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1 | #ifndef CTF_BFCR_H |
2 | #define CTF_BFCR_H | |
3 | ||
4 | /* | |
5 | * Babeltrace - CTF binary field class reader (BFCR) | |
6 | * | |
7 | * Copyright (c) 2015-2016 EfficiOS Inc. and Linux Foundation | |
8 | * Copyright (c) 2015-2016 Philippe Proulx <pproulx@efficios.com> | |
9 | * | |
10 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
11 | * of this software and associated documentation files (the "Software"), to deal | |
12 | * in the Software without restriction, including without limitation the rights | |
13 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
14 | * copies of the Software, and to permit persons to whom the Software is | |
15 | * furnished to do so, subject to the following conditions: | |
16 | * | |
17 | * The above copyright notice and this permission notice shall be included in | |
18 | * all copies or substantial portions of the Software. | |
19 | * | |
20 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
21 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
22 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
23 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
24 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
25 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
26 | * SOFTWARE. | |
27 | */ | |
28 | ||
29 | #include <stdint.h> | |
30 | #include <stddef.h> | |
31 | #include <stdio.h> | |
32 | #include <babeltrace/babeltrace.h> | |
33 | #include <babeltrace/babeltrace-internal.h> | |
34 | ||
35 | #include "../metadata/ctf-meta.h" | |
36 | ||
37 | /** | |
38 | * @file bfcr.h | |
39 | * | |
40 | * Event-driven CTF binary field class reader (BFCR). | |
41 | * | |
42 | * This is a common, internal API used by CTF source plugins. It allows | |
43 | * a binary CTF IR field class to be decoded from user-provided buffers. | |
44 | * As the class is decoded (and, possibly, its nested classes), | |
45 | * registered user callback functions are called. | |
46 | * | |
47 | * This API is only concerned with reading one CTF class at a time from | |
48 | * one or more buffer of bytes. It does not know CTF dynamic scopes, | |
49 | * events, or streams. Sequence lengths and selected variant classes are | |
50 | * requested to the user when needed. | |
51 | */ | |
52 | ||
53 | /** | |
54 | * Binary class reader API status codes. | |
55 | */ | |
56 | enum bt_bfcr_status { | |
57 | /** Out of memory. */ | |
58 | BT_BFCR_STATUS_ENOMEM = -5, | |
59 | /** | |
60 | * The binary stream reader reached the end of the user-provided | |
61 | * buffer, but data is still needed to finish decoding the | |
62 | * requested class. | |
63 | * | |
64 | * The user needs to call bt_bfcr_continue() as long as | |
65 | * #BT_BFCR_STATUS_EOF is returned to complete the decoding | |
66 | * process of a given class. | |
67 | */ | |
68 | BT_BFCR_STATUS_EOF = 1, | |
69 | ||
70 | /** Invalid argument. */ | |
71 | BT_BFCR_STATUS_INVAL = -3, | |
72 | ||
73 | /** General error. */ | |
74 | BT_BFCR_STATUS_ERROR = -1, | |
75 | ||
76 | /** Everything okay. */ | |
77 | BT_BFCR_STATUS_OK = 0, | |
78 | }; | |
79 | ||
80 | /** Field class reader. */ | |
81 | struct bt_bfcr; | |
82 | ||
83 | typedef enum bt_bfcr_status (* bt_bfcr_unsigned_int_cb_func)(uint64_t, | |
84 | struct ctf_field_class *, void *); | |
85 | ||
86 | /* | |
87 | * Field class reader user callback functions. | |
88 | */ | |
89 | struct bt_bfcr_cbs { | |
90 | /** | |
91 | * Field class callback functions. | |
92 | * | |
93 | * This CTF binary class reader is event-driven. The following | |
94 | * functions are called during the decoding process, either when | |
