---
name: "Eet_Data_Group"
section: "3"
platform: "linux"
package: "libeet-doc"
version: "1.3.2-1"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/Eet_Data_Group"
---

# Eet\_Data\_Group(3)

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

## NAME

Eet Data Serialization -

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

### Data Structures

struct **\_Eet\_Data\_Descriptor\_Class**\
 *Instructs Eet about memory management for different needs under serialization and parse process.*

### Modules

**Eet Data Serialization using A Ciphers**\

*Most of the* **Eet Data Serialization** *have alternative versions that accounts for ciphers to protect their content.*

### Defines

\#define **EET\_T\_UNKNOW**   0\
 *Unknown data encoding type.*  #define **EET\_T\_CHAR**   1\
 *Data type: char.*  #define **EET\_T\_SHORT**   2\
 *Data type: short.*  #define **EET\_T\_INT**   3\
 *Data type: int.*  #define **EET\_T\_LONG\_LONG**   4\
 *Data type: long long.*  #define **EET\_T\_FLOAT**   5\
 *Data type: float.*  #define **EET\_T\_DOUBLE**   6\
 *Data type: double.*  #define **EET\_T\_UCHAR**   7\
 *Data type: unsigned char.*  #define **EET\_T\_USHORT**   8\
 *Data type: unsigned short.*  #define **EET\_T\_UINT**   9\
 *Data type: unsigned int.*  #define **EET\_T\_ULONG\_LONG**   10\
 *Data type: unsigned long long.*  #define **EET\_T\_STRING**   11\
 *Data type: char \*.*  #define **EET\_T\_INLINED\_STRING**   12\
 *Data type: char \* (but compressed inside the resulting eet).*  #define **EET\_T\_NULL**   13\
 *Data type: (void \*) (only use it if you know why).*  #define **EET\_T\_F32P32**   14\
 *Data type: fixed point 32.32.*  #define **EET\_T\_F16P16**   15\
 *Data type: fixed point 16.16.*  #define **EET\_T\_F8P24**   16\
 *Data type: fixed point 8.24.*  #define **EET\_T\_LAST**   18\
 *Last data type.*  #define **EET\_G\_UNKNOWN**   100\
 *Unknown group data encoding type.*  #define **EET\_G\_ARRAY**   101\
 *Fixed size array group type.*  #define **EET\_G\_VAR\_ARRAY**   102\
 *Variable size array group type.*  #define **EET\_G\_LIST**   103\
 *Linked list group type.*  #define **EET\_G\_HASH**   104\
 *Hash table group type.*  #define **EET\_G\_UNION**   105\
 *Union group type.*  #define **EET\_G\_VARIANT**   106\
 *Selectable subtype group.*  #define **EET\_G\_LAST**   107\
 *Last group type.*  #define **EET\_I\_LIMIT**   128\
 *Other type exist but are reserved for internal purpose.*  #define **EET\_DATA\_DESCRIPTOR\_CLASS\_VERSION**   3\
 *The version of* **Eet\_Data\_Descriptor\_Class** *at the time of the distribution of the sources.*  #define **EET\_EINA\_STREAM\_DATA\_DESCRIPTOR\_CLASS\_SET**(Clas, Type)   (eet\_eina\_stream\_data\_descriptor\_class\_set(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.*  #define **EET\_EINA\_FILE\_DATA\_DESCRIPTOR\_CLASS\_SET**(Clas, Type)   (eet\_eina\_file\_data\_descriptor\_class\_set(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.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_BASIC**(edd, struct\_type, name, member, type)\
 *Add a basic data element to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_SUB**(edd, struct\_type, name, member, subtype)\
 *Add a sub-element type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_LIST**(edd, struct\_type, name, member, subtype)\
 *Add a linked list type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_HASH**(edd, struct\_type, name, member, subtype)\
 *Add a hash type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_ARRAY**(edd, struct\_type, name, member, subtype)\
 *Add a fixed size array type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_VAR\_ARRAY**(edd, struct\_type, name, member, subtype)\
 *Add a variable size array type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_UNION**(edd, struct\_type, name, member, type\_member, unified\_type)\
 *Add an union type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_VARIANT**(edd, struct\_type, name, member, type\_member, unified\_type)\
 *Add a automatically selectable type to a data descriptor.*  #define **EET\_DATA\_DESCRIPTOR\_ADD\_MAPPING**(unified\_type, name, subtype)   eet\_data\_descriptor\_element\_add(unified\_type, name, EET\_T\_UNKNOW, EET\_G\_UNKNOWN, 0, 0, NULL, subtype);\
 *Add a mapping to a data descriptor that will be used by union, variant or inherited type.*

