Function PyUnicode_EncodeUTF7

Lib/_pycodecs.py:994–1076

(s, size, encodeSetO, encodeWhiteSpace, errors)

def PyUnicode_EncodeUTF7(s, size, encodeSetO, encodeWhiteSpace, errors):
    inShift = False
    base64bits = 0
    base64buffer = 0
    out = []

    for i, ch in enumerate(s):
        ch_ord = ord(ch)
        if inShift:
            if _ENCODE_DIRECT(ch, encodeSetO, encodeWhiteSpace):
                # shifting out
                if base64bits:
                    out.append(B64(base64buffer << (6 - base64bits)))
                    base64buffer = 0
                    base64bits = 0
                inShift = False
                if B64CHAR(ch) or ch == "-":
                    out.append(b"-")
                out.append(bytes([ch_ord]))
            else:
                # encode character in base64
                if ch_ord >= 0x10000:
                    # split into surrogate pair
                    hi = 0xD800 | ((ch_ord - 0x10000) >> 10)
                    lo = 0xDC00 | ((ch_ord - 0x10000) & 0x3FF)
                    base64bits += 16
                    base64buffer = (base64buffer << 16) | hi
                    while base64bits >= 6:
                        out.append(B64(base64buffer >> (base64bits - 6)))
                        base64bits -= 6
                    base64buffer &= (1 << base64bits) - 1 if base64bits else 0
                    ch_ord = lo

                base64bits += 16
                base64buffer = (base64buffer << 16) | ch_ord
                while base64bits >= 6:
                    out.append(B64(base64buffer >> (base64bits - 6)))
                    base64bits -= 6
                base64buffer &= (1 << base64bits) - 1 if base64bits else 0
        else:
            if ch == "+":
                out.append(b"+-")
            elif _ENCODE_DIRECT(ch, encodeSetO, encodeWhiteSpace):
                out.append(bytes([ch_ord]))
            else:
                out.append(b"+")
                inShift = True
                # encode character in base64
                if ch_ord >= 0x10000:
                    hi = 0xD800 | ((ch_ord - 0x10000) >> 10)
                    lo = 0xDC00 | ((ch_ord - 0x10000) & 0x3FF)
                    base64bits += 16
                    base64buffer = (base64buffer << 16) | hi
                    while base64bits >= 6:
                        out.append(B64(base64buffer >> (base64bits - 6)))
                        base64bits -= 6
                    base64buffer &= (1 << base64bits) - 1 if base64bits else 0
                    ch_ord = lo