Convenience functions to serialize and parse complex data structures to binary blobs.

While Eet core just handles binary blobs, it is often required to save some structured data of different types, such as strings, integers, lists, hashes and so on.

Eet can serialize and then parse data types given some construction instructions. These are defined in two levels:

Eet_Data_Descriptor_Class to tell generic memory handling, such as the size of the type, how to allocate memory, strings, lists, hashes and so on.

Eet_Data_Descriptor to tell inside such type, the members and their offsets inside the memory blob, their types and names. These members can be simple types or other Eet_Data_Descriptor, allowing hierarchical types to be defined.

Given that C provides no introspection, this process can be quite cumbersome, so we provide lots of macros and convenience functions to aid creating the types.

We make now a quick overview of some of the most commonly used elements of this part of the library. A simple example of a configuration system will work as a somewhat real life example that is still simple enough to follow. Only the relevant sections will be shown here, but you can get the full code here.

Ignoring the included headers, we'll begin by defining our configuration struct.

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;

When using Eet, you don't think in matters of what data the program needs to run and which you would like to store. It's all the same and if it makes more sense to keep them together, it's perfectly fine to do so. At the time of telling Eet how your data is comprised you can leave out the things that are runtime only and let Eet take care of the rest for you.

The key used to store the config follows, as well as the variable used to store our data descriptor. This last one is very important. It's the one thing that Eet will use to identify your data, both at the time of writing it to the file and when loading from it.

static const char MY_CONF_FILE_ENTRY[] = "config";
static Eet_Data_Descriptor *_my_conf_descriptor;

Now we'll see how to create this descriptor, so Eet knows how to handle our data later on. Begin our function by declaring an Eet_Data_Descriptor_Class, which is used to create the actual descriptor. This class contains the name of our data type, its size and several functions that dictate how Eet should handle memory to allocate the necessary bits to bring our data to life. You, as a user, will very hardly set this class' contents directly. The most common scenario is to use one of the provided macros that set it using the Eina data types, so that's what we'll be doing across all our examples.

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);

Now that we have our descriptor, we need to make it describe something. We do so by telling it which members of our struct we want it to know about and their types. The eet_data_descriptor_element_add() function takes care of this, but it's too cumbersome for normal use, so several macros are provided that make it easier to handle. Even with them, however, code can get very repetitive and it's not uncommon to define custom macros using them to save on typing.

#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 */

Now our descriptor knows about the parts of our structure that we are interesting in saving. You can see that not all of them are there, yet Eet will find those that need saving and do the right thing. When loading our data, any non-described fields in the structure will be zeroed, so there's no need to worry about garbage memory in them. Refer to the documentation of EET_DATA_DESCRIPTOR_ADD_BASIC to understand what our macro does.

We are done with our descriptor init function and it's proper to have the relevant shutdown. Proper coding guidelines indiciate that all memory allocated should be freed when the program ends, and since you will most likely keep your descriptor around for the life or your application, it's only right to free it at the end.

static void
_my_conf_descriptor_shutdown(void)
{
   eet_data_descriptor_free(_my_conf_descriptor);
} /* _my_conf_descriptor_shutdown */

Not listed here, but included in the full example are functions to create a blank configuration and free it. The first one will only be used when no file exists to load from, or nothing is found in it, but the latter is used regardless of where our data comes from. Unless you are reading direct data from the Eet file, you will be in charge of freeing anything loaded from it.

Now it's time to look at how we can load our config from some file. Begin by opening the Eet file normally.

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;
     }

And now we need to read the data from the file and decode it using our descriptor. Fortunately, that's all done in one single step.

   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;

And that's it for all Eet cares about. But since we are dealing with a common case, as is save and load of user configurations, the next fragment of code shows why we have a version field in our struct, and how you can use it to load older configuration files and update them as needed.

   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;
     }

Finally, close the file and return the newly loaded config data.

end:
   eet_close(ef);
   return my_conf;
} /* _my_conf_load */

Saving data is just as easy. The full version of the following function includes code to save to a temporary file first, so you can be sure not to lose all your data in the case of a failure mid-writing. You can look at it here.

static Eina_Bool
_my_conf_save(const My_Conf_Type *my_conf,
              const char         *filename)
{
   Eina_Bool ret;
   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);
   return ret;
} /* _my_conf_save */

To close, our main function, which doesn't do much. Just take some arguments from the command line with the name of the file to load and another one where to save again. If input file doesn't exist, a new config structure will be created and saved to our output file.

The following is a list of more advanced and detailed examples.

