include/babeltrace/component/notification/iterator.h

   1 #ifndef BABELTRACE_COMPONENT_NOTIFICATION_ITERATOR_H
   2 #define BABELTRACE_COMPONENT_NOTIFICATION_ITERATOR_H
   3
   4 /*
   5  * BabelTrace - Plug-in Notification Iterator
   6  *
   7  * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   8  *
   9  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  */
  29
  30 #include <stdint.h>
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 struct bt_notification;
  37 struct bt_notification_iterator;
  38
  39 /**
  40  * Status code. Errors are always negative.
  41  */
  42 enum bt_notification_iterator_status {
  43         /** No more notifications to be delivered. */
  44         BT_NOTIFICATION_ITERATOR_STATUS_END = 1,
  45         /** No error, okay. */
  46         BT_NOTIFICATION_ITERATOR_STATUS_OK = 0,
  47         /** Invalid arguments. */
  48         BT_NOTIFICATION_ITERATOR_STATUS_INVAL = -1,
  49         /** General error. */
  50         BT_NOTIFICATION_ITERATOR_STATUS_ERROR = -2,
  51         /** Out of memory. */
  52         BT_NOTIFICATION_ITERATOR_STATUS_NOMEM = -3,
  53         /** Unsupported iterator feature. */
  54         BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED = -4,
  55
  56 };
  57
  58 /**
  59  * Notification iterator seek reference.
  60  */
  61 enum bt_notification_iterator_seek_origin {
  62         /** Seek at a time relative to the beginning of the trace. */
  63         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_BEGIN = 0,
  64
  65         /** Seek at a time relative to the current position. */
  66         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_CURRENT = 1,
  67
  68         /** Seek at a time relative to the end of the trace. */
  69         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_END = 2,
  70
  71         /** Seek at a time relative to EPOCH. */
  72         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_EPOCH = 3,
  73 };
  74
  75 /**
  76  * Get current notification at iterator's position.
  77  *
  78  * This functions will <b>not</b> advance the cursor's position.
  79  * The returned notification's reference count is already incremented.
  80  *
  81  * @param iterator      Iterator instance
  82  * @returns             Returns a bt_notification instance
  83  *
  84  * @see bt_put()
  85  */
  86 extern struct bt_notification *bt_notification_iterator_get_notification(
  87                 struct bt_notification_iterator *iterator);
  88
  89 /**
  90  * Advance the iterator's position forward.
  91  *
  92  * This function can be called repeatedly to iterate through the iterator's
  93  * associated trace.
  94  *
  95  * @param iterator      Iterator instance
  96  * @returns             Returns a bt_notification instance
  97  *
  98  * @see bt_notification_iterator_get_notification()
  99  */
 100 extern enum bt_notification_iterator_status
 101 bt_notification_iterator_next(struct bt_notification_iterator *iterator);
 102
 103 /**
 104  * Seek iterator to time.
 105  *
 106  * Sets the iterator's position for the trace associated with the iterator.
 107  * The new position is computed by adding \p time to the position specified
 108  * by \p seek_origin.
 109  *
 110  * time is expressed in nanoseconds.
 111  *
 112  * @param iterator      Iterator instance
 113  * @param seek_origin   One of #bt_notification_iterator_seek_type values.
 114  * @returns             One of #bt_notification_iterator_status values;
 115  *                      if \iterator does not support seeking,
 116  *                      #BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED is
 117  *                      returned.
 118  *
 119  * @see bt_notification_iterator_get_notification()
 120  */
 121 extern enum bt_notification_iterator_status bt_notification_iterator_seek_time(
 122                 struct bt_notification_iterator *iterator,
 123                 enum bt_notification_iterator_seek_origin seek_origin,
 124                 int64_t time);
 125
 126 extern struct bt_component *bt_notification_iterator_get_component(
 127                 struct bt_notification_iterator *iterator);
 128
 129 /** bt_notification_iterator */
 130 /**
 131  * Function returning an iterator's current notification.