### Typedefs

typedef struct \_Eet\_Data\_Descriptor **Eet\_Data\_Descriptor**\
 *Opaque handle that have information on a type members.*  typedef struct **\_Eet\_Data\_Descriptor\_Class** **Eet\_Data\_Descriptor\_Class**\
 *Instructs Eet about memory management for different needs under serialization and parse process.*

### Functions

EINA\_DEPRECATED EAPI **Eet\_Data\_Descriptor** \* **eet\_data\_descriptor\_new** (const char \*name, int size, void \*(\*func\_list\_next)(void \*l), void \*(\*func\_list\_append)(void \*l, void \*d), void \*(\*func\_list\_data)(void \*l), void \*(\*func\_list\_free)(void \*l), void(\*func\_hash\_foreach)(void \*h, int(\*func)(void \*h, const char \*k, void \*dt, void \*fdt), void \*fdt), void \*(\*func\_hash\_add)(void \*h, const char \*k, void \*d), void(\*func\_hash\_free)(void \*h))\
 *Create a new empty data structure descriptor.*  EAPI **Eet\_Data\_Descriptor** \* **eet\_data\_descriptor\_stream\_new** (const **Eet\_Data\_Descriptor\_Class** \*eddc)\
 *This function creates a new data descriptore and returns a handle to the new data descriptor.*  EAPI **Eet\_Data\_Descriptor** \* **eet\_data\_descriptor\_file\_new** (const **Eet\_Data\_Descriptor\_Class** \*eddc)\
 *This function creates a new data descriptore and returns a handle to the new data descriptor.*  EAPI Eina\_Bool **eet\_eina\_stream\_data\_descriptor\_class\_set** (**Eet\_Data\_Descriptor\_Class** \*eddc, 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 stream.*  EAPI Eina\_Bool **eet\_eina\_file\_data\_descriptor\_class\_set** (**Eet\_Data\_Descriptor\_Class** \*eddc, 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.*  EAPI void **eet\_data\_descriptor\_free** (**Eet\_Data\_Descriptor** \*edd)\
 *This function frees a data descriptor when it is not needed anymore.*  EAPI 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.*  EAPI void \* **eet\_data\_read** (**Eet\_File** \*ef, **Eet\_Data\_Descriptor** \*edd, const char \*name)\
 *Read a data structure from an eet file and decodes it.*  EAPI int **eet\_data\_write** (**Eet\_File** \*ef, **Eet\_Data\_Descriptor** \*edd, const char \*name, const void \*data, int compress)\
 *Write a data structure from memory and store in an eet file.*  EAPI int **eet\_data\_text\_dump** (const void \*data\_in, int size\_in, void(\*dumpfunc)(void \*data, const char \*str), void \*dumpdata)\
 *Dump an eet encoded data structure into ascii text.*  EAPI void \* **eet\_data\_text\_undump** (const char \*text, int textlen, int \*size\_ret)\
 *Take an ascii encoding from* **eet\_data\_text\_dump()** *and re-encode in binary.*  EAPI int **eet\_data\_dump** (**Eet\_File** \*ef, const char \*name, void(\*dumpfunc)(void \*data, const char \*str), void \*dumpdata)\
 *Dump an eet encoded data structure from an eet file into ascii text.*  EAPI int **eet\_data\_undump** (**Eet\_File** \*ef, const char \*name, const char \*text, int textlen, int compress)\
 *Take an ascii encoding from* **eet\_data\_dump()** *and re-encode in binary.*  EAPI void \* **eet\_data\_descriptor\_decode** (**Eet\_Data\_Descriptor** \*edd, const void \*data\_in, int size\_in)\
 *Decode a data structure from an arbitary location in memory.*  EAPI void \* **eet\_data\_descriptor\_encode** (**Eet\_Data\_Descriptor** \*edd, const void \*data\_in, int \*size\_ret)\
 *Encode a dsata struct to memory and return that encoded data.*

