Nested data example
1 //Compile with:
2 // gcc -o eet-data-nested eet-data-nested.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 // The struct that will be loaded and saved.
13 // note that only the members described in the eet_data_descriptor
14 // will be automatically handled. The other members will have their
15 // space reserved and zeroed (as it uses calloc()), but not
16 // saved or loaded from eet files.
17 typedef struct
18 {
19  unsigned int version; // it is recommended to use versioned configuration!
20  const char *name;
21  int id;
22  int not_saved_value; // example of not saved data inside!
23  Eina_Bool enabled;
24  Eina_List *subs;
25 } My_Conf_Type;
26 
27 typedef struct
28 {
29  const char *server;
30  int port;
31 } My_Conf_Subtype;
32 
33 // string that represents the entry in eet file, you might like to have
34 // different profiles or so in the same file, this is possible with
35 // different strings
36 static const char MY_CONF_FILE_ENTRY[] = "config";
37 
38 // keep the descriptor static global, so it can be
39 // shared by different functions (load/save) of this and only this
40 // file.
41 static Eet_Data_Descriptor *_my_conf_descriptor;
42 static Eet_Data_Descriptor *_my_conf_sub_descriptor;
43 
44 static void
45 _my_conf_descriptor_init(void)
46 {
48 
49  // The class describe the functions to use to create the type and its
50  // full allocated size.
51  //
52  // Eina types are very convenient, so use them to create the descriptor,
53  // so we get eina_list, eina_hash and eina_stringshare automatically!
54  //
55  // The STREAM variant is better for configuration files as the values
56  // will likely change a lot.
57  //
58  // The other variant, FILE, is good for caches and things that are just
59  // appended, but needs to take care when changing strings and files must
60  // be kept open so mmap()ed strings will be kept alive.
61  EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Conf_Type);
62  _my_conf_descriptor = eet_data_descriptor_stream_new(&eddc);
63 
64  EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Conf_Subtype);
65  _my_conf_sub_descriptor = eet_data_descriptor_stream_new(&eddc);
66 
67  // Describe the members to be saved:
68  // Use a temporary macro so we don't type a lot, also avoid errors:
69 #define MY_CONF_ADD_BASIC(member, eet_type) \
70  EET_DATA_DESCRIPTOR_ADD_BASIC \
71  (_my_conf_descriptor, My_Conf_Type, # member, member, eet_type)
72 #define MY_CONF_SUB_ADD_BASIC(member, eet_type) \
73  EET_DATA_DESCRIPTOR_ADD_BASIC \
74  (_my_conf_sub_descriptor, My_Conf_Subtype, # member, member, eet_type)
75 
76  MY_CONF_SUB_ADD_BASIC(server, EET_T_STRING);
77  MY_CONF_SUB_ADD_BASIC(port, EET_T_INT);
78 
79  MY_CONF_ADD_BASIC(version, EET_T_UINT);
80  MY_CONF_ADD_BASIC(name, EET_T_STRING);
81  MY_CONF_ADD_BASIC(id, EET_T_INT);
82  MY_CONF_ADD_BASIC(enabled, EET_T_UCHAR);
83 
84  // And add the sub descriptor as a linked list at 'subs' in the main struct
86  (_my_conf_descriptor, My_Conf_Type, "subs", subs, _my_conf_sub_descriptor);
87 
88 #undef MY_CONF_ADD_BASIC
89 #undef MY_CONF_SUB_ADD_BASIC
90 } /* _my_conf_descriptor_init */
91 
92 static void
93 _my_conf_descriptor_shutdown(void)
94 {
95  eet_data_descriptor_free(_my_conf_sub_descriptor);
96  eet_data_descriptor_free(_my_conf_descriptor);
97 } /* _my_conf_descriptor_shutdown */
98 
99 static My_Conf_Type *
100 _my_conf_new(void)
101 {
102  My_Conf_Type *my_conf = calloc(1, sizeof(My_Conf_Type));
103  My_Conf_Subtype *sub;
104  if (!my_conf)
105  {
106  fprintf(stderr, "ERROR: could not calloc My_Conf_Type\n");
107  return NULL;
108  }
109 
110  my_conf->version = 0x112233;
111  my_conf->enabled = EINA_TRUE;
112 
113  sub = calloc(1, sizeof(My_Conf_Subtype));
114  if (sub)
115  {
116  sub->server = eina_stringshare_add("my-server.com");
117  sub->port = 1234;
118  my_conf->subs = eina_list_append(my_conf->subs, sub);
119  }
120 
121  return my_conf;
122 } /* _my_conf_new */
123 
124 static void
125 _my_conf_free(My_Conf_Type *my_conf)