95 | * a compound class begins/ends, or when a basic class is | |
96 | * completely decoded (along with its value). | |
97 | * | |
98 | * Each function also receives the CTF field class associated | |
99 | * with the call, and user data (registered to the class reader | |
100 | * calling them). | |
101 | * | |
102 | * Actual trace IR fields are \em not created here; this would | |
103 | * be the responsibility of a class reader's user (the provider | |
104 | * of those callback functions). | |
105 | * | |
106 | * All the class callback functions return one of the following | |
107 | * values: | |
108 | * | |
109 | * - <b>#BT_BFCR_STATUS_OK</b>: Everything is okay; | |
110 | * continue the decoding process. | |
111 | * - <b>#BT_BFCR_STATUS_ERROR</b>: General error (reported | |
112 | * to class reader's user). | |
113 | * | |
114 | * Any member of this structure may be set to \c NULL, should | |
d6e69534 | 115 | * a specific message be not needed. |
5cd6d0e5 PP |
116 | */ |
117 | struct { | |
118 | /** | |
119 | * Called when a signed integer class is completely | |
120 | * decoded. This could also be the supporting signed | |
121 | * integer class of an enumeration class (\p class will | |
122 | * indicate this). | |
123 | * | |
124 | * @param value Signed integer value | |
125 | * @param class Integer or enumeration class | |
126 | * @param data User data | |
127 | * @returns #BT_BFCR_STATUS_OK or | |
128 | * #BT_BFCR_STATUS_ERROR | |
129 | */ | |
130 | enum bt_bfcr_status (* signed_int)(int64_t value, | |
131 | struct ctf_field_class *cls, void *data); | |
132 | ||
133 | /** | |
134 | * Called when an unsigned integer class is completely | |
135 | * decoded. This could also be the supporting signed | |
136 | * integer class of an enumeration class (\p class will | |
137 | * indicate this). | |
138 | * | |
139 | * @param value Unsigned integer value | |
140 | * @param class Integer or enumeration class | |
141 | * @param data User data | |
142 | * @returns #BT_BFCR_STATUS_OK or | |
143 | * #BT_BFCR_STATUS_ERROR | |
144 | */ | |
145 | bt_bfcr_unsigned_int_cb_func unsigned_int; | |
146 | ||
147 | /** | |
148 | * Called when a floating point number class is | |
149 | * completely decoded. | |
150 | * | |
151 | * @param value Floating point number value | |
152 | * @param class Floating point number class | |
153 | * @param data User data | |
154 | * @returns #BT_BFCR_STATUS_OK or | |
155 | * #BT_BFCR_STATUS_ERROR | |
156 | */ | |
157 | enum bt_bfcr_status (* floating_point)(double value, | |
158 | struct ctf_field_class *cls, void *data); | |
159 | ||
160 | /** | |
161 | * Called when a string class begins. | |
162 | * | |
163 | * All the following user callback function calls will | |
164 | * be made to bt_bfcr_cbs::classes::string(), each of | |
165 | * them providing one substring of the complete string | |
166 | * class's value. | |
167 | * | |
168 | * @param class Beginning string class | |
169 | * @param data User data | |
170 | * @returns #BT_BFCR_STATUS_OK or | |
171 | * #BT_BFCR_STATUS_ERROR | |
172 | */ | |
173 | enum bt_bfcr_status (* string_begin)( | |
174 | struct ctf_field_class *cls, void *data); | |
175 | ||
176 | /** | |
177 | * Called when a string class's substring is decoded | |
178 | * (between a call to bt_bfcr_cbs::classes::string_begin() | |
179 | * and a call to bt_bfcr_cbs::classes::string_end()). | |
180 | * | |
181 | * @param value String value (\em not null-terminated) | |
182 | * @param len String value length | |
183 | * @param class String class | |
184 | * @param data User data | |
185 | * @returns #BT_BFCR_STATUS_OK or | |
186 | * #BT_BFCR_STATUS_ERROR | |
187 | */ | |
188 | enum bt_bfcr_status (* string)(const char *value, | |
