[multivalued in grilo (v3) 2/5] core: Add new class to handle related keys and its values

["Juan A. Suarez Romero" <jasuarez igalia com>]

Add GrlRelatedKeys class, which helps to keep together and handling related
keys with their values.

Signed-off-by: Juan A. Suarez Romero <jasuarez igalia com>
---
 src/Makefile.am             |    2 +
 src/data/grl-related-keys.c |  579 +++++++++++++++++++++++++++++++++++++++++++
 src/data/grl-related-keys.h |  153 ++++++++++++
 src/grilo.h                 |    1 +
 4 files changed, 735 insertions(+), 0 deletions(-)
 create mode 100644 src/data/grl-related-keys.c
 create mode 100644 src/data/grl-related-keys.h

diff --git a/src/Makefile.am b/src/Makefile.am
index e5b82cc..1b29bdf 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -51,6 +51,7 @@ lib@GRL_NAME@_la_SOURCES =					\
 
 data_c_sources =		\
 	data/grl-data.c		\
+	data/grl-related-keys.c	\
 	data/grl-media.c	\
 	data/grl-media-audio.c	\
 	data/grl-media-video.c	\
@@ -78,6 +79,7 @@ lib@GRL_NAME@inc_HEADERS =	\
 
 data_h_headers =		\
 	data/grl-data.h		\
+	data/grl-related-keys.h	\
 	data/grl-media.h	\
 	data/grl-media-box.h	\
 	data/grl-media-audio.h	\
diff --git a/src/data/grl-related-keys.c b/src/data/grl-related-keys.c
new file mode 100644
index 0000000..56543d0
--- /dev/null
+++ b/src/data/grl-related-keys.c
@@ -0,0 +1,579 @@
+/*
+ * Copyright (C) 2011 Igalia S.L.
+ *
+ * Contact: Iago Toral Quiroga <itoral igalia com>
+ *
+ * Authors: Juan A. Suarez Romero <jasuarez igalia com>
+ *
+ * This library 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; version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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 library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+/**
+ * SECTION:grl-related-keys
+ * @short_description: A class where to store related metadata keys.
+ * @see_also: #GrlPluginRegistry, #GrlData
+ *
+ * When handling media keys, like artist, URI, mime-type, and so on, some of
+ * these keys are somewhat related: they do not make sense if they are not
+ * accompanied by other keys.
+ *
+ * For instance, media URI and and mime-type are related keys: mime-type does
+ * not make sense if it is not accompanied by an URI. Moreover, for each URI
+ * value, it has a correspondance mime-type value.
+ *
+ * #GrlRelatedKeys stores related keys and their values in one place, so user
+ * can handle them in one shot.
+ */
+
+#include "grl-related-keys.h"
+#include "grl-log.h"
+
+struct _GrlRelatedKeysPrivate {
+  GHashTable *data;
+};
+
+static void grl_related_keys_finalize (GObject *object);
+static void free_value (GValue *val);
+
+#define GRL_RELATED_KEYS_GET_PRIVATE(o)                                 \
+  (G_TYPE_INSTANCE_GET_PRIVATE ((o),                                    \
+                                GRL_TYPE_RELATED_KEYS,                  \
+                                GrlRelatedKeysPrivate))
+
+/* ================ GrlRelatedKeys GObject ================ */
+
+G_DEFINE_TYPE (GrlRelatedKeys, grl_related_keys, G_TYPE_OBJECT);
+
+static void
+grl_related_keys_class_init (GrlRelatedKeysClass *klass)
+{
+  GObjectClass *gobject_class = (GObjectClass *)klass;
+
+  gobject_class->finalize = grl_related_keys_finalize;
+
+  g_type_class_add_private (klass, sizeof (GrlRelatedKeysPrivate));
+}
+
+static void
+grl_related_keys_init (GrlRelatedKeys *self)
+{
+  self->priv = GRL_RELATED_KEYS_GET_PRIVATE (self);
+  self->priv->data = g_hash_table_new_full (g_direct_hash,
+                                            g_direct_equal,
+                                            NULL,
+                                            (GDestroyNotify) free_value);
+}
+
+static void
+grl_related_keys_finalize (GObject *object)
+{
+  g_hash_table_unref (GRL_RELATED_KEYS (object)->priv->data);
+  G_OBJECT_CLASS (grl_related_keys_parent_class)->finalize (object);
+}
+
+/* ================ Utitilies ================ */
+
+static void
+free_value (GValue *val)
+{
+  if (val) {
+    g_value_unset (val);
+    g_free (val);
+  }
+}
+
+/* ================ API ================ */
+
+/**
+ * grl_related_keys_new:
+ *
+ * Creates a new place to store related keys and values.