126 {
127  My_Conf_Subtype *sub;
128  EINA_LIST_FREE(my_conf->subs, sub)
129  {
130  eina_stringshare_del(sub->server);
131  free(sub);
132  }
133 
134  eina_stringshare_del(my_conf->name);
135  free(my_conf);
136 } /* _my_conf_free */
137 
138 static My_Conf_Type *
139 _my_conf_load(const char *filename)
140 {
141  My_Conf_Type *my_conf;
142  Eet_File *ef = eet_open(filename, EET_FILE_MODE_READ);
143  if (!ef)
144  {
145  fprintf(stderr, "ERROR: could not open '%s' for read\n", filename);
146  return NULL;
147  }
148 
149  my_conf = eet_data_read(ef, _my_conf_descriptor, MY_CONF_FILE_ENTRY);
150  if (!my_conf)
151  goto end;
152 
153  if (my_conf->version < 0x112233)
154  {
155  fprintf(stderr,
156  "WARNING: version %#x was too old, upgrading it to %#x\n",
157  my_conf->version, 0x112233);
158 
159  my_conf->version = 0x112233;
160  my_conf->enabled = EINA_TRUE;
161  }
162 
163 end:
164  eet_close(ef);
165  return my_conf;
166 } /* _my_conf_load */
167 
168 static Eina_Bool
169 _my_conf_save(const My_Conf_Type *my_conf,
170  const char *filename)
171 {
172  char tmp[PATH_MAX];
173  Eet_File *ef;
174  Eina_Bool ret;
175  unsigned int i, len;
176  struct stat st;
177 
178  len = eina_strlcpy(tmp, filename, sizeof(tmp));
179  if (len + 12 >= (int)sizeof(tmp))
180  {
181  fprintf(stderr, "ERROR: file name is too big: %s\n", filename);
182  return EINA_FALSE;
183  }
184 
185  i = 0;
186  do
187  {
188  snprintf(tmp + len, 12, ".%u", i);
189  i++;
190  }
191  while (stat(tmp, &st) == 0);
192 
193  ef = eet_open(tmp, EET_FILE_MODE_WRITE);
194  if (!ef)
195  {
196  fprintf(stderr, "ERROR: could not open '%s' for write\n", tmp);
197  return EINA_FALSE;
198  }
199 
200  ret = eet_data_write
201  (ef, _my_conf_descriptor, MY_CONF_FILE_ENTRY, my_conf, EINA_TRUE);
202  eet_close(ef);
203 
204  if (ret)
205  {
206  unlink(filename);
207  rename(tmp, filename);
208  }
209 
210  return ret;
211 } /* _my_conf_save */
212 
213 int
214 main(int argc,
215  char *argv[])
216 {
217  My_Conf_Type *my_conf;
218  const My_Conf_Subtype *sub;
219  const Eina_List *l;
220  int ret = 0;
221 
222  if (argc != 3)
223  {
224  fprintf(stderr, "Usage:\n\t%s <input> <output>\n\n", argv[0]);
225  return -1;
226  }
227 
228  eina_init();
229  eet_init();
230  _my_conf_descriptor_init();
231 
232  my_conf = _my_conf_load(argv[1]);
233  if (!my_conf)
234  {
235  printf("creating new configuration.\n");
236  my_conf = _my_conf_new();
237  if (!my_conf)
238  {
239  ret = -2;
240  goto end;
241  }
242  }
243 
244  printf("My_Conf_Type:\n"
245  "\tversion: %#x\n"
246  "\tname...: '%s'\n"
247  "\tid.....: %d\n"
248  "\tenabled: %hhu\n"
249  "\tsubs...:\n",
250  my_conf->version,
251  my_conf->name ? my_conf->name : "",
252  my_conf->id,
253  my_conf->enabled);
254 
255  EINA_LIST_FOREACH(my_conf->subs, l, sub)
256  printf("\t\tserver: '%s', port: %d\n",
257  sub->server ? sub->server : "",
258  sub->port);
259 
260  if (!_my_conf_save(my_conf, argv[2]))
261  ret = -3;
262 
263  _my_conf_free(my_conf);
264 
265 end:
266  _my_conf_descriptor_shutdown();
267  eet_shutdown();
268  eina_shutdown();
269 
270  return ret;
271 } /* main */
272 
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
int eina_init(void)
Initializes the Eina library.
Definition: eina_main.c:279
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
#define EET_EINA_STREAM_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:3034
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
#define EET_T_UCHAR
Data type: unsigned char.
Definition: Eet.h:2585
#define EET_T_INT
Data type: int.
Definition: Eet.h:2581
#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.
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 Eet_Data_Descriptor * eet_data_descriptor_stream_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:2082
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
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
EAPI int eet_init(void)
Initializes the EET library.
Definition: eet_lib.c:540