189 | size_t len, struct ctf_field_class *cls, | |
190 | void *data); | |
191 | ||
192 | /** | |
193 | * Called when a string class ends. | |
194 | * | |
195 | * @param class Ending string class | |
196 | * @param data User data | |
197 | * @returns #BT_BFCR_STATUS_OK or | |
198 | * #BT_BFCR_STATUS_ERROR | |
199 | */ | |
200 | enum bt_bfcr_status (* string_end)( | |
201 | struct ctf_field_class *cls, void *data); | |
202 | ||
203 | /** | |
204 | * Called when a compound class begins. | |
205 | * | |
206 | * All the following class callback function calls will | |
207 | * signal sequential elements of this compound class, | |
208 | * until the next corresponding | |
209 | * bt_bfcr_cbs::classes::compound_end() is called. | |
210 | * | |
211 | * If \p class is a variant class, then only one class | |
212 | * callback function call will follow before the call to | |
213 | * bt_bfcr_cbs::classes::compound_end(). This single | |
214 | * call indicates the selected class of this variant | |
215 | * class. | |
216 | * | |
217 | * @param class Beginning compound class | |
218 | * @param data User data | |
219 | * @returns #BT_BFCR_STATUS_OK or | |
220 | * #BT_BFCR_STATUS_ERROR | |
221 | */ | |
222 | enum bt_bfcr_status (* compound_begin)( | |
223 | struct ctf_field_class *cls, void *data); | |
224 | ||
225 | /** | |
226 | * Called when a compound class ends. | |
227 | * | |
228 | * @param class Ending compound class | |
229 | * @param data User data | |
230 | * @returns #BT_BFCR_STATUS_OK or | |
231 | * #BT_BFCR_STATUS_ERROR | |
232 | */ | |
233 | enum bt_bfcr_status (* compound_end)( | |
234 | struct ctf_field_class *cls, void *data); | |
235 | } classes; | |
236 | ||
237 | /** | |
238 | * Query callback functions are used when the class reader needs | |
239 | * dynamic information, i.e. a sequence class's current length | |
240 | * or a variant class's current selected class. | |
241 | * | |
242 | * Both functions need to be set unless it is known that no | |
243 | * sequences or variants will have to be decoded. | |
244 | */ | |
245 | struct { | |
246 | /** | |
247 | * Called to query the current length of a given sequence | |
248 | * class. | |
249 | * | |
250 | * @param class Sequence class | |
251 | * @param data User data | |
252 | * @returns Sequence length or | |
253 | * #BT_BFCR_STATUS_ERROR on error | |
254 | */ | |
255 | int64_t (* get_sequence_length)(struct ctf_field_class *cls, | |
256 | void *data); | |
257 | ||
258 | /** | |
259 | * Called to query the current selected class of a given | |
260 | * variant class. | |
261 | * | |
262 | * @param class Variant class | |
263 | * @param data User data | |
264 | * @returns Current selected class (owned by | |
265 | * this) or \c NULL on error | |
266 | */ | |
267 | struct ctf_field_class * (* borrow_variant_selected_field_class)( | |
268 | struct ctf_field_class *cls, void *data); | |
269 | } query; | |
270 | }; | |
271 | ||
272 | /** | |
273 | * Creates a CTF binary class reader. | |
274 | * | |
275 | * @param cbs User callback functions | |
276 | * @param data User data (passed to user callback functions) | |
277 | * @returns New binary class reader on success, or \c NULL on error | |
278 | */ | |
279 | BT_HIDDEN | |
280 | struct bt_bfcr *bt_bfcr_create(struct bt_bfcr_cbs cbs, void *data); | |
281 | ||
282 | /** | |
283 | * Destroys a CTF binary class reader, freeing all internal resources. | |
284 | * | |
285 | * @param bfcr Binary class reader | |
286 | */ | |
287 | BT_HIDDEN | |
288 | void bt_bfcr_destroy(struct bt_bfcr *bfcr); | |
289 | ||
290 | /** | |
291 | * Decodes a given CTF class from a buffer of bytes. | |
292 | * | |
