aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/libmysql_r/strings/my_strtoll10.cc
blob: 32eddd2f4fa6044f5ab37ac7accc94a7660645aa (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.

   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 also distributed 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 included with MySQL.

   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.

   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 <limits.h>
#include <sys/types.h>

#include "m_string.h"  // IWYU pragma: keep
#include "my_inttypes.h"
#include "my_sys.h" /* Needed for MY_ERRNO_ERANGE */

#define MAX_NEGATIVE_NUMBER ((ulonglong)0x8000000000000000LL)
#define INIT_CNT 9
#define LFACTOR 1000000000ULL
#define LFACTOR1 10000000000ULL
#define LFACTOR2 100000000000ULL

static unsigned long lfactor[9] = {
    1L, 10L, 100L, 1000L, 10000L, 100000L, 1000000L, 10000000L, 100000000L};

/*
  Convert a string to an to unsigned long long integer value

  SYNOPSYS
    my_strtoll10()
      nptr     in       pointer to the string to be converted
      endptr   in/out   pointer to the end of the string/
                        pointer to the stop character
      error    out      returned error code

  DESCRIPTION
    This function takes the decimal representation of integer number
    from string nptr and converts it to an signed or unsigned
    long long integer value.
    Space characters and tab are ignored.
    A sign character might precede the digit characters. The number
    may have any number of pre-zero digits.

    The function stops reading the string nptr at the first character
    that is not a decimal digit. If endptr is not NULL then the function
    will not read characters after *endptr.

  RETURN VALUES
    Value of string as a signed/unsigned longlong integer

    if no error and endptr != NULL, it will be set to point at the character
    after the number

    The error parameter contains information how things went:
    -1		Number was an ok negative number
    0	 	ok
    ERANGE	If the the value of the converted number exceeded the
                maximum negative/unsigned long long integer.
                In this case the return value is ~0 if value was
                positive and LLONG_MIN if value was negative.
    EDOM	If the string didn't contain any digits. In this case
                the return value is 0.

    If endptr is not NULL the function will store the end pointer to
    the stop character here.
*/

longlong my_strtoll10(const char *nptr, const char **endptr, int *error) {
  const char *s, *end, *start, *n_end, *true_end;
  const char *dummy;
  uchar c;
  unsigned long i, j, k;
  ulonglong li;
  int negative;
  ulong cutoff, cutoff2, cutoff3;

  s = nptr;
  /* If fixed length string */
  if (endptr) {
    end = *endptr;
    while (s != end && (*s == ' ' || *s == '\t')) s++;
    if (s == end) goto no_conv;
  } else {
    endptr = &dummy; /* Easier end test */
    while (*s == ' ' || *s == '\t') s++;
    if (!*s) goto no_conv;
    /* This number must be big to guard against a lot of pre-zeros */
    end = s + 65535; /* Can't be longer than this */
  }

  /* Check for a sign.	*/
  negative = 0;
  if (*s == '-') {
    *error = -1; /* Mark as negative number */
    negative = 1;
    if (++s == end) goto no_conv;
    cutoff = MAX_NEGATIVE_NUMBER / LFACTOR2;
    cutoff2 = (MAX_NEGATIVE_NUMBER % LFACTOR2) / 100;
    cutoff3 = MAX_NEGATIVE_NUMBER % 100;
  } else {
    *error = 0;
    if (*s == '+') {
      if (++s == end) goto no_conv;
    }
    cutoff = ULLONG_MAX / LFACTOR2;
    cutoff2 = ULLONG_MAX % LFACTOR2 / 100;
    cutoff3 = ULLONG_MAX % 100;
  }

  /* Handle case where we have a lot of pre-zero */
  if (*s == '0') {
    i = 0;
    do {
      if (++s == end) goto end_i; /* Return 0 */
    } while (*s == '0');
    n_end = s + INIT_CNT;
  } else {
    /* Read first digit to check that it's a valid number */
    if ((c = (*s - '0')) > 9) goto no_conv;
    i = c;
    n_end = ++s + INIT_CNT - 1;
  }

  /* Handle first 9 digits and store them in i */
  if (n_end > end) n_end = end;
  for (; s != n_end; s++) {
    if ((c = (*s - '0')) > 9) goto end_i;
    i = i * 10 + c;
  }
  if (s == end) goto end_i;

  /* Handle next 9 digits and store them in j */
  j = 0;
  start = s; /* Used to know how much to shift i */
  n_end = true_end = s + INIT_CNT;
  if (n_end > end) n_end = end;
  do {
    if ((c = (*s - '0')) > 9) goto end_i_and_j;
    j = j * 10 + c;
  } while (++s != n_end);
  if (s == end) {
    if (s != true_end) goto end_i_and_j;
    goto end3;
  }
  if ((c = (*s - '0')) > 9) goto end3;

  /* Handle the next 1 or 2 digits and store them in k */
  k = c;
  if (++s == end || (c = (*s - '0')) > 9) goto end4;
  k = k * 10 + c;
  *endptr = ++s;

  /* number string should have ended here */
  if (s != end && (c = (*s - '0')) <= 9) goto overflow;

  /* Check that we didn't get an overflow with the last digit */
  if (i > cutoff ||
      (i == cutoff && (j > cutoff2 || (j == cutoff2 && k > cutoff3))))
    goto overflow;
  li = i * LFACTOR2 + (ulonglong)j * 100 + k;
  return (longlong)li;

overflow: /* *endptr is set here */
  *error = MY_ERRNO_ERANGE;
  return negative ? LLONG_MIN : (longlong)ULLONG_MAX;

end_i:
  *endptr = s;
  return (negative ? ((longlong) - (long)i) : (longlong)i);

end_i_and_j:
  li = (ulonglong)i * lfactor[(uint)(s - start)] + j;
  *endptr = s;
  return (negative ? -((longlong)li) : (longlong)li);

end3:
  li = (ulonglong)i * LFACTOR + (ulonglong)j;
  *endptr = s;
  return (negative ? -((longlong)li) : (longlong)li);

end4:
  li = (ulonglong)i * LFACTOR1 + (ulonglong)j * 10 + k;
  *endptr = s;
  if (negative) {
    if (li > MAX_NEGATIVE_NUMBER) goto overflow;
    if (li == MAX_NEGATIVE_NUMBER) return LLONG_MIN;
    return -((longlong)li);
  }
  return (longlong)li;

no_conv:
  /* There was no number to convert.  */
  *error = MY_ERRNO_EDOM;
  *endptr = nptr;
  return 0;
}