Pass along a userarg with context update callbacks

ChangeLog

@@ -24,6 +24,9 @@
   * Better random number generation with OpenBSD's arc4random
   * Let getdns_address schedule the AAAA query first.  This results in AAAA
     being the first in the just_address_answers sections of the response dict.
+  * New context update callback function to also return a user given argument
+    along with the context and which item was changed.
+    Thanks Scott Hollenbeck.
 
 * 2015-01-16: Version 0.1.6
   * Fix: linking against libev on FreeBSD

src/context.c

@@ -735,7 +735,9 @@ getdns_context_create_with_extended_memory_functions(
 	result->my_mf.mf.ext.realloc = realloc;
 	result->my_mf.mf.ext.free    = free;
 
-	result->update_callback = NULL;
+	result->update_callback  = NULL;
+	result->update_callback2 = NULL;
+	result->update_userarg   = NULL;
 
 	result->mf.mf_arg         = userarg;
 	result->mf.mf.ext.malloc  = malloc;
@@ -899,10 +901,19 @@ getdns_context_set_context_update_callback(struct getdns_context *context,
     return GETDNS_RETURN_GOOD;
 }               /* getdns_context_set_context_update_callback */
 
+getdns_return_t
+getdns_context_set_update_callback(getdns_context *context, void *userarg,
+    void (*value) (getdns_context *, getdns_context_code_t, void *))
+{
+	if (!context) return GETDNS_RETURN_INVALID_PARAMETER;
+	context->update_userarg = userarg;
+	context->update_callback2 = value;
+	return GETDNS_RETURN_GOOD;
+}
+
 /*
  * Helpers to set options on the unbound ctx
  */
-
 static void
 set_ub_string_opt(struct getdns_context *ctx, char *opt, char *value)
 {
@@ -1003,6 +1014,10 @@ rebuild_ub_ctx(struct getdns_context* context) {
 static void
 dispatch_updated(struct getdns_context *context, uint16_t item)
 {
+	if (context->update_callback2)
+		context->update_callback2(
+		    context, item, context->update_userarg);
+
     if (context->update_callback) {
         context->update_callback(context, item);
     }

src/context.h

@@ -60,6 +60,9 @@ enum filechgs { GETDNS_FCHG_ERRORS = -1
 typedef void (*getdns_update_callback) (struct getdns_context *,
     getdns_context_code_t);
 
+typedef void (*getdns_update_callback2) (struct getdns_context *,
+    getdns_context_code_t, void *userarg);
+
 /* internal use only for detecting changes to system files */
 struct filechg {
 	char *fn;
@@ -131,7 +134,9 @@ struct getdns_context {
 	uint8_t edns_do_bit;
 	int edns_maximum_udp_payload_size; /* -1 is unset */
 
-	getdns_update_callback update_callback;
+	getdns_update_callback  update_callback;
+	getdns_update_callback2 update_callback2;
+	void                   *update_userarg;
 
 	int processing;
 	int destroying;

src/getdns/getdns_extra.h

@@ -187,6 +187,7 @@ getdns_context_get_edns_version(getdns_context *context, uint8_t* value);
 getdns_return_t
 getdns_context_get_edns_do_bit(getdns_context *context, uint8_t* value);
 
+
 int
 getdns_pretty_snprint_dict(char *str, size_t size, const getdns_dict *dict);
 
@@ -210,6 +211,9 @@ int
 getdns_snprint_json_list(
     char *str, size_t size, const getdns_list *list, int pretty);
 
+getdns_return_t
+getdns_context_set_update_callback(getdns_context *context, void *userarg,
+    void (*value) (getdns_context *, getdns_context_code_t, void *));
 
 #ifdef __cplusplus
 }