| 1 | #ifndef CTF_MSG_ITER_H |
| 2 | #define CTF_MSG_ITER_H |
| 3 | |
| 4 | /* |
| 5 | * Babeltrace - CTF message iterator |
| 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 <stdio.h> |
| 31 | #include <stddef.h> |
| 32 | #include <babeltrace2/babeltrace.h> |
| 33 | #include <babeltrace2/babeltrace-internal.h> |
| 34 | |
| 35 | #include "../metadata/ctf-meta.h" |
| 36 | |
| 37 | /** |
| 38 | * @file ctf-msg-iter.h |
| 39 | * |
| 40 | * CTF message iterator |
| 41 | * |
| 42 | * This is a common internal API used by CTF source plugins. It allows |
| 43 | * one to get messages from a user-provided medium. |
| 44 | */ |
| 45 | |
| 46 | /** |
| 47 | * Medium operations status codes. |
| 48 | */ |
| 49 | enum bt_msg_iter_medium_status { |
| 50 | /** |
| 51 | * End of file. |
| 52 | * |
| 53 | * The medium function called by the message iterator |
| 54 | * function reached the end of the file. |
| 55 | */ |
| 56 | BT_MSG_ITER_MEDIUM_STATUS_EOF = 1, |
| 57 | |
| 58 | /** |
| 59 | * There is no data available right now, try again later. |
| 60 | */ |
| 61 | BT_MSG_ITER_MEDIUM_STATUS_AGAIN = 11, |
| 62 | |
| 63 | /** Unsupported operation. */ |
| 64 | BT_MSG_ITER_MEDIUM_STATUS_UNSUPPORTED = -3, |
| 65 | |
| 66 | /** Invalid argument. */ |
| 67 | BT_MSG_ITER_MEDIUM_STATUS_INVAL = -2, |
| 68 | |
| 69 | /** General error. */ |
| 70 | BT_MSG_ITER_MEDIUM_STATUS_ERROR = -1, |
| 71 | |
| 72 | /** Everything okay. */ |
| 73 | BT_MSG_ITER_MEDIUM_STATUS_OK = 0, |
| 74 | }; |
| 75 | |
| 76 | /** |
| 77 | * CTF message iterator API status code. |
| 78 | */ |
| 79 | enum bt_msg_iter_status { |
| 80 | /** |
| 81 | * End of file. |
| 82 | * |
| 83 | * The medium function called by the message iterator |
| 84 | * function reached the end of the file. |
| 85 | */ |
| 86 | BT_MSG_ITER_STATUS_EOF = BT_MSG_ITER_MEDIUM_STATUS_EOF, |
| 87 | |
| 88 | /** |
| 89 | * There is no data available right now, try again later. |
| 90 | * |
| 91 | * Some condition resulted in the |
| 92 | * bt_msg_iter_medium_ops::request_bytes() user function not |
| 93 | * having access to any data now. You should retry calling the |
| 94 | * last called message iterator function once the situation |
| 95 | * is resolved. |
| 96 | */ |
| 97 | BT_MSG_ITER_STATUS_AGAIN = BT_MSG_ITER_MEDIUM_STATUS_AGAIN, |
| 98 | |
| 99 | /** Invalid argument. */ |
| 100 | BT_MSG_ITER_STATUS_INVAL = BT_MSG_ITER_MEDIUM_STATUS_INVAL, |
| 101 | |
| 102 | /** Unsupported operation. */ |
| 103 | BT_MSG_ITER_STATUS_UNSUPPORTED = BT_MSG_ITER_MEDIUM_STATUS_UNSUPPORTED, |
| 104 | |
| 105 | /** General error. */ |
| 106 | BT_MSG_ITER_STATUS_ERROR = BT_MSG_ITER_MEDIUM_STATUS_ERROR, |
| 107 | |
| 108 | /** Everything okay. */ |
| 109 | BT_MSG_ITER_STATUS_OK = 0, |
| 110 | }; |
| 111 | |
| 112 | /** |
| 113 | * CTF message iterator seek operation directives. |
| 114 | */ |
| 115 | enum bt_msg_iter_seek_whence { |
| 116 | /** |
| 117 | * Set the iterator's position to an absolute offset in the underlying |
| 118 | * medium. |
| 119 | */ |
| 120 | BT_MSG_ITER_SEEK_WHENCE_SET, |
| 121 | }; |
| 122 | |
| 123 | /** |
| 124 | * Medium operations. |
| 125 | * |
| 126 | * Those user functions are called by the message iterator |
| 127 | * functions to request medium actions. |
| 128 | */ |
| 129 | struct bt_msg_iter_medium_ops { |
| 130 | /** |
| 131 | * Returns the next byte buffer to be used by the binary file |
| 132 | * reader to deserialize binary data. |
| 133 | * |
