vector_conversion.cc

/* Copyright (c) 2024, 2025, Oracle and/or its affiliates.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License, version 2.0,
 as published by the Free Software Foundation.

 This program is designed to work with certain software (including
 but not limited to OpenSSL) that is licensed under separate terms,
 as designated in a particular file or component or in included license
 documentation. The authors of MySQL hereby grant you an additional
 permission to link the program and your derivative works with the
 separately licensed software that they have either included with
 the program or referenced in the documentation.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU General Public License, version 2.0, for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */

#include<sys/types.h>
#include<cerrno>
#include<cmath>
#include<cstddef>
#include<cstdio>
#include<cstdlib>
#include<cstring>

#include"sql_string.h"

boolfrom_string_to_vector(const CHARSET_INFO *cs, constchar *input,
uint32_t input_len, char *output,
uint32_t *max_output_dims) {
if (input_len == 0 || input == nullptr) {
 *max_output_dims = 0;
returntrue;
 }

/* Convert the input to UTF-8 */
const CHARSET_INFO *process_cs = cs;
 String temp_input;
if (!my_charset_is_ascii_based(cs)) {
 process_cs = &my_charset_utf8mb4_bin;
 temp_input.alloc(input_len);
unsigned err = 0;
 input_len = my_convert(temp_input.ptr(), input_len, process_cs, input,
 input_len, cs, &err);
if (err != 0) {
 *max_output_dims = 0;
returntrue;
 }
 input = temp_input.ptr();
 }

// Skip the leading whitespaces
auto len = process_cs->cset->scan(process_cs, input, input + input_len,
 MY_SEQ_SPACES);
if (len >= input_len) {
 *max_output_dims = 0;
returntrue;
 }
 input_len -= len;
 input += len;

// Check that we start with '['
if (input_len == 0 || input[0] != '[') {
 *max_output_dims = 0;
returntrue;
 }

// Check for memory region overlap
size_tconst output_len = sizeof(float) * (*max_output_dims);
 String temp_output(output, output_len, nullptr);
if (output + output_len >= input && input + input_len >= output) {
 temp_output = String(output_len);
 }

constchar *const input_end = input + input_len - 1;
 input = input + 1;
uint32_t dim = 0;
char *end = nullptr;
bool with_success = false;
 errno = 0;
for (float fnum = strtof(input, &end); input != end;
 fnum = strtof(input, &end)) {
 input = end;
if (errno == ERANGE || dim >= *max_output_dims || std::isnan(fnum) ||
std::isinf(fnum)) {
 errno = 0;
break;
 }
memcpy(temp_output.ptr() + dim * sizeof(float), &fnum, sizeof(float));

 input +=
 process_cs->cset->scan(process_cs, input, input_end, MY_SEQ_SPACES);

if (*input == ',') {
// Check that we have delimiter with ','
 input = input + 1;
 dim++;
 } elseif (*input == ']') {
// Check that we end with ']'
 input += 1;
 with_success = true;
 dim++;
break;
 } else {
break;
 }
 }

if (with_success &&
 !check_if_only_end_space(process_cs, input, input_end + 1)) {
 *max_output_dims = 0;
returntrue;
 }

if (temp_output.ptr() != output) {
memcpy(output, temp_output.ptr(), dim * sizeof(float));
 }

 *max_output_dims = dim;
return !with_success;
}

boolfrom_vector_to_string(constchar *input, uint32_t input_dims, char *output,
uint32_t *max_output_len) {
constuint32_t end_cushion = 12;
if (input == nullptr || *max_output_len < end_cushion) {
returntrue;
 }

// Check for memory region overlap
size_tconst input_len = input_dims * sizeof(float);
 String temp_output(output, *max_output_len, nullptr);
if (output + *max_output_len >= input && input + input_len >= output) {
 temp_output = String(*max_output_len);
 }

char *write_ptr = temp_output.ptr();
uint32_t total_length = 1;
 write_ptr[0] = '[';
 write_ptr += 1;
for (uint32_t i = 0; i < input_dims; i++) {
intconst remaining_bytes = *max_output_len - total_length;
int nchars = 0;
if (*max_output_len <= total_length + end_cushion) {
 nchars = snprintf(write_ptr, remaining_bytes, "...");
 i = input_dims;
 } else {
charconst delimiter = (i == input_dims - 1) ? ']' : ',';
float input_value = 0;
memcpy(&input_value, input + i * sizeof(float), sizeof(float));
 nchars = snprintf(write_ptr, remaining_bytes, "%.5e%c", input_value,
 delimiter);
if (nchars < 0 || nchars >= remaining_bytes) {
returntrue; /* LCOV_EXCL_LINE */
 }
 }
 write_ptr += nchars;
 total_length += nchars;
 }

if (temp_output.ptr() != output) {
memcpy(output, temp_output.ptr(), total_length);
 }

 *max_output_len = total_length;
returnfalse;
}