Example_Eet_Data_Simple(3)

NAME
Example_Eet_Data_Simple - 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 {
39    Eet_Data_Descriptor_Class eddc;
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);
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, 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,
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, 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, 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:t%s <input> <output>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.);
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:
203           "	version: %#x
204           "	name...: '%s'
205           "	id.....: %d
206           "	enabled: %hhu,
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