## Detailed Description

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.

Example:

```
 #include <Eet.h>
 #include <Evas.h>
 typedef struct _blah2
 {
    char *string;
 } Blah2;
 typedef struct _blah3
 {
    char *string;
 } Blah3;
 typedef struct _blah
 {
    char character;
    short sixteen;
    int integer;
    long long lots;
    float floating;
    double floating_lots;
    char *string;
    Blah2 *blah2;
    Eina_List *blah3;
 } Blah;
 int
 main(int argc, char **argv)
 {
    Blah blah;
    Blah2 blah2;
    Blah3 blah3;
    Eet_Data_Descriptor *edd, *edd2, *edd3;
    Eet_Data_Descriptor_Class eddc, eddc2, eddc3;
    void *data;
    int size;
    FILE *f;
    Blah *blah_in;
    eet_init();
    EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc3, Blah3);
    edd3 = eet_data_descriptor_stream_new(&eddc3);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd3, Blah3, 'string3', string, EET_T_STRING);
    EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc2, Blah2);
    edd2 = eet_data_descriptor_stream_new(&eddc2);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd2, Blah2, 'string2', string, EET_T_STRING);
    EET_EINA_STREAM_DATA_DESCRIPTOR_CLASS_SET(&eddc, Blah);
    edd = eet_data_descriptor_stream_new(&eddc);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'character', character, EET_T_CHAR);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'sixteen', sixteen, EET_T_SHORT);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'integer', integer, EET_T_INT);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'lots', lots, EET_T_LONG_LONG);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'floating', floating, EET_T_FLOAT);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'floating_lots', floating_lots, EET_T_DOUBLE);
    EET_DATA_DESCRIPTOR_ADD_BASIC(edd, Blah, 'string', string, EET_T_STRING);
    EET_DATA_DESCRIPTOR_ADD_SUB(edd, Blah, 'blah2', blah2, edd2);
    EET_DATA_DESCRIPTOR_ADD_LIST(edd, Blah, 'blah3', blah3, edd3);
    blah3.string = 'PANTS';
    blah2.string = 'subtype string here!';
    blah.character = '7';
    blah.sixteen = 0x7777;
    blah.integer = 0xc0def00d;
    blah.lots = 0xdeadbeef31337777;
    blah.floating = 3.141592654;
    blah.floating_lots = 0.777777777777777;
    blah.string = 'bite me like a turnip';
    blah.blah2 = &blah2;
    blah.blah3 = eina_list_append(NULL, &blah3);
    blah.blah3 = eina_list_append(blah.blah3, &blah3);
    blah.blah3 = eina_list_append(blah.blah3, &blah3);
    blah.blah3 = eina_list_append(blah.blah3, &blah3);
    blah.blah3 = eina_list_append(blah.blah3, &blah3);
    blah.blah3 = eina_list_append(blah.blah3, &blah3);
    blah.blah3 = eina_list_append(blah.blah3, &blah3);
    data = eet_data_descriptor_encode(edd, &blah, &size);
    printf('-----DECODING0);
    blah_in = eet_data_descriptor_decode(edd, data, size);
    printf('-----DECODED!0);
    printf('%c0, blah_in->character);
    printf('%x0, (int)blah_in->sixteen);
    printf('%x0, blah_in->integer);
    printf('%lx0, blah_in->lots);
    printf('%f0, (double)blah_in->floating);
    printf('%f0, (double)blah_in->floating_lots);
    printf('%s0, blah_in->string);
    printf('%p0, blah_in->blah2);
    printf('  %s0, blah_in->blah2->string);
      {
         Eina_List *l;
         Blah3 *blah3_in;
         EINA_LIST_FOREACH(blah_in->blah3, l, blah3_in)
           {
              printf('%p0, blah3_in);
              printf('  %s0, blah3_in->string);
           }
      }
    eet_data_descriptor_free(edd);
    eet_data_descriptor_free(edd2);
    eet_data_descriptor_free(edd3);
    eet_shutdown();
   return 0;
 }
```

