1 #ifndef CTF_NOTIF_ITER_H
2 #define CTF_NOTIF_ITER_H
5 * Babeltrace - CTF notification iterator
7 * Copyright (c) 2015-2016 EfficiOS Inc. and Linux Foundation
8 * Copyright (c) 2015-2016 Philippe Proulx <pproulx@efficios.com>
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:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
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
32 #include <babeltrace/ctf-ir/trace.h>
33 #include <babeltrace/ctf-ir/fields.h>
34 #include <babeltrace/ctf-ir/event.h>
35 #include <babeltrace/graph/clock-class-priority-map.h>
36 #include <babeltrace/babeltrace-internal.h>
39 * @file ctf-notif-iter.h
41 * CTF notification iterator
43 * This is a common internal API used by CTF source plugins. It allows
44 * one to get notifications from a user-provided medium.
48 * Medium operations status codes.
50 enum bt_ctf_notif_iter_medium_status
{
54 * The medium function called by the notification iterator
55 * function reached the end of the file.
57 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF
= -4,
60 * There is no data available right now, try again later.
62 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN
= -3,
64 /** Invalid argument. */
65 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL
= -2,
68 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR
= -1,
70 /** Everything okay. */
71 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK
= 0,
75 * CTF notification iterator API status code.
77 enum bt_ctf_notif_iter_status
{
81 * The medium function called by the notification iterator
82 * function reached the end of the file.
84 BT_CTF_NOTIF_ITER_STATUS_EOF
= -4,
87 * There is no data available right now, try again later.
89 * Some condition resulted in the
90 * bt_ctf_notif_iter_medium_ops::request_bytes() user function not
91 * having access to any data now. You should retry calling the
92 * last called notification iterator function once the situation
95 BT_CTF_NOTIF_ITER_STATUS_AGAIN
= -3,
97 /** Invalid argument. */
98 BT_CTF_NOTIF_ITER_STATUS_INVAL
= -2,
100 /** General error. */
101 BT_CTF_NOTIF_ITER_STATUS_ERROR
= -1,
103 /** Everything okay. */
104 BT_CTF_NOTIF_ITER_STATUS_OK
= 0,
110 * Those user functions are called by the notification iterator
111 * functions to request medium actions.
113 struct bt_ctf_notif_iter_medium_ops
{
115 * Returns the next byte buffer to be used by the binary file
116 * reader to deserialize binary data.
118 * This function \em must be defined.
120 * The purpose of this function is to return a buffer of bytes
121 * to the notification iterator, of a maximum of \p request_sz
122 * bytes. If this function cannot return a buffer of at least
123 * \p request_sz bytes, it may return a smaller buffer. In
124 * either cases, \p buffer_sz must be set to the returned buffer
127 * The returned buffer's ownership remains the medium, in that
128 * it won't be freed by the notification iterator functions. The
129 * returned buffer won't be modified by the notification
130 * iterator functions either.
132 * When this function is called for the first time for a given
133 * file, the offset within the file is considered to be 0. The
134 * next times this function is called, the returned buffer's
135 * byte offset within the complete file must be the previous
136 * offset plus the last returned value of \p buffer_sz by this
139 * This function must return one of the following statuses:
141 * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK</b>: Everything
142 * is okay, i.e. \p buffer_sz is set to a positive value
143 * reflecting the number of available bytes in the buffer
144 * starting at the address written in \p buffer_addr.
145 * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
146 * available right now. In this case, the notification
147 * iterator function called by the user returns
148 * #BT_CTF_NOTIF_ITER_STATUS_AGAIN, and it is the user's
149 * responsibility to make sure enough data becomes available
150 * before calling the \em same notification iterator
151 * function again to continue the decoding process.
152 * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF</b>: The end of
153 * the file was reached, and no more data will ever be
154 * available for this file. In this case, the notification
155 * iterator function called by the user returns
156 * #BT_CTF_NOTIF_ITER_STATUS_EOF. This must \em not be
157 * returned when returning at least one byte of data to the
158 * caller, i.e. this must be returned when there's
159 * absolutely nothing left; should the request size be
160 * larger than what's left in the file, this function must
161 * return what's left, setting \p buffer_sz to the number of
162 * remaining bytes, and return
163 * #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following
165 * - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
166 * error occured during this operation. In this case, the
167 * notification iterator function called by the user returns
168 * #BT_CTF_NOTIF_ITER_STATUS_ERROR.
