Varia's website
https://varia.zone
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
104 lines
2.9 KiB
104 lines
2.9 KiB
from __future__ import annotations
|
|
|
|
from collections.abc import Sequence
|
|
import functools
|
|
import re
|
|
|
|
DECODE_DEFAULT_CHARS = ";/?:@&=+$,#"
|
|
DECODE_COMPONENT_CHARS = ""
|
|
|
|
decode_cache: dict[str, list[str]] = {}
|
|
|
|
|
|
def get_decode_cache(exclude: str) -> Sequence[str]:
|
|
if exclude in decode_cache:
|
|
return decode_cache[exclude]
|
|
|
|
cache: list[str] = []
|
|
decode_cache[exclude] = cache
|
|
|
|
for i in range(128):
|
|
ch = chr(i)
|
|
cache.append(ch)
|
|
|
|
for i in range(len(exclude)):
|
|
ch_code = ord(exclude[i])
|
|
cache[ch_code] = "%" + ("0" + hex(ch_code)[2:].upper())[-2:]
|
|
|
|
return cache
|
|
|
|
|
|
# Decode percent-encoded string.
|
|
#
|
|
def decode(string: str, exclude: str = DECODE_DEFAULT_CHARS) -> str:
|
|
cache = get_decode_cache(exclude)
|
|
repl_func = functools.partial(repl_func_with_cache, cache=cache)
|
|
return re.sub(r"(%[a-f0-9]{2})+", repl_func, string, flags=re.IGNORECASE)
|
|
|
|
|
|
def repl_func_with_cache(match: re.Match, cache: Sequence[str]) -> str:
|
|
seq = match.group()
|
|
result = ""
|
|
|
|
i = 0
|
|
l = len(seq) # noqa: E741
|
|
while i < l:
|
|
b1 = int(seq[i + 1 : i + 3], 16)
|
|
|
|
if b1 < 0x80:
|
|
result += cache[b1]
|
|
i += 3 # emulate JS for loop statement3
|
|
continue
|
|
|
|
if (b1 & 0xE0) == 0xC0 and (i + 3 < l):
|
|
# 110xxxxx 10xxxxxx
|
|
b2 = int(seq[i + 4 : i + 6], 16)
|
|
|
|
if (b2 & 0xC0) == 0x80:
|
|
all_bytes = bytes((b1, b2))
|
|
try:
|
|
result += all_bytes.decode()
|
|
except UnicodeDecodeError:
|
|
result += "\ufffd" * 2
|
|
|
|
i += 3
|
|
i += 3 # emulate JS for loop statement3
|
|
continue
|
|
|
|
if (b1 & 0xF0) == 0xE0 and (i + 6 < l):
|
|
# 1110xxxx 10xxxxxx 10xxxxxx
|
|
b2 = int(seq[i + 4 : i + 6], 16)
|
|
b3 = int(seq[i + 7 : i + 9], 16)
|
|
|
|
if (b2 & 0xC0) == 0x80 and (b3 & 0xC0) == 0x80:
|
|
all_bytes = bytes((b1, b2, b3))
|
|
try:
|
|
result += all_bytes.decode()
|
|
except UnicodeDecodeError:
|
|
result += "\ufffd" * 3
|
|
|
|
i += 6
|
|
i += 3 # emulate JS for loop statement3
|
|
continue
|
|
|
|
if (b1 & 0xF8) == 0xF0 and (i + 9 < l):
|
|
# 111110xx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
b2 = int(seq[i + 4 : i + 6], 16)
|
|
b3 = int(seq[i + 7 : i + 9], 16)
|
|
b4 = int(seq[i + 10 : i + 12], 16)
|
|
|
|
if (b2 & 0xC0) == 0x80 and (b3 & 0xC0) == 0x80 and (b4 & 0xC0) == 0x80:
|
|
all_bytes = bytes((b1, b2, b3, b4))
|
|
try:
|
|
result += all_bytes.decode()
|
|
except UnicodeDecodeError:
|
|
result += "\ufffd" * 4
|
|
|
|
i += 9
|
|
i += 3 # emulate JS for loop statement3
|
|
continue
|
|
|
|
result += "\ufffd"
|
|
i += 3 # emulate JS for loop statement3
|
|
|
|
return result
|
|
|