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 /** @addtogroup 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.
28 * \warning At least, I would like to present those sections in the right order, but doxygen prevents me
29 * from doing so. There is a weird bug I fail to circumvent here. The right order is naturally:
31 * -# Automatic parsing
32 * -# Simple manual definitions
33 * -# Callback Persistant State: Simple push/pop mechanism
34 * -# Callback Persistant State: Full featured mechanism
38 /** @name 1. basic operations
40 * If you only want to send pre-existing types, simply retrieve the pre-defined description with
41 * the \ref gras_datadesc_by_name function. Existing types entail:
42 * - char (both signed and unsigned)
43 * - int (short, regular, long and long long, both signed and unsigned)
45 * - string (which is indeed a reference to a dynamically sized array of char, strlen being used to retrive the size)
47 * Example:\verbatim gras_datadesc_type_t i = gras_datadesc_by_name("int");
48 gras_datadesc_type_t uc = gras_datadesc_by_name("unsigned char");
49 gras_datadesc_type_t str = gras_datadesc_by_name("string");\endverbatim
53 /** @brief Opaque type describing a type description. */
54 typedef struct s_gras_datadesc_type *gras_datadesc_type_t;
56 /** \brief Search a type description from its name */
57 gras_datadesc_type_t gras_datadesc_by_name(const char *name);
61 /** @name 2. Automatic parsing
63 * If you need to declare a new datatype, this is the simplest way to describe it to GRAS. Simply
64 * enclose its type definition into a \ref GRAS_DEFINE_TYPE macro call, and you're set. Here is
65 * an type declaration example: \verbatim GRAS_DEFINE_TYPE(mytype,struct mytype {
69 * The type is then both copied verbatim into your source file and stored for further parsing. This allows
70 * you to let GRAS parse the exact version you are actually using in your program.
71 * You can then retrieve the corresponding type description with \ref gras_datadesc_by_symbol.
72 * Don't worry too much for the performances, the type is only parsed once and a binary representation
73 * is stored and used in any subsequent calls.
75 * If your structure contains any pointer, you have to explain GRAS the size of the pointed array. This
76 * can be 1 in the case of simple references, or more in the case of regular arrays. For that, use the
77 * \ref GRAS_ANNOTE macro within the type declaration you are passing to \ref GRAS_DEFINE_TYPE. This macro
78 * rewrites itself to nothing in the declaration (so they won't pollute the type definition copied verbatim
79 * into your code), and give some information to GRAS about your pointer.
81 * GRAS_ANNOTE takes two arguments being the key name and the key value. For now, the only accepted key name
82 * is "size", to specify the length of the pointed array. It can either be the string "1" (without the quote)
83 * or the name of another field of the structure.
85 * Here is an example:\verbatim GRAS_DEFINE_TYPE(s_clause,
88 int *data GRAS_ANNOTE(size,length);
89 struct s_array *father GRAS_ANNOTE(size,1);
92 * It specifies that the structure s_array contains two fields, and that the size of the array pointed
93 * by \a data is the \a length field, and that the \a father field is a simple reference.
95 * If you cannot express your datadescs with this mechanism, you'll have to use the more advanced
96 * (and somehow complex) one described below.
98 * \warning Since GRAS_DEFINE_TYPE is a macro, you shouldn't put any comma in your type definition
99 * (comma separates macro args).
101 * For example, change \verbatim int a, b;\endverbatim to \verbatim int a;
107 /** @brief Automatically parse C code
110 #define GRAS_DEFINE_TYPE(name,def) \
111 static const char * _gras_this_type_symbol_does_not_exist__##name=#def; def
113 /** @brief Retrieve a datadesc which was previously parsed
116 #define gras_datadesc_by_symbol(name) \
117 (gras_datadesc_by_name(#name) ? \
118 gras_datadesc_by_name(#name) : \
119 gras_datadesc_parse(#name, \
120 _gras_this_type_symbol_does_not_exist__##name) \
124 * @brief Add an annotation to a type to be automatically parsed
126 #define GRAS_ANNOTE(key,val)
131 gras_datadesc_parse(const char *name, const char *C_statement);
133 /** @name 3. Simple manual definitions
135 * Here are the functions to use if you want to declare your description manually.
136 * The function names should be self-explanatory in most cases.
138 * You can add callbacks to the datatypes doing any kind of action you may want. Usually,
139 * pre-send callbacks are used to prepare the type expedition while post-receive callbacks
140 * are used to fix any issue after the receive.
