view mercurial/pure/charencode.py @ 52285:94cf83d9a2c9

sslutil: drop support for Python prior to 3.7

There's also a block of code around line 47 related to `ssl.HAS_TLSv1` to
determine the supported protocols that references "Python 3.7", but I'm not
altering that because the commit referenced there wasn't landed until just prior
to the 3.9 release, and I'm not sure what flavors of py38 might not have a
backport.

Avoid de-indenting for now for a clearer text diff.

# charencode.py - miscellaneous character encoding
#
#  Copyright 2005-2009 Olivia Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import annotations

import array

from .. import pycompat


def isasciistr(s: bytes) -> bool:
    try:
        s.decode('ascii')
        return True
    except UnicodeDecodeError:
        return False


def asciilower(s: bytes) -> bytes:
    """convert a string to lowercase if ASCII

    Raises UnicodeDecodeError if non-ASCII characters are found."""
    s.decode('ascii')
    return s.lower()


def asciiupper(s: bytes) -> bytes:
    """convert a string to uppercase if ASCII

    Raises UnicodeDecodeError if non-ASCII characters are found."""
    s.decode('ascii')
    return s.upper()


_jsonmap = []
_jsonmap.extend(b"\\u%04x" % x for x in range(32))
_jsonmap.extend(pycompat.bytechr(x) for x in range(32, 127))
_jsonmap.append(b'\\u007f')
_jsonmap[0x09] = b'\\t'
_jsonmap[0x0A] = b'\\n'
_jsonmap[0x22] = b'\\"'
_jsonmap[0x5C] = b'\\\\'
_jsonmap[0x08] = b'\\b'
_jsonmap[0x0C] = b'\\f'
_jsonmap[0x0D] = b'\\r'
_paranoidjsonmap = _jsonmap[:]
_paranoidjsonmap[0x3C] = b'\\u003c'  # '<' (e.g. escape "</script>")
_paranoidjsonmap[0x3E] = b'\\u003e'  # '>'
_jsonmap.extend(pycompat.bytechr(x) for x in range(128, 256))


def jsonescapeu8fast(u8chars: bytes, paranoid: bool) -> bytes:
    """Convert a UTF-8 byte string to JSON-escaped form (fast path)

    Raises ValueError if non-ASCII characters have to be escaped.
    """
    if paranoid:
        jm = _paranoidjsonmap
    else:
        jm = _jsonmap
    try:
        return b''.join(jm[x] for x in bytearray(u8chars))
    except IndexError:
        raise ValueError


_utf8strict = r'surrogatepass'


def jsonescapeu8fallback(u8chars: bytes, paranoid: bool) -> bytes:
    """Convert a UTF-8 byte string to JSON-escaped form (slow path)

    Escapes all non-ASCII characters no matter if paranoid is False.
    """
    if paranoid:
        jm = _paranoidjsonmap
    else:
        jm = _jsonmap
    # non-BMP char is represented as UTF-16 surrogate pair
    u16b = u8chars.decode('utf-8', _utf8strict).encode('utf-16', _utf8strict)
    u16codes = array.array('H', u16b)
    u16codes.pop(0)  # drop BOM
    return b''.join(jm[x] if x < 128 else b'\\u%04x' % x for x in u16codes)