## Define Documentation

### #define EET\_DATA\_DESCRIPTOR\_ADD\_ARRAY(edd, struct\_type, name, member, subtype) Value:

```
{         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);      }
```

Add 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 hash to be stored.

**Since:**

1\.0.2

### #define EET\_DATA\_DESCRIPTOR\_ADD\_BASIC(edd, struct\_type, name, member, type) Value:

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

Add 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 eet\_dictionary\_string\_check 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:**

1\.0.0

### #define EET\_DATA\_DESCRIPTOR\_ADD\_HASH(edd, struct\_type, name, member, subtype) Value:

```
{         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);      }
```

Add 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.

**Since:**

1\.0.0

### #define EET\_DATA\_DESCRIPTOR\_ADD\_LIST(edd, struct\_type, name, member, subtype) Value:

```
{         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);      }
```

Add 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:**

1\.0.0

### #define EET\_DATA\_DESCRIPTOR\_ADD\_MAPPING(unified\_type, name, subtype) eet\_data\_descriptor\_element\_add(unified\_type, name, EET\_T\_UNKNOW, EET\_G\_UNKNOWN, 0, 0, NULL, subtype);

Add 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:**

1\.2.4

**See also:**

**Eet\_Data\_Descriptor\_Class**

### #define EET\_DATA\_DESCRIPTOR\_ADD\_SUB(edd, struct\_type, name, member, subtype) Value:

```
{         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);      }
```

Add 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:**

1\.0.0

### #define EET\_DATA\_DESCRIPTOR\_ADD\_UNION(edd, struct\_type, name, member, type\_member, unified\_type) Value:

```
{         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);      }
```

Add 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:**

1\.2.4

**See also:**

**Eet\_Data\_Descriptor\_Class**

### #define EET\_DATA\_DESCRIPTOR\_ADD\_VAR\_ARRAY(edd, struct\_type, name, member, subtype) Value:

```
{         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);      }
```

Add 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 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 hash to be stored.

**Since:**

1\.0.2

### #define EET\_DATA\_DESCRIPTOR\_ADD\_VARIANT(edd, struct\_type, name, member, type\_member, unified\_type) Value:

```
{         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);      }
```

Add 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:**

1\.2.4

**See also:**

**Eet\_Data\_Descriptor\_Class**

### #define EET\_DATA\_DESCRIPTOR\_CLASS\_VERSION 3

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.

### #define EET\_EINA\_FILE\_DATA\_DESCRIPTOR\_CLASS\_SET(Clas, Type) (eet\_eina\_file\_data\_descriptor\_class\_set(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).

**Since:**

1\.2.3

### #define EET\_EINA\_STREAM\_DATA\_DESCRIPTOR\_CLASS\_SET(Clas, Type) (eet\_eina\_stream\_data\_descriptor\_class\_set(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).

**Since:**

1\.2.3

### #define EET\_I\_LIMIT 128

Other type exist but are reserved for internal purpose.

