3 /* gras/datadesc.h - Describing the data you want to exchange */
5 /* Copyright (c) 2003, 2004 Martin Quinson. All rights reserved. */
7 /* This program is free software; you can redistribute it and/or modify it
8 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #ifndef GRAS_DATADESC_H
11 #define GRAS_DATADESC_H
13 #include "xbt/misc.h" /* BEGIN_DECL */
17 /** @defgroup GRAS_dd Data description
18 * @brief Describing data to be exchanged (Communication facility)
22 * Since GRAS takes care of potential representation conversion when the platform is heterogeneous,
23 * any data which transits on the network must be described beforehand.
25 * There is several possible interfaces for this, ranging from the really completely automatic parsing to
26 * completely manual. Let's study each of them from the simplest to the more advanced.
29 /** @name a) basic operations
32 * If you only want to send pre-existing types, simply retrieve the pre-defined description with
33 * the \ref gras_datadesc_by_name function. Existing types entail:
34 * - char (both signed and unsigned)
35 * - int (short, regular, long and long long, both signed and unsigned)
37 * - string (which is indeed a reference to a dynamically sized array of char, strlen being used to retrive the size)
39 * Example:\verbatim gras_datadesc_type_t i = gras_datadesc_by_name("int");
40 gras_datadesc_type_t uc = gras_datadesc_by_name("unsigned char");
41 gras_datadesc_type_t str = gras_datadesc_by_name("string");\endverbatim
45 /** @brief Opaque type describing a type description. */
46 typedef struct s_gras_datadesc_type *gras_datadesc_type_t;
48 /** \brief Search a type description from its name */
49 gras_datadesc_type_t gras_datadesc_by_name(const char *name);
53 /** @name b) Automatic parsing
56 * If you need to declare a new datatype, this is the simplest way to describe it to GRAS. Simply
57 * enclose its type definition into a \ref GRAS_DEFINE_TYPE macro call, and you're set. Here is
58 * an type declaration example: \verbatim GRAS_DEFINE_TYPE(mytype,struct mytype {
62 * The type is then both copied verbatim into your source file and stored for further parsing. This allows
63 * you to let GRAS parse the exact version you are actually using in your program.
64 * You can then retrieve the corresponding type description with \ref gras_datadesc_by_symbol.
65 * Don't worry too much for the performances, the type is only parsed once and a binary representation
66 * is stored and used in any subsequent calls.
68 * If your structure contains any pointer, you have to explain GRAS the size of the pointed array. This
69 * can be 1 in the case of simple references, or more in the case of regular arrays. For that, use the
70 * \ref GRAS_ANNOTE macro within the type declaration you are passing to \ref GRAS_DEFINE_TYPE. This macro
71 * rewrites itself to nothing in the declaration (so they won't pollute the type definition copied verbatim
72 * into your code), and give some information to GRAS about your pointer.
74 * GRAS_ANNOTE takes two arguments being the key name and the key value. For now, the only accepted key name
75 * is "size", to specify the length of the pointed array. It can either be the string "1" (without the quote)
76 * or the name of another field of the structure.
78 * Here is an example:\verbatim GRAS_DEFINE_TYPE(s_clause,
81 int *data GRAS_ANNOTE(size,length);
82 struct s_array *father GRAS_ANNOTE(size,1);
85 * It specifies that the structure s_array contains two fields, and that the size of the array pointed
86 * by \a data is the \a length field, and that the \a father field is a simple reference.
88 * If you cannot express your datadescs with this mecanism, you'll have to use the more advanced
89 * (and somehow complex) one described below.
91 * \warning Since GRAS_DEFINE_TYPE is a macro, you shouldn't put any comma in your type definition
92 * (comma separates macro args).
94 * For example, change \verbatim int a, b;\endverbatim to \verbatim int a;
100 /** @brief Automatically parse C code
103 #define GRAS_DEFINE_TYPE(name,def) \
104 static const char * _gras_this_type_symbol_does_not_exist__##name=#def; def
106 /** @brief Retrieve a datadesc which was previously parsed
109 #define gras_datadesc_by_symbol(name) \
110 (gras_datadesc_by_name(#name) ? \
111 gras_datadesc_by_name(#name) : \
112 gras_datadesc_parse(#name, \
113 _gras_this_type_symbol_does_not_exist__##name) \
117 * @brief Add an annotation to a type to be automatically parsed
119 #define GRAS_ANNOTE(key,val)
124 gras_datadesc_parse(const char *name, const char *C_statement);
126 /** @name c) Simple manual definitions
129 * Here are the functions to use if you want to declare your description manually.
130 * The function names should be self-explanatory in most cases.
132 * You can add callbacks to the datatypes doing any kind of action you may want. Usually,
133 * pre-send callbacks are used to prepare the type expedition while post-receive callbacks
134 * are used to fix any issue after the receive.
