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 */
14 #include "xbt/dynar.h" /* void_f_pvoid_t */
18 /** @addtogroup GRAS_dd Data description
19 * @brief Describing data to be exchanged (Communication facility)
23 * Since GRAS takes care of potential representation conversion when the platform is heterogeneous,
24 * any data which transits on the network must be described beforehand.
26 * There is several possible interfaces for this, ranging from the really completely automatic parsing to
27 * completely manual. Let's study each of them from the simplest to the more advanced.
29 * \warning At least, I would like to present those sections in the right order, but doxygen prevents me
30 * from doing so. There is a weird bug I fail to circumvent here. The right order is naturally:
32 * -# Automatic parsing
33 * -# Simple manual definitions
34 * -# Callback Persistant State: Simple push/pop mechanism
35 * -# Callback Persistant State: Full featured mechanism
39 /** @name 1. basic operations
41 * If you only want to send pre-existing types, simply retrieve the pre-defined description with
42 * the \ref gras_datadesc_by_name function. Existing types entail:
43 * - char (both signed and unsigned)
44 * - int (short, regular, long and long long, both signed and unsigned)
46 * - string (which is indeed a reference to a dynamically sized array of char, strlen being used to retrive the size)
48 * Example:\verbatim gras_datadesc_type_t i = gras_datadesc_by_name("int");
49 gras_datadesc_type_t uc = gras_datadesc_by_name("unsigned char");
50 gras_datadesc_type_t str = gras_datadesc_by_name("string");\endverbatim
54 /** @brief Opaque type describing a type description. */
55 typedef struct s_gras_datadesc_type *gras_datadesc_type_t;
57 /** \brief Search a type description from its name */
58 gras_datadesc_type_t gras_datadesc_by_name(const char *name);
62 /** @name 2. Automatic parsing
64 * If you need to declare a new datatype, this is the simplest way to describe it to GRAS. Simply
65 * enclose its type definition into a \ref GRAS_DEFINE_TYPE macro call, and you're set. Here is
66 * an type declaration example: \verbatim GRAS_DEFINE_TYPE(mytype,struct mytype {
70 * The type is then both copied verbatim into your source file and stored for further parsing. This allows
71 * you to let GRAS parse the exact version you are actually using in your program.
72 * You can then retrieve the corresponding type description with \ref gras_datadesc_by_symbol.
73 * Don't worry too much for the performances, the type is only parsed once and a binary representation
74 * is stored and used in any subsequent calls.
76 * If your structure contains any pointer, you have to explain GRAS the size of the pointed array. This
77 * can be 1 in the case of simple references, or more in the case of regular arrays. For that, use the
78 * \ref GRAS_ANNOTE macro within the type declaration you are passing to \ref GRAS_DEFINE_TYPE. This macro
79 * rewrites itself to nothing in the declaration (so they won't pollute the type definition copied verbatim
80 * into your code), and give some information to GRAS about your pointer.
82 * GRAS_ANNOTE takes two arguments being the key name and the key value. For now, the only accepted key name
83 * is "size", to specify the length of the pointed array. It can either be the string "1" (without the quote)
84 * or the name of another field of the structure.
86 * Here is an example:\verbatim GRAS_DEFINE_TYPE(s_clause,
89 int *data GRAS_ANNOTE(size,length);
90 struct s_array *father GRAS_ANNOTE(size,1);
93 * It specifies that the structure s_array contains two fields, and that the size of the array pointed
94 * by \a data is the \a length field, and that the \a father field is a simple reference.
96 * If you cannot express your datadescs with this mechanism, you'll have to use the more advanced
97 * (and somehow complex) one described below.
99 * \warning Since GRAS_DEFINE_TYPE is a macro, you shouldn't put any comma in your type definition
100 * (comma separates macro args).
102 * For example, change \verbatim int a, b;\endverbatim to \verbatim int a;
108 /** @brief Automatically parse C code
111 #define GRAS_DEFINE_TYPE(name,def) \
112 static const char * _gras_this_type_symbol_does_not_exist__##name=#def; def
114 /** @brief Retrieve a datadesc which was previously parsed
117 #define gras_datadesc_by_symbol(name) \
118 (gras_datadesc_by_name(#name) ? \
119 gras_datadesc_by_name(#name) : \
120 gras_datadesc_parse(#name, \
121 _gras_this_type_symbol_does_not_exist__##name) \
125 * @brief Add an annotation to a type to be automatically parsed
127 #define GRAS_ANNOTE(key,val)
132 gras_datadesc_parse(const char *name, const char *C_statement);
134 /** @name 3. Simple manual definitions
136 * Here are the functions to use if you want to declare your description manually.
