File descriptor data example
1 //Compile with:
2 // gcc -o eet-data-file_descriptor_01 eet-data-file_descriptor_01.c `pkg-config --cflags --libs eet eina`
3 
4 #include <Eina.h>
5 #include <Eet.h>
6 #include <stdio.h>
7 #include <limits.h>
8 #include <sys/types.h>
9 #include <sys/stat.h>
10 #include <unistd.h>
11 
12 // complex real-world structures based on elmdentica database
13 typedef struct
14 {
15  const char *screen_name;
16  const char *name;
17  const char *message;
18  unsigned int id;
19  unsigned int status_id;
20  unsigned int date;
21  unsigned int timeline;
22 } My_Message;
23 
24 typedef struct
25 {
26  const char *dm_to;
27  const char *message;
28 } My_Post;
29 
30 typedef struct
31 {
32  unsigned int id;
33  const char *name;
34  Eina_List *messages;
35  My_Post *posts;
36  int posts_count;
37 } My_Account;
38 
39 typedef struct
40 {
41  unsigned int version; // it is recommended to use versioned configuration!
42  Eina_Hash *accounts;
43 } My_Cache;
44 
45 // string that represents the entry in eet file, you might like to have
46 // different profiles or so in the same file, this is possible with
47 // different strings
48 static const char MY_CACHE_FILE_ENTRY[] = "cache";
49 
50 // keep the descriptor static global, so it can be
51 // shared by different functions (load/save) of this and only this
52 // file.
53 static Eet_Data_Descriptor *_my_cache_descriptor;
54 static Eet_Data_Descriptor *_my_account_descriptor;
55 static Eet_Data_Descriptor *_my_message_descriptor;
56 static Eet_Data_Descriptor *_my_post_descriptor;
57 
58 // keep file handle alive, so mmap()ed strings are all alive as well
59 static Eet_File *_my_cache_file = NULL;
60 static Eet_Dictionary *_my_cache_dict = NULL;
61 
62 static void
63 _my_cache_descriptor_init(void)
64 {
66 
67  // The FILE variant is good for caches and things that are just
68  // appended, but needs to take care when changing strings and files must
69  // be kept open so mmap()ed strings will be kept alive.
71  _my_cache_descriptor = eet_data_descriptor_file_new(&eddc);
72 
73  EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Account);
74  _my_account_descriptor = eet_data_descriptor_file_new(&eddc);
75 
76  EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Message);
77  _my_message_descriptor = eet_data_descriptor_file_new(&eddc);
78 
80  _my_post_descriptor = eet_data_descriptor_file_new(&eddc);
81 
82  // Describe the members to be saved:
83  // Use a temporary macro so we don't type a lot, also avoid errors:
84 
85 #define ADD_BASIC(member, eet_type) \
86  EET_DATA_DESCRIPTOR_ADD_BASIC \
87  (_my_message_descriptor, My_Message, # member, member, eet_type)
88  ADD_BASIC(screen_name, EET_T_STRING);
89  ADD_BASIC(name, EET_T_STRING);
90  ADD_BASIC(message, EET_T_STRING);
91  ADD_BASIC(id, EET_T_UINT);
92  ADD_BASIC(status_id, EET_T_UINT);
93  ADD_BASIC(date, EET_T_UINT);
94  ADD_BASIC(timeline, EET_T_UINT);
95 #undef ADD_BASIC
96 
97 #define ADD_BASIC(member, eet_type) \
98  EET_DATA_DESCRIPTOR_ADD_BASIC \
99  (_my_post_descriptor, My_Post, # member, member, eet_type)
100  ADD_BASIC(dm_to, EET_T_STRING);