Functions
Eet_Data_Descriptor *	eet_data_descriptor_stream_new (const Eet_Data_Descriptor_Class *eddc)
Eet_Data_Descriptor *	eet_data_descriptor_file_new (const Eet_Data_Descriptor_Class *eddc)
Eina_Bool	eet_eina_stream_data_descriptor_class_set (Eet_Data_Descriptor_Class eddc, unsigned int eddc_size, const char name, int size)
Eina_Bool	eet_eina_file_data_descriptor_class_set (Eet_Data_Descriptor_Class eddc, unsigned int eddc_size, const char name, int size)
void	eet_data_descriptor_free (Eet_Data_Descriptor *edd)
	This function frees a data descriptor when it is not needed anymore.
const char *	eet_data_descriptor_name_get (const Eet_Data_Descriptor *edd)
	This function returns the name of a data descriptor.
void	eet_data_descriptor_element_add (Eet_Data_Descriptor edd, const char name, int type, int group_type, int offset, int count, const char counter_name, Eet_Data_Descriptor subtype)
	This function is an internal used by macros.
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.
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.
int	eet_data_text_dump (const void data_in, int size_in, Eet_Dump_Callback dumpfunc, void dumpdata)
	Dumps an eet encoded data structure into ascii text.
void *	eet_data_text_undump (const char text, int textlen, int size_ret)
	Takes an ascii encoding from eet_data_text_dump() and re-encode in binary.
int	eet_data_dump (Eet_File ef, const char name, Eet_Dump_Callback dumpfunc, void *dumpdata)
	Dumps an eet encoded data structure from an eet file into ascii text.
int	eet_data_undump (Eet_File ef, const char name, const char *text, int textlen, int compress)
	Takes an ascii encoding from eet_data_dump() and re-encode in binary.
void *	eet_data_descriptor_decode (Eet_Data_Descriptor edd, const void data_in, int size_in)
	Decodes a data structure from an arbitrary location in memory.
void *	eet_data_descriptor_encode (Eet_Data_Descriptor edd, const void data_in, int *size_ret)
	Encodes a dsata struct to memory and return that encoded data.
Typedefs
typedef struct _Eet_Data_Descriptor	Eet_Data_Descriptor
typedef struct _Eet_Data_Descriptor_Class	Eet_Data_Descriptor_Class
typedef int(*	Eet_Descriptor_Hash_Foreach_Callback_Callback )(void h, const char k, void dt, void fdt)
typedef void (	Eet_Descriptor_Mem_Alloc_Callback )(size_t size)
typedef void(*	Eet_Descriptor_Mem_Free_Callback )(void *mem)
typedef char (	Eet_Descriptor_Str_Alloc_Callback )(const char *str)
typedef void(*	Eet_Descriptor_Str_Free_Callback )(const char *str)
typedef void (	Eet_Descriptor_List_Next_Callback )(void *l)
typedef void (	Eet_Descriptor_List_Append_Callback )(void l, void d)
typedef void (	Eet_Descriptor_List_Data_Callback )(void *l)
typedef void (	Eet_Descriptor_List_Free_Callback )(void *l)
typedef void(*	Eet_Descriptor_Hash_Foreach_Callback )(void h, Eet_Descriptor_Hash_Foreach_Callback_Callback func, void fdt)
typedef void (	Eet_Descriptor_Hash_Add_Callback )(void h, const char k, void *d)
typedef void(*	Eet_Descriptor_Hash_Free_Callback )(void *h)
typedef const char (	Eet_Descriptor_Type_Get_Callback )(const void data, Eina_Bool unknow)
typedef Eina_Bool(*	Eet_Descriptor_Type_Set_Callback )(const char type, void data, Eina_Bool unknow)
typedef void (	Eet_Descriptor_Array_Alloc_Callback )(size_t size)
typedef void(*	Eet_Descriptor_Array_Free_Callback )(void *mem)
Defines
#define	EET_T_UNKNOW 0
#define	EET_T_CHAR 1
#define	EET_T_SHORT 2
#define	EET_T_INT 3
#define	EET_T_LONG_LONG 4
#define	EET_T_FLOAT 5
#define	EET_T_DOUBLE 6
#define	EET_T_UCHAR 7
#define	EET_T_USHORT 8
#define	EET_T_UINT 9
#define	EET_T_ULONG_LONG 10
#define	EET_T_STRING 11
#define	EET_T_INLINED_STRING 12
#define	EET_T_NULL 13
#define	EET_T_F32P32 14
#define	EET_T_F16P16 15
#define	EET_T_F8P24 16
#define	EET_T_VALUE 17
#define	EET_T_LAST 18
#define	EET_G_UNKNOWN 100
#define	EET_G_ARRAY 101
#define	EET_G_VAR_ARRAY 102
#define	EET_G_LIST 103
#define	EET_G_HASH 104
#define	EET_G_UNION 105
#define	EET_G_VARIANT 106
#define	EET_G_UNKNOWN_NESTED 107
#define	EET_G_LAST 108
#define	EET_I_LIMIT 128
#define	EET_DATA_DESCRIPTOR_CLASS_VERSION 4
#define	EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(clas, type) (eet_eina_stream_data_descriptor_class_set(clas, sizeof (*(clas)), # type, sizeof(type)))
#define	EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET(clas, type) (eet_eina_file_data_descriptor_class_set(clas, sizeof (*(clas)), # type, sizeof(type)))
#define	EET_DATA_DESCRIPTOR_ADD_BASIC(edd, struct_type, name, member, type)
	Adds a basic data element to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_SUB(edd, struct_type, name, member, subtype)
	Adds a sub-element type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_SUB_NESTED(edd, struct_type, name, member, subtype)
	Adds a nested sub-element type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_LIST(edd, struct_type, name, member, subtype)
	Adds a linked list type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_LIST_STRING(edd, struct_type, name, member)
	Adds a linked list of string to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_HASH(edd, struct_type, name, member, subtype)
	Adds a hash type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_HASH_STRING(edd, struct_type, name, member)
	Adds a hash of string to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_BASIC_ARRAY(edd, struct_type, name, member, type)
	Adds an array of basic data elements to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_BASIC_VAR_ARRAY(edd, struct_type, name, member, type)
	Adds a variable array of basic data elements to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_ARRAY(edd, struct_type, name, member, subtype)
	Adds a fixed size array type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_VAR_ARRAY(edd, struct_type, name, member, subtype)
	Adds a variable size array type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_VAR_ARRAY_STRING(edd, struct_type, name, member)
	Adds a variable size array type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_UNION(edd, struct_type, name, member, type_member, unified_type)
	Adds an union type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_VARIANT(edd, struct_type, name, member, type_member, unified_type)
	Adds a automatically selectable type to a data descriptor.
#define	EET_DATA_DESCRIPTOR_ADD_MAPPING(unified_type, name, subtype)
	Adds a mapping to a data descriptor that will be used by union, variant or inherited type.
#define	EET_DATA_DESCRIPTOR_ADD_MAPPING_BASIC(unified_type, name, basic_type)
	Adds a mapping of a basic type to a data descriptor that will be used by a union type.

