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,
251  const void *key,
252  void *data,
253  void *fdata)
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  My_Account *acc;
263  eina_hash_foreach(my_cache->accounts, _my_cache_account_free_cb, NULL);
264  eina_hash_free(my_cache->accounts);
265  free(my_cache);
266 } /* _my_cache_free */
267 
268 static My_Account *
269 _my_cache_account_find(My_Cache *my_cache,
270  const char *name)
271 {
272  return eina_hash_find(my_cache->accounts, name);
273 } /* _my_cache_account_find */
274 
275 static My_Cache *
276 _my_cache_load(const char *filename)
277 {
278  My_Cache *my_cache;
279  Eet_File *ef = eet_open(filename, EET_FILE_MODE_READ);
280  if (!ef)
281  {
282  fprintf(stderr, "ERROR: could not open '%s' for read\n", filename);
283  return NULL;
284  }
285 
286  my_cache = eet_data_read(ef, _my_cache_descriptor, MY_CACHE_FILE_ENTRY);
287  if (!my_cache)
288  {
289  eet_close(ef);
290  return NULL;
291  }
292 
293  if (my_cache->version < 1)
294  {
295  fprintf(stderr,
296  "WARNING: version %#x was too old, upgrading it to %#x\n",
297  my_cache->version, 1);
298 
299  my_cache->version = 1;
300  }
301 
302  if (_my_cache_file)
303  eet_close(_my_cache_file);
304 
305  _my_cache_file = ef;
306  _my_cache_dict = eet_dictionary_get(ef);
307 
308  return my_cache;
309 } /* _my_cache_load */
310 
311 static Eina_Bool
312 _my_cache_save(const My_Cache *my_cache,
313  const char *filename)
314 {
315  char tmp[PATH_MAX];
316  Eet_File *ef;
317  Eina_Bool ret;
318  unsigned int i, len;
319  struct stat st;
320 
321  len = eina_strlcpy(tmp, filename, sizeof(tmp));
322  if (len + 12 >= (int)sizeof(tmp))
323  {
324  fprintf(stderr, "ERROR: file name is too big: %s\n", filename);
325  return EINA_FALSE;
326  }
327 
328  i = 0;
329  do
330  {
331  snprintf(tmp + len, 12, ".%u", i);
332  i++;
333  }
334  while (stat(tmp, &st) == 0);
335 
336  ef = eet_open(tmp, EET_FILE_MODE_WRITE);
337  if (!ef)
338  {
339  fprintf(stderr, "ERROR: could not open '%s' for write\n", tmp);
340  return EINA_FALSE;
341  }
342 
343  ret = eet_data_write
344  (ef, _my_cache_descriptor, MY_CACHE_FILE_ENTRY, my_cache, EINA_TRUE);
345 
346  // VERY IMPORTANT NOTE:
347  // after eet_close(), all strings mmaped from file will be GONE, invalid!
348  // you'll need to free the old cache and open the new one.
349  // For cache this is okay, as you should be saving not so often or just
350  // at end.
351  //
352  // This is a trade off, you save memory by using mmap()ed strings, but
353  // you have to care about this.
354  eet_close(ef);
355 
356  if (ret)
357  {
358  unlink(filename);
359  rename(tmp, filename);
360  }
361 
362  return ret;
363 } /* _my_cache_save */
364 
365 int
366 main(int argc,
367  char *argv[])
368 {
369  My_Cache *my_cache;
370  const Eina_List *l_acc;
371  Eina_Iterator *it;
372  My_Account *acc;
373  int ret = 0;
374 
375  if (argc < 3)
376  {
377  fprintf(stderr,
378  "Usage:\n\t%s <input> <output> [action] [action-params]\n\n"
379  "Where actions and their parameters:\n"
380  "\tacc <name>\n"
381  "\tpost <account-name> <message>\n"
382  "\tmessage <account-name> <message>\n"
383  "\n",
384  argv[0]);
385  return -1;
386  }
387 
388  eina_init();
389  eet_init();
390  _my_cache_descriptor_init();
391 
392  my_cache = _my_cache_load(argv[1]);
393  if (!my_cache)
394  {
395  printf("creating new cache.\n");
396  my_cache = _my_cache_new();
397  if (!my_cache)
398  {
399  ret = -2;
400  goto end;
401  }
402  }
403 
404  if (argc > 3)
405  {
406  if (strcmp(argv[3], "acc") == 0)
407  {
408  if (argc == 5)
409  {
410  My_Account *acc = _my_cache_account_find(my_cache, argv[4]);