101  ADD_BASIC(message, EET_T_STRING);
102 #undef ADD_BASIC
103 
104 #define ADD_BASIC(member, eet_type) \
105  EET_DATA_DESCRIPTOR_ADD_BASIC \
106  (_my_account_descriptor, My_Account, # member, member, eet_type)
107  ADD_BASIC(name, EET_T_STRING);
108  ADD_BASIC(id, EET_T_UINT);
109 #undef ADD_BASIC
110 
112  (_my_account_descriptor, My_Account, "messages", messages,
113  _my_message_descriptor);
115  (_my_account_descriptor, My_Account, "posts", posts,
116  _my_post_descriptor);
117 
118 #define ADD_BASIC(member, eet_type) \
119  EET_DATA_DESCRIPTOR_ADD_BASIC \
120  (_my_cache_descriptor, My_Cache, # member, member, eet_type)
121  ADD_BASIC(version, EET_T_UINT);
122 #undef ADD_BASIC
123 
125  (_my_cache_descriptor, My_Cache, "accounts", accounts,
126  _my_account_descriptor);
127 } /* _my_cache_descriptor_init */
128 
129 static void
130 _my_cache_descriptor_shutdown(void)
131 {
132  eet_data_descriptor_free(_my_cache_descriptor);
133  eet_data_descriptor_free(_my_account_descriptor);
134  eet_data_descriptor_free(_my_message_descriptor);
135  eet_data_descriptor_free(_my_post_descriptor);
136 } /* _my_cache_descriptor_shutdown */
137 
138 // need to check if the pointer came from mmaped area in eet_dictionary
139 // or it was allocated with eina_stringshare_add()
140 static void
141 _eet_string_free(const char *str)
142 {
143  if (!str)
144  return;
145 
146  if ((_my_cache_dict) && (eet_dictionary_string_check(_my_cache_dict, str)))
147  return;
148 
150 } /* _eet_string_free */
151 
152 static My_Message *
153 _my_message_new(const char *message)
154 {
155  My_Message *msg = calloc(1, sizeof(My_Message));
156  if (!msg)
157  {
158  fprintf(stderr, "ERROR: could not calloc My_Message\n");
159  return NULL;
160  }
161 
162  msg->message = eina_stringshare_add(message);
163  return msg;
164 } /* _my_message_new */
165 
166 static void
167 _my_message_free(My_Message *msg)
168 {
169  _eet_string_free(msg->screen_name);
170  _eet_string_free(msg->name);
171  _eet_string_free(msg->message);
172  free(msg);
173 } /* _my_message_free */
174 
175 static Eina_Bool
176 _my_post_add(My_Account *acc,
177  const char *message)
178 {
179  int new_count = acc->posts_count + 1;
180  My_Post *post = realloc(acc->posts, new_count * sizeof(My_Post));
181  if (!post)
182  {
183  fprintf(stderr, "ERROR: could add My_Post\n");
184  return EINA_FALSE;
185  }
186 
187  post[acc->posts_count].message = eina_stringshare_add(message);
188  post[acc->posts_count].dm_to = NULL;
189  acc->posts_count = new_count;
190  acc->posts = post;
191  return EINA_TRUE;
192 } /* _my_post_new */
193 
194 static void
195 _my_post_free(My_Post *post)
196 {
197  _eet_string_free(post->dm_to);
198  _eet_string_free(post->message);
199 } /* _my_post_free */
200 
201 static My_Account *
202 _my_account_new(const char *name)
203 {
204  My_Account *acc = calloc(1, sizeof(My_Account));
205  if (!acc)
206  {
207  fprintf(stderr, "ERROR: could not calloc My_Account\n");
208  return NULL;
209  }
210 
211  acc->name = eina_stringshare_add(name);
212  return acc;
213 } /* _my_account_new */
214 
215 static void
216 _my_account_free(My_Account *acc)
217 {
