include/babeltrace/plugin/notification/iterator.h

   1 #ifndef BABELTRACE_PLUGIN_NOTIFICATION_ITERATOR_H
   2 #define BABELTRACE_PLUGIN_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         /** Invalid arguments. */
  44         /* -22 for compatibility with -EINVAL */
  45         BT_NOTIFICATION_ITERATOR_STATUS_EINVAL = -22,
  46
  47         /** End of trace. */
  48         BT_NOTIFICATION_ITERATOR_STATUS_EOT = -3,
  49
  50         /** General error. */
  51         BT_NOTIFICATION_ITERATOR_STATUS_ERROR = -2,
  52
  53         /** Unsupported iterator feature. */
  54         BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED = -1,
  55
  56         /** No error, okay. */
  57         BT_NOTIFICATION_ITERATOR_STATUS_OK = 0,
  58 };
  59
  60 enum bt_notification_iterator_seek_type {
  61         /** Seek at a time relative to the beginning of the trace. */
  62         BT_NOTIFICATION_ITERATOR_SEEK_TYPE_BEGIN = 0,
  63
  64         /** Seek at a time relative to the current position */
  65         BT_NOTIFICATION_ITERATOR_SEEK_TYPE_CURRENT = 1,
  66
  67         /** Seek at a absolute time */
  68         BT_NOTIFICATION_ITERATOR_SEEK_TYPE_SET = 2,
  69 };
  70
  71 /**
  72  * Get current notification at iterator's position.
  73  *
  74  * This functions will <b>not</b> advance the cursor's position.
  75  * The returned notification's reference count is already incremented.
  76  *
  77  * @param Iterator      Iterator instance
  78  * @returns             Returns a bt_notification instance
  79  *
  80  * @see bt_notification_put()
  81  */
  82 extern struct bt_notification *bt_notification_iterator_get_notification(
  83                 struct bt_notification_iterator *iterator);
  84
  85 /**
  86  * Advance the iterator's position forward.
  87  *
  88  * This function can be called repeatedly to iterate through the iterator's
  89  * associated trace.
  90  *
  91  * @param iterator      Iterator instance
  92  * @returns             Returns a bt_notification instance
  93  *
  94  * @see bt_notification_iterator_get_notification()
  95  */
  96 extern enum bt_notification_iterator_status
  97 bt_notification_iterator_next(struct bt_notification_iterator *iterator);
  98
  99 /**
 100  * Seek iterator to position.
 101  *
 102  * Sets the iterator's position for the trace associated with the iterator.
 103  * The new position is computed by adding \p time to the position specified
 104  * by \p whence.
 105  *
 106  * @param iterator      Iterator instance
 107  * @param whence        One of #bt_notification_iterator_seek_type values.
 108  * @returns             One of #bt_notification_iterator_status values;
 109  *                      if \iterator does not support seeking,
 110  *                      #BT_NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED is
 111  *                      returned.
 112  *
 113  * @see bt_notification_iterator_get_notification()
 114  */
 115 extern enum bt_notification_iterator_status *bt_notification_iterator_seek(
 116                 struct bt_notification_iterator *iterator,
 117                 int whence,
 118                 int64_t time);
 119
 120 /**
 121  * Increments the reference count of \p iterator.
 122  *
 123  * @param iterator      Iterator of which to increment the reference count
 124  *
 125  * @see bt_notification_iterator_put()
 126  */
 127 extern void bt_notification_iterator_get(
 128                 struct bt_notification_iterator *iterator);
 129
 130 /**
 131  * Decrements the reference count of \p iterator, destroying it when this
 132  * count reaches 0.
 133  *
 134  * @param iterator      Iterator of which to decrement the reference count
 135  *
 136  * @see bt_notification_iterator_get()
 137  */
 138 extern void bt_notification_iterator_put(
 139                 struct bt_notification_iterator *iterator);
 140
 141 #ifdef __cplusplus
 142 }
 143 #endif
 144
 145 #endif /* BABELTRACE_PLUGIN_NOTIFICATION_ITERATOR_H */