aboutsummaryrefslogtreecommitdiff
path: root/odb/schema-catalog.cxx
blob: d223647291f86975b9ff5d72efc48e85140449d5 (plain)
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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
// file      : odb/schema-catalog.cxx
// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
// license   : GNU GPL v2; see accompanying LICENSE file

#include <map>
#include <vector>
#include <cassert>

#include <odb/exceptions.hxx>
#include <odb/schema-catalog.hxx>
#include <odb/schema-catalog-impl.hxx>

using namespace std;

namespace odb
{
  // Schema.
  //
  typedef bool (*create_function) (database&, unsigned short pass, bool drop);
  typedef bool (*migrate_function) (database&, unsigned short pass, bool pre);

  typedef pair<database_id, string> key;
  typedef vector<create_function> create_functions;
  typedef vector<migrate_function> migrate_functions;
  typedef map<schema_version, migrate_functions> version_map;

  struct schema_functions
  {
    create_functions create;
    version_map migrate;
  };
  typedef map<key, schema_functions> schema_map;

  // Data. Normally the code would be database-independent, though there
  // could be database-specific migration steps.
  //
  typedef pair<string, schema_version> data_key;

  struct data_function
  {
    typedef schema_catalog::data_migration_function_type function_type;

    data_function () {}
    data_function (database_id i, function_type m): id (i), migrate (m) {}

    database_id id;
    function_type migrate;
  };
  typedef vector<data_function> data_functions;
  typedef map<data_key, data_functions> data_map;

  struct schema_catalog_impl
  {
    schema_map schema;
    data_map data;
  };

  // Static initialization.
  //
  schema_catalog_impl* schema_catalog_init::catalog = 0;
  size_t schema_catalog_init::count = 0;

  struct schema_catalog_init_extra
  {
    bool initialized;

    schema_catalog_init_extra (): initialized (false) {}
    ~schema_catalog_init_extra ()
    {
      if (initialized && --schema_catalog_init::count == 0)
        delete schema_catalog_init::catalog;
    }
  };

  static schema_catalog_init_extra schema_catalog_init_extra_;

  bool schema_catalog::
  exists (database_id id, const string& name)
  {
    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    return c.schema.find (key (id, name)) != c.schema.end ();
  }

  void schema_catalog::
  create_schema (database& db, const string& name, bool drop)
  {
    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    schema_map::const_iterator i (c.schema.find (key (db.id (), name)));

    if (i == c.schema.end ())
      throw unknown_schema (name);

    const create_functions& fs (i->second.create);

    if (drop)
      drop_schema (db, name);

    // Run the passes until we ran them all or all the functions
    // return false, which means no more passes necessary.
    //
    for (unsigned short pass (1); pass < 3; ++pass)
    {
      bool done (true);

      for (create_functions::const_iterator j (fs.begin ()), e (fs.end ());
           j != e; ++j)
      {
        if ((*j) (db, pass, false))
          done = false;
      }

      if (done)
        break;
    }
  }

  void schema_catalog::
  drop_schema (database& db, const string& name)
  {
    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    schema_map::const_iterator i (c.schema.find (key (db.id (), name)));

    if (i == c.schema.end ())
      throw unknown_schema (name);

    const create_functions& fs (i->second.create);

    // Run the passes until we ran them all or all the functions
    // return false, which means no more passes necessary.
    //
    for (unsigned short pass (1); pass < 3; ++pass)
    {
      bool done (true);

      for (create_functions::const_iterator j (fs.begin ()), e (fs.end ());
           j != e; ++j)
      {
        if ((*j) (db, pass, true))
          done = false;
      }

      if (done)
        break;
    }
  }

  void schema_catalog::
  migrate_schema_impl (database& db,
                       schema_version v,
                       const string& name,
                       migrate_mode m)
  {
    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    schema_map::const_iterator i (c.schema.find (key (db.id (), name)));

    if (i == c.schema.end ())
      throw unknown_schema (name);

    const version_map& vm (i->second.migrate);
    version_map::const_iterator j (vm.find (v));

    if (j == vm.end ())
      throw unknown_schema_version (v);

    const migrate_functions& fs (j->second);

    // Run the passes until we ran them all or all the functions
    // return false, which means no more passes necessary.
    //
    for (bool pre (m != migrate_post);; pre = false)
    {
      for (unsigned short pass (1); pass < 3; ++pass)
      {
        bool done (true);

        for (migrate_functions::const_iterator i (fs.begin ()), e (fs.end ());
             i != e; ++i)
        {
          if ((*i) (db, pass, pre))
            done = false;
        }

        if (done)
          break;
      }

      if (!pre || m != migrate_both)
        break;
    }

    // Update the schema version on the database instance.
    //
    db.schema_version_migration (v, m == migrate_pre, name);
  }

  size_t schema_catalog::
  migrate_data (database& db, schema_version v, const string& name)
  {
    if (v == 0)
    {
      if (!db.schema_migration ())
        return 0;

      v = db.schema_version ();
    }

    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    data_map::const_iterator i (c.data.find (data_key (name, v)));

    if (i == c.data.end ())
      return 0; // No data migration for this schema/version.

