[Libguestfs] [PATCH nbdkit INCOMPLETE 6/6] filters: Implement chain of filters in front of ordinary plugin methods.

[Richard W.M. Jones]

---
 src/plugins.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 54 insertions(+), 7 deletions(-)

diff --git a/src/plugins.c b/src/plugins.c
index 3600293..085366b 100644
--- a/src/plugins.c
+++ b/src/plugins.c
@@ -406,8 +406,8 @@ plugin_dump_fields (void)
     plugin.dump_plugin ();
 }
 
-void
-plugin_config (const char *key, const char *value)
+static int
+final_plugin_config (const char *key, const char *value)
 {
   assert (dl);
 
@@ -422,21 +422,68 @@ plugin_config (const char *key, const char *value)
     exit (EXIT_FAILURE);
   }
 
-  if (plugin.config (key, value) == -1)
-    exit (EXIT_FAILURE);
+  return plugin.config (key, value);
+}
+
+static int
+filter_plugin_config (void *data, const char *key, const char *value)
+{
+  if (data == NULL)
+    return final_plugin_config (key, value);
+  else {
+    struct filter *f = data;
+
+    debug ("%s: config key=%s, value=%s", f->filename, key, value);
+
+    if (f->filter.config)
+      if (f->filter.config (key, value, filter_plugin_config, f->next) == -1)
+        return -1;
+    return 0;
+  }
 }
 
 void
-plugin_config_complete (void)
+plugin_config (const char *key, const char *value)
+{
+  if (filter_plugin_config (filters, key, value) == -1)
+    exit (EXIT_FAILURE);
+}
+
+static int
+final_plugin_config_complete (void)
 {
   assert (dl);
 
   debug ("%s: config_complete", filename);
 
   if (!plugin.config_complete)
-    return;
+    return 0;
+
+  return plugin.config_complete ();
+}
+
+static int
+filter_plugin_config_complete (void *data)
+{
+  if (data == NULL)
+    return final_plugin_config_complete ();
+  else {
+    struct filter *f = data;
+
+    debug ("%s: config_complete", f->filename);
 
-  if (plugin.config_complete () == -1)
+    if (f->filter.config_complete)
+      if (f->filter.config_complete (filter_plugin_config_complete,
+                                     f->next) == -1)
+        return -1;
+    return 0;
+  }
+}
+
+void
+plugin_config_complete (void)
+{
+  if (filter_plugin_config_complete (filters) == -1)
     exit (EXIT_FAILURE);
 }
 
-- 
2.15.1