 132  *
 133  * @param iterator      Notification iterator instance
 134  * @returns             A notification instance
 135  */
 136 typedef struct bt_notification *(*bt_notification_iterator_get_cb)(
 137                 struct bt_notification_iterator *iterator);
 138
 139 /**
 140  * Function advancing an iterator's position of one element.
 141  *
 142  * @param iterator      Notification iterator instance
 143  * @returns             One of #bt_notification_iterator_status values
 144  */
 145 typedef enum bt_notification_iterator_status (*bt_notification_iterator_next_cb)(
 146                 struct bt_notification_iterator *iterator);
 147
 148 /**
 149  * Function advancing an iterator's position to a given time (relative to Epoch).
 150  *
 151  * @param iterator      Notification iterator instance
 152  * @param time          Time at which to seek, expressed in ns since Epoch
 153  * @returns             One of #bt_notification_iterator_status values
 154  */
 155 typedef enum bt_notification_iterator_status
 156                 (*bt_notification_iterator_seek_time_cb)(
 157                 struct bt_notification_iterator *iterator, int64_t time);
 158
 159 /**
 160  * Function cleaning-up an iterator's private data on destruction.
 161  *
 162  * @param iterator      Notification iterator instance
 163  */
 164 typedef void (*bt_notification_iterator_destroy_cb)(
 165                 struct bt_notification_iterator *iterator);
 166
 167 /**
 168  * Set an iterator's "get" callback which return the current notification.
 169  *
 170  * @param iterator      Notification iterator instance
 171  * @param get           Notification return callback
 172  * @returns             One of #bt_notification_iterator_status values
 173  */
 174 extern enum bt_notification_iterator_status
 175 bt_notification_iterator_set_get_cb(struct bt_notification_iterator *iterator,
 176                 bt_notification_iterator_get_cb get);
 177
 178 /**
 179  * Set an iterator's "next" callback which advances the iterator's position.
 180  *
 181  * @param iterator      Notification iterator instance
 182  * @param next          Iterator "next" callback
 183  * @returns             One of #bt_notification_iterator_status values
 184  */
 185 extern enum bt_notification_iterator_status
 186 bt_notification_iterator_set_next_cb(struct bt_notification_iterator *iterator,
 187                 bt_notification_iterator_next_cb next);
 188
 189 /**
 190  * Set an iterator's "seek_time" callback which sets the iterator's position to
 191  *      provided time (in ns since Epoch).
 192  *
 193  * @param iterator      Notification iterator instance
 194  * @param seek_timetime Iterator "seek_time" callback
 195  * @returns             One of #bt_notification_iterator_status values
 196  */
 197 extern enum bt_notification_iterator_status
 198 bt_notification_iterator_set_seek_time_cb(struct bt_notification_iterator *iterator,
 199                 bt_notification_iterator_seek_time_cb seek_time);
 200
 201 /**
 202  * Set an iterator's "destroy" callback.
 203  *
 204  * @param iterator      Notification iterator instance
 205  * @param next          Iterator destruction callback
 206  * @returns             One of #bt_notification_iterator_status values
 207  */
 208 extern enum bt_notification_iterator_status
 209 bt_notification_iterator_set_destroy_cb(
 210                 struct bt_notification_iterator *iterator,
 211                 bt_notification_iterator_destroy_cb destroy);
 212
 213 /**
 214  * Set an iterator's private data.
 215  *
 216  * @param iterator      Notification iterator instance
 217  * @param data          Iterator private data
 218  * @returns             One of #bt_notification_iterator_status values
 219  */
 220 extern enum bt_notification_iterator_status
 221 bt_notification_iterator_set_private_data(
 222                 struct bt_notification_iterator *iterator, void *data);
 223
 224 /**
 225  * Get an iterator's private data.
 226  *
 227  * @param iterator      Notification iterator instance
 228  * @returns             Iterator instance private data
 229  */
 230 extern void *bt_notification_iterator_get_private_data(
 231                 struct bt_notification_iterator *iterator);
 232
 233
 234 #ifdef __cplusplus
 235 }
 236 #endif
 237
 238 #endif /* BABELTRACE_COMPONENT_NOTIFICATION_ITERATOR_H */