Merge pull request #1 from drobilla/master

Clean up metadata.h and fix Doxygen markup.

metadata.h

@@ -1,17 +1,17 @@
 /*
   Copyright (C) 2011 David Robillard
   Copyright (C) 2013 Paul Davis
-    
+
   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or (at
   your option) any later version.
-    
+
   This program is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.
-    
+
   You should have received a copy of the GNU Lesser General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
@@ -42,38 +42,41 @@ extern "C" {
  * A single property (key:value pair).
  */
 typedef struct {
-    const char* key;   /**< The key of this property (URI string). */
-    const char* data;  /**< The property value (null-terminated string) */
-    const char* type;  /**< MIME type of data. Likely values are:
-                        *
-                        *  text/utf8  (for an null terminated string)
-                        *  image/png;base64 (for a data-URI converted image)
-                        *
-                        * If type is null (or empty), the type should
-                        * be assumed to be "text/utf8" and the memory
-                        * pointed to by "data" should be interpreted
-                        * as a null-terminated string encoded using UTF-8.
-                        *
-                        * If the type is image/png;base64, the memory 
-                        * pointed to by "data" should be interpreted as 
-                        * a base64 encoded PNG image.
-                        *
-                        * Other types are subject to the shared understanding
-                        * of the mime type by both the setter and retriever
-                        * of the property.
-                        */
+    /** The key of this property (URI string). */
+    const char* key;
+
+    /** The property value (null-terminated string). */
+    const char* data;
+
+    /**
+     * Type of data, either a MIME type or URI.
+     *
+     * If type is NULL or empty, the data is assumed to be a UTF-8 encoded
+     * string (text/plain). The data is a null-terminated string regardless of
+     * type, so values can always be copied, but clients should not try to
+     * interpret values of an unknown type.
+     *
+     * Example values:
+     * - image/png;base64 (base64 encoded PNG image)
+     * - http://www.w3.org/2001/XMLSchema#int (integer)
+     *
+     * Official types are preferred, but clients may use any syntactically
+     * valid MIME type (which start with a type and slash, like "text/...").
+     * If a URI type is used, it must be a complete absolute URI
+     * (which start with a scheme and colon, like "http:").
+     */
+    const char* type;
 } jack_property_t;
 
-        
 /**
- * Set a property on @c subject.
+ * Set a property on @p subject.
  *
- * See the above documentation for rules about @c subject and @c key.
+ * See the above documentation for rules about @p subject and @p key.
  * @param subject The subject to set the property on.
  * @param key The key of the property.
  * @param value The value of the property.
- * @param type The MIME type of the property. See the discussion of
- *              types in the definition of jack_property_t above.
+ * @param type The type of the property. See the discussion of
+ *             types in the definition of jack_property_t above.
  * @return 0 on success.
  */
 int
@@ -84,18 +87,17 @@ jack_set_property(jack_client_t*,
                   const char* type);
 
 /**
- * Get a property on @c subject.
+ * Get a property on @p subject.
  *
  * @param subject The subject to get the property from.
  * @param key The key of the property.
  * @param value Set to the value of the property if found, or NULL otherwise.
  *              The caller must free this value with jack_free().
- * @param type The MIME type of the property if set, or
- *              NULL. See the discussion of types in the definition of
- *              jack_property_t above.  If non-null, the caller must free
- *              this value with jack_free().
+ * @param type The type of the property if set, or NULL. See the discussion
+ *             of types in the definition of jack_property_t above.
+ *             If non-null, the caller must free this value with jack_free().
  *
- * @return 0 on success, -1 if the @c subject has no @c key property.
+ * @return 0 on success, -1 if the @p subject has no @p key property.
  */
 int
 jack_get_property(jack_uuid_t subject,
@@ -107,10 +109,10 @@ jack_get_property(jack_uuid_t subject,
  * A description of a subject (a set of properties).
  */
 typedef struct {
-    jack_uuid_t      subject;     /**< The subject being described. */
-    uint32_t         property_cnt;/**< The number of properties stored in "properties" */
-    jack_property_t* properties;  /**< An array of properties. */
-    uint32_t         property_size; /**< private, don't use or touch */
+    jack_uuid_t      subject;        /**< Subject being described. */
+    uint32_t         property_cnt;   /**< Number of elements in "properties". */
+    jack_property_t* properties;     /**< Array of properties. */
+    uint32_t         property_size;  /**< Private, do not use. */
 } jack_description_t;
 