+ *
+ * Returns: a new object.
+ **/
+GrlRelatedKeys *
+grl_related_keys_new (void)
+{
+  return g_object_new (GRL_TYPE_RELATED_KEYS, NULL);
+}
+
+/**
+ * grl_related_keys_new_valist:
+ * @key: first key
+ * @args: #va_list of value, followed by (key,value) pairs to insert
+ *
+ * Creates a new #GrlRelatedKeys containing pairs of (key, value). Finish the
+ * list with %NULL.
+ *
+ * In case of a binary-type key, the expected element is (key, value, size).
+ *
+ * value type will be extracted from key information.
+ *
+ * Returns: a new #GrlRelatedKeys
+ **/
+GrlRelatedKeys *
+grl_related_keys_new_valist (GrlKeyID key,
+                             va_list args)
+{
+  GType key_type;
+  GrlKeyID next_key;
+  GrlRelatedKeys *prop;
+  gpointer next_value;
+
+  prop = grl_related_keys_new ();
+
+  next_key = key;
+  while (next_key) {
+    key_type = GRL_METADATA_KEY_GET_TYPE (next_key);
+    if (key_type == G_TYPE_STRING) {
+      grl_related_keys_set_string (prop, next_key, va_arg (args, gchar *));
+    } else if (key_type == G_TYPE_INT) {
+      grl_related_keys_set_int (prop, next_key, va_arg (args, gint));
+    } else if (key_type == G_TYPE_FLOAT) {
+      grl_related_keys_set_float (prop, next_key, va_arg (args, double));
+    } else if (key_type == G_TYPE_BYTE_ARRAY) {
+      next_value = va_arg (args, gpointer);
+      grl_related_keys_set_binary (prop,
+                                   next_key,
+                                   next_value,
+                                   va_arg (args, gsize));
+    }
+    next_key = va_arg (args, GrlKeyID);
+  }
+
+  return prop;
+}
+
+/**
+ * grl_related_keys_new_with_keys: (skip)
+ * @key: first key
+ * @...: value, following by list of (key, value)
+ *
+ * Creates a initial #GrlRelatedKeys containing the list of (key, value)
+ * pairs. Finish the list with %NULL.
+ *
+ * For more information see #grl_related_keys_new_valist.
+
+ * Returns: a new #GrlRelatedKeys
+ **/
+GrlRelatedKeys *
+grl_related_keys_new_with_keys (GrlKeyID key,
+                                ...)
+{
+  GrlRelatedKeys *prop;
+  va_list args;
+
+  va_start (args, key);
+  prop = grl_related_keys_new_valist (key, args);
+  va_end (args);
+
+  return prop;
+}
+
+
+/**
+ * grl_related_keys_get:
+ * @relkeys: set of related keys to retrieve value
+ * @key: (type Grl.KeyID): key to look up.
+ *
+ * Get the value associated with @key from @relkeys. If it does not contain any
+ * value, %NULL will be returned.
+ *
+ * Returns: (transfer none): a #GValue. This value should not be modified nor
+ * freed by user.
+ **/
+const GValue *
+grl_related_keys_get (GrlRelatedKeys *relkeys,
+                      GrlKeyID key)
+{
+  g_return_val_if_fail (GRL_IS_RELATED_KEYS (relkeys), NULL);
+  g_return_val_if_fail (key, NULL);
+
+  return g_hash_table_lookup (relkeys->priv->data, key);
+}
+
+/**
+ * grl_related_keys_set:
+ * @relkeys: set of related keys to modify
+ * @key: (type Grl.KeyID): key to change or add
+ * @value: the new value
+ *
+ * Sets the value associated with @key into @relkeys. Old value is freed and
+ * the new one is set.
+ *
+ * Also, checks that @value is compliant with @key specification, modifying it
+ * accordingly. For instance, if @key requires a number between 0 and 10, but
+ * value is outside this range, it will be adapted accordingly.
