Drizzled Public API Documentation

quote.cc
1 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
3  *
4  * Copyright (C) 2008 Sun Microsystems, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License.
9  *
10  * This program is distributed in the hope that it will be useful,
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.
14  *
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 "quote.h"
23 
24 #include <drizzled/lex_string.h>
25 
26 namespace drizzled
27 {
28 
29 inline
30 static uint32_t get_esc_bit(unsigned char *mask, unsigned char num)
31 {
32  return (1 & (*((mask) + ((num) >> 3))) >> ((num) & 7));
33 }
34 
53 {
54  assert(fixed == 1);
55  /*
56  Bit mask that has 1 for set for the position of the following characters:
57  0, \, ' and ^Z
58  */
59 
60  static unsigned char escmask[32]=
61  {
62  0x01, 0x00, 0x00, 0x04, 0x80, 0x00, 0x00, 0x00,
63  0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00,
64  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
65  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
66  };
67 
68  char *from, *to, *end, *start;
69  String *arg= args[0]->val_str(str);
70  uint32_t arg_length, new_length;
71  if (!arg) // Null argument
72  {
73  /* Return the string 'NULL' */
74  str->copy(STRING_WITH_LEN("NULL"), collation.collation);
75  null_value= 0;
76  return str;
77  }
78 
79  arg_length= arg->length();
80  new_length= arg_length+2; /* for beginning and ending ' signs */
81 
82  for (from= (char*) arg->ptr(), end= from + arg_length; from < end; from++)
83  new_length+= get_esc_bit(escmask, (unsigned char) *from);
84 
85  tmp_value.alloc(new_length);
86 
87  /*
88  We replace characters from the end to the beginning
89  */
90  to= (char*) tmp_value.ptr() + new_length - 1;
91  *to--= '\'';
92  for (start= (char*) arg->ptr(),end= start + arg_length; end-- != start; to--)
93  {
94  /*
95  We can't use the bitmask here as we want to replace \O and ^Z with 0
96  and Z
97  */
98  switch (*end) {
99  case 0:
100  *to--= '0';
101  *to= '\\';
102  break;
103  case '\032':
104  *to--= 'Z';
105  *to= '\\';
106  break;
107  case '\'':
108  case '\\':
109  *to--= *end;
110  *to= '\\';
111  break;
112  default:
113  *to= *end;
114  break;
115  }
116  }
117  *to= '\'';
118  tmp_value.length(new_length);
119  tmp_value.set_charset(collation.collation);
120  null_value= 0;
121  return &tmp_value;
122 }
123 
124 } /* namespace drizzled */
bool fixed
Definition: item.h:120
bool null_value
Definition: item.h:122
String * val_str(String *)
Returns the argument string in single quotes suitable for using in a SQL statement.
Definition: quote.cc:52
virtual String * val_str(String *str)=0