411  if (!acc)
412  {
413  acc = _my_account_new(argv[4]);
414  eina_hash_direct_add(my_cache->accounts, acc->name, acc);
415  }
416  else
417  fprintf(stderr, "ERROR: account '%s' already exists.\n",
418  argv[4]);
419  }
420  else
421  fprintf(stderr,
422  "ERROR: wrong number of parameters (%d).\n",
423  argc);
424  }
425  else if (strcmp(argv[3], "post") == 0)
426  {
427  if (argc == 6)
428  {
429  My_Account *acc = _my_cache_account_find(my_cache, argv[4]);
430  if (acc)
431  {
432  _my_post_add(acc, argv[5]);
433  }
434  else
435  fprintf(stderr, "ERROR: unknown account: '%s'\n", argv[4]);
436  }
437  else
438  fprintf(stderr,
439  "ERROR: wrong number of parameters (%d).\n",
440  argc);
441  }
442  else if (strcmp(argv[3], "message") == 0)
443  {
444  if (argc == 6)
445  {
446  My_Account *acc = _my_cache_account_find(my_cache, argv[4]);
447  if (acc)
448  {
449  My_Message *msg = _my_message_new(argv[5]);
450  acc->messages = eina_list_append(acc->messages, msg);
451  }
452  else
453  fprintf(stderr, "ERROR: unknown account: '%s'\n", argv[4]);
454  }
455  else
456  fprintf(stderr,
457  "ERROR: wrong number of parameters (%d).\n",
458  argc);
459  }
460  else
461  fprintf(stderr, "ERROR: unknown action '%s'\n", argv[2]);
462  }
463 
464  printf("My_Cache:\n"
465  "\tversion.: %#x\n"
466  "\taccounts: %u\n",
467  my_cache->version,
468  eina_hash_population(my_cache->accounts));
469  it = eina_hash_iterator_data_new(my_cache->accounts);
470  EINA_ITERATOR_FOREACH(it, acc)
471  {
472  const My_Post *post;
473 
474  printf("\t > %-#8x '%.20s' stats: m=%u, p=%u\n",
475  acc->id, acc->name ? acc->name : "",
476  eina_list_count(acc->messages),
477  acc->posts_count);
478 
479  if (eina_list_count(acc->messages))
480  {
481  const Eina_List *l;
482  const My_Message *msg;
483  printf("\t |messages:\n");
484 
485  EINA_LIST_FOREACH(acc->messages, l, msg)
486  {
487  printf("\t | %-8x '%s' [%s]: '%.20s'\n",
488  msg->id,
489  msg->name ? msg->name : "",
490  msg->screen_name ? msg->screen_name : "",
491  msg->message ? msg->message : "");
492  }
493  }
494 
495  if (acc->posts_count)
496  {
497  const My_Post *post;
498  int i;
499  printf("\t |posts:\n");
500 
501  for (i = 0; i < acc->posts_count; i++)
502  {
503  post = &acc->posts[i];
504  if (post->dm_to)
505  printf("\t | @%s: '%.20s'\n", post->dm_to, post->message);
506  else
507  printf("\t | '%.20s'\n", post->message);
508  }
509  }
510 
511  printf("\n");
512  }
513  eina_iterator_free(it);
514 
515  if (!_my_cache_save(my_cache, argv[2]))
516  ret = -3;
517 
518  _my_cache_free(my_cache);
519 
520 end:
521  if (_my_cache_file)
522  eet_close(_my_cache_file);
523  _my_cache_descriptor_shutdown();
524  eet_shutdown();
525  eina_shutdown();
526 
527  return ret;
528 } /* main */
529 
EAPI void eina_stringshare_del(Eina_Stringshare *str)
Note that the given string has lost an instance.
Definition: eina_stringshare.c:537
EAPI Eina_Stringshare * eina_stringshare_add(const char *str)
Retrieve an instance of a string for use in a program.
Definition: eina_stringshare.c:610
#define EET_DATA_DESCRIPTOR_ADD_VAR_ARRAY(edd, struct_type, name, member, subtype)
Add a variable size array type to a data descriptor.
Definition: Eet.h:3340
EAPI Eet_File * eet_open(const char *file, Eet_File_Mode mode)
Open an eet file on disk, and returns a handle to it.
Definition: eet_lib.c:1502
#define rename(src, dst)
Wrapper around evil_rename().
Definition: evil_stdio.h:226
EAPI int eet_data_write(Eet_File *ef, Eet_Data_Descriptor *edd, const char *name, const void *data, int compress)
Write a data structure from memory and store in an eet file.