    size_t r (0);

    const data_functions& df (i->second);
    for (data_functions::const_iterator i (df.begin ()), e (df.end ());
         i != e; ++i)
    {
      if (i->id == id_common || i->id == db.id ())
      {
        i->migrate (db);
        r++;
      }
    }

    return r;
  }

  void schema_catalog::
  data_migration_function (database_id id,
                           schema_version v,
                           data_migration_function_type f,
                           const string& name)
  {
    // This function can be called from a static initializer in which
    // case the catalog might not have yet been created.
    //
    if (schema_catalog_init::count == 0)
    {
      schema_catalog_init::catalog = new schema_catalog_impl;
      ++schema_catalog_init::count;
      schema_catalog_init_extra_.initialized = true;
    }

    schema_catalog_impl& c (*schema_catalog_init::catalog);
    c.data[data_key (name, v)].push_back (data_function (id, f));
  }

  void schema_catalog::
  migrate (database& db, schema_version v, const string& name)
  {
    schema_version cur (current_version (db, name));

    if (v == 0)
      v = cur;
    else if (v > cur)
      throw unknown_schema_version (v);

    schema_version i (db.schema_version (name));

    // If there is no schema, then "migrate" by creating it.
    //
    if (i == 0)
    {
      // Schema creation can only "migrate" straight to current.
      //
      if (v != cur)
        throw unknown_schema_version (v);

      create_schema (db, name, false);
      return;
    }

    for (i = next_version (db, i, name);
         i <= v;
         i = next_version (db, i, name))
    {
      migrate_schema_pre (db, i, name);
      migrate_data (db, i, name);
      migrate_schema_post (db, i, name);
    }
  }

  schema_version schema_catalog::
  base_version (database_id id, const string& name)
  {
    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    schema_map::const_iterator i (c.schema.find (key (id, name)));

    if (i == c.schema.end ())
      throw unknown_schema (name);

    const version_map& vm (i->second.migrate);
    assert (!vm.empty ());
    return vm.begin ()->first;
  }

  schema_version schema_catalog::
  current_version (database_id id, const string& name)
  {
    const schema_catalog_impl& c (*schema_catalog_init::catalog);
    schema_map::const_iterator i (c.schema.find (key (id, name)));

    if (i == c.schema.end ())
      throw unknown_schema (name);

    const version_map& vm (i->second.migrate);
    assert (!vm.empty ());
    return vm.rbegin ()->first;
  }

  schema_version schema_catalog::
  next_version (database_id id, schema_version v, const string& name)
  {
    const schema_catalog_impl& sc (*schema_catalog_init::catalog);
    schema_map::const_iterator i (sc.schema.find (key (id, name)));

    if (i == sc.schema.end ())
      throw unknown_schema (name);

    const version_map& vm (i->second.migrate); // Cannot be empty.

    schema_version b (vm.begin ()->first);
    schema_version c (vm.rbegin ()->first);

    if (v == 0)
      return c; // "Migration" to the current via schema creation.
    else if (v < b)
      throw unknown_schema_version (v); // Unsupported migration.

    version_map::const_iterator j (vm.upper_bound (v));
    return j != vm.end () ? j->first : c + 1;
  }

  // schema_catalog_init
  //
  schema_catalog_init::
  schema_catalog_init ()
  {
    if (count == 0)
      catalog = new schema_catalog_impl;

    ++count;
  }

  schema_catalog_init::
  ~schema_catalog_init ()
  {
    if (--count == 0)
      delete catalog;
  }

  // schema_catalog_create_entry
  //
  schema_catalog_create_entry::
  schema_catalog_create_entry (database_id id,
                               const char* name,
                               create_function cf)
  {
    schema_catalog_impl& c (*schema_catalog_init::catalog);
    c.schema[key(id, name)].create.push_back (cf);
  }

  // schema_catalog_migrate_entry
  //
  schema_catalog_migrate_entry::
  schema_catalog_migrate_entry (database_id id,
                                const char* name,
                                schema_version v,
                                migrate_function mf)
  {
    schema_catalog_impl& c (*schema_catalog_init::catalog);
    c.schema[key(id, name)].migrate[v].push_back (mf);
  }
}