136 * If your types are dynamic, you'll need to add some extra callback. For example, there is a
137 * specific callback for the string type which is in charge of computing the length of the char
138 * array. This is done with the cbps mecanism, explained in next section.
140 * If your types may contain pointer cycle, you must specify it to GRAS using the @ref gras_datadesc_cycle_set.
145 unsigned long int l1;
147 unsigned long int l2;
150 my_type=gras_datadesc_struct("mystruct");
151 gras_datadesc_struct_append(my_type,"c1", gras_datadesc_by_name("unsigned char"));
152 gras_datadesc_struct_append(my_type,"l1", gras_datadesc_by_name("unsigned long"));
153 gras_datadesc_struct_append(my_type,"c2", gras_datadesc_by_name("unsigned char"));
154 gras_datadesc_struct_append(my_type,"l2", gras_datadesc_by_name("unsigned long int"));
155 gras_datadesc_struct_close(my_type);
157 my_type=gras_datadesc_ref("mystruct*", gras_datadesc_by_name("mystruct"));
159 [Use my_type to send pointers to mystruct data]\endverbatim
164 /** \brief Opaque type describing a type description callback persistant state. */
165 typedef struct s_gras_cbps *gras_cbps_t;
167 /* callbacks prototypes */
168 /** \brief Prototype of type callbacks returning nothing. */
169 typedef void (*gras_datadesc_type_cb_void_t)(gras_cbps_t vars, void *data);
170 /** \brief Prototype of type callbacks returning an int. */
171 typedef int (*gras_datadesc_type_cb_int_t)(gras_cbps_t vars, void *data);
172 /** \brief Prototype of type callbacks selecting a type. */
173 typedef gras_datadesc_type_t (*gras_datadesc_selector_t)(gras_cbps_t vars, void *data);
176 /******************************************
177 **** Declare datadescription yourself ****
178 ******************************************/
180 /** \brief Declare a new structure description */
181 gras_datadesc_type_t gras_datadesc_struct(const char *name);
183 /** \brief Append a new field to a structure description */
185 gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
187 gras_datadesc_type_t field_type);
188 /** \brief Close a structure description */
190 gras_datadesc_struct_close(gras_datadesc_type_t struct_type);
192 /** \brief Declare a new union description */
194 gras_datadesc_union(const char *name,
195 gras_datadesc_type_cb_int_t selector);
196 /** \brief Append a new field to an union description */
198 gras_datadesc_union_append(gras_datadesc_type_t union_type,
200 gras_datadesc_type_t field_type);
201 /** \brief Close an union description */
203 gras_datadesc_union_close(gras_datadesc_type_t union_type);
206 /** \brief Declare a new type being a reference to the one passed in arg */
208 gras_datadesc_ref(const char *name,
209 gras_datadesc_type_t referenced_type);
210 /** \brief Declare a new type being a generic reference. */
212 gras_datadesc_ref_generic(const char *name,
213 gras_datadesc_selector_t selector);
215 /** \brief Declare a new type being an array of fixed size and content */
217 gras_datadesc_array_fixed(const char *name,
218 gras_datadesc_type_t element_type,
219 long int fixed_size);
221 /** \brief Declare a new type being an array of fixed size, but accepting several content types. */
223 gras_datadesc_array_dyn(const char *name,
224 gras_datadesc_type_t element_type,
225 gras_datadesc_type_cb_int_t dynamic_size);
227 /** \brief Declare a new type being an array which size can be found with \ref gras_cbps_i_pop */
229 gras_datadesc_ref_pop_arr(gras_datadesc_type_t element_type);
231 /*********************************
232 * Change stuff within datadescs *
233 *********************************/
235 /** \brief Specify that this type may contain cycles */
236 void gras_datadesc_cycle_set(gras_datadesc_type_t type);
237 /** \brief Specify that this type do not contain any cycles (default) */
238 void gras_datadesc_cycle_unset(gras_datadesc_type_t type);
239 /** \brief Add a pre-send callback to this datadesc. */
240 void gras_datadesc_cb_send (gras_datadesc_type_t type,
241 gras_datadesc_type_cb_void_t pre);
242 /** \brief Add a post-receive callback to this datadesc.*/
243 void gras_datadesc_cb_recv(gras_datadesc_type_t type,
244 gras_datadesc_type_cb_void_t post);
245 /** \brief Add a pre-send callback to the given field of the datadesc */
246 void gras_datadesc_cb_field_send (gras_datadesc_type_t type,
247 const char *field_name,
248 gras_datadesc_type_cb_void_t pre);
249 /** \brief Add a post-receive callback to the given field of the datadesc */
250 void gras_datadesc_cb_field_recv(gras_datadesc_type_t type,
251 const char *field_name,
252 gras_datadesc_type_cb_void_t post);
253 /** \brief Add a pre-send callback to the given field resulting in its value to be pushed */
254 void gras_datadesc_cb_field_push (gras_datadesc_type_t type,
255 const char *field_name);
257 /******************************
258 * Get stuff within datadescs *
259 ******************************/
260 /** \brief Returns the name of a datadescription */
261 char * gras_datadesc_get_name(gras_datadesc_type_t ddt);
262 /** \brief Returns the identifier of a datadescription */
263 int gras_datadesc_get_id(gras_datadesc_type_t ddt);
267 /** @name Callback Persistant State: Simple push/pop mecanism
270 * Sometimes, one of the callbacks need to leave information for the next ones. If this is a simple integer (such as
271 * an array size), you can use the functions described here. If not, you'll have to play with the complete cbps interface.
