ClickHouse

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#include <DataTypes/DataTypeString.h>
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#include <Functions/FunctionFactory.h>
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#include <Functions/FunctionStringOrArrayToT.h>
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#include <Common/isValidUTF8.h>
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namespace DB
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{
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namespace ErrorCodes
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{
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    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
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}
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/// inspired by https://github.com/cyb70289/utf8/
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struct ValidUTF8Impl
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{
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    /*
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MIT License
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Copyright (c) 2019 Yibo Cai
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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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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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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 THE
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SOFTWARE.
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*/
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    /*
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 * http://www.unicode.org/versions/Unicode6.0.0/ch03.pdf - page 94
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 *
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 * Table 3-7. Well-Formed UTF-8 Byte Sequences
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 *
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 * +--------------------+------------+-------------+------------+-------------+
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 * | Code Points        | First Byte | Second Byte | Third Byte | Fourth Byte |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+0000..U+007F     | 00..7F     |             |            |             |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+0080..U+07FF     | C2..DF     | 80..BF      |            |             |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+0800..U+0FFF     | E0         | A0..BF      | 80..BF     |             |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+1000..U+CFFF     | E1..EC     | 80..BF      | 80..BF     |             |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+D000..U+D7FF     | ED         | 80..9F      | 80..BF     |             |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+E000..U+FFFF     | EE..EF     | 80..BF      | 80..BF     |             |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+10000..U+3FFFF   | F0         | 90..BF      | 80..BF     | 80..BF      |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+40000..U+FFFFF   | F1..F3     | 80..BF      | 80..BF     | 80..BF      |
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 * +--------------------+------------+-------------+------------+-------------+
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 * | U+100000..U+10FFFF | F4         | 80..8F      | 80..BF     | 80..BF      |
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 * +--------------------+------------+-------------+------------+-------------+
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 */
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#ifndef __SSE4_1__
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    static inline UInt8 isValidUTF8(const UInt8 * data, UInt64 len) { return DB::UTF8::isValidUTF8(data, len); }
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#else
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    static inline UInt8 isValidUTF8(const UInt8 * data, UInt64 len)
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    {
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        /*
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        * Map high nibble of "First Byte" to legal character length minus 1
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        * 0x00 ~ 0xBF --> 0
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        * 0xC0 ~ 0xDF --> 1
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        * 0xE0 ~ 0xEF --> 2
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        * 0xF0 ~ 0xFF --> 3
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        */
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        const __m128i first_len_tbl = _mm_setr_epi8(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3);
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        /* Map "First Byte" to 8-th item of range table (0xC2 ~ 0xF4) */
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        const __m128i first_range_tbl = _mm_setr_epi8(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 8, 8);
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        /*
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        * Range table, map range index to min and max values
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        */
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        const __m128i range_min_tbl
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            = _mm_setr_epi8(0x00, 0x80, 0x80, 0x80, 0xA0, 0x80, 0x90, 0x80, 0xC2, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F);
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        const __m128i range_max_tbl
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            = _mm_setr_epi8(0x7F, 0xBF, 0xBF, 0xBF, 0xBF, 0x9F, 0xBF, 0x8F, 0xF4, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80);
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        /*
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        * Tables for fast handling of four special First Bytes(E0,ED,F0,F4), after
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        * which the Second Byte are not 80~BF. It contains "range index adjustment".
