include/babeltrace/graph/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         /** Try again. */
  44         BT_NOTIFICATION_ITERATOR_STATUS_AGAIN = 11,
  45         /** No more notifications to be delivered. */
  46         BT_NOTIFICATION_ITERATOR_STATUS_END = 1,
  47         /** No error, okay. */
  48         BT_NOTIFICATION_ITERATOR_STATUS_OK = 0,
  49         /** Invalid arguments. */
  50         BT_NOTIFICATION_ITERATOR_STATUS_INVALID = -22,
  51         /** General error. */
  52         BT_NOTIFICATION_ITERATOR_STATUS_ERROR = -1,
  53         /** Out of memory. */
  54         BT_NOTIFICATION_ITERATOR_STATUS_NOMEM = -12,
  55         /** Unsupported iterator feature. */
  56         BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED = -2,
  57 };
  58
  59 /**
  60  * Notification iterator seek reference.
  61  */
  62 enum bt_notification_iterator_seek_origin {
  63         /** Seek at a time relative to the beginning of the trace. */
  64         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_BEGIN = 0,
  65
  66         /** Seek at a time relative to the current position. */
  67         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_CURRENT = 1,
  68
  69         /** Seek at a time relative to the end of the trace. */
  70         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_END = 2,
  71
  72         /** Seek at a time relative to EPOCH. */
  73         BT_NOTIFICATION_ITERATOR_SEEK_ORIGIN_EPOCH = 3,
  74 };
  75
  76 struct bt_notification_iterator_next_return {
  77         struct bt_notification *notification;
  78         enum bt_notification_iterator_status status;
  79 };
  80
  81 /**
  82  * Get current notification at iterator's position.
  83  *
  84  * This functions will <b>not</b> advance the cursor's position.
  85  * The returned notification's reference count is already incremented.
  86  *
  87  * @param iterator      Iterator instance
  88  * @returns             Returns a bt_notification instance
  89  *
  90  * @see bt_put()
  91  */
  92 extern struct bt_notification *bt_notification_iterator_get_notification(
  93                 struct bt_notification_iterator *iterator);
  94
  95 /**
  96  * Advance the iterator's position forward.
  97  *
  98  * This function can be called repeatedly to iterate through the iterator's
  99  * associated trace.
 100  *
 101  * @param iterator      Iterator instance
 102  * @returns             Returns a bt_notification instance
 103  *
 104  * @see bt_notification_iterator_get_notification()
 105  */
 106 extern enum bt_notification_iterator_status
 107 bt_notification_iterator_next(struct bt_notification_iterator *iterator);
 108
 109 /**
 110  * Seek iterator to time.
 111  *
 112  * Sets the iterator's position for the trace associated with the iterator.
 113  * The new position is computed by adding \p time to the position specified
 114  * by \p seek_origin.
 115  *
 116  * time is expressed in nanoseconds.
 117  *
 118  * @param iterator      Iterator instance
 119  * @param seek_origin   One of #bt_notification_iterator_seek_type values.
 120  * @returns             One of #bt_notification_iterator_status values;
 121  *                      if \iterator does not support seeking,
 122  *                      #BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED is
 123  *                      returned.
 124  *
 125  * @see bt_notification_iterator_get_notification()
 126  */
 127 extern enum bt_notification_iterator_status bt_notification_iterator_seek_time(
 128                 struct bt_notification_iterator *iterator,
 129                 enum bt_notification_iterator_seek_origin seek_origin,
 130                 int64_t time);
 131
 132 extern struct bt_component *bt_notification_iterator_get_component(
 133                 struct bt_notification_iterator *iterator);
 134
 135 #ifdef __cplusplus
 136 }
 137 #endif
 138
 139 #endif /* BABELTRACE_COMPONENT_NOTIFICATION_ITERATOR_H */