Define Documentation

#define EET_DATA_DESCRIPTOR_ADD_ARRAY	(	edd,
		struct_type,
		name,
		member,
		subtype
	)

Value:

do {                                                                           \
       struct_type ___ett;                                                       \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_ARRAY,     \
                                       (char *)(& (___ett.member)) -             \
                                       (char *)(& (___ett)),                     \
                                       /* 0,  */ sizeof(___ett.member) /         \
                                       sizeof(___ett.member[0]), NULL, subtype); \
    } while (0)

Adds a fixed size array type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
subtype	The type of hash member to add.

This macro lets you easily add a fixed size array of other data types. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(), with the subtype being the exception. This must be the data descriptor of the element that is in each member of the array to be stored. The array must be defined with a fixed size in the declaration of the struct containing it.

Since (EFL) :: 1.0.2

#define EET_DATA_DESCRIPTOR_ADD_BASIC	(	edd,
		struct_type,
		name,
		member,
		type
	)

Value:

do {                                                                      \
       struct_type ___ett;                                                  \
       eet_data_descriptor_element_add(edd, name, type, EET_G_UNKNOWN,      \
                                       (char *)(& (___ett.member)) -        \
                                       (char *)(& (___ett)),                \
                                       0, /* 0,  */ NULL, NULL);            \
    } while(0)

Adds a basic data element to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
type	The type of the member to encode.

This macro is a convenience macro provided to add a member to the data descriptor edd. The type of the structure is provided as the struct_type parameter (for example: struct my_struct). The name parameter defines a string that will be used to uniquely name that member of the struct (it is suggested to use the struct member itself). The member parameter is the actual struct member itself (for example: values), and type is the basic data type of the member which must be one of: EET_T_CHAR, EET_T_SHORT, EET_T_INT, EET_T_LONG_LONG, EET_T_FLOAT, EET_T_DOUBLE, EET_T_UCHAR, EET_T_USHORT, EET_T_UINT, EET_T_ULONG_LONG or EET_T_STRING.

Since (EFL) :: 1.0.0

Examples:: eet-data-file_descriptor_02.c.

#define EET_DATA_DESCRIPTOR_ADD_BASIC_ARRAY	(	edd,
		struct_type,
		name,
		member,
		type
	)

Value:

do {                                                                            \
       struct_type ___ett;                                                        \
       eet_data_descriptor_element_add(edd, name, type, EET_G_ARRAY,              \
                                       (char *)(& (___ett.member)) -              \
                                       (char *)(& (___ett)),                      \
                                       sizeof(___ett.member) /                    \
                                       sizeof(___ett.member[0]),                  \
                                       NULL, NULL);                               \
    } while(0)

Adds an array of basic data elements to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
type	The type of the member to encode.

This macro lets you easily add a fixed size array of basic data types. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(). The array must be defined with a fixed size in the declaration of the struct containing it.

Since (EFL) :: 1.5.0

#define EET_DATA_DESCRIPTOR_ADD_BASIC_VAR_ARRAY	(	edd,
		struct_type,
		name,
		member,
		type
	)

Value:

do {                                                                                \
       struct_type ___ett;                                                            \
       eet_data_descriptor_element_add(edd, name, type, EET_G_VAR_ARRAY,              \
                                       (char *)(& (___ett.member)) -                  \
                                       (char *)(& (___ett)),                          \
                                       (char *)(& (___ett.member ## _count)) -        \
                                       (char *)(& (___ett)),                          \
                                       NULL,                                          \
                                       NULL);                                         \
    } while(0)

Adds a variable array of basic data elements to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
type	The type of the member to encode.

This macro lets you easily add a variable size array of basic data types. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(). This assumes you have a struct member (of type EET_T_INT) called member_count (note the _count appended to the member) that holds the number of items in the array. This array will be allocated separately to the struct it is in.

Since (EFL) :: 1.6.0

#define EET_DATA_DESCRIPTOR_ADD_HASH	(	edd,
		struct_type,
		name,
		member,
		subtype
	)

Value:

do {                                                                        \
       struct_type ___ett;                                                    \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_HASH,   \
                                       (char *)(& (___ett.member)) -          \
                                       (char *)(& (___ett)),                  \
                                       0, /* 0,  */ NULL, subtype);           \
    } while (0)

Adds a hash type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
subtype	The type of hash member to add.

This macro lets you easily add a hash of other data types. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(), with the subtype being the exception. This must be the data descriptor of the element that is in each member of the hash to be stored. The hash keys must be strings.

Since (EFL) :: 1.0.0

Examples:: eet-data-file_descriptor_01.c.

#define EET_DATA_DESCRIPTOR_ADD_HASH_STRING	(	edd,
		struct_type,
		name,
		member
	)

Value:

do {                                                                      \
       struct_type ___ett;                                                  \
       eet_data_descriptor_element_add(edd, name, EET_T_STRING, EET_G_HASH, \
                                       (char *)(& (___ett.member)) -        \
                                       (char *)(& (___ett)),                \
                                       0, /* 0,  */ NULL, NULL);            \
    } while (0)

Adds a hash of string to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.

This macro lets you easily add a hash of string elements. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_HASH().

Since (EFL) :: 1.3.4

#define EET_DATA_DESCRIPTOR_ADD_LIST	(	edd,
		struct_type,
		name,
		member,
		subtype
	)

Value:

do {                                                                        \
       struct_type ___ett;                                                    \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_LIST,   \
                                       (char *)(& (___ett.member)) -          \
                                       (char *)(& (___ett)),                  \
                                       0, /* 0,  */ NULL, subtype);           \
    } while (0)

Adds a linked list type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
subtype	The type of linked list member to add.

This macro lets you easily add a linked list of other data types. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(), with the subtype being the exception. This must be the data descriptor of the element that is in each member of the linked list to be stored.

Since (EFL) :: 1.0.0

Examples:: eet-data-file_descriptor_01.c, eet-data-file_descriptor_02.c, and eet-data-nested.c.

#define EET_DATA_DESCRIPTOR_ADD_LIST_STRING	(	edd,
		struct_type,
		name,
		member
	)

Value:

do {                                                                      \
       struct_type ___ett;                                                  \
       eet_data_descriptor_element_add(edd, name, EET_T_STRING, EET_G_LIST, \
                                       (char *)(& (___ett.member)) -        \
                                       (char *)(& (___ett)),                \
                                       0, /* 0,  */ NULL, NULL);            \
    } while (0)

Adds a linked list of string to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.

