lib-index: Allow multiple hooks for transaction creation

src/lib-index/mail-index-transaction-private.h

@@ -107,8 +107,10 @@ struct mail_index_transaction {
 	 (array_is_created(&(t)->updates) && array_count(&(t)->updates) > 0) || \
 	 (t)->index_deleted || (t)->index_undeleted)
 
-extern void (*hook_mail_index_transaction_created)
-		(struct mail_index_transaction *t);
+typedef void hook_mail_index_transaction_created_t(struct mail_index_transaction *t);
+
+void mail_index_transaction_hook_register(const hook_mail_index_transaction_created_t *hook);
+void mail_index_transaction_hook_unregister(const hook_mail_index_transaction_created_t *hook);
 
 struct mail_index_record *
 mail_index_transaction_lookup(struct mail_index_transaction *t, uint32_t seq);

src/lib-index/mail-index-transaction.c

@@ -9,9 +9,36 @@
 #include "mail-transaction-log-private.h"
 #include "mail-index-transaction-private.h"
 
+static ARRAY(const hook_mail_index_transaction_created_t *)
+	hook_mail_index_transaction_created;
+
+void mail_index_transaction_hook_register(const hook_mail_index_transaction_created_t *hook)
+{
+	if (!array_is_created(&hook_mail_index_transaction_created))
+		i_array_init(&hook_mail_index_transaction_created, 8);
+	array_append(&hook_mail_index_transaction_created, &hook, 1);
+}
+
+void mail_index_transaction_hook_unregister(const hook_mail_index_transaction_created_t *hook)
+{
+	unsigned int idx;
+	bool found = FALSE;
+
+	i_assert(array_is_created(&hook_mail_index_transaction_created));
+	for(idx = 0; idx < array_count(&hook_mail_index_transaction_created); idx++) {
+		const hook_mail_index_transaction_created_t *const *hook_ptr =
+			array_idx(&hook_mail_index_transaction_created, idx);
+		if (*hook_ptr == hook) {
+			array_delete(&hook_mail_index_transaction_created, idx, 1);
+			found = TRUE;
+			break;
+		}
+	}
+	i_assert(found == TRUE);
+	if (array_count(&hook_mail_index_transaction_created) == 0)
+		array_free(&hook_mail_index_transaction_created);
+}
 
-void (*hook_mail_index_transaction_created)
-		(struct mail_index_transaction *t) = NULL;
 
 struct mail_index_view *
 mail_index_transaction_get_view(struct mail_index_transaction *t)
@@ -321,7 +348,11 @@ mail_index_transaction_begin(struct mail_index_view *view,
 		     I_MIN(5, mail_index_module_register.id));
 	DLLIST_PREPEND(&view->transactions_list, t);
 
-	if (hook_mail_index_transaction_created != NULL)
-		hook_mail_index_transaction_created(t);
+	if (array_is_created(&hook_mail_index_transaction_created)) {
+		const hook_mail_index_transaction_created_t *const *ptr;
+		array_foreach(&hook_mail_index_transaction_created, ptr) {
+			(*ptr)(t);
+		}
+	}
 	return t;
 }