218  My_Message *m;
219  int i;
220 
221  _eet_string_free(acc->name);
222 
223  EINA_LIST_FREE(acc->messages, m)
224  _my_message_free(m);
225 
226  for (i = 0; i < acc->posts_count; i++)
227  _my_post_free(&acc->posts[i]);
228  free(acc->posts);
229 
230  free(acc);
231 } /* _my_account_free */
232 
233 static My_Cache *
234 _my_cache_new(void)
235 {
236  My_Cache *my_cache = calloc(1, sizeof(My_Cache));
237  if (!my_cache)
238  {
239  fprintf(stderr, "ERROR: could not calloc My_Cache\n");
240  return NULL;
241  }
242 
243  my_cache->accounts = eina_hash_string_small_new(NULL);
244 
245  my_cache->version = 1;
246  return my_cache;
247 } /* _my_cache_new */
248 
249 static Eina_Bool
250 _my_cache_account_free_cb(const Eina_Hash *hash EINA_UNUSED,
251  const void *key EINA_UNUSED,
252  void *data,
253  void *fdata EINA_UNUSED)
254 {
255  _my_account_free(data);
256  return EINA_TRUE;
257 }
258 
259 static void
260 _my_cache_free(My_Cache *my_cache)
261 {
262  eina_hash_foreach(my_cache->accounts, _my_cache_account_free_cb, NULL);
263  eina_hash_free(my_cache->accounts);
264  free(my_cache);
265 } /* _my_cache_free */
266 
267 static My_Account *
268 _my_cache_account_find(My_Cache *my_cache,
269  const char *name)
270 {
271  return eina_hash_find(my_cache->accounts, name);
272 } /* _my_cache_account_find */
273 
274 static My_Cache *
275 _my_cache_load(const char *filename)
276 {
277  My_Cache *my_cache;
278  Eet_File *ef = eet_open(filename, EET_FILE_MODE_READ);
279  if (!ef)
280  {
281  fprintf(stderr, "ERROR: could not open '%s' for read\n", filename);
282  return NULL;
283  }
284 
285  my_cache = eet_data_read(ef, _my_cache_descriptor, MY_CACHE_FILE_ENTRY);
286  if (!my_cache)
287  {
288  eet_close(ef);
289  return NULL;
290  }
291 
292  if (my_cache->version < 1)
293  {
294  fprintf(stderr,
295  "WARNING: version %#x was too old, upgrading it to %#x\n",
296  my_cache->version, 1);
297 
298  my_cache->version = 1;
299  }
300 
301  if (_my_cache_file)
302  eet_close(_my_cache_file);
303 
304  _my_cache_file = ef;
305  _my_cache_dict = eet_dictionary_get(ef);
306 
307  return my_cache;
308 } /* _my_cache_load */
309 
310 static Eina_Bool
311 _my_cache_save(const My_Cache *my_cache,
312  const char *filename)
313 {
314  char tmp[PATH_MAX];
315  Eet_File *ef;
316  Eina_Bool ret;
317  unsigned int i, len;
318  struct stat st;
319 
320  len = eina_strlcpy(tmp, filename, sizeof(tmp));
321  if (len + 12 >= (int)sizeof(tmp))
322  {
323  fprintf(stderr, "ERROR: file name is too big: %s\n", filename);
324  return EINA_FALSE;
325  }
326 
327  i = 0;
328  do
329  {
330  snprintf(tmp + len, 12, ".%u", i);
331  i++;
332  }
333  while (stat(tmp, &st) == 0);
334 
335  ef = eet_open(tmp, EET_FILE_MODE_WRITE);
336  if (!ef)
337  {
338  fprintf(stderr, "ERROR: could not open '%s' for write\n", tmp);
339  return EINA_FALSE;
340  }
341 
342  ret = eet_data_write
343  (ef, _my_cache_descriptor, MY_CACHE_FILE_ENTRY, my_cache, EINA_TRUE);
344 
345  // VERY IMPORTANT NOTE:
346  // after eet_close(), all strings mmaped from file will be GONE, invalid!
347  // you'll need to free the old cache and open the new one.