+ **/
+void
+grl_related_keys_set (GrlRelatedKeys *relkeys,
+                      GrlKeyID key,
+                      const GValue *value)
+{
+  GValue *copy = NULL;
+
+  g_return_if_fail (GRL_IS_RELATED_KEYS (relkeys));
+  g_return_if_fail (key);
+
+  /* Dup value */
+  if (value) {
+    if (G_VALUE_TYPE (value) == GRL_METADATA_KEY_GET_TYPE (key)) {
+      copy = g_new0 (GValue, 1);
+      g_value_init (copy, G_VALUE_TYPE (value));
+      g_value_copy (value, copy);
+    } else {
+      GRL_WARNING ("value has type %s, but expected %s",
+                   g_type_name (G_VALUE_TYPE (value)),
+                   g_type_name (GRL_METADATA_KEY_GET_TYPE (key)));
+    }
+  }
+
+  if (copy && g_param_value_validate (key, copy)) {
+    GRL_WARNING ("'%s' value invalid, adjusting",
+                 GRL_METADATA_KEY_GET_NAME (key));
+  }
+  g_hash_table_insert (relkeys->priv->data, key, copy);
+}
+
+/**
+ * grl_related_keys_set_string:
+ * @relkeys: set of related keys to modify
+ * @key: (type Grl.KeyID): key to change or add
+ * @strvalue: the new value
+ *
+ * Sets the value associated with @key into @relkeys. @key must have been
+ * registered as a strying-type key. Old value is freed and the new one is set.
+ **/
+void
+grl_related_keys_set_string (GrlRelatedKeys *relkeys,
+                             GrlKeyID key,
+                             const gchar *strvalue)
+{
+  if (strvalue) {
+    GValue value = { 0 };
+    g_value_init (&value, G_TYPE_STRING);
+    g_value_set_string (&value, strvalue);
+    grl_related_keys_set (relkeys, key, &value);
+    g_value_unset (&value);
+  } else {
+    grl_related_keys_set (relkeys, key, NULL);
+  }
+}
+
+/**
+ * grl_related_keys_get_string:
+ * @relkeys: set of related keys to inspect
+ * @key: (type Grl.KeyID): key to use
+ *
+ * Returns the value associated with @key from @relkeys. If @key has no value,
+ * or value is not string, or @key is not in @relkeys, then %NULL is returned.
+ *
+ * Returns: string associated with @key, or %NULL in other case. Caller should
+ * not change nor free the value.
+ **/
+const gchar *
+grl_related_keys_get_string (GrlRelatedKeys *relkeys,
+                             GrlKeyID key)
+{
+  const GValue *value = grl_related_keys_get (relkeys, key);
+
+  if (!value || !G_VALUE_HOLDS_STRING (value)) {
+    return NULL;
+  } else {
+    return g_value_get_string (value);
+  }
+}
+
+/**
+ * grl_related_keys_set_int:
+ * @relkeys: set of related keys to change
+ * @key: (type Grl.KeyID): key to change or add
+ * @intvalue: the new value
+ *
+ * Sets the value associated with @key into @relkeys. @key must have been
+ * registered as an int-type key. Old value is replaced by the new one.
+ **/
+void
+grl_related_keys_set_int (GrlRelatedKeys *relkeys,
+                          GrlKeyID key,
+                          gint intvalue)
+{
+  GValue value = { 0 };
+  g_value_init (&value, G_TYPE_INT);
+  g_value_set_int (&value, intvalue);
+  grl_related_keys_set (relkeys, key, &value);
+}
+
+/**
+ * grl_related_keys_get_int:
+ * @relkeys: set of related keys to inspect
+ * @key: (type Grl.KeyID): key to use
+ *
+ * Returns the value associated with @key from @relkeys. If @key has no value,
+ * or value is not a gint, or @key is not in @relkeys, then 0 is returned.
+ *
+ * Returns: int value associated with @key, or 0 in other case.
+ **/
+gint
+grl_related_keys_get_int (GrlRelatedKeys *relkeys,
+                          GrlKeyID key)
+{
+  const GValue *value = grl_related_keys_get (relkeys, key);
+
+  if (!value || !G_VALUE_HOLDS_INT (value)) {
+    return 0;
+  } else {
+    return g_value_get_int (value);
+  }
+}
+
+/**
+ * grl_related_keys_set_float:
+ * @relkeys: set of related keys to change
+ * @key: (type Grl.KeyID): key to change or add
+ * @floatvalue: the new value
+ *
+ * Sets the value associated with @key into @relkeys. @key must have been
+ * registered as a float-type key. Old value is replaced by the new one.
