75 lines
2.5 KiB
C
75 lines
2.5 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "shared-module/usb/utf16le.h"
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typedef struct {
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const uint16_t *buf;
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size_t len;
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} utf16_str;
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STATIC uint32_t utf16str_peek_unit(utf16_str *utf) {
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if (!utf->len) {
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return 0;
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}
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return *utf->buf;
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}
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STATIC uint32_t utf16str_next_unit(utf16_str *utf) {
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uint32_t result = utf16str_peek_unit(utf);
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if (utf->len) {
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utf->len--;
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utf->buf++;
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}
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return result;
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}
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STATIC uint32_t utf16str_next_codepoint(utf16_str *utf) {
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uint32_t unichr = utf16str_next_unit(utf);
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if (unichr >= 0xd800 && unichr < 0xdc00) {
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uint32_t low_surrogate = utf16str_peek_unit(utf);
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if (low_surrogate >= 0xdc00 && low_surrogate < 0xe000) {
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(void)utf16str_next_unit(utf);
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unichr = (unichr - 0xd800) * 0x400 + low_surrogate - 0xdc00 + 0x10000;
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}
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}
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return unichr;
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}
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STATIC void _convert_utf16le_to_utf8(vstr_t *vstr, utf16_str *utf) {
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while (utf->len) {
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vstr_add_char(vstr, utf16str_next_codepoint(utf));
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}
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}
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mp_obj_t utf16le_to_string(const uint16_t *buf, size_t utf16_len) {
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// will grow if necessary, but will never grow for an all-ASCII descriptor
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vstr_t vstr;
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vstr_init(&vstr, utf16_len);
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utf16_str utf = {buf, utf16_len};
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_convert_utf16le_to_utf8(&vstr, &utf);
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return mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
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}
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