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         /** 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 struct bt_notification_iterator_next_return {
  76         struct bt_notification *notification;
  77         enum bt_notification_iterator_status status;
  78 };
  79
  80 /**
  81  * Get current notification at iterator's position.
  82  *
  83  * This functions will <b>not</b> advance the cursor's position.
  84  * The returned notification's reference count is already incremented.
  85  *
  86  * @param iterator      Iterator instance
  87  * @returns             Returns a bt_notification instance
  88  *
  89  * @see bt_put()
  90  */
  91 extern struct bt_notification *bt_notification_iterator_get_notification(
  92                 struct bt_notification_iterator *iterator);
  93
  94 /**
  95  * Advance the iterator's position forward.
  96  *
  97  * This function can be called repeatedly to iterate through the iterator's
  98  * associated trace.
  99  *
 100  * @param iterator      Iterator instance
 101  * @returns             Returns a bt_notification instance
 102  *
 103  * @see bt_notification_iterator_get_notification()
 104  */
 105 extern enum bt_notification_iterator_status
 106 bt_notification_iterator_next(struct bt_notification_iterator *iterator);
 107
 108 /**
 109  * Seek iterator to time.
 110  *
 111  * Sets the iterator's position for the trace associated with the iterator.
 112  * The new position is computed by adding \p time to the position specified
 113  * by \p seek_origin.
 114  *
 115  * time is expressed in nanoseconds.
 116  *
 117  * @param iterator      Iterator instance
 118  * @param seek_origin   One of #bt_notification_iterator_seek_type values.
 119  * @returns             One of #bt_notification_iterator_status values;
 120  *                      if \iterator does not support seeking,
 121  *                      #BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED is
 122  *                      returned.
 123  *
 124  * @see bt_notification_iterator_get_notification()
 125  */
 126 extern enum bt_notification_iterator_status bt_notification_iterator_seek_time(
 127                 struct bt_notification_iterator *iterator,
 128                 enum bt_notification_iterator_seek_origin seek_origin,
 129                 int64_t time);
 130
 131 extern struct bt_component *bt_notification_iterator_get_component(
 132                 struct bt_notification_iterator *iterator);
 133
 134 #ifdef __cplusplus
 135 }
 136 #endif
 137
 138 #endif /* BABELTRACE_COMPONENT_NOTIFICATION_ITERATOR_H */