142 * If your types are dynamic, you'll need to add some extra callback. For example, there is a
143 * specific callback for the string type which is in charge of computing the length of the char
144 * array. This is done with the cbps mechanism, explained in next section.
146 * If your types may contain pointer cycle, you must specify it to GRAS using the @ref gras_datadesc_cycle_set.
151 unsigned long int l1;
153 unsigned long int l2;
156 my_type=gras_datadesc_struct("mystruct");
157 gras_datadesc_struct_append(my_type,"c1", gras_datadesc_by_name("unsigned char"));
158 gras_datadesc_struct_append(my_type,"l1", gras_datadesc_by_name("unsigned long"));
159 gras_datadesc_struct_append(my_type,"c2", gras_datadesc_by_name("unsigned char"));
160 gras_datadesc_struct_append(my_type,"l2", gras_datadesc_by_name("unsigned long int"));
161 gras_datadesc_struct_close(my_type);
163 my_type=gras_datadesc_ref("mystruct*", gras_datadesc_by_name("mystruct"));
165 [Use my_type to send pointers to mystruct data]\endverbatim
170 /** \brief Opaque type describing a type description callback persistant state. */
171 typedef struct s_gras_cbps *gras_cbps_t;
173 /* callbacks prototypes */
174 /** \brief Prototype of type callbacks returning nothing. */
175 typedef void (*gras_datadesc_type_cb_void_t)(gras_cbps_t vars, void *data);
176 /** \brief Prototype of type callbacks returning an int. */
177 typedef int (*gras_datadesc_type_cb_int_t)(gras_cbps_t vars, void *data);
178 /** \brief Prototype of type callbacks selecting a type. */
179 typedef gras_datadesc_type_t (*gras_datadesc_selector_t)(gras_cbps_t vars, void *data);
182 /******************************************
183 **** Declare datadescription yourself ****
184 ******************************************/
186 gras_datadesc_type_t gras_datadesc_struct(const char *name);
187 void gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
189 gras_datadesc_type_t field_type);
190 void gras_datadesc_struct_close(gras_datadesc_type_t struct_type);
193 gras_datadesc_type_t gras_datadesc_union(const char *name,
194 gras_datadesc_type_cb_int_t selector);
195 void gras_datadesc_union_append(gras_datadesc_type_t union_type,
197 gras_datadesc_type_t field_type);
198 void gras_datadesc_union_close(gras_datadesc_type_t union_type);
202 gras_datadesc_ref(const char *name,
203 gras_datadesc_type_t referenced_type);
205 gras_datadesc_ref_generic(const char *name,
206 gras_datadesc_selector_t selector);
209 gras_datadesc_array_fixed(const char *name,
210 gras_datadesc_type_t element_type,
211 long int fixed_size);
213 gras_datadesc_array_dyn(const char *name,
214 gras_datadesc_type_t element_type,
215 gras_datadesc_type_cb_int_t dynamic_size);
217 gras_datadesc_ref_pop_arr(gras_datadesc_type_t element_type);
219 /*********************************
220 * Change stuff within datadescs *
221 *********************************/
223 /** \brief Specify that this type may contain cycles */
224 void gras_datadesc_cycle_set(gras_datadesc_type_t type);
225 /** \brief Specify that this type do not contain any cycles (default) */
226 void gras_datadesc_cycle_unset(gras_datadesc_type_t type);
227 /** \brief Add a pre-send callback to this datadesc. */
228 void gras_datadesc_cb_send (gras_datadesc_type_t type,
229 gras_datadesc_type_cb_void_t pre);
230 /** \brief Add a post-receive callback to this datadesc.*/
231 void gras_datadesc_cb_recv(gras_datadesc_type_t type,
232 gras_datadesc_type_cb_void_t post);
233 /** \brief Add a pre-send callback to the given field of the datadesc */
234 void gras_datadesc_cb_field_send (gras_datadesc_type_t type,
235 const char *field_name,
236 gras_datadesc_type_cb_void_t pre);
237 /** \brief Add a post-receive callback to the given field of the datadesc */
238 void gras_datadesc_cb_field_recv(gras_datadesc_type_t type,
239 const char *field_name,
240 gras_datadesc_type_cb_void_t post);
241 /** \brief Add a pre-send callback to the given field resulting in its value to be pushed */
242 void gras_datadesc_cb_field_push (gras_datadesc_type_t type,
243 const char *field_name);
245 /******************************
246 * Get stuff within datadescs *
247 ******************************/
248 /** \brief Returns the name of a datadescription */
249 char * gras_datadesc_get_name(gras_datadesc_type_t ddt);
250 /** \brief Returns the identifier of a datadescription */
251 int gras_datadesc_get_id(gras_datadesc_type_t ddt);
255 /** @name 4. Callback Persistant State: Simple push/pop mechanism
257 * Sometimes, one of the callbacks need to leave information for the next ones. If this is a simple integer (such as
258 * an array size), you can use the functions described here. If not, you'll have to play with the complete cbps interface.