## Typedef Documentation

### Eet\_Data\_Descriptor

Opaque handle that have information on a type members. 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()**

## Function Documentation

### EAPI void\* eet\_data\_descriptor\_decode (Eet\_Data\_Descriptor \* edd, const void \* data\_in, int size\_in)

Decode a data structure from an arbitary 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:**

1\.0.0

References eet\_data\_descriptor\_decode\_cipher().

### EAPI 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 speficy 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:**

1\.0.0

References eet\_data\_descriptor\_element\_add(), EET\_G\_LAST, EET\_G\_UNION, EET\_G\_UNKNOWN, EET\_G\_VAR\_ARRAY, EET\_G\_VARIANT, EET\_T\_LAST, EET\_T\_NULL, EET\_T\_STRING, and EET\_T\_UNKNOW.

Referenced by eet\_data\_descriptor\_element\_add().

### EAPI void\* eet\_data\_descriptor\_encode (Eet\_Data\_Descriptor \* edd, const void \* data\_in, int \* size\_ret)

Encode 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, endianess 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:**

1\.0.0

References eet\_data\_descriptor\_encode\_cipher().

### EAPI Eet\_Data\_Descriptor\* eet\_data\_descriptor\_file\_new (const Eet\_Data\_Descriptor\_Class \* eddc)

This function creates a new data descriptore 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 data descriptor to free.

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-independant serialised data chunks for transmission across a a network or more.

This function use str\_direct\_alloc and str\_direct\_free. It is usefull when the eet\_data you are reading come from a file and have a dictionnary. This will reduce memory use, improve the possibility for the OS to page this string out. But be carrefull all EET\_T\_STRING are pointer to a mmapped area and it will point to nowhere if you close the file. So as long as you use this strings, you need to have the Eet\_File open.

**Since:**

1\.2.3

### EAPI 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:**

1\.0.0

### EINA\_DEPRECATED EAPI Eet\_Data\_Descriptor\* eet\_data\_descriptor\_new (const char \* name, int size, void \*(\*)(void \*l) func\_list\_next, void \*(\*)(void \*l, void \*d) func\_list\_append, void \*(\*)(void \*l) func\_list\_data, void \*(\*)(void \*l) func\_list\_free, void(\*)(void \*h, int(\*func)(void \*h, const char \*k, void \*dt, void \*fdt), void \*fdt) func\_hash\_foreach, void \*(\*)(void \*h, const char \*k, void \*d) func\_hash\_add, void(\*)(void \*h) func\_hash\_free)

Create a new empty data structure descriptor. **Parameters:**

*name* The string name of this data structure (most be a global constant and never change). \
 *size* The size of the struct (in bytes). \
 *func\_list\_next* The function to get the next list node. \
 *func\_list\_append* The function to append a member to a list. \
 *func\_list\_data* The function to get the data from a list node. \
 *func\_list\_free* The function to free an entire linked list. \
 *func\_hash\_foreach* The function to iterate through all hash table entries. \
 *func\_hash\_add* The function to add a member to a hash table. \
 *func\_hash\_free* The function to free an entire hash table.

**Returns:**

A new empty data descriptor.

This function creates a new data descriptore 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.

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-independant serialised data chunks for transmission across a a network or more.

The function pointers to the list and hash table functions are only needed if you use those data types, else you can pass NULL instead.

**Since:**

1\.0.0

**Deprecated**

use **eet\_data\_descriptor\_stream\_new()** or **eet\_data\_descriptor\_file\_new()**

References \_Eet\_Data\_Descriptor\_Class::hash\_add, \_Eet\_Data\_Descriptor\_Class::hash\_foreach, \_Eet\_Data\_Descriptor\_Class::hash\_free, \_Eet\_Data\_Descriptor\_Class::list\_append, \_Eet\_Data\_Descriptor\_Class::list\_data, \_Eet\_Data\_Descriptor\_Class::list\_free, \_Eet\_Data\_Descriptor\_Class::list\_next, \_Eet\_Data\_Descriptor\_Class::name, \_Eet\_Data\_Descriptor\_Class::size, and \_Eet\_Data\_Descriptor\_Class::version.