348  // For cache this is okay, as you should be saving not so often or just
349  // at end.
350  //
351  // This is a trade off, you save memory by using mmap()ed strings, but
352  // you have to care about this.
353  eet_close(ef);
354 
355  if (ret)
356  {
357  unlink(filename);
358  rename(tmp, filename);
359  }
360 
361  return ret;
362 } /* _my_cache_save */
363 
364 int
365 main(int argc,
366  char *argv[])
367 {
368  My_Cache *my_cache;
369  Eina_Iterator *it;
370  My_Account *acc;
371  int ret = 0;
372 
373  if (argc < 3)
374  {
375  fprintf(stderr,
376  "Usage:\n\t%s <input> <output> [action] [action-params]\n\n"
377  "Where actions and their parameters:\n"
378  "\tacc <name>\n"
379  "\tpost <account-name> <message>\n"
380  "\tmessage <account-name> <message>\n"
381  "\n",
382  argv[0]);
383  return -1;
384  }
385 
386  eina_init();
387  eet_init();
388  _my_cache_descriptor_init();
389 
390  my_cache = _my_cache_load(argv[1]);
391  if (!my_cache)
392  {
393  printf("creating new cache.\n");
394  my_cache = _my_cache_new();
395  if (!my_cache)
396  {
397  ret = -2;
398  goto end;
399  }
400  }
401 
402  if (argc > 3)
403  {
404  if (strcmp(argv[3], "acc") == 0)
405  {
406  if (argc == 5)
407  {
408  My_Account *acc_ = _my_cache_account_find(my_cache, argv[4]);
409  if (!acc_)
410  {
411  acc_ = _my_account_new(argv[4]);
412  eina_hash_direct_add(my_cache->accounts, acc_->name, acc_);
413  }
414  else
415  fprintf(stderr, "ERROR: account '%s' already exists.\n",
416  argv[4]);
417  }
418  else
419  fprintf(stderr,
420  "ERROR: wrong number of parameters (%d).\n",
421  argc);
422  }
423  else if (strcmp(argv[3], "post") == 0)
424  {
425  if (argc == 6)
426  {
427  My_Account *acc_ = _my_cache_account_find(my_cache, argv[4]);
428  if (acc_)
429  {
430  _my_post_add(acc_, argv[5]);
431  }
432  else
433  fprintf(stderr, "ERROR: unknown account: '%s'\n", argv[4]);
434  }
435  else
436  fprintf(stderr,
437  "ERROR: wrong number of parameters (%d).\n",
438  argc);
439  }
440  else if (strcmp(argv[3], "message") == 0)
441  {
442  if (argc == 6)
443  {
444  My_Account *acc_ = _my_cache_account_find(my_cache, argv[4]);
445  if (acc_)
446  {
447  My_Message *msg = _my_message_new(argv[5]);
448  acc_->messages = eina_list_append(acc_->messages, msg);
449  }
450  else
451  fprintf(stderr, "ERROR: unknown account: '%s'\n", argv[4]);
452  }
453  else
454  fprintf(stderr,
455  "ERROR: wrong number of parameters (%d).\n",
456  argc);
457  }
458  else
459  fprintf(stderr, "ERROR: unknown action '%s'\n", argv[2]);
460  }
461 
462  printf("My_Cache:\n"
463  "\tversion.: %#x\n"
464  "\taccounts: %u\n",
465  my_cache->version,
466  eina_hash_population(my_cache->accounts));
467  it = eina_hash_iterator_data_new(my_cache->accounts);
468  EINA_ITERATOR_FOREACH(it, acc)
469  {
470  printf("\t > %-#8x '%.20s' stats: m=%u, p=%u\n",
471  acc->id, acc->name ? acc->name : "",
472  eina_list_count(acc->messages),
473  acc->posts_count);
474 
475  if (eina_list_count(acc->messages))
476  {
477  const Eina_List *l;
478  const My_Message *msg;
479  printf("\t |messages:\n");
480 
481  EINA_LIST_FOREACH(acc->messages, l, msg)