260 * Here is an example:\verbatim
266 my_type=gras_datadesc_struct("s_array");
267 gras_datadesc_struct_append(my_type,"length", gras_datadesc_by_name("int"));
268 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
270 gras_datadesc_struct_append(my_type,"data",
271 gras_datadesc_array_dyn ("s_array::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
272 gras_datadesc_struct_close(my_type);
279 gras_cbps_i_push(gras_cbps_t ps, int val);
281 gras_cbps_i_pop(gras_cbps_t ps);
283 int gras_datadesc_cb_pop(gras_cbps_t vars, void *data);
284 void gras_datadesc_cb_push_int(gras_cbps_t vars, void *data);
285 void gras_datadesc_cb_push_uint(gras_cbps_t vars, void *data);
286 void gras_datadesc_cb_push_lint(gras_cbps_t vars, void *data);
287 void gras_datadesc_cb_push_ulint(gras_cbps_t vars, void *data);
292 /** @name 5. Callback Persistant State: Full featured mechanism
294 * Sometimes, one of the callbacks need to leave information for the next ones. If the simple push/pop mechanism
295 * introduced in previous section isn't enough, you can always use this full featured one.
301 gras_cbps_v_pop (gras_cbps_t ps,
303 /* OUT */ gras_datadesc_type_t *ddt,
304 /* OUT */ void **res);
306 gras_cbps_v_push(gras_cbps_t ps,
309 gras_datadesc_type_t ddt);
311 gras_cbps_v_set (gras_cbps_t ps,
314 gras_datadesc_type_t ddt);
317 gras_cbps_v_get (gras_cbps_t ps,
319 /* OUT */ gras_datadesc_type_t *ddt);
322 gras_cbps_block_begin(gras_cbps_t ps);
324 gras_cbps_block_end(gras_cbps_t ps);
330 /*******************************
331 **** About data convertion ****
332 *******************************/
333 int gras_arch_selfid(void); /* ID of this arch */
336 /*****************************
337 **** NWS datadescription * FIXME: obsolete?
338 *****************************/
341 * Basic types we can embeed in DataDescriptors.
344 {CHAR_TYPE, DOUBLE_TYPE, FLOAT_TYPE, INT_TYPE, LONG_TYPE, SHORT_TYPE,
345 UNSIGNED_INT_TYPE, UNSIGNED_LONG_TYPE, UNSIGNED_SHORT_TYPE, STRUCT_TYPE}
347 #define SIMPLE_TYPE_COUNT 9
349 /*! \brief Describe a collection of data.
351 ** A description of a collection of #type# data. #repetitions# is used only
352 ** for arrays; it contains the number of elements. #offset# is used only for
353 ** struct members in host format; it contains the offset of the member from the
354 ** beginning of the struct, taking into account internal padding added by the
355 ** compiler for alignment purposes. #members#, #length#, and #tailPadding# are
356 ** used only for STRUCT_TYPE data; the #length#-long array #members# describes
357 ** the members of the nested struct, and #tailPadding# indicates how many
358 ** padding bytes the compiler adds to the end of the structure.
361 typedef struct DataDescriptorStruct {
365 /*@null@*/ struct DataDescriptorStruct *members;
369 /** DataDescriptor for an array */
370 #define SIMPLE_DATA(type,repetitions) \
371 {type, repetitions, 0, NULL, 0, 0}
372 /** DataDescriptor for an structure member */
373 #define SIMPLE_MEMBER(type,repetitions,offset) \
374 {type, repetitions, offset, NULL, 0, 0}
375 /** DataDescriptor for padding bytes */
376 #define PAD_BYTES(structType,lastMember,memberType,repetitions) \
377 sizeof(structType) - offsetof(structType, lastMember) - \
378 sizeof(memberType) * repetitions
381 gras_datadesc_import_nws(const char *name,
382 const DataDescriptor *desc,
383 unsigned long howmany,
384 /* OUT */ gras_datadesc_type_t *dst);
389 #endif /* GRAS_DATADESC_H */