libnm-util: add nm_connection_diff()

Returns a list of keys that differ between the settings in each
connection.  nm_connection_compare() can't do that.

1 files changed, 137 insertions, 13 deletions

diff --git a/libnm-util/nm-setting.c b/libnm-util/nm-setting.c
index b5a8b71f64..f134754b18 100644
--- a/libnm-util/nm-setting.c
+++ b/libnm-util/nm-setting.c
@@ -332,6 +332,29 @@ nm_setting_verify (NMSetting *setting, GSList *all_settings, GError **error)
 	return TRUE;
 }
 
+static inline gboolean
+should_compare_prop (NMSetting *setting,
+                     const char *prop_name,
+                     NMSettingCompareFlags comp_flags,
+                     GParamFlags prop_flags)
+{
+	/* Fuzzy compare ignores secrets and properties defined with the FUZZY_IGNORE flag */
+	if (   (comp_flags & NM_SETTING_COMPARE_FLAG_FUZZY)
+	    && (prop_flags & (NM_SETTING_PARAM_FUZZY_IGNORE | NM_SETTING_PARAM_SECRET)))
+		return FALSE;
+
+	if (   (comp_flags & NM_SETTING_COMPARE_FLAG_IGNORE_SECRETS)
+	    && (prop_flags & NM_SETTING_PARAM_SECRET))
+		return FALSE;
+
+	if (   (comp_flags & NM_SETTING_COMPARE_FLAG_IGNORE_ID)
+	    && NM_IS_SETTING_CONNECTION (setting)
+	    && !strcmp (prop_name, NM_SETTING_CONNECTION_ID))
+		return FALSE;
+
+	return TRUE;
+}
+
 /**
  * nm_setting_compare:
  * @a: a #NMSetting
@@ -370,19 +393,8 @@ nm_setting_compare (NMSetting *a,
 		GValue value1 = { 0 };
 		GValue value2 = { 0 };
 
-		/* Fuzzy compare ignores secrets and properties defined with the
-		 * FUZZY_IGNORE flag
-		 */
-		if (   (flags & NM_SETTING_COMPARE_FLAG_FUZZY)
-		    && (prop_spec->flags & (NM_SETTING_PARAM_FUZZY_IGNORE | NM_SETTING_PARAM_SECRET)))
-			continue;
-
-		if ((flags & NM_SETTING_COMPARE_FLAG_IGNORE_SECRETS) && (prop_spec->flags & NM_SETTING_PARAM_SECRET))
-			continue;
-
-		if (   (flags & NM_SETTING_COMPARE_FLAG_IGNORE_ID)
-			   && !strcmp (nm_setting_get_name (a), NM_SETTING_CONNECTION_SETTING_NAME)
-		    && !strcmp (prop_spec->name, NM_SETTING_CONNECTION_ID))
+		/* Handle compare flags */
+		if (!should_compare_prop (a, prop_spec->name, flags, prop_spec->flags))
 			continue;
 
 		g_value_init (&value1, prop_spec->value_type);
@@ -403,6 +415,118 @@ nm_setting_compare (NMSetting *a,
 }
 