Definition: eet_data.c:2357
#define EINA_FALSE
boolean value FALSE (numerical value 0)
Definition: eina_types.h:311
struct _Eet_File Eet_File
Opaque handle that defines an Eet file (or memory).
Definition: Eet.h:485
Eina_Bool eina_hash_direct_add(Eina_Hash *hash, const void *key, const void *data)
Add an entry to the given hash table without duplicating the string key.
Definition: eina_hash.c:911
Eina_Hash * eina_hash_string_small_new(Eina_Free_Cb data_free_cb)
Create a new hash table for use with strings with small bucket size.
Definition: eina_hash.c:762
void eina_iterator_free(Eina_Iterator *iterator)
Free an iterator.
Definition: eina_iterator.c:96
File is read-only.
Definition: Eet.h:466
EAPI int eet_shutdown(void)
Shut down the EET library.
Definition: eet_lib.c:622
int eina_init(void)
Initialize the Eina library.
Definition: eina_main.c:247
static unsigned int eina_list_count(const Eina_List *list)
Get the count of the number of items in a list.
#define EET_DATA_DESCRIPTOR_ADD_HASH(edd, struct_type, name, member, subtype)
Add a hash type to a data descriptor.
Definition: Eet.h:3195
void eina_hash_foreach(const Eina_Hash *hash, Eina_Hash_Foreach func, const void *fdata)
Call a function on every member stored in the hash table.
Definition: eina_hash.c:1187
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:2104
#define EET_T_STRING
Data type: char *.
Definition: Eet.h:2379
#define EINA_ITERATOR_FOREACH(itr,data)
Macro to iterate over all elements easily.
Definition: eina_iterator.h:332
#define EET_T_UINT
Data type: unsigned int.
Definition: Eet.h:2377
void eina_hash_free(Eina_Hash *hash)
Free the given hash table resources.
Definition: eina_hash.c:830
struct _Eet_Dictionary Eet_Dictionary
Opaque handle that defines a file-backed (mmaped) dictionary of strings.
Definition: Eet.h:491
EAPI int eet_dictionary_string_check(Eet_Dictionary *ed, const char *string)
Check if a given string comes from a given dictionary.
Definition: eet_dictionary.c:499
#define EINA_TRUE
boolean value TRUE (numerical value 1)
Definition: eina_types.h:317
int eina_shutdown(void)
Shut down the Eina library.
Definition: eina_main.c:317
Eina_List * eina_list_append(Eina_List *list, const void *data)
Append the given data to the given linked list.
Definition: eina_list.c:530
The file that provides the eet functions.
struct _Eina_Hash Eina_Hash
Type for a generic hash table.
Definition: eina_hash.h:288
File is write-only.
Definition: Eet.h:467
EAPI size_t eina_strlcpy(char *dst, const char *src, size_t siz) EINA_ARG_NONNULL(1
Copy a c-string to another.
EAPI void * eet_data_read(Eet_File *ef, Eet_Data_Descriptor *edd, const char *name)
Read a data structure from an eet file and decodes it.
Definition: eet_data.c:2323
Eina Utility library.
Instructs Eet about memory management for different needs under serialization and parse process...
Definition: Eet.h:2473
unsigned char Eina_Bool
Type to mimic a boolean.
Definition: eina_types.h:305
#define EET_DATA_DESCRIPTOR_ADD_LIST(edd, struct_type, name, member, subtype)
Add a linked list type to a data descriptor.
Definition: Eet.h:3145
EAPI Eet_Error eet_close(Eet_File *ef)
Close an eet file handle and flush pending writes.
Definition: eet_lib.c:1752
struct _Eet_Data_Descriptor Eet_Data_Descriptor
Opaque handle that have information on a type members.
Definition: Eet.h:2421
#define EINA_LIST_FREE(list, data)
Macro to remove each list node while having access to each node&#39;s data.
Definition: eina_list.h:1599
void * eina_hash_find(const Eina_Hash *hash, const void *key)
Retrieve a specific entry in the given hash table.
Definition: eina_hash.c:1033
Eina_Iterator * eina_hash_iterator_data_new(const Eina_Hash *hash)
Returned a new iterator associated to hash data.
Definition: eina_hash.c:1210
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:2090
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:820
Type for a generic double linked list.
Definition: eina_list.h:320
#define EINA_LIST_FOREACH(list, l, data)
Macro to iterate over a list.
Definition: eina_list.h:1387
#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:2720
EAPI Eet_Dictionary * eet_dictionary_get(Eet_File *ef)
Return a handle to the shared string dictionary of the Eet file.
Definition: eet_lib.c:2649
EAPI int eet_init(void)
Initialize the EET library.
Definition: eet_lib.c:539