Drizzled Public API Documentation

find_in_set.cc
1 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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3  *
4  * Copyright (C) 2008 Sun Microsystems, Inc.
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6  * This program is free software; you can redistribute it and/or modify
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8  * the Free Software Foundation; version 2 of the License.
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11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
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15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 #include <config.h>
21 
22 #include <drizzled/charset.h>
23 #include <drizzled/function/find_in_set.h>
24 
25 /* Search after a string in a string of strings separated by ',' */
26 /* Returns number of found type >= 1 or 0 if not found */
27 /* This optimizes searching in enums to bit testing! */
28 
29 namespace drizzled
30 {
31 
32 void Item_func_find_in_set::fix_length_and_dec()
33 {
34  decimals=0;
35  max_length=3; // 1-999
36  agg_arg_charsets(cmp_collation, args, 2, MY_COLL_CMP_CONV, 1);
37 }
38 
39 static const char separator=',';
40 
42 {
43  assert(fixed == 1);
44  if (enum_value)
45  {
46  uint64_t tmp=(uint64_t) args[1]->val_int();
47  if (!(null_value=args[1]->null_value || args[0]->null_value))
48  {
49  if (tmp & enum_bit)
50  return enum_value;
51  }
52  return 0L;
53  }
54 
55  String *find=args[0]->val_str(&value);
56  String *buffer=args[1]->val_str(&value2);
57  if (!find || !buffer)
58  {
59  null_value=1;
60  return 0;
61  }
62  null_value=0;
63 
64  if (buffer->length() >= find->length())
65  {
66  my_wc_t wc;
67  const charset_info_st * const cs= cmp_collation.collation;
68  const char *str_begin= buffer->ptr();
69  const char *str_end= buffer->ptr();
70  const char *real_end= str_end+buffer->length();
71  const unsigned char *find_str= (const unsigned char *) find->ptr();
72  uint32_t find_str_len= find->length();
73  int position= 0;
74  while (1)
75  {
76  int symbol_len;
77  if ((symbol_len= cs->cset->mb_wc(cs, &wc, (unsigned char*) str_end, (unsigned char*) real_end)) > 0)
78  {
79  const char *substr_end= str_end + symbol_len;
80  bool is_last_item= (substr_end == real_end);
81  bool is_separator= (wc == (my_wc_t) separator);
82  if (is_separator || is_last_item)
83  {
84  position++;
85  if (is_last_item && !is_separator)
86  str_end= substr_end;
87  if (!my_strnncoll(cs, (const unsigned char *) str_begin,
88  str_end - str_begin,
89  find_str, find_str_len))
90  return (int64_t) position;
91  else
92  str_begin= substr_end;
93  }
94  str_end= substr_end;
95  }
96  else if (str_end - str_begin == 0 &&
97  find_str_len == 0 &&
98  wc == (my_wc_t) separator)
99  return (int64_t) ++position;
100  else
101  return 0;
102  }
103  }
104  return 0;
105 }
106 
107 } /* namespace drizzled */
bool fixed
Definition: item.h:120
bool null_value
Definition: item.h:122
virtual String * val_str(String *str)=0