### EAPI Eet\_Data\_Descriptor\* eet\_data\_descriptor\_stream\_new (const Eet\_Data\_Descriptor\_Class \* eddc)

This function creates a new data descriptore 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 data descriptor to free.

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-independant serialised data chunks for transmission across a a network or more.

This function specially ignore str\_direct\_alloc and str\_direct\_free. It is usefull when the eet\_data you are reading don't have a dictionnary like network stream or ipc. It also mean that all string will be allocated and duplicated in memory.

**Since:**

1\.2.3

### EAPI int eet\_data\_dump (Eet\_File \* ef, const char \* name, void(\*)(void \*data, const char \*str) dumpfunc, void \* dumpdata)

Dump 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:**

1\.0.0

References eet\_data\_dump\_cipher().

### EAPI void\* eet\_data\_read (Eet\_File \* ef, Eet\_Data\_Descriptor \* edd, const char \* name)

Read 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:**

1\.0.0

References eet\_data\_read\_cipher().

### EAPI int eet\_data\_text\_dump (const void \* data\_in, int size\_in, void(\*)(void \*data, const char \*str) dumpfunc, void \* dumpdata)

Dump 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, 'r');
   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:**

1\.0.0

References eet\_data\_text\_dump\_cipher().

### EAPI void\* eet\_data\_text\_undump (const char \* text, int textlen, int \* size\_ret)

Take 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:**

1\.0.0

References eet\_data\_text\_undump\_cipher().

### EAPI int eet\_data\_undump (Eet\_File \* ef, const char \* name, const char \* text, int textlen, int compress)

Take 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:**

1\.0.0

References eet\_data\_undump\_cipher().

### EAPI int eet\_data\_write (Eet\_File \* ef, Eet\_Data\_Descriptor \* edd, const char \* name, const void \* data, int compress)

Write 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 ssave 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.

**See also:**

**eet\_data\_write\_cipher()**

**Since:**

1\.0.0

References eet\_data\_write\_cipher().

### EAPI Eina\_Bool eet\_eina\_file\_data\_descriptor\_class\_set (Eet\_Data\_Descriptor\_Class \* eddc, 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. \
 *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).

**Since:**

1\.2.3

References eet\_eina\_stream\_data\_descriptor\_class\_set(), \_Eet\_Data\_Descriptor\_Class::hash\_add, \_Eet\_Data\_Descriptor\_Class::str\_direct\_alloc, \_Eet\_Data\_Descriptor\_Class::str\_direct\_free, and \_Eet\_Data\_Descriptor\_Class::version.

### EAPI Eina\_Bool eet\_eina\_stream\_data\_descriptor\_class\_set (Eet\_Data\_Descriptor\_Class \* eddc, 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 stream. **Parameters:**

*eddc* The Eet\_Data\_Descriptor\_Class you want to set. \
 *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).

**Since:**

1\.2.3

References \_Eet\_Data\_Descriptor\_Class::hash\_add, \_Eet\_Data\_Descriptor\_Class::hash\_foreach, \_Eet\_Data\_Descriptor\_Class::hash\_free, \_Eet\_Data\_Descriptor\_Class::list\_append, \_Eet\_Data\_Descriptor\_Class::list\_data, \_Eet\_Data\_Descriptor\_Class::list\_free, \_Eet\_Data\_Descriptor\_Class::list\_next, \_Eet\_Data\_Descriptor\_Class::mem\_alloc, \_Eet\_Data\_Descriptor\_Class::mem\_free, \_Eet\_Data\_Descriptor\_Class::name, \_Eet\_Data\_Descriptor\_Class::size, \_Eet\_Data\_Descriptor\_Class::str\_alloc, \_Eet\_Data\_Descriptor\_Class::str\_free, and \_Eet\_Data\_Descriptor\_Class::version.

Referenced by eet\_eina\_file\_data\_descriptor\_class\_set().

## Author

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