Eet Data Serialization

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


Modules

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

Data Structures

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

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   4
 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, 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.
#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.
#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_LIST_STRING(edd, struct_type, name, member)
 Add a linked list of string 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_HASH_STRING(edd, struct_type, name, member)
 Add a hash of string to a data descriptor.
#define EET_DATA_DESCRIPTOR_ADD_BASIC_ARRAY(edd, struct_type, name, member, type)
 Add an array of basic data elements 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_VAR_ARRAY_STRING(edd, struct_type, name, member)
 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)
 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.
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 char *(* Eet_Descriptor_Str_Direct_Alloc_Callback )(const char *str)
typedef void(* Eet_Descriptor_Str_Direct_Free_Callback )(const char *str)
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)

Functions

EINA_DEPRECATED
Eet_Data_Descriptor
eet_data_descriptor_new (const char *name, int size, Eet_Descriptor_List_Next_Callback func_list_next, Eet_Descriptor_List_Append_Callback func_list_append, Eet_Descriptor_List_Data_Callback func_list_data, Eet_Descriptor_List_Free_Callback func_list_free, Eet_Descriptor_Hash_Foreach_Callback func_hash_foreach, Eet_Descriptor_Hash_Add_Callback func_hash_add, Eet_Descriptor_Hash_Free_Callback func_hash_free)
 Create a new empty data structure descriptor.
Eet_Data_Descriptoreet_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.
Eet_Data_Descriptoreet_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.
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.
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.
void eet_data_descriptor_free (Eet_Data_Descriptor *edd)
 This function frees a data descriptor when it is not needed anymore.
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)
 Read 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)
 Write 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)
 Dump an eet encoded data structure into ascii text.
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.
int eet_data_dump (Eet_File *ef, const char *name, Eet_Dump_Callback dumpfunc, void *dumpdata)
 Dump 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)
 Take 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)
 Decode 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)
 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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.


Define Documentation

#define EET_I_LIMIT   128

Other type exist but are reserved for internal purpose.

#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.

Referenced by eet_eina_file_data_descriptor_class_set(), and eet_eina_stream_data_descriptor_class_set().

#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:
1.2.3

#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:
1.2.3

#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)
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 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_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)
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_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)
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_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)
Add 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:
1.5.0

#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)
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. The hash keys must be strings.

Since:
1.0.0

#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)
Add 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:
1.3.4

#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)
Add 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:
1.5.0

#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)
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 array to be stored. The array must be defined with a fixed size in the declaration of the struct containing it.

Since:
1.0.2

#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)
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 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:
1.0.2

#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)
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.
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:
1.4.0

#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)
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_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)
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_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)
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


Typedef Documentation

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()


Function Documentation

EINA_DEPRECATED Eet_Data_Descriptor* eet_data_descriptor_new ( const char *  name,
int  size,
Eet_Descriptor_List_Next_Callback  func_list_next,
Eet_Descriptor_List_Append_Callback  func_list_append,
Eet_Descriptor_List_Data_Callback  func_list_data,
Eet_Descriptor_List_Free_Callback  func_list_free,
Eet_Descriptor_Hash_Foreach_Callback  func_hash_foreach,
Eet_Descriptor_Hash_Add_Callback  func_hash_add,
Eet_Descriptor_Hash_Free_Callback  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-independent 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::func, _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.

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.
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 savedi, 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 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:
1.2.3

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.
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 savedi, 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:
1.2.3

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:
1.2.3

References _Eet_Data_Descriptor_Class::array_alloc, _Eet_Data_Descriptor_Class::array_free, EET_DATA_DESCRIPTOR_CLASS_VERSION, _Eet_Data_Descriptor_Class::func, _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().

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:
1.2.3

References EET_DATA_DESCRIPTOR_CLASS_VERSION, eet_eina_stream_data_descriptor_class_set(), _Eet_Data_Descriptor_Class::func, _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.

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

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().

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().

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. 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:
1.0.0

References eet_data_write_cipher().

int eet_data_text_dump ( const void *  data_in,
int  size_in,
Eet_Dump_Callback  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().

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().

int eet_data_dump ( Eet_File ef,
const char *  name,
Eet_Dump_Callback  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().

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().

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

Decode 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:
1.0.0

References eet_data_descriptor_decode_cipher().

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().