293 | * The number of \em bits consumed by this function is returned. | |
294 | * | |
295 | * The \p status output parameter is where a status is written, amongst | |
296 | * the following: | |
297 | * | |
298 | * - <b>#BT_BFCR_STATUS_OK</b>: Decoding is done. | |
299 | * - <b>#BT_BFCR_STATUS_EOF</b>: The end of the buffer was reached, | |
300 | * but more data is needed to finish the decoding process of the | |
301 | * requested class. The user needs to call bt_bfcr_continue() | |
302 | * as long as #BT_BFCR_STATUS_EOF is returned to complete the | |
303 | * decoding process of the original class. | |
304 | * - <b>#BT_BFCR_STATUS_INVAL</b>: Invalid argument. | |
305 | * - <b>#BT_BFCR_STATUS_ERROR</b>: General error. | |
306 | * | |
307 | * Calling this function resets the class reader's internal state. If | |
308 | * #BT_BFCR_STATUS_EOF is returned, bt_bfcr_continue() needs to | |
309 | * be called next, \em not bt_bfcr_decode(). | |
310 | * | |
311 | * @param bfcr Binary class reader | |
312 | * @param class Field class to decode | |
313 | * @param buf Buffer | |
314 | * @param offset Offset of first bit from \p buf (bits) | |
315 | * @param packet_offset Offset of \p offset within the CTF | |
316 | * binary packet containing \p class (bits) | |
317 | * @param sz Size of buffer in bytes (from \p buf) | |
318 | * @param status Returned status (see description above) | |
319 | * @returns Number of consumed bits | |
320 | */ | |
321 | BT_HIDDEN | |
322 | size_t bt_bfcr_start(struct bt_bfcr *bfcr, | |
323 | struct ctf_field_class *cls, const uint8_t *buf, | |
324 | size_t offset, size_t packet_offset, size_t sz, | |
325 | enum bt_bfcr_status *status); | |
326 | ||
327 | /** | |
328 | * Continues the decoding process a given CTF class. | |
329 | * | |
330 | * The number of bits consumed by this function is returned. | |
331 | * | |
332 | * The \p status output parameter is where a status is placed, amongst | |
333 | * the following: | |
334 | * | |
335 | * - <b>#BT_BFCR_STATUS_OK</b>: decoding is done. | |
336 | * - <b>#BT_BFCR_STATUS_EOF</b>: the end of the buffer was reached, | |
337 | * but more data is needed to finish the decoding process of the | |
338 | * requested class. The user needs to call bt_bfcr_continue() | |
339 | * as long as #BT_BFCR_STATUS_EOF is returned to complete the | |
340 | * decoding process of the original class. | |
341 | * - <b>#BT_BFCR_STATUS_INVAL</b>: invalid argument. | |
342 | * - <b>#BT_BFCR_STATUS_ERROR</b>: general error. | |
343 | * | |
344 | * @param bfcr Binary class reader | |
345 | * @param buf Buffer | |
346 | * @param sz Size of buffer in bytes (from \p offset) | |
347 | * @param status Returned status (see description above) | |
348 | * @returns Number of consumed bits | |
349 | */ | |
350 | BT_HIDDEN | |
351 | size_t bt_bfcr_continue(struct bt_bfcr *bfcr, | |
352 | const uint8_t *buf, size_t sz, | |
353 | enum bt_bfcr_status *status); | |
354 | ||
355 | BT_HIDDEN | |
356 | void bt_bfcr_set_unsigned_int_cb(struct bt_bfcr *bfcr, | |
357 | bt_bfcr_unsigned_int_cb_func cb); | |
358 | ||
359 | static inline | |
360 | const char *bt_bfcr_status_string(enum bt_bfcr_status status) | |
361 | { | |
362 | switch (status) { | |
363 | case BT_BFCR_STATUS_ENOMEM: | |
364 | return "BT_BFCR_STATUS_ENOMEM"; | |
365 | case BT_BFCR_STATUS_EOF: | |
366 | return "BT_BFCR_STATUS_EOF"; | |
367 | case BT_BFCR_STATUS_INVAL: | |
368 | return "BT_BFCR_STATUS_INVAL"; | |
369 | case BT_BFCR_STATUS_ERROR: | |
370 | return "BT_BFCR_STATUS_ERROR"; | |
371 | case BT_BFCR_STATUS_OK: | |
372 | return "BT_BFCR_STATUS_OK"; | |
373 | default: | |
374 | return "(unknown)"; | |
375 | } | |
376 | } | |
377 | ||
378 | #endif /* CTF_BFCR_H */ |