properties: add generic property bag

Add a structure to hold string key/value pairs. This is basically a thin
wrapper around GHashTable with some extra API.

src/client/properties.c

@@ -0,0 +1,203 @@
+/* Pinos
+ * Copyright (C) 2015 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library 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.
+ */
+
+#include <glib-object.h>
+
+#include "client/properties.h"
+
+struct _PinosProperties {
+  GHashTable *hashtable;
+};
+
+static void
+copy_func (const gchar *key, const gchar *value, GHashTable *copy)
+{
+  g_hash_table_insert (copy, g_strdup (key), g_strdup (value));
+}
+
+/**
+ * pinos_properties_new:
+ * @key: first key
+ * @...: value
+ *
+ * Make a new #PinosProperties with given, NULL-terminated key/value pairs.
+ *
+ * Returns: a new #PinosProperties
+ */
+PinosProperties *
+pinos_properties_new (const gchar *key, ...)
+{
+  PinosProperties *props;
+  va_list varargs;
+  const gchar *value;
+
+  props = g_new (PinosProperties, 1);
+  props->hashtable = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+
+  va_start (varargs, key);
+  while (key != NULL) {
+    value = va_arg (varargs, gchar *);
+    copy_func (key, value, props->hashtable);
+    key = va_arg (varargs, gchar *);
+  }
+  va_end (varargs);
+
+  return props;
+}
+
+/**
+ * pinos_properties_copy:
+ * @properties: a #PinosProperties
+ *
+ * Make a copy of @properties.
+ *
+ * Returns: a copy of @properties
+ */
+PinosProperties *
+pinos_properties_copy (PinosProperties *properties)
+{
+  PinosProperties *copy;
+
+  g_return_val_if_fail (properties != NULL, NULL);
+
+  copy = pinos_properties_new (NULL);
+  g_hash_table_foreach (properties->hashtable, (GHFunc) copy_func, copy->hashtable);
+
+  return copy;
+}
+
+/**
+ * pinos_properties_free:
+ * @properties: a #PinosProperties
+ *
+ * Free @properties
+ */
+void
+pinos_properties_free (PinosProperties *properties)
+{
+  g_return_if_fail (properties != NULL);
+
+  g_hash_table_unref (properties->hashtable);
+  g_free (properties);
+}
+
+void
+pinos_properties_set (PinosProperties *properties,
+                      const gchar     *key,
+                      const gchar     *value)
+{
+  g_return_if_fail (properties != NULL);
+  g_return_if_fail (key != NULL);
+  g_return_if_fail (value != NULL);
+
+  g_hash_table_replace (properties->hashtable, g_strdup (key), g_strdup (value));
+}
+
+const gchar *
+pinos_properties_get (PinosProperties *properties,
+                      const gchar     *key)
+{
+  g_return_val_if_fail (properties != NULL, NULL);
+  g_return_val_if_fail (key != NULL, NULL);
+
+  return g_hash_table_lookup (properties->hashtable, key);
+}
+void
+pinos_properties_remove (PinosProperties *properties,
+                         const gchar     *key)
+{
+  g_return_if_fail (properties != NULL);
+  g_return_if_fail (key != NULL);
+
+  g_hash_table_remove (properties->hashtable, key);
+}
+
+const gchar *
+pinos_properties_iterate (PinosProperties     *properties,
+                          gpointer            *state)
+{
+  static gpointer dummy = GINT_TO_POINTER (1);
+  const gchar *res = NULL;
+  GList *items;
+
+  g_return_val_if_fail (properties != NULL, NULL);
+  g_return_val_if_fail (state != NULL, NULL);
+
+  if (*state == dummy)
+    return NULL;
+
+  if (*state == NULL) {
+    items = g_hash_table_get_keys (properties->hashtable);
+  } else {
+    items = *state;
+  }
+
+  if (items) {
+    res = items->data;
+    items = g_list_delete_link (items, items);
+    if (items == NULL)
+      items = dummy;
+  }
+  *state = items;
+
+  return res;
+}
+
+static void
+add_to_variant (const gchar *key, const gchar *value, GVariantBuilder *b)
+{
+  g_variant_builder_add (b, "{sv}", key, g_variant_new_string (value));
+}
+
+GVariant *
+pinos_properties_to_variant (PinosProperties *properties)
+{
+  GVariantBuilder builder;
+
+  g_return_val_if_fail (properties != NULL, NULL);
+
+  g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{sv}"));
+  g_hash_table_foreach (properties->hashtable, (GHFunc) add_to_variant, &builder);
+  return g_variant_builder_end (&builder);
+}
+
+PinosProperties *
+pinos_properties_from_variant (GVariant *variant)
+{
+  PinosProperties *props;
+  GVariantIter iter;
+  GVariant *value;
+  gchar *key;
+
+  g_return_val_if_fail (variant != NULL, NULL);
+
+  props = pinos_properties_new (NULL);
+
+  g_variant_iter_init (&iter, variant);
+  while (g_variant_iter_loop (&iter, "{sv}", &key, &value))
+    g_hash_table_replace (props->hashtable,
+                          g_strdup (key),
+                          g_variant_dup_string (value, NULL));
+
+  return props;
+}
+
+G_DEFINE_BOXED_TYPE (PinosProperties, pinos_properties,
+        pinos_properties_copy, pinos_properties_free);
+