _callback_property("_start") + #: The stop point of the range (non-inclusive) or `None`. Can only be + #: `None` if also start is `None`. + stop = _callback_property("_stop") + #: The length of the range or `None`. + length = _callback_property("_length") + + def set(self, start, stop, length=None, units="bytes"): + """Simple method to update the ranges.""" + assert http.is_byte_range_valid(start, stop, length), "Bad range provided" + self._units = units + self._start = start + self._stop = stop + self._length = length + if self.on_update is not None: + self.on_update(self) + + def unset(self): + """Sets the units to `None` which indicates that the header should + no longer be used. + """ + self.set(None, None, units=None) + + def to_header(self): + if self.units is None: + return "" + if self.length is None: + length = "*" + else: + length = self.length + if self.start is None: + return f"{self.units} */{length}" + return f"{self.units} {self.start}-{self.stop - 1}/{length}" + + def __bool__(self): + return self.units is not None + + def __str__(self): + return self.to_header() + + def __repr__(self): + return f"<{type(self).__name__} {str(self)!r}>" + + +# circular dependencies +from .. import http |