This macro lets you easily add a linked list of char *. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC().

Since (EFL) :: 1.5.0

#define EET_DATA_DESCRIPTOR_ADD_MAPPING	(	unified_type,
		name,
		subtype
	)

Value:

eet_data_descriptor_element_add(unified_type,                      \
                                  name,                              \
                                  EET_T_UNKNOW,                      \
                                  EET_G_UNKNOWN,                     \
                                  0,                                 \
                                  0,                                 \
                                  NULL,                              \
                                  subtype)

Adds a mapping to a data descriptor that will be used by union, variant or inherited type.

Parameters:

unified_type	The data descriptor to add the mapping to.
name	The string name to get/set type.
subtype	The matching data descriptor.

Since (EFL) :: 1.2.4

See also:: Eet_Data_Descriptor_Class

Examples:: eet-data-file_descriptor_02.c.

#define EET_DATA_DESCRIPTOR_ADD_MAPPING_BASIC	(	unified_type,
		name,
		basic_type
	)

Value:

eet_data_descriptor_element_add(unified_type,                               \
                                  name,                                       \
                                  basic_type,                                 \
                                  EET_G_UNKNOWN,                              \
                                  0,                                          \
                                  0,                                          \
                                  NULL,                                       \
                                  NULL)

Adds a mapping of a basic type to a data descriptor that will be used by a union type.

Parameters:

unified_type	The data descriptor to add the mapping to.
name	The string name to get/set type.
basic_type	The matching basic type.

Since (EFL) :: 1.8

See also:: Eet_Data_Descriptor_Class

Examples:: eet-data-file_descriptor_02.c.

#define EET_DATA_DESCRIPTOR_ADD_SUB	(	edd,
		struct_type,
		name,
		member,
		subtype
	)

Value:

do {                                                                         \
       struct_type ___ett;                                                     \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_UNKNOWN, \
                                       (char *)(& (___ett.member)) -           \
                                       (char *)(& (___ett)),                   \
                                       0, /* 0,  */ NULL, subtype);            \
    } while (0)

Adds a sub-element type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
subtype	The type of sub-type struct to add.

This macro lets you easily add a sub-type (a struct that's pointed to by this one). All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(), with the subtype being the exception. This must be the data descriptor of the struct that is pointed to by this element.

Since (EFL) :: 1.0.0

#define EET_DATA_DESCRIPTOR_ADD_SUB_NESTED	(	edd,
		struct_type,
		name,
		member,
		subtype
	)

Value:

do {                                                                         \
       struct_type ___ett;                                                     \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_UNKNOWN_NESTED, \
                                       (char *)(& (___ett.member)) -           \
                                       (char *)(& (___ett)),                   \
                                       0, /* 0,  */ NULL, subtype);            \
    } while (0)

Adds a nested sub-element type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
subtype	The type of sub-type struct to add.

This macro lets you easily add a sub-type: a struct that is nested into this one. If your data is pointed by this element instead of being nested, you should use EET_DATA_DESCRIPTOR_ADD_SUB(). All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_SUB().

Since (EFL) :: 1.8.0

#define EET_DATA_DESCRIPTOR_ADD_UNION	(	edd,
		struct_type,
		name,
		member,
		type_member,
		unified_type
	)

Value:

do {                                                                                           \
       struct_type ___ett;                                                                       \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_UNION,                     \
                                       (char *)(& (___ett.member)) -                             \
                                       (char *)(& (___ett)),                                     \
                                       (char *)(& (___ett.type_member)) -                        \
                                       (char *)(& (___ett)),                                     \
                                       NULL, unified_type);                                      \
    } while (0)

Adds an union type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
type_member	The member that give hints on what is in the union.
unified_type	Describe all possible type the union could handle.

This macro lets you easily add an union with a member that specify what is inside. The unified_type is an Eet_Data_Descriptor, but only the entry that match the name returned by type_get will be used for each serialized data. The type_get and type_set callback of unified_type should be defined.

Since (EFL) :: 1.2.4

See also:: Eet_Data_Descriptor_Class

Examples:: eet-data-file_descriptor_02.c.

#define EET_DATA_DESCRIPTOR_ADD_VAR_ARRAY	(	edd,
		struct_type,
		name,
		member,
		subtype
	)

Value:

do {                                                                             \
       struct_type ___ett;                                                         \
       eet_data_descriptor_element_add(edd,                                        \
                                       name,                                       \
                                       EET_T_UNKNOW,                               \
                                       EET_G_VAR_ARRAY,                            \
                                       (char *)(& (___ett.member)) -               \
                                       (char *)(& (___ett)),                       \
                                       (char *)(& (___ett.member ## _count)) -     \
                                       (char *)(& (___ett)),                       \
                                       /* 0,  */ NULL,                             \
                                       subtype);                                   \
    } while (0)

Adds a variable size array type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
subtype	The type of hash member to add.

This macro lets you easily add a variable size array of other data types. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC(), with the subtype being the exception. This must be the data descriptor of the element that is in each member of the array to be stored. This assumes you have a struct member (of type EET_T_INT) called member_count (note the _count appended to the member) that holds the number of items in the array. This array will be allocated separately to the struct it is in.

Since (EFL) :: 1.0.2

Examples:: eet-data-file_descriptor_01.c.

#define EET_DATA_DESCRIPTOR_ADD_VAR_ARRAY_STRING	(	edd,
		struct_type,
		name,
		member
	)

Value:

do {                                                                           \
       struct_type ___ett;                                                       \
       eet_data_descriptor_element_add(edd,                                      \
                                       name,                                     \
                                       EET_T_STRING,                             \
                                       EET_G_VAR_ARRAY,                          \
                                       (char *)(& (___ett.member)) -             \
                                       (char *)(& (___ett)),                     \
                                       (char *)(& (___ett.member ## _count)) -   \
                                       (char *)(& (___ett)),                     \
                                       /* 0,  */ NULL,                           \
                                       NULL);                                    \
    } while (0)

Adds a variable size array type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.