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        * +------------+---------------+------------------+----------------+
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        * | First Byte | original range| range adjustment | adjusted range |
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        * +------------+---------------+------------------+----------------+
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        * | E0         | 2             | 2                | 4              |
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        * +------------+---------------+------------------+----------------+
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        * | ED         | 2             | 3                | 5              |
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        * +------------+---------------+------------------+----------------+
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        * | F0         | 3             | 3                | 6              |
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        * +------------+---------------+------------------+----------------+
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        * | F4         | 4             | 4                | 8              |
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        * +------------+---------------+------------------+----------------+
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        */
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        /* index1 -> E0, index14 -> ED */
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        const __m128i df_ee_tbl = _mm_setr_epi8(0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0);
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        /* index1 -> F0, index5 -> F4 */
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        const __m128i ef_fe_tbl = _mm_setr_epi8(0, 3, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
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        __m128i prev_input = _mm_set1_epi8(0);
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        __m128i prev_first_len = _mm_set1_epi8(0);
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        __m128i error = _mm_set1_epi8(0);
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        auto check_packed = [&](__m128i input) noexcept
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        {
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            /* high_nibbles = input >> 4 */
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            const __m128i high_nibbles = _mm_and_si128(_mm_srli_epi16(input, 4), _mm_set1_epi8(0x0F));
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            /* first_len = legal character length minus 1 */
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            /* 0 for 00~7F, 1 for C0~DF, 2 for E0~EF, 3 for F0~FF */
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            /* first_len = first_len_tbl[high_nibbles] */
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            __m128i first_len = _mm_shuffle_epi8(first_len_tbl, high_nibbles);
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            /* First Byte: set range index to 8 for bytes within 0xC0 ~ 0xFF */
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            /* range = first_range_tbl[high_nibbles] */
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            __m128i range = _mm_shuffle_epi8(first_range_tbl, high_nibbles);
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            /* Second Byte: set range index to first_len */
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            /* 0 for 00~7F, 1 for C0~DF, 2 for E0~EF, 3 for F0~FF */
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            /* range |= (first_len, prev_first_len) << 1 byte */
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            range = _mm_or_si128(range, _mm_alignr_epi8(first_len, prev_first_len, 15));
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            /* Third Byte: set range index to saturate_sub(first_len, 1) */
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            /* 0 for 00~7F, 0 for C0~DF, 1 for E0~EF, 2 for F0~FF */
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            __m128i tmp1;
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            __m128i tmp2;
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            /* tmp1 = saturate_sub(first_len, 1) */
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            tmp1 = _mm_subs_epu8(first_len, _mm_set1_epi8(1));
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            /* tmp2 = saturate_sub(prev_first_len, 1) */
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            tmp2 = _mm_subs_epu8(prev_first_len, _mm_set1_epi8(1));
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            /* range |= (tmp1, tmp2) << 2 bytes */
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            range = _mm_or_si128(range, _mm_alignr_epi8(tmp1, tmp2, 14));
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            /* Fourth Byte: set range index to saturate_sub(first_len, 2) */
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            /* 0 for 00~7F, 0 for C0~DF, 0 for E0~EF, 1 for F0~FF */
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            /* tmp1 = saturate_sub(first_len, 2) */
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            tmp1 = _mm_subs_epu8(first_len, _mm_set1_epi8(2));
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            /* tmp2 = saturate_sub(prev_first_len, 2) */
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            tmp2 = _mm_subs_epu8(prev_first_len, _mm_set1_epi8(2));
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            /* range |= (tmp1, tmp2) << 3 bytes */
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            range = _mm_or_si128(range, _mm_alignr_epi8(tmp1, tmp2, 13));
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            /*
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             * Now we have below range indices calculated
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             * Correct cases:
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             * - 8 for C0~FF
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             * - 3 for 1st byte after F0~FF
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             * - 2 for 1st byte after E0~EF or 2nd byte after F0~FF
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             * - 1 for 1st byte after C0~DF or 2nd byte after E0~EF or
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             *         3rd byte after F0~FF
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             * - 0 for others
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             * Error cases:
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             *   9,10,11 if non ascii First Byte overlaps
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             *   E.g., F1 80 C2 90 --> 8 3 10 2, where 10 indicates error
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             */
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            /* Adjust Second Byte range for special First Bytes(E0,ED,F0,F4) */
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            /* Overlaps lead to index 9~15, which are illegal in range table */
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            __m128i shift1, pos, range2;
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            /* shift1 = (input, prev_input) << 1 byte */
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            shift1 = _mm_alignr_epi8(input, prev_input, 15);
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            pos = _mm_sub_epi8(shift1, _mm_set1_epi8(0xEF));