+ **/
+void
+grl_related_keys_set_float (GrlRelatedKeys *relkeys,
+                            GrlKeyID key,
+                            float floatvalue)
+{
+  GValue value = { 0 };
+  g_value_init (&value, G_TYPE_FLOAT);
+  g_value_set_float (&value, floatvalue);
+  grl_related_keys_set (relkeys, key, &value);
+}
+
+/**
+ * grl_related_keys_get_float:
+ * @relkeys: set of related keys to inspect
+ * @key: (type Grl.KeyID): key to use
+ *
+ * Returns the value associated with @key from @relkeys. If @key has no value,
+ * or value is not a gfloat, or @key is not in @relkeys, then 0 is returned.
+ *
+ * Returns: float value associated with @key, or 0 in other case.
+ **/
+gfloat
+grl_related_keys_get_float (GrlRelatedKeys *relkeys,
+                            GrlKeyID key)
+{
+  const GValue *value = grl_related_keys_get (relkeys, key);
+
+  if (!value || !G_VALUE_HOLDS_FLOAT (value)) {
+    return 0;
+  } else {
+    return g_value_get_float (value);
+  }
+}
+
+/**
+ * grl_related_keys_set_binary:
+ * @relkeys: set of related keys to change
+ * @key: (type Grl.KeyID): key to change or add
+ * @buf: buffer holding the relkeys
+ * @size: size of the buffer
+ *
+ * Sets the value associated with @key into @relkeys. @key must have been
+ * registered as a binary-type key. Old value is replaced by the new one.
+ **/
+void
+grl_related_keys_set_binary (GrlRelatedKeys *relkeys,
+                             GrlKeyID key,
+                             const guint8 *buf,
+                             gsize size)
+{
+  GValue v = { 0 };
+  GByteArray *array;
+
+  array = g_byte_array_append (g_byte_array_sized_new(size),
+                               buf,
+                               size);
+
+  g_value_init (&v, g_byte_array_get_type ());
+  g_value_take_boxed (&v, array);
+  grl_related_keys_set (relkeys, key, &v);
+  g_value_unset (&v);
+}
+
+/**
+ * grl_related_keys_get_binary:
+ * @relkeys: set of related keys to inspect
+ * @key: (type Grl.KeyID): key to use
+ * @size: (out): location to store the buffer size
+ *
+ * Returns the value associated with @key from @relkeys. If @key has no value,
+ * or value is not a binary, or @key is not in @relkeys, then 0 is returned.
+ *
+ * Returns: buffer location associated with @key, or %NULL in other case. If
+ * successful @size will be set to the buffer size.
+ **/
+const guint8 *
+grl_related_keys_get_binary (GrlRelatedKeys *relkeys,
+                             GrlKeyID key,
+                             gsize *size)
+{
+  g_return_val_if_fail (size, NULL);
+
+  const GValue *value = grl_related_keys_get (relkeys, key);
+
+  if (!value || !G_VALUE_HOLDS_BOXED (value)) {
+    return NULL;
+  } else {
+    GByteArray * array;
+
+    array = g_value_get_boxed (value);
+    *size = array->len;
+    return (const guint8 *) array->data;
+  }
+}
+
+/**
+ * grl_related_keys_add:
+ * @relkeys: set of related keys to change
+ * @key: (type Grl.KeyID): key to add
+ *
+ * Adds a new @key to @relkeys, with no value. If @key already exists, it does
+ * nothing.
+ **/
+void
+grl_related_keys_add (GrlRelatedKeys *relkeys,
+                      GrlKeyID key)
+{
+  if (!grl_related_keys_has_key (relkeys, key)) {
+    grl_related_keys_set (relkeys, key, NULL);
+  }
+}
+
+/**
+ * grl_related_keys_has_key:
+ * @relkeys: set of related keys to inspect
+ * @key: (type Grl.KeyID): key to search
+ *
+ * Checks if @key is in @relkeys.
+ *
+ * Returns: %TRUE if @key is in @relkeys, %FALSE in other case.
+ **/
+gboolean
+grl_related_keys_has_key (GrlRelatedKeys *relkeys,
+                          GrlKeyID key)
+{
+  g_return_val_if_fail (GRL_IS_RELATED_KEYS (relkeys), FALSE);
+
+  return g_hash_table_lookup_extended (relkeys->priv->data, key, NULL, NULL);
+}
+
+/**
+ * grl_related_keys_get_keys:
+ * @relkeys: set of related keys to inspect
+ * @include_unknown: %TRUE if keys with no value must be included
+ *
+ * Returns a list with keys contained in @relkeys. If @include_unknown is
+ * %FALSE, only those keys in @relkeys that have actually a value will be
+ * returned.