482  {
483  printf("\t | %-8x '%s' [%s]: '%.20s'\n",
484  msg->id,
485  msg->name ? msg->name : "",
486  msg->screen_name ? msg->screen_name : "",
487  msg->message ? msg->message : "");
488  }
489  }
490 
491  if (acc->posts_count)
492  {
493  const My_Post *post;
494  int i;
495  printf("\t |posts:\n");
496 
497  for (i = 0; i < acc->posts_count; i++)
498  {
499  post = &acc->posts[i];
500  if (post->dm_to)
501  printf("\t | @%s: '%.20s'\n", post->dm_to, post->message);
502  else
503  printf("\t | '%.20s'\n", post->message);
504  }
505  }
506 
507  printf("\n");
508  }
509  eina_iterator_free(it);
510 
511  if (!_my_cache_save(my_cache, argv[2]))
512  ret = -3;
513 
514  _my_cache_free(my_cache);
515 
516 end:
517  if (_my_cache_file)
518  eet_close(_my_cache_file);
519  _my_cache_descriptor_shutdown();
520  eet_shutdown();
521  eina_shutdown();
522 
523  return ret;
524 } /* main */
525 
#define EINA_ITERATOR_FOREACH(itr, data)
Definition for the macro to iterate over all elements easily.
Definition: eina_iterator.h:448
#define EET_DATA_DESCRIPTOR_ADD_VAR_ARRAY(edd, struct_type, name, member, subtype)
Adds a variable size array type to a data descriptor.
Definition: Eet.h:3752
EAPI Eet_File * eet_open(const char *file, Eet_File_Mode mode)
Opens an eet file on disk, and returns a handle to it.
Definition: eet_lib.c:1499
EAPI int eet_data_write(Eet_File *ef, Eet_Data_Descriptor *edd, const char *name, const void *data, int compress)
Writes a data structure from memory and store in an eet file.
Definition: eet_data.c:2414
#define EINA_FALSE
boolean value FALSE (numerical value 0)
Definition: eina_types.h:533
struct _Eet_File Eet_File
Opaque handle that defines an Eet file (or memory).
Definition: Eet.h:527
Eina_Bool eina_hash_direct_add(Eina_Hash *hash, const void *key, const void *data)
Adds an entry to the given hash table without duplicating the string.
Definition: eina_hash.c:948
Eina_Hash * eina_hash_string_small_new(Eina_Free_Cb data_free_cb)
Creates a new hash table for use with strings with small bucket size.
Definition: eina_hash.c:800
int eina_init(void)
Initializes the Eina library.
Definition: eina_main.c:279
void eina_iterator_free(Eina_Iterator *iterator)
Frees an iterator.
Definition: eina_iterator.c:98
int eina_shutdown(void)
Shuts down the Eina library.
Definition: eina_main.c:350
File is read-only.
Definition: Eet.h:479
EAPI int eet_shutdown(void)
Shuts down the EET library.
Definition: eet_lib.c:594
static unsigned int eina_list_count(const Eina_List *list)
Gets the count of the number of items in a list.
#define EET_DATA_DESCRIPTOR_ADD_HASH(edd, struct_type, name, member, subtype)
Adds a hash type to a data descriptor.
Definition: Eet.h:3584
void eina_hash_foreach(const Eina_Hash *hash, Eina_Hash_Foreach func, const void *fdata)
Calls a function on every member stored in the hash table.
Definition: eina_hash.c:1223
EAPI void eet_data_descriptor_free(Eet_Data_Descriptor *edd)
This function frees a data descriptor when it is not needed anymore.
Definition: eet_data.c:2102
#define EET_T_STRING
Data type: char *.
Definition: Eet.h:2589
#define EET_T_UINT
Data type: unsigned int.