This macro lets you easily add a variable size array of strings. All the parameters are the same as for EET_DATA_DESCRIPTOR_ADD_BASIC().

Since (EFL) :: 1.4.0

#define EET_DATA_DESCRIPTOR_ADD_VARIANT	(	edd,
		struct_type,
		name,
		member,
		type_member,
		unified_type
	)

Value:

do {                                                                                             \
       struct_type ___ett;                                                                         \
       eet_data_descriptor_element_add(edd, name, EET_T_UNKNOW, EET_G_VARIANT,                     \
                                       (char *)(& (___ett.member)) -                               \
                                       (char *)(& (___ett)),                                       \
                                       (char *)(& (___ett.type_member)) -                          \
                                       (char *)(& (___ett)),                                       \
                                       NULL, unified_type);                                        \
    } while (0)

Adds a automatically selectable type to a data descriptor.

Parameters:

edd	The data descriptor to add the type to.
struct_type	The type of the struct.
name	The string name to use to encode/decode this member (must be a constant global and never change).
member	The struct member itself to be encoded.
type_member	The member that give hints on what is in the union.
unified_type	Describe all possible type the union could handle.

This macro lets you easily define what the content of member points to depending of the content of type_member. The type_get and type_set callback of unified_type should be defined. If the the type is not know at the time of restoring it, eet will still call type_set of unified_type but the pointer will be set to a serialized binary representation of what eet know. This make it possible, to save this pointer again by just returning the string given previously and telling it by setting unknow to EINA_TRUE.

Since (EFL) :: 1.2.4

See also:: Eet_Data_Descriptor_Class

Examples:: eet-data-file_descriptor_02.c.

#define EET_DATA_DESCRIPTOR_CLASS_VERSION 4

The version of Eet_Data_Descriptor_Class at the time of the distribution of the sources. One should define this to its version member so it is compatible with abi changes, or at least will not crash with them.

Examples:: eet-data-file_descriptor_02.c.

#define EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET	(	clas,
		type
	)	(eet_eina_file_data_descriptor_class_set(clas, sizeof (*(clas)), # type, sizeof(type)))

This macro is an helper that set all the parameter of an Eet_Data_Descriptor_Class correctly when you use Eina data type with file.

Parameters:

clas	The Eet_Data_Descriptor_Class you want to set.
type	The type of the structure described by this class.

Returns:: EINA_TRUE if the structure was correctly set (The only reason that could make it fail is if you did give wrong parameter).

See also:: eet_data_descriptor_file_new

Since (EFL) :: 1.2.3

Examples:: eet-data-file_descriptor_01.c, and eet-data-file_descriptor_02.c.

#define EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET	(	clas,
		type
	)	(eet_eina_stream_data_descriptor_class_set(clas, sizeof (*(clas)), # type, sizeof(type)))

This macro is an helper that set all the parameter of an Eet_Data_Descriptor_Class correctly when you use Eina data type with stream.

Parameters:

clas	The Eet_Data_Descriptor_Class you want to set.
type	The type of the structure described by this class.

Returns:: EINA_TRUE if the structure was correctly set (The only reason that could make it fail is if you did give wrong parameter).

See also:: eet_data_descriptor_stream_new

Since (EFL) :: 1.2.3

Examples:: eet-data-nested.c, and eet-data-simple.c.

#define EET_G_ARRAY 101

Fixed size array group type

#define EET_G_HASH 104

Hash table group type

#define EET_G_LAST 108

Last group type

#define EET_G_LIST 103

Linked list group type

#define EET_G_UNION 105

Union group type

#define EET_G_UNKNOWN 100

Unknown group data encoding type

#define EET_G_UNKNOWN_NESTED 107

Unknown nested group type.

Since (EFL) :: 1.8

#define EET_G_VAR_ARRAY 102

Variable size array group type

#define EET_G_VARIANT 106

Selectable subtype group

#define EET_I_LIMIT 128

Other type exist but are reserved for internal purpose.

#define EET_T_CHAR 1

Data type: char

#define EET_T_DOUBLE 6

Data type: double

Examples:: eet-data-file_descriptor_02.c.

#define EET_T_F16P16 15

Data type: fixed point 16.16

#define EET_T_F32P32 14

Data type: fixed point 32.32

#define EET_T_F8P24 16

Data type: fixed point 8.24

#define EET_T_FLOAT 5

Data type: float

Examples:: eet-data-file_descriptor_02.c.

#define EET_T_INLINED_STRING 12

Data type: char * (but compressed inside the resulting eet)

#define EET_T_INT 3

Data type: int

Examples:: eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

#define EET_T_LAST 18

Last data type

#define EET_T_LONG_LONG 4

Data type: long long

#define EET_T_NULL 13

Data type: (void *) (only use it if you know why)

#define EET_T_SHORT 2

Data type: short

#define EET_T_STRING 11

Data type: char *

Examples:: eet-data-file_descriptor_01.c, eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

#define EET_T_UCHAR 7

Data type: unsigned char

Examples:: eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

#define EET_T_UINT 9

Data type: unsigned int

Examples:: eet-data-file_descriptor_01.c, eet-data-nested.c, and eet-data-simple.c.

#define EET_T_ULONG_LONG 10

Data type: unsigned long long

Examples:: eet-data-file_descriptor_02.c.

#define EET_T_UNKNOW 0

Unknown data encoding type

#define EET_T_USHORT 8

Data type: unsigned short

#define EET_T_VALUE 17

Data type: pointer to Eina_Value

Since (EFL) :: 1.8

Typedef Documentation

Eet_Data_Descriptor

Opaque handle that have information on a type members.

