build fixes

[babeltrace.git] / include / babeltrace / plugin / plugin.h

diff --git a/include/babeltrace/plugin/plugin.h b/include/babeltrace/plugin/plugin.h
index 9c2c5f00606bb581b397e8a243bba9aeff30d7a6..77204d9d76e5647bc055c81e488f2ae620a40e76 100644 (file)
--- a/include/babeltrace/plugin/plugin.h
+++ b/include/babeltrace/plugin/plugin.h
@@ -2,7 +2,7 @@
 #define BABELTRACE_PLUGIN_H
 
 /*
- * BabelTrace - Plug-in
+ * BabelTrace - Babeltrace Plug-in Interface
  *
  * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
@@ -27,44 +27,106 @@
  * SOFTWARE.
  */
 
-#include <stdint.h>
+#include <errno.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-struct bt_plugin;
-struct bt_notification;
-
+/**
+ * Plug-in type.
+ */
 enum bt_plugin_type {
-       BT_PLUGIN_TYPE_UNKNOWN = -1,
-       /* A source plug-in is a notification generator. */
-       BT_PLUGIN_TYPE_SOURCE = 0,
-       /* A sink plug-in handles incoming notifications. */
-       BT_PLUGIN_TYPE_SINK = 1,
-       /* A filter plug-in implements both SOURCE and SINK interfaces. */
-       BT_PLUGIN_TYPE_FILTER = 2,
+       BT_PLUGIN_TYPE_UNKNOWN =        -1,
+
+       /** A source plug-in is a notification generator. */
+       BT_PLUGIN_TYPE_SOURCE =         0,
+
+       /** A sink plug-in handles incoming notifications. */
+       BT_PLUGIN_TYPE_SINK =           1,
+
+       /** A filter plug-in implements both Source and Sink interfaces. */
+       BT_PLUGIN_TYPE_FILTER =         2,
+};
+
+/**
+ * Status code. Errors are always negative.
+ */
+enum bt_plugin_status {
+       /** Memory allocation failure. */
+       /* -12 for compatibility with -ENOMEM */
+       BT_PLUGIN_STATUS_NOMEM =        -12,
+
+       /** Invalid arguments. */
+       /* -22 for compatibility with -EINVAL */
+       BT_PLUGIN_STATUS_INVAL =        -22,
+
+       /** Unsupported plug-in feature. */
+       BT_PLUGIN_STATUS_UNSUPPORTED =  -2,
+
+       /** General error. */
+       BT_PLUGIN_STATUS_ERROR =        -1,
+
+       /** No error, okay. */
+       BT_PLUGIN_STATUS_OK =           0,
 };
 
+struct bt_plugin;
+
+/**
+ * Get plug-in instance name.
+ *
+ * @param plugin       Plug-in instance of which to get the name
+ * @returns            Returns a pointer to the plug-in's name
+ */
+extern const char *bt_plugin_get_name(struct bt_plugin *plugin);
+
 /**
- * Plug-in discovery functions.
+ * Set plug-in instance name.
  *
- * The Babeltrace plug-in architecture mandates that a given plug-in shared
- * object only define one plug-in. These functions are used to query a about
- * shared object about its attributes.
+ * @param plugin       Plug-in instance of which to set the name
+ * @param name         New plug-in name (will be copied)
+ * @returns            One of #bt_plugin_status values
+ */
+extern enum bt_plugin_status bt_plugin_set_name(
+               struct bt_plugin *plugin, const char *name);
+
+/**
+ * Get plug-in instance type.
+ *
+ * @param plugin       Plug-in instance of which to get the type
+ * @returns            One of #bt_plugin_type values
+ */
+extern enum bt_plugin_type bt_plugin_get_type(struct bt_plugin *plugin);
+
+/**
+ * Set a plug-in instance's error stream.
  *
- * The functions marked as mandatory MUST be exported by the shared object
- * to be considered a valid plug-in.
+ * @param plugin       Plug-in instance
+ * @param error_stream Error stream
+ * @returns            One of #bt_plugin_status values
  */
-enum bt_plugin_type bt_plugin_get_type(void);
-const char *bt_plugin_get_name(void);
+extern enum bt_plugin_status bt_plugin_set_error_stream(
+               struct bt_plugin *plugin, FILE *error_stream);
 
-/* TODO: document mandatory fields and their expected types */
-int bt_plugin_set_parameters(struct bt_plugin *plugin,
-               struct bt_ctf_field *field);
+/**
+ * Increments the reference count of \p plugin.
+ *
+ * @param plugin       Plug-in of which to increment the reference count
+ *
+ * @see bt_plugin_put()
+ */
+extern void bt_plugin_get(struct bt_plugin *plugin);
 
-void bt_plugin_get(struct bt_plugin *plugin);
-void bt_plugin_put(struct bt_plugin *plugin);
+/**
+ * Decrements the reference count of \p plugin, destroying it when this
+ * count reaches 0.
+ *
+ * @param plugin       Plug-in of which to decrement the reference count
+ *
+ * @see bt_plugin_get()
+ */
+extern void bt_plugin_put(struct bt_plugin *plugin);
 
 #ifdef __cplusplus
 }