 /**
@@ -120,18 +122,18 @@ typedef struct {
  * @param free_description_itself if non-zero, then @param desc will also be passed to free()
  */
 void
-jack_free_description(jack_description_t* desc, int free_description_itself);
+jack_free_description (jack_description_t* desc, int free_description_itself);
 
 /**
- * Get a description of @c subject.
+ * Get a description of @p subject.
  * @param subject The subject to get all properties of.
  * @param desc Set to the description of subject if found, or NULL otherwise.
  *             The caller must free this value with jack_free_desription().
- * @return 0 on success, -1 if no @c subject with any properties exists.
+ * @return 0 on success, -1 if no @p subject with any properties exists.
  */
 int
-jack_get_properties (jack_uuid_t          subject,
-                     jack_description_t*  desc);
+jack_get_properties (jack_uuid_t         subject,
+                     jack_description_t* desc);
 
 /**
  * Get descriptions for all subjects with metadata.
@@ -143,7 +145,8 @@ jack_get_properties (jack_uuid_t          subject,
 int
 jack_get_all_properties (jack_description_t** descs);
 
-/** Remove a single property on a subject
+/**
+ * Remove a single property on a subject.
  *
  * @param client The JACK client making the request to remove the property.
  * @param subject The subject to remove the property from.
@@ -153,21 +156,23 @@ jack_get_all_properties (jack_description_t** descs);
  */
 int jack_remove_property (jack_client_t* client, jack_uuid_t subject, const char* key);
 
-/** Remove all properties on a subject
+/**
+ * Remove all properties on a subject.
  *
  * @param client The JACK client making the request to remove some properties.
  * @param subject The subject to remove all properties from.
  *
- * @return a count of the number of properties removed, or -1 if an error occurs
+ * @return a count of the number of properties removed, or -1 on error.
  */
 int jack_remove_properties (jack_client_t* client, jack_uuid_t subject);
 
-/** Remove all properties
+/**
+ * Remove all properties.
  *
- * WARNING!! This deletes all metadata managed by a running JACK server. 
+ * WARNING!! This deletes all metadata managed by a running JACK server.
  * Data lost cannot be recovered (though it can be recreated by new calls
- * to jack_set_property()). 
- * 
+ * to jack_set_property()).
+ *
  * @param client The JACK client making the request to remove all properties
  *
  * @return 0 on success, -1 otherwise
@@ -180,13 +185,14 @@ typedef enum {
         PropertyDeleted
 } jack_property_change_t;
 
-typedef void (*JackPropertyChangeCallback)(jack_uuid_t subject,
-                                           const char* key,
+typedef void (*JackPropertyChangeCallback)(jack_uuid_t            subject,
+                                           const char*            key,
                                            jack_property_change_t change,
-                                           void* arg);
+                                           void*                  arg);
 
-/** Arrange for @param client to call @param callback whenever
- * a property is created, changed or deleted.
+/**
+ * Arrange for @p client to call @p callback whenever a property is created,
+ * changed or deleted.
  *
  * @param client the JACK client making the request
  * @param callback the function to be invoked when a property change occurs
@@ -194,9 +200,9 @@ typedef void (*JackPropertyChangeCallback)(jack_uuid_t subject,
  *
  * @return 0 success, -1 otherwise.
  */
-int jack_set_property_change_callback (jack_client_t* client,
+int jack_set_property_change_callback (jack_client_t*             client,
                                        JackPropertyChangeCallback callback,
-                                       void *arg);
+                                       void*                      arg);
 
 #ifdef __cplusplus
 } /* namespace */