Definition: Eet.h:2587
void eina_hash_free(Eina_Hash *hash)
Frees the given hash table's resources.
Definition: eina_hash.c:868
struct _Eet_Dictionary Eet_Dictionary
Opaque handle that defines a file-backed (mmaped) dictionary of strings.
Definition: Eet.h:533
EAPI int eet_dictionary_string_check(Eet_Dictionary *ed, const char *string)
Checks if a given string comes from a given dictionary.
Definition: eet_dictionary.c:493
#define EINA_TRUE
boolean value TRUE (numerical value 1)
Definition: eina_types.h:539
EAPI Eina_List * eina_list_append(Eina_List *list, const void *data)
Appends the given data to the given linked list.
Definition: eina_list.c:584
The file that provides the eet functions.
struct _Eina_Hash Eina_Hash
Type for a generic hash table.
Definition: eina_hash.h:285
File is write-only.
Definition: Eet.h:480
EAPI size_t eina_strlcpy(char *dst, const char *src, size_t siz) EINA_ARG_NONNULL(1
Copies a c-string to another.
EAPI void * eet_data_read(Eet_File *ef, Eet_Data_Descriptor *edd, const char *name)
Reads a data structure from an eet file and decodes it.
Definition: eet_data.c:2377
Eina Utility library.
void eina_stringshare_del(Eina_Stringshare *str)
Notes that the given string has lost an instance.
Definition: eina_stringshare.c:533
Instructs Eet about memory management for different needs under serialization and parse process.
Definition: Eet.h:2827
unsigned char Eina_Bool
Type to mimic a boolean.
Definition: eina_types.h:527
#define EINA_LIST_FOREACH(list, l, _data)
Definition for the macro to iterate over a list.
Definition: eina_list.h:1415
#define EET_DATA_DESCRIPTOR_ADD_LIST(edd, struct_type, name, member, subtype)
Adds a linked list type to a data descriptor.
Definition: Eet.h:3511
EAPI Eet_Error eet_close(Eet_File *ef)
Closes an eet file handle and flush pending writes.
Definition: eet_lib.c:1899
struct _Eet_Data_Descriptor Eet_Data_Descriptor
Opaque handle that have information on a type members.
Definition: Eet.h:2631
#define EINA_LIST_FREE(list, data)
Definition for the macro to remove each list node while having access to each node's data.
Definition: eina_list.h:1629
void * eina_hash_find(const Eina_Hash *hash, const void *key)
Retrieves a specific entry in the given hash table.
Definition: eina_hash.c:1069
Eina_Iterator * eina_hash_iterator_data_new(const Eina_Hash *hash)
Returns a new iterator associated with a hash.
Definition: eina_hash.c:1246
EAPI Eet_Data_Descriptor * eet_data_descriptor_file_new(const Eet_Data_Descriptor_Class *eddc)
This function creates a new data descriptor and returns a handle to the new data descriptor.
Definition: eet_data.c:2088
structure of an iterator
Definition: eina_iterator.h:158
int eina_hash_population(const Eina_Hash *hash)
Returns the number of entries in the given hash table.
Definition: eina_hash.c:858
Type for a generic double linked list.
Definition: eina_list.h:317
Eina_Stringshare * eina_stringshare_add(const char *str)
Retrieves an instance of a string for use in a program.
Definition: eina_stringshare.c:606
#define EINA_UNUSED
Used to indicate that a function parameter is purposely unused.
Definition: eina_types.h:339
#define EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(clas, type)
This macro is an helper that set all the parameter of an Eet_Data_Descriptor_Class correctly when you...
Definition: Eet.h:3075
EAPI Eet_Dictionary * eet_dictionary_get(Eet_File *ef)
Returns a handle to the shared string dictionary of the Eet file.
Definition: eet_lib.c:2564
EAPI int eet_init(void)
Initializes the EET library.
Definition: eet_lib.c:540