Simple data example
//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 */
Eet.h
The file that provides the eet functions.
Eina.h
Eina Utility library.
EET_T_UCHAR
#define EET_T_UCHAR
Data type: unsigned char.
Definition Eet.h:2602
EET_T_STRING
#define EET_T_STRING
Data type: char *.
Definition Eet.h:2606
eet_data_descriptor_free
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
eet_data_read
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:2379
EET_T_INT
#define EET_T_INT
Data type: int.
Definition Eet.h:2598
eet_data_descriptor_stream_new
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:2084
EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET
#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:3051
eet_data_write
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:2416
Eet_Data_Descriptor
struct _Eet_Data_Descriptor Eet_Data_Descriptor
Opaque handle that have information on a type members.
Definition Eet.h:2648
EET_T_UINT
#define EET_T_UINT
Data type: unsigned int.
Definition Eet.h:2604
Eet_Data_Descriptor_Class
struct _Eet_Data_Descriptor_Class Eet_Data_Descriptor_Class
Instructs Eet about memory management for different needs under serialization and parse process.
Definition Eet.h:2665
eet_close
EAPI Eet_Error eet_close(Eet_File *ef)
Closes an eet file handle and flush pending writes.
Definition eet_lib.c:1934
Eet_File
struct _Eet_File Eet_File
Opaque handle that defines an Eet file (or memory).
Definition Eet.h:527
eet_open
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:1525
EET_FILE_MODE_READ
@ EET_FILE_MODE_READ
File is read-only.
Definition Eet.h:479
EET_FILE_MODE_WRITE
@ EET_FILE_MODE_WRITE
File is write-only.
Definition Eet.h:480
eet_init
EAPI int eet_init(void)
Initializes the EET library.
Definition eet_lib.c:543
eet_shutdown
EAPI int eet_shutdown(void)
Shuts down the EET library.
Definition eet_lib.c:597
eina_shutdown
EINA_API int eina_shutdown(void)
Shuts down the Eina library.
Definition eina_main.c:379
eina_init
EINA_API int eina_init(void)
Initializes the Eina library.
Definition eina_main.c:291
eina_strlcpy
EINA_API size_t eina_strlcpy(char *dst, const char *src, size_t siz)
Copies a c-string to another.
Definition eina_str.c:317
eina_stringshare_del
EINA_API void eina_stringshare_del(Eina_Stringshare *str)
Notes that the given string has lost an instance.
Definition eina_stringshare.c:533
EINA_TRUE
#define EINA_TRUE
boolean value TRUE (numerical value 1)
Definition eina_types.h:539
EINA_FALSE
#define EINA_FALSE
boolean value FALSE (numerical value 0)
Definition eina_types.h:533
Eina_Bool
unsigned char Eina_Bool
Type to mimic a boolean.
Definition eina_types.h:527