eet-data-simple.c

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eet-data-simple.c
//Compile with:
// gcc -o eet-data-simple eet-data-simple.c `pkg-config --cflags --libs eet eina`
#include <Eina.h>
#include <Eet.h>
#include <stdio.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
// The struct that will be loaded and saved.
// note that only the members described in the eet_data_descriptor
// will be automatically handled. The other members will have their
// space reserved and zeroed (as it uses calloc()), but not
// saved or loaded from eet files.
typedef struct
{
unsigned int version; // it is recommended to use versioned configuration!
const char *name;
int id;
int not_saved_value; // example of not saved data inside!
Eina_Bool enabled;
} My_Conf_Type;
// string that represents the entry in eet file, you might like to have
// different profiles or so in the same file, this is possible with
// different strings
static const char MY_CONF_FILE_ENTRY[] = "config";
// keep the descriptor static global, so it can be
// shared by different functions (load/save) of this and only this
// file.
static Eet_Data_Descriptor *_my_conf_descriptor;
static void
_my_conf_descriptor_init(void)
{
Eet_Data_Descriptor_Class eddc;
// The class describe the functions to use to create the type and its
// full allocated size.
//
// Eina types are very convenient, so use them to create the descriptor,
// so we get eina_list, eina_hash and eina_stringshare automatically!
//
// The STREAM variant is better for configuration files as the values
// will likely change a lot.
//
// The other variant, FILE, is good for caches and things that are just
// appended, but needs to take care when changing strings and files must
// be kept open so mmap()ed strings will be kept alive.
EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc, My_Conf_Type);
_my_conf_descriptor = eet_data_descriptor_stream_new(&eddc);
// Describe the members to be saved:
// Use a temporary macro so we don't type a lot, also avoid errors:
#define MY_CONF_ADD_BASIC(member, eet_type) \
EET_DATA_DESCRIPTOR_ADD_BASIC \
(_my_conf_descriptor, My_Conf_Type, # member, member, eet_type)
MY_CONF_ADD_BASIC(version, EET_T_UINT);
MY_CONF_ADD_BASIC(name, EET_T_STRING);
MY_CONF_ADD_BASIC(id, EET_T_INT);
MY_CONF_ADD_BASIC(enabled, EET_T_UCHAR);
#undef MY_CONF_ADD_BASIC
} /* _my_conf_descriptor_init */
static void
_my_conf_descriptor_shutdown(void)
{
eet_data_descriptor_free(_my_conf_descriptor);
} /* _my_conf_descriptor_shutdown */
static My_Conf_Type *
_my_conf_new(void)
{
My_Conf_Type *my_conf = calloc(1, sizeof(My_Conf_Type));
if (!my_conf)
{
fprintf(stderr, "ERROR: could not calloc My_Conf_Type\n");
return NULL;
}
my_conf->version = 0x112233;
my_conf->enabled = EINA_TRUE;
return my_conf;
} /* _my_conf_new */
static void
_my_conf_free(My_Conf_Type *my_conf)
{
eina_stringshare_del(my_conf->name);
free(my_conf);
} /* _my_conf_free */
static My_Conf_Type *
_my_conf_load(const char *filename)
{
My_Conf_Type *my_conf;
Eet_File *ef = eet_open(filename, EET_FILE_MODE_READ);
if (!ef)
{
fprintf(stderr, "ERROR: could not open '%s' for read\n", filename);
return NULL;
}
my_conf = eet_data_read(ef, _my_conf_descriptor, MY_CONF_FILE_ENTRY);
if (!my_conf)
goto end;
if (my_conf->version < 0x112233)
{
fprintf(stderr,
"WARNING: version %#x was too old, upgrading it to %#x\n",
my_conf->version, 0x112233);
my_conf->version = 0x112233;
my_conf->enabled = EINA_TRUE;
}
end:
eet_close(ef);
return my_conf;
} /* _my_conf_load */
static Eina_Bool
_my_conf_save(const My_Conf_Type *my_conf,
const char *filename)
{
char tmp[PATH_MAX];
Eet_File *ef;
Eina_Bool ret;
unsigned int i, len;
struct stat st;
len = eina_strlcpy(tmp, filename, sizeof(tmp));
if (len + 12 >= (int)sizeof(tmp))
{
fprintf(stderr, "ERROR: file name is too big: %s\n", filename);
return EINA_FALSE;
}
i = 0;
do
{
snprintf(tmp + len, 12, ".%u", i);
i++;
}
while (stat(tmp, &st) == 0);
ef = eet_open(tmp, EET_FILE_MODE_WRITE);
if (!ef)
{
fprintf(stderr, "ERROR: could not open '%s' for write\n", tmp);
return EINA_FALSE;
}
ret = eet_data_write
(ef, _my_conf_descriptor, MY_CONF_FILE_ENTRY, my_conf, EINA_TRUE);
eet_close(ef);
if (ret)
{
unlink(filename);
rename(tmp, filename);
}
return ret;
} /* _my_conf_save */
int
main(int argc,
char *argv[])
{
My_Conf_Type *my_conf;
int ret = 0;
if (argc != 3)
{
fprintf(stderr, "Usage:\n\t%s <input> <output>\n\n", argv[0]);
return -1;
}
eina_init();
eet_init();
_my_conf_descriptor_init();
my_conf = _my_conf_load(argv[1]);
if (!my_conf)
{
printf("creating new configuration.\n");
my_conf = _my_conf_new();
if (!my_conf)
{
ret = -2;
goto end;
}
}
printf("My_Conf_Type:\n"
"\tversion: %#x\n"
"\tname...: '%s'\n"
"\tid.....: %d\n"
"\tenabled: %hhu\n",
my_conf->version,
my_conf->name ? my_conf->name : "",
my_conf->id,
my_conf->enabled);
if (!_my_conf_save(my_conf, argv[2]))
ret = -3;
_my_conf_free(my_conf);
end:
_my_conf_descriptor_shutdown();
eet_shutdown();
eina_shutdown();
return ret;
} /* main */