Descriptors are created using an Eet_Data_Descriptor_Class, and they describe the contents of the structure that will be serialized by Eet. Not all members need be described by it, just those that should be handled by Eet. This way it's possible to have one structure with both data to be saved to a file, like application configuration, and runtime information that would be meaningless to store, but is appropriate to keep together during the program execution. The members are added by means of EET_DATA_DESCRIPTOR_ADD_BASIC(), EET_DATA_DESCRIPTOR_ADD_SUB(), EET_DATA_DESCRIPTOR_ADD_LIST(), EET_DATA_DESCRIPTOR_ADD_HASH() or eet_data_descriptor_element_add().

See also:: eet_data_descriptor_stream_new(); eet_data_descriptor_file_new(); eet_data_descriptor_free()

Eet_Data_Descriptor_Class

Instructs Eet about memory management for different needs under serialization and parse process.

Callback protoype for Eet_Dump

Parameters:

data	To passe to the callback
str	The string to dump

Eet_Descriptor_Array_Alloc_Callback

Callback prototype for Eet_Descriptor_Array_Alloc

Parameters:

size	The size of the array

Eet_Descriptor_Array_Free_Callback

Callback prototype for Eet_Descriptor_Array_Free

Parameters:

size	The size of the array

Eet_Descriptor_Hash_Add_Callback

Callback prototype for Eet_Descriptor_Hash_Add

Parameters:

h	The hash
k	The key
d	The data to associate with the 'k' key

Eet_Descriptor_Hash_Foreach_Callback

Callback for Eet_Descriptor_Hash_Foreach

Parameters:

h	The hash
func	The function callback to call on each iteration
fdt	The data to pass to the callbac setted in param func

Eet_Descriptor_Hash_Foreach_Callback_Callback

Callback prototype for Eet_Descriptor_Hash_Foreach_Callback

Parameters:

h	The hash
k	The key
dt	The data
fdt	The data passed to the callback

Returns:: An integer

Eet_Descriptor_Hash_Free_Callback

Callback prototype for Eet_Descriptor_Hash_Free

Parameters:

h	The hash to free

Eet_Descriptor_List_Append_Callback

Callback prototype for Eet_Descriptor_List_Append

Parameters:

l	Must be a pointer to the list
d	The data to append to the list

Returns:: Must be a pointer to the list

Eet_Descriptor_List_Data_Callback

Callback prototype for Eet_Descriptor_List_Data

Parameters:

l	Must be a pointer to the list

Returns:: Must be a pointer to the list

Eet_Descriptor_List_Free_Callback

Callback prototype for Eet_Descriptor_List_Free

Parameters:

l	Must be a pointer to the list to free

Eet_Descriptor_List_Next_Callback

Callback prototype for Eet_Descriptor_List_Next

Parameters:

l	Must be a pointer to the list

Returns:: Must be a pointer to the list

Eet_Descriptor_Mem_Alloc_Callback

Callback prototype for Eet_Descriptor_Mem_Alloc.

Parameters:

size	Is the size of memory to alloc on call of the callback

Eet_Descriptor_Mem_Free_Callback

Callback prototype for Eet_Descriptor_Mem_Alloc

Parameters:

mem	Must be a pointer to free on call of the callback

Eet_Descriptor_Str_Alloc_Callback

Callback prototype for Eet_Descriptor_Str_Alloc

Parameters:

str	Must be the string to alloc

Returns:: have Must be an allocated char * for the given string

Callback prototype for Eet_Descriptor_Str_Alloc

Parameters:

str	The string to allocate

Returns:: An allocated pointer to the string

Eet_Descriptor_Str_Free_Callback

Callback prototype for Eet_Descriptor_Str_Free

Parameters:

str	Must be an allocated string to free

Callback prototype for Eet_Descriptor_Str_Free

Parameters:

str	The string to free

Eet_Descriptor_Type_Get_Callback

Callback prototype for Eet_Descriptor_Type_Get

Parameters:

data	Data to pass to the callback
unknow	Eina_Bool __FIXME__

Eet_Descriptor_Type_Set_Callback

Callback prototype for Eet_Descriptor_Type_Set

Parameters:

type	The type to set
data	To pass to the callback
unknow	Eina_Bool __FIXME__

Function Documentation

void* eet_data_descriptor_decode	(	Eet_Data_Descriptor *	edd,
		const void *	data_in,
		int	size_in
	)

Decodes a data structure from an arbitrary location in memory.

Parameters:

edd	The data descriptor to use when decoding.
data_in	The pointer to the data to decode into a struct.
size_in	The size of the data pointed to in bytes.

Returns:: NULL on failure, or a valid decoded struct pointer on success.

This function will decode a data structure that has been encoded using eet_data_descriptor_encode(), and return a data structure with all its elements filled out, if successful, or NULL on failure.

The data to be decoded is stored at the memory pointed to by data_in, and is described by the descriptor pointed to by edd. The data size is passed in as the value to size_in, ande must be greater than 0 to succeed.

This function is useful for decoding data structures delivered to the application by means other than an eet file, such as an IPC or socket connection, raw files, shared memory etc.

Please see eet_data_read() for more information.

See also:: eet_data_descriptor_decode_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

void eet_data_descriptor_element_add	(	Eet_Data_Descriptor *	edd,
		const char *	name,
		int	type,
		int	group_type,
		int	offset,
		int	count,
		const char *	counter_name,
		Eet_Data_Descriptor *	subtype
	)

This function is an internal used by macros.

This function is used by macros EET_DATA_DESCRIPTOR_ADD_BASIC(), EET_DATA_DESCRIPTOR_ADD_SUB() and EET_DATA_DESCRIPTOR_ADD_LIST(). It is complex to use by hand and should be left to be used by the macros, and thus is not documented.