170 * If #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK is not returned, the
171 * values of \p buffer_sz and \p buffer_addr are \em ignored by
174 * @param request_sz Requested buffer size (bytes)
175 * @param buffer_addr Returned buffer address
176 * @param buffer_sz Returned buffer's size (bytes)
177 * @param data User data
178 * @returns Status code (see description above)
180 enum bt_ctf_notif_iter_medium_status (* request_bytes
)(
181 size_t request_sz
, uint8_t **buffer_addr
,
182 size_t *buffer_sz
, void *data
);
185 * Returns a stream instance (weak reference) for the given
188 * This is called after a packet header is read, and the
189 * corresponding stream class is found by the notification
192 * @param stream_class Stream class associated to the stream
193 * @param data User data
194 * @returns Stream instance (weak reference) or
197 struct bt_ctf_stream
* (* get_stream
)(
198 struct bt_ctf_stream_class
*stream_class
, void *data
);
201 /** CTF notification iterator. */
202 struct bt_ctf_notif_iter
;
204 // TODO: Replace by the real thing
205 enum bt_ctf_notif_iter_notif_type
{
206 BT_CTF_NOTIF_ITER_NOTIF_NEW_PACKET
,
207 BT_CTF_NOTIF_ITER_NOTIF_END_OF_PACKET
,
208 BT_CTF_NOTIF_ITER_NOTIF_EVENT
,
211 struct bt_ctf_notif_iter_notif
{
212 enum bt_ctf_notif_iter_notif_type type
;
215 struct bt_ctf_notif_iter_notif_new_packet
{
216 struct bt_ctf_notif_iter_notif base
;
217 struct bt_ctf_packet
*packet
;
220 struct bt_ctf_notif_iter_notif_end_of_packet
{
221 struct bt_ctf_notif_iter_notif base
;
222 struct bt_ctf_packet
*packet
;
225 struct bt_ctf_notif_iter_notif_event
{
226 struct bt_ctf_notif_iter_notif base
;
227 struct bt_ctf_event
*event
;
231 * Creates a CTF notification iterator.
233 * Upon successful completion, the reference count of \p trace is
236 * @param trace Trace to read
237 * @param cc_prio_map Clock class priority map to use when
238 * creating the event notifications
239 * @param max_request_sz Maximum buffer size, in bytes, to
241 * bt_ctf_notif_iter_medium_ops::request_bytes()
243 * @param medops Medium operations
244 * @param medops_data User data (passed to medium operations)
245 * @param err_stream Error stream (can be \c NULL to disable)
246 * @returns New CTF notification iterator on
247 * success, or \c NULL on error
250 struct bt_ctf_notif_iter
*bt_ctf_notif_iter_create(struct bt_ctf_trace
*trace
,
251 struct bt_clock_class_priority_map
*cc_prio_map
,
252 size_t max_request_sz
, struct bt_ctf_notif_iter_medium_ops medops
,
253 void *medops_data
, FILE *err_stream
);
256 * Destroys a CTF notification iterator, freeing all internal resources.
258 * The registered trace's reference count is decremented.
260 * @param notif_iter CTF notification iterator
263 void bt_ctf_notif_iter_destroy(struct bt_ctf_notif_iter
*notif_iter
);
266 * Returns the next notification from a CTF notification iterator.
268 * Upon successful completion, #BT_CTF_NOTIF_ITER_STATUS_OK is
269 * returned, and the next notification is written to \p notif.
270 * In this case, the caller is responsible for calling
271 * bt_notification_put() on the returned notification.
273 * If this function returns #BT_CTF_NOTIF_ITER_STATUS_AGAIN, the caller
274 * should make sure that data becomes available to its medium, and
275 * call this function again, until another status is returned.
277 * @param notif_iter CTF notification iterator
278 * @param notification Returned notification if the function's
279 * return value is #BT_CTF_NOTIF_ITER_STATUS_OK
280 * @returns One of #bt_ctf_notif_iter_status values
283 enum bt_ctf_notif_iter_status
bt_ctf_notif_iter_get_next_notification(
284 struct bt_ctf_notif_iter
*notit
,
285 struct bt_notification
**notification
);
287 #endif /* CTF_NOTIF_ITER_H */