| 134 | * This function \em must be defined. |
| 135 | * |
| 136 | * The purpose of this function is to return a buffer of bytes |
| 137 | * to the message iterator, of a maximum of \p request_sz |
| 138 | * bytes. If this function cannot return a buffer of at least |
| 139 | * \p request_sz bytes, it may return a smaller buffer. In |
| 140 | * either cases, \p buffer_sz must be set to the returned buffer |
| 141 | * size (in bytes). |
| 142 | * |
| 143 | * The returned buffer's ownership remains the medium, in that |
| 144 | * it won't be freed by the message iterator functions. The |
| 145 | * returned buffer won't be modified by the message |
| 146 | * iterator functions either. |
| 147 | * |
| 148 | * When this function is called for the first time for a given |
| 149 | * file, the offset within the file is considered to be 0. The |
| 150 | * next times this function is called, the returned buffer's |
| 151 | * byte offset within the complete file must be the previous |
| 152 | * offset plus the last returned value of \p buffer_sz by this |
| 153 | * medium. |
| 154 | * |
| 155 | * This function must return one of the following statuses: |
| 156 | * |
| 157 | * - <b>#BT_MSG_ITER_MEDIUM_STATUS_OK</b>: Everything |
| 158 | * is okay, i.e. \p buffer_sz is set to a positive value |
| 159 | * reflecting the number of available bytes in the buffer |
| 160 | * starting at the address written in \p buffer_addr. |
| 161 | * - <b>#BT_MSG_ITER_MEDIUM_STATUS_AGAIN</b>: No data is |
| 162 | * available right now. In this case, the message |
| 163 | * iterator function called by the user returns |
| 164 | * #BT_MSG_ITER_STATUS_AGAIN, and it is the user's |
| 165 | * responsibility to make sure enough data becomes available |
| 166 | * before calling the \em same message iterator |
| 167 | * function again to continue the decoding process. |
| 168 | * - <b>#BT_MSG_ITER_MEDIUM_STATUS_EOF</b>: The end of |
| 169 | * the file was reached, and no more data will ever be |
| 170 | * available for this file. In this case, the message |
| 171 | * iterator function called by the user returns |
| 172 | * #BT_MSG_ITER_STATUS_EOF. This must \em not be |
| 173 | * returned when returning at least one byte of data to the |
| 174 | * caller, i.e. this must be returned when there's |
| 175 | * absolutely nothing left; should the request size be |
| 176 | * larger than what's left in the file, this function must |
| 177 | * return what's left, setting \p buffer_sz to the number of |
| 178 | * remaining bytes, and return |
| 179 | * #BT_MSG_ITER_MEDIUM_STATUS_EOF on the \em following |
| 180 | * call. |
| 181 | * - <b>#BT_MSG_ITER_MEDIUM_STATUS_ERROR</b>: A fatal |
| 182 | * error occured during this operation. In this case, the |
| 183 | * message iterator function called by the user returns |
| 184 | * #BT_MSG_ITER_STATUS_ERROR. |
| 185 | * |
| 186 | * If #BT_MSG_ITER_MEDIUM_STATUS_OK is not returned, the |
| 187 | * values of \p buffer_sz and \p buffer_addr are \em ignored by |
| 188 | * the caller. |
| 189 | * |
| 190 | * @param request_sz Requested buffer size (bytes) |
| 191 | * @param buffer_addr Returned buffer address |
| 192 | * @param buffer_sz Returned buffer's size (bytes) |
| 193 | * @param data User data |
| 194 | * @returns Status code (see description above) |
| 195 | */ |
| 196 | enum bt_msg_iter_medium_status (* request_bytes)(size_t request_sz, |
| 197 | uint8_t **buffer_addr, size_t *buffer_sz, void *data); |
| 198 | |
