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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 | ||
e98a2d6e PP |
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 | */ | |
2cf1d51e | 246 | BT_HIDDEN |
e98a2d6e PP |
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 | */ | |
2cf1d51e | 258 | BT_HIDDEN |
e98a2d6e PP |
259 | void bt_ctf_notif_iter_destroy(struct bt_ctf_notif_iter *notif_iter); |
260 | ||
e98a2d6e PP |
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 | */ | |
2cf1d51e | 278 | BT_HIDDEN |
e98a2d6e | 279 | enum bt_ctf_notif_iter_status bt_ctf_notif_iter_get_next_notification( |
78586d8a JG |
280 | struct bt_ctf_notif_iter *notit, |
281 | struct bt_notification **notification); | |
e98a2d6e PP |
282 | |
283 | #endif /* CTF_NOTIF_ITER_H */ |