| 1 | #ifndef CTF_NOTIF_ITER_H |
| 2 | #define CTF_NOTIF_ITER_H |
| 3 | |
| 4 | /* |
| 5 | * Babeltrace - CTF notification 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 <babeltrace/ctf-ir/trace.h> |
| 33 | #include <babeltrace/ctf-ir/fields.h> |
| 34 | #include <babeltrace/ctf-ir/event.h> |
| 35 | #include <babeltrace/babeltrace-internal.h> |
| 36 | |
| 37 | /** |
| 38 | * @file ctf-notif-iter.h |
| 39 | * |
| 40 | * CTF notification iterator |
| 41 | * ¯¯¯¯¯ ¯¯¯¯ |
| 42 | * This is a common internal API used by CTF source plugins. It allows |
| 43 | * one to get notifications from a user-provided medium. |
| 44 | */ |
| 45 | |
| 46 | /** |
| 47 | * Medium operations status codes. |
| 48 | */ |
| 49 | enum bt_ctf_notif_iter_medium_status { |
| 50 | /** |
| 51 | * End of file. |
| 52 | * |
| 53 | * The medium function called by the notification iterator |
| 54 | * function reached the end of the file. |
| 55 | */ |
| 56 | BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF = -4, |
| 57 | |
| 58 | /** |
| 59 | * There is no data available right now, try again later. |
| 60 | */ |
| 61 | BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN = -3, |
| 62 | |
| 63 | /** Invalid argument. */ |
| 64 | BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL = -2, |
| 65 | |
| 66 | /** General error. */ |
| 67 | BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR = -1, |
| 68 | |
| 69 | /** Everything okay. */ |
| 70 | BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK = 0, |
| 71 | }; |
| 72 | |
| 73 | /** |
| 74 | * CTF notification iterator API status code. |
| 75 | */ |
| 76 | enum bt_ctf_notif_iter_status { |
| 77 | /** |
| 78 | * End of file. |
| 79 | * |
| 80 | * The medium function called by the notification iterator |
| 81 | * function reached the end of the file. |
| 82 | */ |
| 83 | BT_CTF_NOTIF_ITER_STATUS_EOF = -4, |
| 84 | |
| 85 | /** |
| 86 | * There is no data available right now, try again later. |
| 87 | * |
| 88 | * Some condition resulted in the |
| 89 | * bt_ctf_notif_iter_medium_ops::request_bytes() user function not |
| 90 | * having access to any data now. You should retry calling the |
| 91 | * last called notification iterator function once the situation |
| 92 | * is resolved. |
| 93 | */ |
| 94 | BT_CTF_NOTIF_ITER_STATUS_AGAIN = -3, |
| 95 | |
| 96 | /** Invalid argument. */ |
| 97 | BT_CTF_NOTIF_ITER_STATUS_INVAL = -2, |
| 98 | |
| 99 | /** General error. */ |
| 100 | BT_CTF_NOTIF_ITER_STATUS_ERROR = -1, |
| 101 | |
| 102 | /** Everything okay. */ |
| 103 | BT_CTF_NOTIF_ITER_STATUS_OK = 0, |
| 104 | }; |
| 105 | |
| 106 | /** |
| 107 | * Medium operations. |
| 108 | * |
| 109 | * Those user functions are called by the notification iterator |
| 110 | * functions to request medium actions. |
| 111 | */ |
| 112 | struct bt_ctf_notif_iter_medium_ops { |
| 113 | /** |
| 114 | * Returns the next byte buffer to be used by the binary file |
| 115 | * reader to deserialize binary data. |
| 116 | * |
| 117 | * This function \em must be defined. |
| 118 | * |
| 119 | * The purpose of this function is to return a buffer of bytes |
| 120 | * to the notification iterator, of a maximum of \p request_sz |
| 121 | * bytes. If this function cannot return a buffer of at least |
| 122 | * \p request_sz bytes, it may return a smaller buffer. In |
| 123 | * either cases, \p buffer_sz must be set to the returned buffer |
| 124 | * size (in bytes). |
| 125 | * |
| 126 | * The returned buffer's ownership remains the medium, in that |