Parameters:

edd	The data descriptor handle to add element (member).
name	The name of element to be serialized.
type	The type of element to be serialized, like EET_T_INT. If EET_T_UNKNOW, then it is considered to be a group, list or hash.
group_type	If element type is EET_T_UNKNOW, then the `group_type` will specify if it is a list (EET_G_LIST), array (EET_G_ARRAY) and so on. If EET_G_UNKNOWN, then the member is a subtype (pointer to another type defined by another Eet_Data_Descriptor).
offset	byte offset inside the source memory to be serialized.
count	number of elements (if EET_G_ARRAY or EET_G_VAR_ARRAY).
counter_name	variable that defines the name of number of elements.
subtype	If contains a subtype, then its data descriptor.

Since (EFL) :: 1.0.0

Since :: 3.0

void* eet_data_descriptor_encode	(	Eet_Data_Descriptor *	edd,
		const void *	data_in,
		int *	size_ret
	)

Encodes a dsata struct to memory and return that encoded data.

Parameters:

edd	The data descriptor to use when encoding.
data_in	The pointer to the struct to encode into data.
size_ret	pointer to the an int to be filled with the decoded size.

Returns:: NULL on failure, or a valid encoded data chunk on success.

This function takes a data structutre in memory and encodes it into a serialised chunk of data that can be decoded again by eet_data_descriptor_decode(). This is useful for being able to transmit data structures across sockets, pipes, IPC or shared file mechanisms, without having to worry about memory space, machine type, endianness etc.

The parameter edd must point to a valid data descriptor, and data_in must point to the right data structure to encode. If not, the encoding may fail.

On success a non NULL valid pointer is returned and what size_ret points to is set to the size of this decoded data, in bytes. When the encoded data is no longer needed, call free() on it. On failure NULL is returned and what size_ret points to is set to 0.

Please see eet_data_write() for more information.

See also:: eet_data_descriptor_encode_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

Eet_Data_Descriptor* eet_data_descriptor_file_new ( const Eet_Data_Descriptor_Class * eddc )

This function creates a new data descriptor and returns a handle to the new data descriptor. On creation it will be empty, containing no contents describing anything other than the shell of the data structure.

Parameters:

eddc	The class from where to create the data descriptor.

Returns:: A handle to the new data descriptor.

You add structure members to the data descriptor using the macros EET_DATA_DESCRIPTOR_ADD_BASIC(), EET_DATA_DESCRIPTOR_ADD_SUB() and EET_DATA_DESCRIPTOR_ADD_LIST(), depending on what type of member you are adding to the description.

Once you have described all the members of a struct you want loaded or saved, eet can load and save those members for you, encode them into endian-independent serialised data chunks for transmission across a a network or more.

This function uses str_direct_alloc and str_direct_free. It is useful when the eet_data you are reading come from a file and have a dictionary. This will reduce memory use and improve the possibility for the OS to page this string out. However, the load speed and memory saving comes with some drawbacks to keep in mind. If you never modify the contents of the structures loaded from the file, all you need to remember is that closing the eet file will make the strings go away. On the other hand, should you need to free a string, before doing so you have to verify that it's not part of the eet dictionary. You can do this in the following way, assuming ef is a valid Eet_File and str is a string loaded from said file.

 void eet_string_free(Eet_File *ef, const char *str)
 {
    Eet_Dictionary *dict = eet_dictionary_get(ef);
    if (dict && eet_dictionary_string_check(dict, str))
      {
         // The file contains a dictionary and the given string is a part of
         // of it, so we can't free it, just return.
         return;
      }
    // We assume eina_stringshare was used on the descriptor
    eina_stringshare_del(str);
 }

Since (EFL) :: 1.2.3

Since :: 3.0

Examples:: eet-data-file_descriptor_01.c, and eet-data-file_descriptor_02.c.

void eet_data_descriptor_free ( Eet_Data_Descriptor * edd )

This function frees a data descriptor when it is not needed anymore.

Parameters:

edd	The data descriptor to free.

This function takes a data descriptor handle as a parameter and frees all data allocated for the data descriptor and the handle itself. After this call the descriptor is no longer valid.

Since (EFL) :: 1.0.0

Since :: 3.0

Examples:: eet-data-file_descriptor_01.c, eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

const char* eet_data_descriptor_name_get ( const Eet_Data_Descriptor * edd )

This function returns the name of a data descriptor.

Since (EFL) :: 1.8.0

Since :: 3.0

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. On creation it will be empty, containing no contents describing anything other than the shell of the data structure.

Parameters:

eddc	The class from where to create the data descriptor.

Returns:: A handle to the new data descriptor.

You add structure members to the data descriptor using the macros EET_DATA_DESCRIPTOR_ADD_BASIC(), EET_DATA_DESCRIPTOR_ADD_SUB() and EET_DATA_DESCRIPTOR_ADD_LIST(), depending on what type of member you are adding to the description.

Once you have described all the members of a struct you want loaded or saved, eet can load and save those members for you, encode them into endian-independent serialised data chunks for transmission across a network or more.

This function specially ignores str_direct_alloc and str_direct_free. It is useful when the eet_data you are reading doesn't have a dictionary, like network stream or IPC. It also mean that all string will be allocated and duplicated in memory.

Since (EFL) :: 1.2.3

Since :: 3.0

Examples:: eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

int eet_data_dump	(	Eet_File *	ef,
		const char *	name,
		Eet_Dump_Callback	dumpfunc,
		void *	dumpdata
	)

Dumps an eet encoded data structure from an eet file into ascii text.

Parameters:

ef	A valid eet file handle.
name	Name of the entry. eg: "/base/file_i_want".
dumpfunc	The function to call passed a string when new data is converted to text
dumpdata	The data to pass to the `dumpfunc` callback.

Returns:: 1 on success, 0 on failure

This function will take an open and valid eet file from eet_open() request the data encoded by eet_data_descriptor_encode() corresponding to the key name and convert it into human readable ascii text. It does this by calling the dumpfunc callback for all new text that is generated. This callback should append to any existing text buffer and will be passed the pointer dumpdata as a parameter as well as a string with new text to be appended.

See also:: eet_data_dump_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

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.