+ *
+ * Returns: (transfer container) (element-type Grl.KeyID): an array
+ * with the keys. The content of the list should not be modified or freed. Use
+ * g_list_free() when done using the list.
+ **/
+GList *
+grl_related_keys_get_keys (GrlRelatedKeys *relkeys,
+                           gboolean include_unknown)
+{
+  GList *keylist;
+
+  g_return_val_if_fail (GRL_IS_RELATED_KEYS (relkeys), NULL);
+
+  keylist = g_hash_table_get_keys (relkeys->priv->data);
+
+  if (!include_unknown) {
+    keylist = g_list_remove_all (keylist, NULL);
+  }
+
+  return keylist;
+}
+
+/**
+ * grl_related_keys_key_is_known:
+ * @relkeys: set of related keys to inspect
+ * @key: (type Grl.KeyID): key to search
+ *
+ * Checks if @key has a value in @relkeys.
+ *
+ * Returns: %TRUE if @key has a value.
+ **/
+gboolean
+grl_related_keys_key_is_known (GrlRelatedKeys *relkeys,
+                               GrlKeyID key)
+{
+  GValue *v;
+
+  g_return_val_if_fail (GRL_IS_RELATED_KEYS (relkeys), FALSE);
+
+  v = g_hash_table_lookup (relkeys->priv->data, key);
+
+  if (!v) {
+    return FALSE;
+  }
+
+  if (G_VALUE_HOLDS_STRING (v)) {
+    return g_value_get_string (v) != NULL;
+  }
+
+  return TRUE;
+}
+
+/**
+ * grl_related_keys_dup:
+ * @relkeys: set of related keys to duplicate
+ *
+ * Makes a deep copy of @relkeys and its contents.
+ *
+ * Returns: a new #GrlRelatedKeys. Free it with #g_object_unref.
+ **/
+GrlRelatedKeys *
+grl_related_keys_dup (GrlRelatedKeys *relkeys)
+{
+  GList *keys, *key;
+  const GValue *value;
+  GValue *value_copy;
+  GrlRelatedKeys *dup_relkeys;
+
+  g_return_val_if_fail (relkeys, NULL);
+
+  dup_relkeys = grl_related_keys_new ();
+
+  keys = grl_related_keys_get_keys (relkeys, TRUE);
+  for (key = keys; key; key = g_list_next (key)) {
+    value = grl_related_keys_get (relkeys, key->data);
+    if (value) {
+      value_copy = g_new0 (GValue, 1);
+      g_value_init (value_copy, G_VALUE_TYPE (value));
+      g_value_copy (value, value_copy);
+    } else {
+      value_copy = NULL;
+    }
+    g_hash_table_insert (dup_relkeys->priv->data, key->data, value_copy);
+  }
+
+  g_list_free (keys);
+
+  return dup_relkeys;
+}
diff --git a/src/data/grl-related-keys.h b/src/data/grl-related-keys.h
new file mode 100644
index 0000000..659ccfb
--- /dev/null
+++ b/src/data/grl-related-keys.h
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2011 Igalia S.L.
+ *
+ * Contact: Iago Toral Quiroga <itoral igalia com>
+ *
+ * Authors: Juan A. Suarez Romero <jasuarez igalia com>
+ *
+ * This library 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; version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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 library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#if !defined (_GRILO_H_INSIDE_) && !defined (GRILO_COMPILATION)
+#error "Only <grilo.h> can be included directly."