| 127 | * it won't be freed by the notification iterator functions. The |
| 128 | * returned buffer won't be modified by the notification |
| 129 | * iterator functions either. |
| 130 | * |
| 131 | * When this function is called for the first time for a given |
| 132 | * file, the offset within the file is considered to be 0. The |
| 133 | * next times this function is called, the returned buffer's |
| 134 | * byte offset within the complete file must be the previous |
| 135 | * offset plus the last returned value of \p buffer_sz by this |
| 136 | * medium. |
| 137 | * |
| 138 | * This function must return one of the following statuses: |
| 139 | * |
| 140 | * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK</b>: Everything |
| 141 | * is okay, i.e. \p buffer_sz is set to a positive value |
| 142 | * reflecting the number of available bytes in the buffer |
| 143 | * starting at the address written in \p buffer_addr. |
| 144 | * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN</b>: No data is |
| 145 | * available right now. In this case, the notification |
| 146 | * iterator function called by the user returns |
| 147 | * #BT_CTF_NOTIF_ITER_STATUS_AGAIN, and it is the user's |
| 148 | * responsibility to make sure enough data becomes available |
| 149 | * before calling the \em same notification iterator |
| 150 | * function again to continue the decoding process. |
| 151 | * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF</b>: The end of |
| 152 | * the file was reached, and no more data will ever be |
| 153 | * available for this file. In this case, the notification |
| 154 | * iterator function called by the user returns |
| 155 | * #BT_CTF_NOTIF_ITER_STATUS_EOF. This must \em not be |
| 156 | * returned when returning at least one byte of data to the |
| 157 | * caller, i.e. this must be returned when there's |
| 158 | * absolutely nothing left; should the request size be |
| 159 | * larger than what's left in the file, this function must |
| 160 | * return what's left, setting \p buffer_sz to the number of |
| 161 | * remaining bytes, and return |
| 162 | * #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following |
| 163 | * call. |
| 164 | * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR</b>: A fatal |
| 165 | * error occured during this operation. In this case, the |
| 166 | * notification iterator function called by the user returns |
| 167 | * #BT_CTF_NOTIF_ITER_STATUS_ERROR. |
| 168 | * |
| 169 | * If #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK is not returned, the |
| 170 | * values of \p buffer_sz and \p buffer_addr are \em ignored by |
| 171 | * the caller. |
| 172 | * |
| 173 | * @param request_sz Requested buffer size (bytes) |
| 174 | * @param buffer_addr Returned buffer address |
| 175 | * @param buffer_sz Returned buffer's size (bytes) |
| 176 | * @param data User data |
| 177 | * @returns Status code (see description above) |
| 178 | */ |
| 179 | enum bt_ctf_notif_iter_medium_status (* request_bytes)( |
| 180 | size_t request_sz, uint8_t **buffer_addr, |
| 181 | size_t *buffer_sz, void *data); |
| 182 | |
| 183 | /** |
| 184 | * Returns a stream instance (weak reference) for the given |
| 185 | * stream class. |
| 186 | * |
| 187 | * This is called after a packet header is read, and the |
| 188 | * corresponding stream class is found by the notification |
| 189 | * iterator. |
| 190 | * |
| 191 | * @param stream_class Stream class associated to the stream |
| 192 | * @param data User data |
| 193 | * @returns Stream instance (weak reference) or |