273 * Here is an example:\verbatim
279 my_type=gras_datadesc_struct("s_array");
280 gras_datadesc_struct_append(my_type,"length", gras_datadesc_by_name("int"));
281 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
283 gras_datadesc_struct_append(my_type,"data",
284 gras_datadesc_array_dyn ("s_array::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
285 gras_datadesc_struct_close(my_type);
292 gras_cbps_i_push(gras_cbps_t ps, int val);
294 gras_cbps_i_pop(gras_cbps_t ps);
296 int gras_datadesc_cb_pop(gras_cbps_t vars, void *data);
297 void gras_datadesc_cb_push_int(gras_cbps_t vars, void *data);
298 void gras_datadesc_cb_push_uint(gras_cbps_t vars, void *data);
299 void gras_datadesc_cb_push_lint(gras_cbps_t vars, void *data);
300 void gras_datadesc_cb_push_ulint(gras_cbps_t vars, void *data);
305 /** @name Callback Persistant State: Full featured mecanism
308 * Sometimes, one of the callbacks need to leave information for the next ones. If the simple push/pop mecanism
309 * introduced in previous section isn't enough, you can always use this full featured one.
315 gras_cbps_v_pop (gras_cbps_t ps,
317 /* OUT */ gras_datadesc_type_t *ddt,
318 /* OUT */ void **res);
320 gras_cbps_v_push(gras_cbps_t ps,
323 gras_datadesc_type_t ddt);
325 gras_cbps_v_set (gras_cbps_t ps,
328 gras_datadesc_type_t ddt);
331 gras_cbps_v_get (gras_cbps_t ps,
333 /* OUT */ gras_datadesc_type_t *ddt);
336 gras_cbps_block_begin(gras_cbps_t ps);
338 gras_cbps_block_end(gras_cbps_t ps);
343 /*******************************
344 **** About data convertion ****
345 *******************************/
346 int gras_arch_selfid(void); /* ID of this arch */
349 /*****************************
350 **** NWS datadescription * FIXME: obsolete?
351 *****************************/
354 * Basic types we can embeed in DataDescriptors.
357 {CHAR_TYPE, DOUBLE_TYPE, FLOAT_TYPE, INT_TYPE, LONG_TYPE, SHORT_TYPE,
358 UNSIGNED_INT_TYPE, UNSIGNED_LONG_TYPE, UNSIGNED_SHORT_TYPE, STRUCT_TYPE}
360 #define SIMPLE_TYPE_COUNT 9
362 /*! \brief Describe a collection of data.
364 ** A description of a collection of #type# data. #repetitions# is used only
365 ** for arrays; it contains the number of elements. #offset# is used only for
366 ** struct members in host format; it contains the offset of the member from the
367 ** beginning of the struct, taking into account internal padding added by the
368 ** compiler for alignment purposes. #members#, #length#, and #tailPadding# are
369 ** used only for STRUCT_TYPE data; the #length#-long array #members# describes
370 ** the members of the nested struct, and #tailPadding# indicates how many
371 ** padding bytes the compiler adds to the end of the structure.
374 typedef struct DataDescriptorStruct {
378 /*@null@*/ struct DataDescriptorStruct *members;
382 /** DataDescriptor for an array */
383 #define SIMPLE_DATA(type,repetitions) \
384 {type, repetitions, 0, NULL, 0, 0}
385 /** DataDescriptor for an structure member */
386 #define SIMPLE_MEMBER(type,repetitions,offset) \
387 {type, repetitions, offset, NULL, 0, 0}
388 /** DataDescriptor for padding bytes */
389 #define PAD_BYTES(structType,lastMember,memberType,repetitions) \
390 sizeof(structType) - offsetof(structType, lastMember) - \
391 sizeof(memberType) * repetitions
394 gras_datadesc_import_nws(const char *name,
395 const DataDescriptor *desc,
396 unsigned long howmany,
397 /* OUT */ gras_datadesc_type_t *dst);
402 #endif /* GRAS_DATADESC_H */