+#endif
+
+#ifndef _GRL_RELATED_KEYS_H_
+#define _GRL_RELATED_KEYS_H_
+
+#include <glib-object.h>
+#include <grl-metadata-key.h>
+#include <grl-definitions.h>
+
+G_BEGIN_DECLS
+
+#define GRL_TYPE_RELATED_KEYS                   \
+  (grl_related_keys_get_type())
+
+#define GRL_RELATED_KEYS(obj)                           \
+  (G_TYPE_CHECK_INSTANCE_CAST ((obj),                   \
+                               GRL_TYPE_RELATED_KEYS,   \
+                               GrlRelatedKeys))
+
+#define GRL_RELATED_KEYS_CLASS(klass)                   \
+  (G_TYPE_CHECK_CLASS_CAST ((klass),                    \
+                            GRL_TYPE_RELATED_KEYS,      \
+                            GrlRelatedKeysClass))
+
+#define GRL_IS_RELATED_KEYS(obj)                        \
+  (G_TYPE_CHECK_INSTANCE_TYPE ((obj),                   \
+                               GRL_TYPE_RELATED_KEYS))
+
+#define GRL_IS_RELATED_KEYS_CLASS(klass)                \
+  (G_TYPE_CHECK_CLASS_TYPE ((klass),                    \
+                            GRL_TYPE_RELATED_KEYS))
+
+#define GRL_RELATED_KEYS_GET_CLASS(obj)                 \
+  (G_TYPE_INSTANCE_GET_CLASS ((obj),                    \
+                              GRL_TYPE_RELATED_KEYS,    \
+                              GrlRelatedKeysClass))
+
+typedef struct _GrlRelatedKeys        GrlRelatedKeys;
+typedef struct _GrlRelatedKeysPrivate GrlRelatedKeysPrivate;
+typedef struct _GrlRelatedKeysClass   GrlRelatedKeysClass;
+
+/**
+ * GrlRelatedKeysClass:
+ * @parent_class: the parent class structure
+ *
+ * Grilo Data Multivalued class
+ */
+struct _GrlRelatedKeysClass
+{
+  GObjectClass parent_class;
+
+  /*< private >*/
+  gpointer _grl_reserved[GRL_PADDING];
+};
+
+struct _GrlRelatedKeys
+{
+  GObject parent;
+
+  /*< private >*/
+  GrlRelatedKeysPrivate *priv;
+
+  gpointer _grl_reserved[GRL_PADDING_SMALL];
+};
+
+GType grl_related_keys_get_type (void) G_GNUC_CONST;
+
+GrlRelatedKeys *grl_related_keys_new (void);
+
+GrlRelatedKeys *grl_related_keys_new_valist (GrlKeyID key, va_list args);
+
+GrlRelatedKeys *grl_related_keys_new_with_keys (GrlKeyID key, ...);
+
+void grl_related_keys_set (GrlRelatedKeys *relkeys,
+                           GrlKeyID key,
+                           const GValue *value);
+
+void grl_related_keys_set_string (GrlRelatedKeys *relkeys,
+                                  GrlKeyID key,
+                                  const gchar *strvalue);
+
+void grl_related_keys_set_int (GrlRelatedKeys *relkeys,
+                               GrlKeyID key,
+                               gint intvalue);
+
+void grl_related_keys_set_float (GrlRelatedKeys *relkeys,
+                                 GrlKeyID key,
+                                 gfloat floatvalue);
+
+void grl_related_keys_set_binary(GrlRelatedKeys *relkeys,
+                                 GrlKeyID key,
+                                 const guint8 *buf,
+                                 gsize size);
+
+const GValue *grl_related_keys_get (GrlRelatedKeys *relkeys,
+                                    GrlKeyID key);
+
+const gchar *grl_related_keys_get_string (GrlRelatedKeys *relkeys,
+                                          GrlKeyID key);
+
+gint grl_related_keys_get_int (GrlRelatedKeys *relkeys,
+                               GrlKeyID key);
+
+gfloat grl_related_keys_get_float (GrlRelatedKeys *relkeys,
+                                   GrlKeyID key);
+
+const guint8 *grl_related_keys_get_binary(GrlRelatedKeys *relkeys,
+                                          GrlKeyID key,
+                                          gsize *size);
+
+void grl_related_keys_add (GrlRelatedKeys *relkeys,
+                           GrlKeyID key);
+
+gboolean grl_related_keys_has_key (GrlRelatedKeys *relkeys,
+                                   GrlKeyID key);
+
+GList *grl_related_keys_get_keys (GrlRelatedKeys *relkeys,
+                                  gboolean include_unknown);
+
+gboolean grl_related_keys_key_is_known (GrlRelatedKeys *relkeys,
+                                        GrlKeyID key);
+
+GrlRelatedKeys *grl_related_keys_dup (GrlRelatedKeys *relkeys);
+
+G_END_DECLS
+
+#endif /* _GRL_RELATED_KEYS_H_ */
diff --git a/src/grilo.h b/src/grilo.h
index cff47a0..6d4ab71 100644
--- a/src/grilo.h
+++ b/src/grilo.h
@@ -41,6 +41,7 @@
 #include <grl-media-image.h>
 #include <grl-media-box.h>
 #include <grl-config.h>
+#include <grl-related-keys.h>
 #include <grl-multiple.h>
 #include <grl-util.h>
 #include <grl-definitions.h>
-- 
1.7.1