Parameters:

ef	The eet file handle to read from.
edd	The data descriptor handle to use when decoding.
name	The key the data is stored under in the eet file.

Returns:: A pointer to the decoded data structure.

This function decodes a data structure stored in an eet file, returning a pointer to it if it decoded successfully, or NULL on failure. This can save a programmer dozens of hours of work in writing configuration file parsing and writing code, as eet does all that work for the program and presents a program-friendly data structure, just as the programmer likes. Eet can handle members being added or deleted from the data in storage and safely zero-fills unfilled members if they were not found in the data. It checks sizes and headers whenever it reads data, allowing the programmer to not worry about corrupt data.

Once a data structure has been described by the programmer with the fields they wish to save or load, storing or retrieving a data structure from an eet file, or from a chunk of memory is as simple as a single function call.

See also:: eet_data_read_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

Examples:: eet-data-file_descriptor_01.c, eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

int eet_data_text_dump	(	const void *	data_in,
		int	size_in,
		Eet_Dump_Callback	dumpfunc,
		void *	dumpdata
	)

Dumps an eet encoded data structure into ascii text.

Parameters:

data_in	The pointer to the data to decode into a struct.
size_in	The size of the data pointed to in bytes.
dumpfunc	The function to call passed a string when new data is converted to text
dumpdata	The data to pass to the `dumpfunc` callback.

Returns:: 1 on success, 0 on failure

This function will take a chunk of data encoded by eet_data_descriptor_encode() and convert it into human readable ascii text. It does this by calling the dumpfunc callback for all new text that is generated. This callback should append to any existing text buffer and will be passed the pointer dumpdata as a parameter as well as a string with new text to be appended.

Example:

 void output(void *data, const char *string)
 {
   printf("%s", string);
 }

 void dump(const char *file)
 {
   FILE *f;
   int len;
   void *data;

   f = fopen(file, "rb");
   fseek(f, 0, SEEK_END);
   len = ftell(f);
   rewind(f);
   data = malloc(len);
   fread(data, len, 1, f);
   fclose(f);
   eet_data_text_dump(data, len, output, NULL);
 }

See also:: eet_data_text_dump_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

void* eet_data_text_undump	(	const char *	text,
		int	textlen,
		int *	size_ret
	)

Takes an ascii encoding from eet_data_text_dump() and re-encode in binary.

Parameters:

text	The pointer to the string data to parse and encode.
textlen	The size of the string in bytes (not including 0 byte terminator).
size_ret	This gets filled in with the encoded data blob size in bytes.

Returns:: The encoded data on success, NULL on failure.

This function will parse the string pointed to by text and return an encoded data lump the same way eet_data_descriptor_encode() takes an in-memory data struct and encodes into a binary blob. text is a normal C string.

See also:: eet_data_text_undump_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

int eet_data_undump	(	Eet_File *	ef,
		const char *	name,
		const char *	text,
		int	textlen,
		int	compress
	)

Takes an ascii encoding from eet_data_dump() and re-encode in binary.

Parameters:

ef	A valid eet file handle.
name	Name of the entry. eg: "/base/file_i_want".
text	The pointer to the string data to parse and encode.
textlen	The size of the string in bytes (not including 0 byte terminator).
compress	Compression flags (1 == compress, 0 = don't compress).

Returns:: 1 on success, 0 on failure

This function will parse the string pointed to by text, encode it the same way eet_data_descriptor_encode() takes an in-memory data struct and encodes into a binary blob.

The data (optionally compressed) will be in ram, pending a flush to disk (it will stay in ram till the eet file handle is closed though).

See also:: eet_data_undump_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

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.

Parameters:

ef	The eet file handle to write to.
edd	The data descriptor to use when encoding.
name	The key to store the data under in the eet file.
data	A pointer to the data structure to save and encode.
compress	Compression flags for storage.

Returns:: bytes Written on successful write, 0 on failure.

This function is the reverse of eet_data_read(), saving a data structure to an eet file. The file must have been opening in write mode and the data will be kept in memory until the file is either closed or eet_sync() is called to flush any unwritten changes.

See also:: eet_data_write_cipher()

Since (EFL) :: 1.0.0

Since :: 3.0

Examples:: eet-data-file_descriptor_01.c, eet-data-file_descriptor_02.c, eet-data-nested.c, and eet-data-simple.c.

Eina_Bool eet_eina_file_data_descriptor_class_set	(	Eet_Data_Descriptor_Class *	eddc,
		unsigned int	eddc_size,
		const char *	name,
		int	size
	)

This function is an helper that set all the parameter of an Eet_Data_Descriptor_Class correctly when you use Eina data type with a file.

Parameters:

eddc	The Eet_Data_Descriptor_Class you want to set.
eddc_size	The size of the Eet_Data_Descriptor_Class at the compilation time.
name	The name of the structure described by this class.
size	The size of the structure described by this class.

Returns:: EINA_TRUE if the structure was correctly set (The only reason that could make it fail is if you did give wrong parameter).

Note:: Unless there's a very specific reason to use this function directly, the EET_EINA_FILE_DATA_DESCRIPTOR_CLASS_SET macro is recommended.

Since (EFL) :: 1.2.3

Since :: 3.0

Eina_Bool eet_eina_stream_data_descriptor_class_set	(	Eet_Data_Descriptor_Class *	eddc,
		unsigned int	eddc_size,
		const char *	name,
		int	size
	)

This function is an helper that set all the parameters of an Eet_Data_Descriptor_Class correctly when you use Eina data type with a stream.

Parameters:

eddc	The Eet_Data_Descriptor_Class you want to set.
eddc_size	The size of the Eet_Data_Descriptor_Class at the compilation time.
name	The name of the structure described by this class.
size	The size of the structure described by this class.

Returns:: EINA_TRUE if the structure was correctly set (The only reason that could make it fail is if you did give wrong parameter).

Note:: Unless there's a very specific reason to use this function directly, the EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET macro is recommended.

Since (EFL) :: 1.2.3

Since :: 3.0

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