Simple data example
1 //Compile with:
2 // gcc -o eet-data-simple eet-data-simple.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 } My_Conf_Type;
25 
26 // string that represents the entry in eet file, you might like to have
27 // different profiles or so in the same file, this is possible with
28 // different strings
29 static const char MY_CONF_FILE_ENTRY[] = "config";
30 
31 // keep the descriptor static global, so it can be
32 // shared by different functions (load/save) of this and only this
33 // file.
34 static Eet_Data_Descriptor *_my_conf_descriptor;
35 
36 static void
37 _my_conf_descriptor_init(void)
38 {
40 
41  // The class describe the functions to use to create the type and its
42  // full allocated size.
43  //
44  // Eina types are very convenient, so use them to create the descriptor,
45  // so we get eina_list, eina_hash and eina_stringshare automatically!
46  //
47  // The STREAM variant is better for configuration files as the values
48  // will likely change a lot.
49  //
50  // The other variant, FILE, is good for caches and things that are just
51  // appended, but needs to take care when changing strings and files must
52  // be kept open so mmap()ed strings will be kept alive.
53  EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Conf_Type);
54  _my_conf_descriptor = eet_data_descriptor_stream_new(&eddc);
55 
56  // Describe the members to be saved:
57  // Use a temporary macro so we don't type a lot, also avoid errors:
58 #define MY_CONF_ADD_BASIC(member, eet_type) \
59  EET_DATA_DESCRIPTOR_ADD_BASIC \
60  (_my_conf_descriptor, My_Conf_Type, # member, member, eet_type)
61 
62  MY_CONF_ADD_BASIC(version, EET_T_UINT);
63  MY_CONF_ADD_BASIC(name, EET_T_STRING);
64  MY_CONF_ADD_BASIC(id, EET_T_INT);
65  MY_CONF_ADD_BASIC(enabled, EET_T_UCHAR);
66 
67 #undef MY_CONF_ADD_BASIC
68 } /* _my_conf_descriptor_init */
69 
70 static void
71 _my_conf_descriptor_shutdown(void)
72 {
73  eet_data_descriptor_free(_my_conf_descriptor);
74 } /* _my_conf_descriptor_shutdown */
75 
76 static My_Conf_Type *
77 _my_conf_new(void)
78 {
79  My_Conf_Type *my_conf = calloc(1, sizeof(My_Conf_Type));
80  if (!my_conf)
81  {
82  fprintf(stderr, "ERROR: could not calloc My_Conf_Type\n");
83  return NULL;
84  }
85 
86  my_conf->version = 0x112233;
87  my_conf->enabled = EINA_TRUE;
88  return my_conf;
89 } /* _my_conf_new */
90 
91 static void
92 _my_conf_free(My_Conf_Type *my_conf)
93 {
94  eina_stringshare_del(my_conf->name);
95  free(my_conf);
96 } /* _my_conf_free */
97 
98 static My_Conf_Type *
99 _my_conf_load(const char *filename)
100 {
101  My_Conf_Type *my_conf;
102  Eet_File *ef = eet_open(filename, EET_FILE_MODE_READ);
103  if (!ef)
104  {
105  fprintf(stderr, "ERROR: could not open '%s' for read\n", filename);
106  return NULL;
107  }
108 
109  my_conf = eet_data_read(ef, _my_conf_descriptor, MY_CONF_FILE_ENTRY);
110  if (!my_conf)
111  goto end;
112 
113  if (my_conf->version < 0x112233)
114  {
115  fprintf(stderr,
116  "WARNING: version %#x was too old, upgrading it to %#x\n",
117  my_conf->version, 0x112233);
118 
119  my_conf->version = 0x112233;
120  my_conf->enabled = EINA_TRUE;
121  }
122 
123 end:
124  eet_close(ef);
125  return my_conf;
126 } /* _my_conf_load */
127 
128 static Eina_Bool
129 _my_conf_save(const My_Conf_Type *my_conf,
130  const char *filename)
131 {
132  char tmp[PATH_MAX];
133  Eet_File *ef;
134  Eina_Bool ret;
135  unsigned int i, len;
136  struct stat st;
137 
138  len = eina_strlcpy(tmp, filename, sizeof(tmp));
139  if (len + 12 >= (int)sizeof(tmp))
140  {
141  fprintf(stderr, "ERROR: file name is too big: %s\n", filename);
142  return EINA_FALSE;
143  }
144 
145  i = 0;
146  do
147  {
148  snprintf(tmp + len, 12, ".%u", i);
149  i++;
150  }
151  while (stat(tmp, &st) == 0);
152 
153  ef = eet_open(tmp, EET_FILE_MODE_WRITE);
154  if (!ef)
155  {
156  fprintf(stderr, "ERROR: could not open '%s' for write\n", tmp);
157  return EINA_FALSE;
158  }
159 
160  ret = eet_data_write
161  (ef, _my_conf_descriptor, MY_CONF_FILE_ENTRY, my_conf, EINA_TRUE);
162  eet_close(ef);
163 
164  if (ret)
165  {
166  unlink(filename);
167  rename(tmp, filename);
168  }
169 
170  return ret;
171 } /* _my_conf_save */
172 
173 int
174 main(int argc,
175  char *argv[])
176 {
177  My_Conf_Type *my_conf;
178  int ret = 0;
179 
180  if (argc != 3)
181  {
182  fprintf(stderr, "Usage:\n\t%s <input> <output>\n\n", argv[0]);
183  return -1;
184  }
185 
186  eina_init();
187  eet_init();
188  _my_conf_descriptor_init();
189 
190  my_conf = _my_conf_load(argv[1]);
191  if (!my_conf)
192  {
193  printf("creating new configuration.\n");
194  my_conf = _my_conf_new();
195  if (!my_conf)
196  {
197  ret = -2;
198  goto end;
199  }
200  }
201 
202  printf("My_Conf_Type:\n"
203  "\tversion: %#x\n"
204  "\tname...: '%s'\n"
205  "\tid.....: %d\n"
206  "\tenabled: %hhu\n",
207  my_conf->version,
208  my_conf->name ? my_conf->name : "",
209  my_conf->id,
210  my_conf->enabled);
211 
212  if (!_my_conf_save(my_conf, argv[2]))
213  ret = -3;
214 
215  _my_conf_free(my_conf);
216 
217 end:
218  _my_conf_descriptor_shutdown();
219  eet_shutdown();
220  eina_shutdown();
221 
222  return ret;
223 } /* main */
224 
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
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
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
EAPI int eet_init(void)
Initializes the EET library.
Definition: eet_lib.c:540