 /**
+ * nm_setting_diff:
+ * @a: a #NMSetting
+ * @b: a second #NMSetting to compare with the first
+ * @flags: compare flags, e.g. %NM_SETTING_COMPARE_FLAG_EXACT
+ * @invert_results: this parameter is used internally by libnm-util and should
+ * be set to %FALSE.  If %TRUE inverts the meaning of the #NMSettingDiffResult.
+ * @results: (element-type utf8 guint32): if the settings differ, on return a
+ * hash table mapping the differing keys to one or more #NMSettingDiffResult
+ * values OR-ed together.  If the settings do not differ, any hash table passed
+ * in is unmodified.  If no hash table is passed in, a new one is created.
+ *
+ * Compares two #NMSetting objects for similarity, with comparison behavior
+ * modified by a set of flags.  See the documentation for #NMSettingCompareFlags
+ * for a description of each flag's behavior.  If the settings differ, the keys
+ * of each setting that differ from the other are added to @results, mapped to
+ * one or more #NMSettingDiffResult values.
+ *
+ * Returns: %TRUE if the settings contain the same values, %FALSE if they do not
+ **/
+gboolean
+nm_setting_diff (NMSetting *a,
+                 NMSetting *b,
+                 NMSettingCompareFlags flags,
+                 gboolean invert_results,
+                 GHashTable **results)
+{
+	GParamSpec **property_specs;
+	guint n_property_specs;
+	guint i;
+	NMSettingDiffResult a_result = NM_SETTING_DIFF_RESULT_IN_A;
+	NMSettingDiffResult b_result = NM_SETTING_DIFF_RESULT_IN_B;
+	gboolean results_created = FALSE;
+
+	g_return_val_if_fail (results != NULL, FALSE);
+	g_return_val_if_fail (a != NULL, FALSE);
+	g_return_val_if_fail (NM_IS_SETTING (a), FALSE);
+	if (b) {
+		g_return_val_if_fail (NM_IS_SETTING (b), FALSE);
+		g_return_val_if_fail (G_OBJECT_TYPE (a) == G_OBJECT_TYPE (b), FALSE);
+	}
+
+	/* If the caller is calling this function in a pattern like this to get
+	 * complete diffs:
+	 *
+	 * nm_setting_diff (A, B, FALSE, &results);
+	 * nm_setting_diff (B, A, TRUE, &results);
+	 *
+	 * and wants us to invert the results so that the second invocation comes
+	 * out correctly, do that here.
+	 */
+	if (invert_results) {
+		a_result = NM_SETTING_DIFF_RESULT_IN_B;
+		b_result = NM_SETTING_DIFF_RESULT_IN_A;
+	}
+
+	if (*results == NULL) {
+		*results = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
+		results_created = TRUE;
+	}
+
+	/* And now all properties */
+	property_specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (a), &n_property_specs);
+
+	for (i = 0; i < n_property_specs; i++) {
+		GParamSpec *prop_spec = property_specs[i];
+		GValue a_value = { 0 }, b_value = { 0 };
+		NMSettingDiffResult r = NM_SETTING_DIFF_RESULT_UNKNOWN, tmp;
+		gboolean different = TRUE;
+
+		/* Handle compare flags */
+		if (!should_compare_prop (a, prop_spec->name, flags, prop_spec->flags))
+			continue;
+		if (strcmp (prop_spec->name, NM_SETTING_NAME) == 0)
+			continue;
+
+		if (b) {
+			g_value_init (&a_value, prop_spec->value_type);
+			g_object_get_property (G_OBJECT (a), prop_spec->name, &a_value);
+
+			g_value_init (&b_value, prop_spec->value_type);
+			g_object_get_property (G_OBJECT (b), prop_spec->name, &b_value);
+
+			different = !!g_param_values_cmp (prop_spec, &a_value, &b_value);
+			if (different) {
+				if (!g_param_value_defaults (prop_spec, &a_value))
+					r |= a_result;
+				if (!g_param_value_defaults (prop_spec, &b_value))
+					r |= b_result;
+			}
+
+			g_value_unset (&a_value);
+			g_value_unset (&b_value);
+		} else
+			r = a_result;  /* only in A */
+
+		if (different) {
+			tmp = GPOINTER_TO_UINT (g_hash_table_lookup (*results, prop_spec->name));
+			g_hash_table_insert (*results, g_strdup (prop_spec->name), GUINT_TO_POINTER (tmp | r));
+		}
+	}
+	g_free (property_specs);
+
+	/* Don't return an empty hash table */
+	if (results_created && !g_hash_table_size (*results)) {
+		g_hash_table_destroy (*results);
+		*results = NULL;
+	}
+
+	return !(*results);
+}
+
+/**
  * nm_setting_enumerate_values:
  * @setting: the #NMSetting
  * @func: (scope call): user-supplied function called for each property of the setting