137 * The function names should be self-explanatory in most cases.
139 * You can add callbacks to the datatypes doing any kind of action you may want. Usually,
140 * pre-send callbacks are used to prepare the type expedition while post-receive callbacks
141 * are used to fix any issue after the receive.
143 * If your types are dynamic, you'll need to add some extra callback. For example, there is a
144 * specific callback for the string type which is in charge of computing the length of the char
145 * array. This is done with the cbps mechanism, explained in next section.
147 * If your types may contain pointer cycle, you must specify it to GRAS using the @ref gras_datadesc_cycle_set.
152 unsigned long int l1;
154 unsigned long int l2;
157 my_type=gras_datadesc_struct("mystruct");
158 gras_datadesc_struct_append(my_type,"c1", gras_datadesc_by_name("unsigned char"));
159 gras_datadesc_struct_append(my_type,"l1", gras_datadesc_by_name("unsigned long"));
160 gras_datadesc_struct_append(my_type,"c2", gras_datadesc_by_name("unsigned char"));
161 gras_datadesc_struct_append(my_type,"l2", gras_datadesc_by_name("unsigned long int"));
162 gras_datadesc_struct_close(my_type);
164 my_type=gras_datadesc_ref("mystruct*", gras_datadesc_by_name("mystruct"));
166 [Use my_type to send pointers to mystruct data]\endverbatim
171 /** \brief Opaque type describing a type description callback persistant state. */
172 typedef struct s_gras_cbps *gras_cbps_t;
174 /* callbacks prototypes */
175 /** \brief Prototype of type callbacks returning nothing. */
176 typedef void (*gras_datadesc_type_cb_void_t)(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
177 /** \brief Prototype of type callbacks returning an int. */
178 typedef int (*gras_datadesc_type_cb_int_t)(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
179 /** \brief Prototype of type callbacks selecting a type. */
180 typedef gras_datadesc_type_t (*gras_datadesc_selector_t)(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
183 /******************************************
184 **** Declare datadescription yourself ****
185 ******************************************/
187 gras_datadesc_type_t gras_datadesc_struct(const char *name);
188 void gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
190 gras_datadesc_type_t field_type);
191 void gras_datadesc_struct_close(gras_datadesc_type_t struct_type);
194 gras_datadesc_type_t gras_datadesc_union(const char *name,
195 gras_datadesc_type_cb_int_t selector);
196 void gras_datadesc_union_append(gras_datadesc_type_t union_type,
198 gras_datadesc_type_t field_type);
199 void gras_datadesc_union_close(gras_datadesc_type_t union_type);
203 gras_datadesc_ref(const char *name,
204 gras_datadesc_type_t referenced_type);
206 gras_datadesc_ref_generic(const char *name,
207 gras_datadesc_selector_t selector);
210 gras_datadesc_array_fixed(const char *name,
211 gras_datadesc_type_t element_type,
212 long int fixed_size);
214 gras_datadesc_array_dyn(const char *name,
215 gras_datadesc_type_t element_type,
216 gras_datadesc_type_cb_int_t dynamic_size);
218 gras_datadesc_ref_pop_arr(gras_datadesc_type_t element_type);
221 gras_datadesc_dynar(gras_datadesc_type_t elm_t,
222 void_f_pvoid_t *free_func);
224 /*********************************
225 * Change stuff within datadescs *
226 *********************************/
228 /** \brief Specify that this type may contain cycles */
229 void gras_datadesc_cycle_set(gras_datadesc_type_t type);
230 /** \brief Specify that this type do not contain any cycles (default) */
231 void gras_datadesc_cycle_unset(gras_datadesc_type_t type);
232 /** \brief Add a pre-send callback to this datadesc. */
233 void gras_datadesc_cb_send (gras_datadesc_type_t type,
234 gras_datadesc_type_cb_void_t pre);
235 /** \brief Add a post-receive callback to this datadesc.*/
236 void gras_datadesc_cb_recv(gras_datadesc_type_t type,
237 gras_datadesc_type_cb_void_t post);
238 /** \brief Add a pre-send callback to the given field of the datadesc */
239 void gras_datadesc_cb_field_send (gras_datadesc_type_t type,
240 const char *field_name,
241 gras_datadesc_type_cb_void_t pre);
242 /** \brief Add a post-receive callback to the given field of the datadesc */
243 void gras_datadesc_cb_field_recv(gras_datadesc_type_t type,
244 const char *field_name,
245 gras_datadesc_type_cb_void_t post);
246 /** \brief Add a pre-send callback to the given field resulting in its value to be pushed */
247 void gras_datadesc_cb_field_push (gras_datadesc_type_t type,
248 const char *field_name);
250 /******************************
251 * Get stuff within datadescs *
252 ******************************/
253 /** \brief Returns the name of a datadescription */
254 const char * gras_datadesc_get_name(gras_datadesc_type_t ddt);
255 /** \brief Returns the identifier of a datadescription */
256 int gras_datadesc_get_id(gras_datadesc_type_t ddt);
260 /** @name 4. Callback Persistant State: Simple push/pop mechanism
262 * Sometimes, one of the callbacks need to leave information for the next ones. If this is a simple integer (such as
263 * an array size), you can use the functions described here. If not, you'll have to play with the complete cbps interface.