| 199 | /** |
| 200 | * Repositions the underlying stream's position. |
| 201 | * |
| 202 | * This *optional* method repositions the underlying stream |
| 203 | * to a given absolute or relative position, as indicated by |
| 204 | * the whence directive. |
| 205 | * |
| 206 | * @param whence One of #bt_msg_iter_seek_whence values |
| 207 | * @param offset Offset to use for the given directive |
| 208 | * @param data User data |
| 209 | * @returns One of #bt_msg_iter_medium_status values |
| 210 | */ |
| 211 | enum bt_msg_iter_medium_status (* seek)( |
| 212 | enum bt_msg_iter_seek_whence whence, |
| 213 | off_t offset, void *data); |
| 214 | |
| 215 | /** |
| 216 | * Returns a stream instance (weak reference) for the given |
| 217 | * stream class. |
| 218 | * |
| 219 | * This is called after a packet header is read, and the |
| 220 | * corresponding stream class is found by the message |
| 221 | * iterator. |
| 222 | * |
| 223 | * @param stream_class Stream class of the stream to get |
| 224 | * @param stream_id Stream (instance) ID of the stream |
| 225 | * to get (-1ULL if not available) |
| 226 | * @param data User data |
| 227 | * @returns Stream instance (weak reference) or |
| 228 | * \c NULL on error |
| 229 | */ |
| 230 | bt_stream * (* borrow_stream)(bt_stream_class *stream_class, |
| 231 | int64_t stream_id, void *data); |
| 232 | }; |
| 233 | |
| 234 | /** CTF message iterator. */ |
| 235 | struct bt_msg_iter; |
| 236 | |
| 237 | /** |
| 238 | * Creates a CTF message iterator. |
| 239 | * |
| 240 | * Upon successful completion, the reference count of \p trace is |
| 241 | * incremented. |
| 242 | * |
| 243 | * @param trace Trace to read |
| 244 | * @param max_request_sz Maximum buffer size, in bytes, to |
| 245 | * request to |
| 246 | * bt_msg_iter_medium_ops::request_bytes() |
| 247 | * at a time |
| 248 | * @param medops Medium operations |
| 249 | * @param medops_data User data (passed to medium operations) |
| 250 | * @returns New CTF message iterator on |
| 251 | * success, or \c NULL on error |
| 252 | */ |
| 253 | BT_HIDDEN |
| 254 | struct bt_msg_iter *bt_msg_iter_create(struct ctf_trace_class *tc, |
| 255 | size_t max_request_sz, struct bt_msg_iter_medium_ops medops, |
| 256 | void *medops_data); |
| 257 | |
| 258 | /** |
| 259 | * Destroys a CTF message iterator, freeing all internal resources. |
| 260 | * |
| 261 | * The registered trace's reference count is decremented. |
| 262 | * |
| 263 | * @param msg_iter CTF message iterator |
| 264 | */ |
| 265 | BT_HIDDEN |
| 266 | void bt_msg_iter_destroy(struct bt_msg_iter *msg_iter); |
| 267 | |
| 268 | /** |
| 269 | * Returns the next message from a CTF message iterator. |
| 270 | * |
| 271 | * Upon successful completion, #BT_MSG_ITER_STATUS_OK is |
| 272 | * returned, and the next message is written to \p msg. |
| 273 | * In this case, the caller is responsible for calling |
| 274 | * bt_message_put() on the returned message. |
| 275 | * |
| 276 | * If this function returns #BT_MSG_ITER_STATUS_AGAIN, the caller |
| 277 | * should make sure that data becomes available to its medium, and |
| 278 | * call this function again, until another status is returned. |
| 279 | * |
| 280 | * @param msg_iter CTF message iterator |
| 281 | * @param message Returned message if the function's |
| 282 | * return value is #BT_MSG_ITER_STATUS_OK |
| 283 | * @returns One of #bt_msg_iter_status values |
| 284 | */ |
| 285 | BT_HIDDEN |
