include/babeltrace/plugin/component.h

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