`urllib.unquote_to_bytes` and `urllib.unquote` could both potentially generate `O(len(string))` intermediate `bytes` or `str` objects while computing the unquoted final result depending on the input provided. As Python objects are relatively large, this could consume a lot of ram.
This switches the implementation to using an expanding `bytearray` and a generator internally instead of precomputed `split()` style operations.
Microbenchmarks with some antagonistic inputs like `mess = "\u0141%%%20a%fe"*1000` show this is 10-20% slower for unquote and unquote_to_bytes and no different for typical inputs that are short or lack much unicode or % escaping. But the functions are already quite fast anyways so not a big deal. The slowdown scales consistently linear with input size as expected.
Memory usage observed manually using `/usr/bin/time -v` on `python -m timeit` runs of larger inputs. Unittesting memory consumption is difficult and does not seem worthwhile.
Observed memory usage is ~1/2 for `unquote()` and <1/3 for `unquote_to_bytes()` using `python -m timeit -s 'from urllib.parse import unquote, unquote_to_bytes; v="\u0141%01\u0161%20"*500_000' 'unquote_to_bytes(v)'` as a test.
Prevent urllib.parse.urlparse from accepting schemes that don't begin with an alphabetical ASCII character.
RFC 3986 defines a scheme like this: `scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )`
RFC 2234 defines an ALPHA like this: `ALPHA = %x41-5A / %x61-7A`
The WHATWG URL spec defines a scheme like this:
`"A URL-scheme string must be one ASCII alpha, followed by zero or more of ASCII alphanumeric, U+002B (+), U+002D (-), and U+002E (.)."`
Switch to lru_cache in urllib.parse.
urllib.parse now uses functool.lru_cache for its internal URL splitting and
quoting caches instead of rolling its own like its the 90s.
The undocumented internal Quoted class API is now deprecated
as it had no reason to be public and no existing OSS users were found.
The clear_cache() API remains undocumented but gets an explicit test as it
is used in a few projects' (twisted, gevent) tests as well as our own regrtest.
bpo-42967: [security] Address a web cache-poisoning issue reported in urllib.parse.parse_qsl().
urllib.parse will only us "&" as query string separator by default instead of both ";" and "&" as allowed in earlier versions. An optional argument seperator with default value "&" is added to specify the separator.
Co-authored-by: Éric Araujo <merwok@netwok.org>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Co-authored-by: Éric Araujo <merwok@netwok.org>
* bpo-27657: Fix urlparse() with numeric paths
Revert parsing decision from bpo-754016 in favor of the documented
consensus in bpo-16932 of how to treat strings without a // to
designate the netloc.
* bpo-22891: Remove urlsplit() optimization for 'http' prefixed inputs.
Fixes some mistakes and misleadings in the quote function docstring:
- reserved chars are never actually used by quote code, unreserved chars are
- reserved chars were wrong and incomplete
- mentioned that use-case is not minimal quoting wrt. RFC, but cautious quoting
Adding `max_num_fields` to `cgi.FieldStorage` to make DOS attacks harder by
limiting the number of `MiniFieldStorage` objects created by `FieldStorage`.
The current regex based splitting produces a wrong result. For example::
http://abc#@def
Web browsers parse that URL as ``http://abc/#@def``, that is, the host
is ``abc``, the path is ``/``, and the fragment is ``#@def``.
* bpo-16285: Update urllib quoting to RFC 3986
urllib.parse.quote is now based on RFC 3986, and hence
includes `'~'` in the set of characters that is not escaped
by default.
Patch by Christian Theune and Ratnadeep Debnath.