| 286 | enum bt_msg_iter_status bt_msg_iter_get_next_message( |
| 287 | struct bt_msg_iter *notit, |
| 288 | bt_self_message_iterator *msg_iter, |
| 289 | bt_message **message); |
| 290 | |
| 291 | struct bt_msg_iter_packet_properties { |
| 292 | int64_t exp_packet_total_size; |
| 293 | int64_t exp_packet_content_size; |
| 294 | uint64_t stream_class_id; |
| 295 | int64_t data_stream_id; |
| 296 | |
| 297 | struct { |
| 298 | uint64_t discarded_events; |
| 299 | uint64_t packets; |
| 300 | uint64_t beginning_clock; |
| 301 | uint64_t end_clock; |
| 302 | } snapshots; |
| 303 | }; |
| 304 | |
| 305 | BT_HIDDEN |
| 306 | enum bt_msg_iter_status bt_msg_iter_get_packet_properties( |
| 307 | struct bt_msg_iter *notit, |
| 308 | struct bt_msg_iter_packet_properties *props); |
| 309 | |
| 310 | BT_HIDDEN |
| 311 | void bt_msg_iter_set_medops_data(struct bt_msg_iter *notit, |
| 312 | void *medops_data); |
| 313 | |
| 314 | BT_HIDDEN |
| 315 | enum bt_msg_iter_status bt_msg_iter_seek( |
| 316 | struct bt_msg_iter *notit, off_t offset); |
| 317 | |
| 318 | /* |
| 319 | * Resets the iterator so that the next requested medium bytes are |
| 320 | * assumed to be the first bytes of a new stream. Depending on |
| 321 | * bt_msg_iter_set_emit_stream_beginning_message(), the first message |
| 322 | * which this iterator emits after calling bt_msg_iter_reset() is of |
| 323 | * type `BT_MESSAGE_TYPE_STREAM_BEGINNING`. |
| 324 | */ |
| 325 | BT_HIDDEN |
| 326 | void bt_msg_iter_reset(struct bt_msg_iter *notit); |
| 327 | |
| 328 | /* |
| 329 | * Like bt_msg_iter_reset(), but preserves stream-dependent state. |
| 330 | */ |
| 331 | BT_HIDDEN |
| 332 | void bt_msg_iter_reset_for_next_stream_file(struct bt_msg_iter *notit); |
| 333 | |
| 334 | BT_HIDDEN |
| 335 | void bt_msg_iter_set_emit_stream_beginning_message(struct bt_msg_iter *notit, |
| 336 | bool val); |
| 337 | |
| 338 | BT_HIDDEN |
| 339 | void bt_msg_iter_set_emit_stream_end_message(struct bt_msg_iter *notit, |
| 340 | bool val); |
| 341 | |
| 342 | static inline |
| 343 | const char *bt_msg_iter_medium_status_string( |
| 344 | enum bt_msg_iter_medium_status status) |
| 345 | { |
| 346 | switch (status) { |
| 347 | case BT_MSG_ITER_MEDIUM_STATUS_EOF: |
| 348 | return "BT_MSG_ITER_MEDIUM_STATUS_EOF"; |
| 349 | case BT_MSG_ITER_MEDIUM_STATUS_AGAIN: |
| 350 | return "BT_MSG_ITER_MEDIUM_STATUS_AGAIN"; |
| 351 | case BT_MSG_ITER_MEDIUM_STATUS_INVAL: |
| 352 | return "BT_MSG_ITER_MEDIUM_STATUS_INVAL"; |
| 353 | case BT_MSG_ITER_MEDIUM_STATUS_ERROR: |
| 354 | return "BT_MSG_ITER_MEDIUM_STATUS_ERROR"; |
| 355 | case BT_MSG_ITER_MEDIUM_STATUS_OK: |
| 356 | return "BT_MSG_ITER_MEDIUM_STATUS_OK"; |
| 357 | default: |
| 358 | return "(unknown)"; |
| 359 | } |
| 360 | } |
| 361 | |
| 362 | static inline |
| 363 | const char *bt_msg_iter_status_string( |
| 364 | enum bt_msg_iter_status status) |
| 365 | { |
| 366 | switch (status) { |
| 367 | case BT_MSG_ITER_STATUS_EOF: |
| 368 | return "BT_MSG_ITER_STATUS_EOF"; |
| 369 | case BT_MSG_ITER_STATUS_AGAIN: |
| 370 | return "BT_MSG_ITER_STATUS_AGAIN"; |
| 371 | case BT_MSG_ITER_STATUS_INVAL: |
| 372 | return "BT_MSG_ITER_STATUS_INVAL"; |
| 373 | case BT_MSG_ITER_STATUS_ERROR: |
| 374 | return "BT_MSG_ITER_STATUS_ERROR"; |
| 375 | case BT_MSG_ITER_STATUS_OK: |
| 376 | return "BT_MSG_ITER_STATUS_OK"; |
| 377 | default: |
| 378 | return "(unknown)"; |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | #endif /* CTF_MSG_ITER_H */ |