| 194 | * \c NULL on error |
| 195 | */ |
| 196 | struct bt_ctf_stream * (* get_stream)( |
| 197 | struct bt_ctf_stream_class *stream_class, void *data); |
| 198 | }; |
| 199 | |
| 200 | /** CTF notification iterator. */ |
| 201 | struct bt_ctf_notif_iter; |
| 202 | |
| 203 | // TODO: Replace by the real thing |
| 204 | enum bt_ctf_notif_iter_notif_type { |
| 205 | BT_CTF_NOTIF_ITER_NOTIF_NEW_PACKET, |
| 206 | BT_CTF_NOTIF_ITER_NOTIF_END_OF_PACKET, |
| 207 | BT_CTF_NOTIF_ITER_NOTIF_EVENT, |
| 208 | }; |
| 209 | |
| 210 | struct bt_ctf_notif_iter_notif { |
| 211 | enum bt_ctf_notif_iter_notif_type type; |
| 212 | }; |
| 213 | |
| 214 | struct bt_ctf_notif_iter_notif_new_packet { |
| 215 | struct bt_ctf_notif_iter_notif base; |
| 216 | struct bt_ctf_packet *packet; |
| 217 | }; |
| 218 | |
| 219 | struct bt_ctf_notif_iter_notif_end_of_packet { |
| 220 | struct bt_ctf_notif_iter_notif base; |
| 221 | struct bt_ctf_packet *packet; |
| 222 | }; |
| 223 | |
| 224 | struct bt_ctf_notif_iter_notif_event { |
| 225 | struct bt_ctf_notif_iter_notif base; |
| 226 | struct bt_ctf_event *event; |
| 227 | }; |
| 228 | |
| 229 | /** |
| 230 | * Creates a CTF notification iterator. |
| 231 | * |
| 232 | * Upon successful completion, the reference count of \p trace is |
| 233 | * incremented. |
| 234 | * |
| 235 | * @param trace Trace to read |
| 236 | * @param max_request_sz Maximum buffer size, in bytes, to |
| 237 | * request to |
| 238 | * bt_ctf_notif_iter_medium_ops::request_bytes() |
| 239 | * at a time |
| 240 | * @param medops Medium operations |
| 241 | * @param medops_data User data (passed to medium operations) |
| 242 | * @param err_stream Error stream (can be \c NULL to disable) |
| 243 | * @returns New CTF notification iterator on |
| 244 | * success, or \c NULL on error |
| 245 | */ |
| 246 | BT_HIDDEN |
| 247 | struct bt_ctf_notif_iter *bt_ctf_notif_iter_create(struct bt_ctf_trace *trace, |
| 248 | size_t max_request_sz, struct bt_ctf_notif_iter_medium_ops medops, |
| 249 | void *medops_data, FILE *err_stream); |
| 250 | |
| 251 | /** |
| 252 | * Destroys a CTF notification iterator, freeing all internal resources. |
| 253 | * |
| 254 | * The registered trace's reference count is decremented. |
| 255 | * |
| 256 | * @param notif_iter CTF notification iterator |
| 257 | */ |
| 258 | BT_HIDDEN |
| 259 | void bt_ctf_notif_iter_destroy(struct bt_ctf_notif_iter *notif_iter); |
| 260 | |
| 261 | /** |
| 262 | * Returns the next notification from a CTF notification iterator. |
| 263 | * |
| 264 | * Upon successful completion, #BT_CTF_NOTIF_ITER_STATUS_OK is |
| 265 | * returned, and the next notification is written to \p notif. |
| 266 | * In this case, the caller is responsible for calling |
| 267 | * bt_notification_put() on the returned notification. |
| 268 | * |
| 269 | * If this function returns #BT_CTF_NOTIF_ITER_STATUS_AGAIN, the caller |
| 270 | * should make sure that data becomes available to its medium, and |
| 271 | * call this function again, until another status is returned. |
| 272 | * |
| 273 | * @param notif_iter CTF notification iterator |
| 274 | * @param notification Returned notification if the function's |
| 275 | * return value is #BT_CTF_NOTIF_ITER_STATUS_OK |
| 276 | * @returns One of #bt_ctf_notif_iter_status values |
| 277 | */ |
| 278 | BT_HIDDEN |
| 279 | enum bt_ctf_notif_iter_status bt_ctf_notif_iter_get_next_notification( |
| 280 | struct bt_ctf_notif_iter *notit, |
| 281 | struct bt_notification **notification); |
| 282 | |
| 283 | #endif /* CTF_NOTIF_ITER_H */ |