265 * Here is an example:\verbatim
271 my_type=gras_datadesc_struct("s_array");
272 gras_datadesc_struct_append(my_type,"length", gras_datadesc_by_name("int"));
273 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
275 gras_datadesc_struct_append(my_type,"data",
276 gras_datadesc_array_dyn ("s_array::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
277 gras_datadesc_struct_close(my_type);
284 gras_cbps_i_push(gras_cbps_t ps, int val);
286 gras_cbps_i_pop(gras_cbps_t ps);
288 int gras_datadesc_cb_pop(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
289 void gras_datadesc_cb_push_int(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
290 void gras_datadesc_cb_push_uint(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
291 void gras_datadesc_cb_push_lint(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
292 void gras_datadesc_cb_push_ulint(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
297 /** @name 5. Callback Persistant State: Full featured mechanism
299 * Sometimes, one of the callbacks need to leave information for the next ones. If the simple push/pop mechanism
300 * introduced in previous section isn't enough, you can always use this full featured one.
306 gras_cbps_v_pop (gras_cbps_t ps,
308 /* OUT */ gras_datadesc_type_t *ddt,
309 /* OUT */ void **res);
311 gras_cbps_v_push(gras_cbps_t ps,
314 gras_datadesc_type_t ddt);
316 gras_cbps_v_set (gras_cbps_t ps,
319 gras_datadesc_type_t ddt);
322 gras_cbps_v_get (gras_cbps_t ps,
324 /* OUT */ gras_datadesc_type_t *ddt);
327 gras_cbps_block_begin(gras_cbps_t ps);
329 gras_cbps_block_end(gras_cbps_t ps);
335 /*******************************
336 **** About data convertion ****
337 *******************************/
338 int gras_arch_selfid(void); /* ID of this arch */
341 /*****************************
342 **** NWS datadescription * FIXME: obsolete?
343 *****************************/
346 * Basic types we can embeed in DataDescriptors.
349 {CHAR_TYPE, DOUBLE_TYPE, FLOAT_TYPE, INT_TYPE, LONG_TYPE, SHORT_TYPE,
350 UNSIGNED_INT_TYPE, UNSIGNED_LONG_TYPE, UNSIGNED_SHORT_TYPE, STRUCT_TYPE}
352 #define SIMPLE_TYPE_COUNT 9
354 /*! \brief Describe a collection of data.
356 ** A description of a collection of #type# data. #repetitions# is used only
357 ** for arrays; it contains the number of elements. #offset# is used only for
358 ** struct members in host format; it contains the offset of the member from the
359 ** beginning of the struct, taking into account internal padding added by the
360 ** compiler for alignment purposes. #members#, #length#, and #tailPadding# are
361 ** used only for STRUCT_TYPE data; the #length#-long array #members# describes
362 ** the members of the nested struct, and #tailPadding# indicates how many
363 ** padding bytes the compiler adds to the end of the structure.
366 typedef struct DataDescriptorStruct {
370 /*@null@*/ struct DataDescriptorStruct *members;
374 /** DataDescriptor for an array */
375 #define SIMPLE_DATA(type,repetitions) \
376 {type, repetitions, 0, NULL, 0, 0}
377 /** DataDescriptor for an structure member */
378 #define SIMPLE_MEMBER(type,repetitions,offset) \
379 {type, repetitions, offset, NULL, 0, 0}
380 /** DataDescriptor for padding bytes */
381 #define PAD_BYTES(structType,lastMember,memberType,repetitions) \
382 sizeof(structType) - offsetof(structType, lastMember) - \
383 sizeof(memberType) * repetitions
386 gras_datadesc_import_nws(const char *name,
387 const DataDescriptor *desc,
388 unsigned long howmany,
389 /* OUT */ gras_datadesc_type_t *dst);
394 #endif /* GRAS_DATADESC_H */