include/babeltrace/babeltrace.h

   1 #ifndef _BABELTRACE_H
   2 #define _BABELTRACE_H
   3
   4 /*
   5  * BabelTrace API
   6  *
   7  * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  */
  19
  20 #include <glib.h>
  21 #include <babeltrace/format.h>
  22
  23 typedef GQuark bt_event_name;
  24
  25 /* Forward declarations */
  26 struct bt_iter;
  27 struct ctf_stream_event;
  28 struct ctf_stream;
  29 struct bt_dependencies;
  30
  31 enum bt_cb_ret {
  32         BT_CB_OK                = 0,
  33         BT_CB_OK_STOP           = 1,
  34         BT_CB_ERROR_STOP        = 2,
  35         BT_CB_ERROR_CONTINUE    = 3,
  36 };
  37
  38 struct bt_ctf_data {
  39         struct ctf_stream_event *event;
  40         struct ctf_stream *stream;
  41 };
  42
  43 /*
  44  * Receives a variable number of strings as parameter, ended with NULL.
  45  */
  46 struct bt_dependencies *babeltrace_dependencies_create(const char *first, ...);
  47
  48 /*
  49  * struct bt_dependencies must be destroyed explicitly if not passed as
  50  * parameter to a bt_iter_add_callback().
  51  */
  52 void babeltrace_dependencies_destroy(struct bt_dependencies *dep);
  53
  54 /*
  55  * bt_iter_add_callback: Add a callback to iterator.
  56  *
  57  * @iter: trace collection iterator (input)
  58  * @event: event to target. 0 for all events.
  59  * @private_data: private data pointer to pass to the callback
  60  * @flags: specific flags controlling the behavior of this callback
  61  *         (or'd).
  62  *
  63  * @callback: function pointer to call
  64  * @depends: struct bt_dependency detailing the required computation results.
  65  *           Ends with 0.
  66  * @weak_depends: struct bt_dependency detailing the optional computation
  67  *                results that can be optionally consumed by this
  68  *                callback.
  69  * @provides: struct bt_dependency detailing the computation results
  70  *            provided by this callback.
  71  *            Ends with 0.
  72  *
  73  * "depends", "weak_depends" and "provides" memory is handled by the
  74  * babeltrace library after this call succeeds or fails. These objects
  75  * can still be used by the caller until the babeltrace iterator is
  76  * destroyed, but they belong to the babeltrace library.
  77  *
  78  * (note to implementor: we need to keep a gptrarray of struct
  79  * bt_dependencies to "garbage collect" in struct bt_iter, and
  80  * dependencies need to have a refcount to handle the case where they
  81  * would be passed to more than one iterator. Upon iterator detroy, we
  82  * iterate on all the gc ptrarray and decrement the refcounts, freeing
  83  * if we reach 0.)
  84  * (note to implementor: we calculate the dependency graph when
  85  * bt_iter_read_event() is executed after a
  86  * bt_iter_add_callback(). Beware that it is valid to create/add
  87  * callbacks/read/add more callbacks/read some more.)
  88  */
  89 int bt_iter_add_callback(struct bt_iter *iter,
  90                 bt_event_name event, void *private_data, int flags,
  91                 enum bt_cb_ret (*callback)(struct bt_ctf_data *ctf_data,
  92                                            void *caller_data),
  93                 struct bt_dependencies *depends,
  94                 struct bt_dependencies *weak_depends,
  95                 struct bt_dependencies *provides);
  96
  97 /*
  98  * For flags parameter above.
  99  */
 100 enum {
 101         BT_FLAGS_FREE_PRIVATE_DATA      = (1 << 0),
 102 };
 103
 104 #endif /* _BABELTRACE_H */