~drizzle-trunk/drizzle/development

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
/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 *
 *  Copyright (C) 2008 Sun Microsystems, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  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 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 <config.h>

#include <string>

#include <drizzled/foreign_key.h>
#include <drizzled/error.h>
#include <drizzled/create_field.h>
#include <drizzled/internal/my_sys.h>
#include <drizzled/table_ident.h>

namespace drizzled
{

extern const charset_info_st *system_charset_info;

void add_foreign_key_to_table_message(
    message::Table *table_message,
    const char* fkey_name,
    List<Key_part_spec> &cols,
    Table_ident *table,
    List<Key_part_spec> &ref_cols,
    message::Table::ForeignKeyConstraint::ForeignKeyOption delete_opt_arg,
    message::Table::ForeignKeyConstraint::ForeignKeyOption update_opt_arg,
    message::Table::ForeignKeyConstraint::ForeignKeyMatchOption match_opt_arg)
{
  message::Table::ForeignKeyConstraint *pfkey= table_message->add_fk_constraint();
  if (fkey_name)
    pfkey->set_name(fkey_name);
  else if (table_message->has_name())
  {
    std::string name(table_message->name());
    char number[20];

    name.append("_ibfk_");
    snprintf(number, sizeof(number), "%d", table_message->fk_constraint_size());
    name.append(number);

    pfkey->set_name(name);
  }

  pfkey->set_match(match_opt_arg);
  pfkey->set_update_option(update_opt_arg);
  pfkey->set_delete_option(delete_opt_arg);

  pfkey->set_references_table_name(table->table.str);

  Key_part_spec *keypart;
  List<Key_part_spec>::iterator col_it(cols.begin());
  while ((keypart= col_it++))
  {
    pfkey->add_column_names(keypart->field_name.str);
  }

  List<Key_part_spec>::iterator ref_it(ref_cols.begin());
  while ((keypart= ref_it++))
  {
    pfkey->add_references_columns(keypart->field_name.str);
  }

}

/**
  Make a deep copy of each list element.

  @note A template function and not a template method of class List
  is employed because of explicit template instantiation:
  in server code there are explicit instantiations of List<T> and
  an explicit instantiation of a template requires that any method
  of the instantiated class used in the template can be resolved.
  Evidently not all template arguments have clone() method with
  the right signature.

  @return You must query the error state in Session for out-of-memory
  situation after calling this function.
*/

template <typename T>
void list_copy_and_replace_each_value(List<T> &list, memory::Root *mem_root)
{
  /* Make a deep copy of each element */
  typename List<T>::iterator it(list.begin());
  T *el;
  while ((el= it++))
    it.replace(el->clone(mem_root));
}

Foreign_key::Foreign_key(const Foreign_key &rhs, memory::Root *mem_root)
  :Key(rhs),
  ref_table(rhs.ref_table),
  ref_columns(rhs.ref_columns),
  delete_opt(rhs.delete_opt),
  update_opt(rhs.update_opt),
  match_opt(rhs.match_opt)
{
  list_copy_and_replace_each_value(ref_columns, mem_root);
}

/*
  Test if a foreign key (= generated key) is a prefix of the given key
  (ignoring key name, key type and order of columns)

  NOTES:
    This is only used to test if an index for a FOREIGN KEY exists

  IMPLEMENTATION
    We only compare field names

  RETURN
    0	Generated key is a prefix of other key
    1	Not equal
*/
bool foreign_key_prefix(Key *a, Key *b)
{
  /* Ensure that 'a' is the generated key */
  if (a->generated)
  {
    if (b->generated && a->columns.size() > b->columns.size())
      std::swap(a, b);                       // Put shorter key in 'a'
  }
  else
  {
    if (!b->generated)
      return true;                              // No foreign key
    std::swap(a, b);                       // Put generated key in 'a'
  }

  /* Test if 'a' is a prefix of 'b' */
  if (a->columns.size() > b->columns.size())
    return true;                                // Can't be prefix

  List<Key_part_spec>::iterator col_it1(a->columns.begin());
  List<Key_part_spec>::iterator col_it2(b->columns.begin());
  const Key_part_spec *col1, *col2;

#ifdef ENABLE_WHEN_INNODB_CAN_HANDLE_SWAPED_FOREIGN_KEY_COLUMNS
  while ((col1= col_it1++))
  {
    bool found= 0;
    col_it2=b->columns.begin();
    while ((col2= col_it2++))
    {
      if (*col1 == *col2)
      {
        found= true;
	break;
      }
    }
    if (!found)
      return true;                              // Error
  }
  return false;                                 // Is prefix
#else
  while ((col1= col_it1++))
  {
    col2= col_it2++;
    if (!(*col1 == *col2))
      return true;
  }
  return false;                                 // Is prefix
#endif
}

/*
  Check if the foreign key options are compatible with columns
  on which the FK is created.

  RETURN
    0   Key valid
    1   Key invalid
*/
bool Foreign_key::validate(List<CreateField> &table_fields)
{
  CreateField  *sql_field;
  Key_part_spec *column;
  List<Key_part_spec>::iterator cols(columns.begin());
  List<CreateField>::iterator it(table_fields.begin());
  while ((column= cols++))
  {
    it= table_fields.begin();
    while ((sql_field= it++) &&
           my_strcasecmp(system_charset_info,
                         column->field_name.str,
                         sql_field->field_name)) {}
    if (!sql_field)
    {
      my_error(ER_KEY_COLUMN_DOES_NOT_EXITS, MYF(0), column->field_name.str);
      return true;
    }
  }
  return false;
}

} /* namespace drizzled */