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            /*
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             * shift1:  | EF  F0 ... FE | FF  00  ... ...  DE | DF  E0 ... EE |
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             * pos:     | 0   1      15 | 16  17           239| 240 241    255|
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             * pos-240: | 0   0      0  | 0   0            0  | 0   1      15 |
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             * pos+112: | 112 113    127|       >= 128        |     >= 128    |
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             */
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            tmp1 = _mm_subs_epu8(pos, _mm_set1_epi8(0xF0));
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            range2 = _mm_shuffle_epi8(df_ee_tbl, tmp1);
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            tmp2 = _mm_adds_epu8(pos, _mm_set1_epi8(112));
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            range2 = _mm_add_epi8(range2, _mm_shuffle_epi8(ef_fe_tbl, tmp2));
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            range = _mm_add_epi8(range, range2);
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            /* Load min and max values per calculated range index */
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            __m128i minv = _mm_shuffle_epi8(range_min_tbl, range);
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            __m128i maxv = _mm_shuffle_epi8(range_max_tbl, range);
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            /* Check value range */
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            error = _mm_or_si128(error, _mm_cmplt_epi8(input, minv));
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            error = _mm_or_si128(error, _mm_cmpgt_epi8(input, maxv));
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            prev_input = input;
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            prev_first_len = first_len;
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            data += 16;
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            len -= 16;
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        };
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        while (len >= 16) // NOLINT
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            check_packed(_mm_loadu_si128(reinterpret_cast<const __m128i *>(data)));
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        /// 0 <= len <= 15 for now. Reading data from data - 1 because of right padding of 15 and left padding
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        /// Then zero some bytes from the unknown memory and check again.
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        alignas(16) char buf[32];
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        _mm_store_si128(reinterpret_cast<__m128i *>(buf), _mm_loadu_si128(reinterpret_cast<const __m128i *>(data - 1)));
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        memset(buf + len + 1, 0, 16);
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        check_packed(_mm_loadu_si128(reinterpret_cast<__m128i *>(buf + 1)));
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        return _mm_testz_si128(error, error);
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    }
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#endif
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    static constexpr bool is_fixed_to_constant = false;
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    static void vector(const ColumnString::Chars & data, const ColumnString::Offsets & offsets, PaddedPODArray<UInt8> & res)
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    {
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        size_t size = offsets.size();
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        size_t prev_offset = 0;
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        for (size_t i = 0; i < size; ++i)
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        {
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            res[i] = isValidUTF8(data.data() + prev_offset, offsets[i] - 1 - prev_offset);
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            prev_offset = offsets[i];
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        }
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    }
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    static void vectorFixedToConstant(const ColumnString::Chars & /*data*/, size_t /*n*/, UInt8 & /*res*/) {}
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    static void vectorFixedToVector(const ColumnString::Chars & data, size_t n, PaddedPODArray<UInt8> & res)
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    {
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        size_t size = data.size() / n;
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        for (size_t i = 0; i < size; ++i)
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            res[i] = isValidUTF8(data.data() + i * n, n);
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    }
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    [[noreturn]] static void array(const ColumnString::Offsets &, PaddedPODArray<UInt8> &)
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    {
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        throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Cannot apply function isValidUTF8 to Array argument");
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    }
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    [[noreturn]] static void uuid(const ColumnUUID::Container &, size_t &, PaddedPODArray<UInt8> &)
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    {
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        throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Cannot apply function isValidUTF8 to UUID argument");
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    }
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    [[noreturn]] static void ipv6(const ColumnIPv6::Container &, size_t &, PaddedPODArray<UInt8> &)
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    {
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        throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Cannot apply function isValidUTF8 to IPv6 argument");
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    }
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    [[noreturn]] static void ipv4(const ColumnIPv4::Container &, size_t &, PaddedPODArray<UInt8> &)
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    {
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        throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Cannot apply function isValidUTF8 to IPv4 argument");
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    }
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};
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struct NameIsValidUTF8
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{
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    static constexpr auto name = "isValidUTF8";
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};
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using FunctionValidUTF8 = FunctionStringOrArrayToT<ValidUTF8Impl, NameIsValidUTF8, UInt8>;
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REGISTER_FUNCTION(IsValidUTF8)
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{
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    factory.registerFunction<FunctionValidUTF8>();
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}
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}
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