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 <babeltrace/context.h>
  21 #include <babeltrace/format.h>
  22 #include <babeltrace/iterator.h>
  23 #include <babeltrace/trace-collection.h>
  24 #include <babeltrace/trace-handle.h>
  25 #include <babeltrace/ctf/events.h>
  26
  27 /* Forward declarations */
  28 struct bt_iter;
  29 struct ctf_stream_event;
  30 struct ctf_stream;
  31 struct bt_dependencies;
  32
  33 enum bt_cb_ret {
  34         BT_CB_OK                = 0,
  35         BT_CB_OK_STOP           = 1,
  36         BT_CB_ERROR_STOP        = 2,
  37         BT_CB_ERROR_CONTINUE    = 3,
  38 };
  39
  40 struct bt_ctf_data {
  41         struct ctf_stream_event *event;
  42         struct ctf_stream *stream;
  43 };
  44
  45 /*
  46  * Receives a variable number of strings as parameter, ended with NULL.
  47  */
  48 struct bt_dependencies *babeltrace_dependencies_create(const char *first, ...);
  49
  50 /*
  51  * struct bt_dependencies must be destroyed explicitly if not passed as
  52  * parameter to a bt_iter_add_callback().
  53  */
  54 void babeltrace_dependencies_destroy(struct bt_dependencies *dep);
  55
  56 /*
  57  * bt_iter_add_callback: Add a callback to iterator.
  58  *
  59  * @iter: trace collection iterator (input)
  60  * @event: event to target. 0 for all events.
  61  * @private_data: private data pointer to pass to the callback
  62  * @flags: specific flags controlling the behavior of this callback
  63  *         (or'd).
  64  *
  65  * @callback: function pointer to call
  66  * @depends: struct bt_dependency detailing the required computation results.
  67  *           Ends with 0.
  68  * @weak_depends: struct bt_dependency detailing the optional computation
  69  *                results that can be optionally consumed by this
  70  *                callback.
  71  * @provides: struct bt_dependency detailing the computation results
  72  *            provided by this callback.
  73  *            Ends with 0.
  74  *
  75  * "depends", "weak_depends" and "provides" memory is handled by the
  76  * babeltrace library after this call succeeds or fails. These objects
  77  * can still be used by the caller until the babeltrace iterator is
  78  * destroyed, but they belong to the babeltrace library.
  79  *
  80  * (note to implementor: we need to keep a gptrarray of struct
  81  * bt_dependencies to "garbage collect" in struct bt_iter, and
  82  * dependencies need to have a refcount to handle the case where they
  83  * would be passed to more than one iterator. Upon iterator detroy, we
  84  * iterate on all the gc ptrarray and decrement the refcounts, freeing
  85  * if we reach 0.)
  86  * (note to implementor: we calculate the dependency graph when
  87  * bt_iter_read_event() is executed after a
  88  * bt_iter_add_callback(). Beware that it is valid to create/add
  89  * callbacks/read/add more callbacks/read some more.)
  90  */
  91 int bt_iter_add_callback(struct bt_iter *iter,
  92                 bt_intern_str event, void *private_data, int flags,
  93                 enum bt_cb_ret (*callback)(struct bt_ctf_data *ctf_data,
  94                                            void *caller_data),
  95                 struct bt_dependencies *depends,
  96                 struct bt_dependencies *weak_depends,
  97                 struct bt_dependencies *provides);
  98
  99 /*
 100  * For flags parameter above.
 101  */
 102 enum {
 103         BT_FLAGS_FREE_PRIVATE_DATA      = (1 << 0),
 104 };
 105
 106 #endif /* _BABELTRACE_H */