include/babeltrace/plugin/plugin.h

   1 #ifndef BABELTRACE_PLUGIN_H
   2 #define BABELTRACE_PLUGIN_H
   3
   4 /*
   5  * BabelTrace - Babeltrace Plug-in Interface
   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 <errno.h>
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /**
  37  * Plug-in type.
  38  */
  39 enum bt_plugin_type {
  40         BT_PLUGIN_TYPE_UNKNOWN =        -1,
  41
  42         /** A source plug-in is a notification generator. */
  43         BT_PLUGIN_TYPE_SOURCE =         0,
  44
  45         /** A sink plug-in handles incoming notifications. */
  46         BT_PLUGIN_TYPE_SINK =           1,
  47
  48         /** A filter plug-in implements both Source and Sink interfaces. */
  49         BT_PLUGIN_TYPE_FILTER =         2,
  50 };
  51
  52 /**
  53  * Status code. Errors are always negative.
  54  */
  55 enum bt_plugin_status {
  56         /** Memory allocation failure. */
  57         /* -12 for compatibility with -ENOMEM */
  58         BT_PLUGIN_STATUS_NOMEM =        -12,
  59
  60         /** Invalid arguments. */
  61         /* -22 for compatibility with -EINVAL */
  62         BT_PLUGIN_STATUS_INVAL =        -22,
  63
  64         /** Unsupported plug-in feature. */
  65         BT_PLUGIN_STATUS_UNSUPPORTED =  -2,
  66
  67         /** General error. */
  68         BT_PLUGIN_STATUS_ERROR =        -1,
  69
  70         /** No error, okay. */
  71         BT_PLUGIN_STATUS_OK =           0,
  72 };
  73
  74 struct bt_plugin;
  75
  76 /**
  77  * Get plug-in instance name.
  78  *
  79  * @param plugin        Plug-in instance of which to get the name
  80  * @returns             Returns a pointer to the plug-in's name
  81  */
  82 extern const char *bt_plugin_get_name(struct bt_plugin *plugin);
  83
  84 /**
  85  * Set plug-in instance name.
  86  *
  87  * @param plugin        Plug-in instance of which to set the name
  88  * @param name          New plug-in name (will be copied)
  89  * @returns             One of #bt_plugin_status values
  90  */
  91 extern enum bt_plugin_status bt_plugin_set_name(
  92                 struct bt_plugin *plugin, const char *name);
  93
  94 /**
  95  * Get plug-in instance type.
  96  *
  97  * @param plugin        Plug-in instance of which to get the type
  98  * @returns             One of #bt_plugin_type values
  99  */
 100 extern enum bt_plugin_type bt_plugin_get_type(struct bt_plugin *plugin);
 101
 102 /**
 103  * Set a plug-in instance's error stream.
 104  *
 105  * @param plugin        Plug-in instance
 106  * @param error_stream  Error stream
 107  * @returns             One of #bt_plugin_status values
 108  */
 109 extern enum bt_plugin_status bt_plugin_set_error_stream(
 110                 struct bt_plugin *plugin, FILE *error_stream);
 111
 112 /**
 113  * Increments the reference count of \p plugin.
 114  *
 115  * @param plugin        Plug-in of which to increment the reference count
 116  *
 117  * @see bt_plugin_put()
 118  */
 119 extern void bt_plugin_get(struct bt_plugin *plugin);
 120
 121 /**
 122  * Decrements the reference count of \p plugin, destroying it when this
 123  * count reaches 0.
 124  *
 125  * @param plugin        Plug-in of which to decrement the reference count
 126  *
 127  * @see bt_plugin_get()
 128  */
 129 extern void bt_plugin_put(struct bt_plugin *plugin);
 130
 131 #ifdef __cplusplus
 132 }
 133 #endif
 134
 135 #endif /* BABELTRACE_PLUGIN_H */