merchant

commit ec6a7c0478c517f334d013969cd492d3d52e49e8
parent 0e86dfd5135d9ee706224be894915ab873a57a77
Author: Christian Grothoff <grothoff@gnunet.org>
Date:   Tue, 14 Jul 2026 23:37:54 +0200

limit donau /keys fetches

Diffstat:
M
src/backend/taler-merchant-donaukeyupdate.c
 | 
87
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---

1 file changed, 84 insertions(+), 3 deletions(-)
diff --git a/src/backend/taler-merchant-donaukeyupdate.c b/src/backend/taler-merchant-donaukeyupdate.c
@@ -169,6 +169,27 @@ struct ForceCharityCtx
    * Handle to the charity update request.
    */
   struct DONAU_CharityGetHandle *h;
+
+  /**
+   * Scheduler task for retrying a failed /charity_id request.
+   * This task will trigger the next attempt to download the charity
+   * details if the previous request could not be started.
+   */
+  struct GNUNET_SCHEDULER_Task *retry_task;
+
+  /**
+   * The delay before the next retry for fetching /charity_id.
+   * Used to implement exponential backoff in case of failures.
+   */
+  struct GNUNET_TIME_Relative retry_delay;
+
+  /**
+   * A flag indicating whether this charity inquiry is currently
+   * rate-limited.  If true, the inquiry was postponed because we
+   * were at the #OPEN_INQUIRY_LIMIT and must be re-driven from
+   * end_inquiry() once a slot frees up.
+   */
+  bool limited;
 };
 
 /**
@@ -245,6 +266,15 @@ download_keys (void *cls);
 
 
 /**
+ * Function that initiates a /charity_id download for a Donau instance.
+ *
+ * @param cls closure with a `struct ForceCharityCtx *`
+ */
+static void
+download_charity_id (void *cls);
+
+
+/**
  * An inquiry finished, check if we need to start more.
  */
 static void
@@ -269,6 +299,19 @@ end_inquiry (void)
       if (at_limit)
         break;
     }
+    for (struct ForceCharityCtx *fcc = fcc_head;
+         NULL != fcc;
+         fcc = fcc->next)
+    {
+      if (at_limit)
+        break;
+      if (! fcc->limited)
+        continue;
+      fcc->limited = false;
+      /* done synchronously so that the active_inquiries
+         is updated immediately */
+      download_charity_id (fcc);
+    }
   }
   if ( (! at_limit) &&
        (0 == active_inquiries) &&
@@ -621,13 +664,14 @@ donau_charity_cb (void *cls,
 /**
  * Download the charity_id for a Donau instance.
  *
- * @param cls closure with a `struct Donau *`
+ * @param cls closure with a `struct ForceCharityCtx *`
  */
 static void
 download_charity_id (void *cls)
 {
   struct ForceCharityCtx *fcc = cls;
 
+  fcc->retry_task = NULL;
   /* nothing to do if a request is already outstanding */
   if (NULL != fcc->h)
     return;
@@ -638,6 +682,10 @@ download_charity_id (void *cls)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                 "Cannot start more charity inquiries, already at limit\n");
+    /* remember to re-drive this inquiry from end_inquiry()
+       once we are substantially below the limit again */
+    fcc->limited = true;
+    at_limit = true;
     return;
   }
 
@@ -655,6 +703,7 @@ download_charity_id (void *cls)
 
   if (NULL != fcc->h)
   {
+    fcc->retry_delay = GNUNET_TIME_UNIT_ZERO;
     active_inquiries++;
   }
   else
@@ -662,8 +711,14 @@ download_charity_id (void *cls)
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Failed to initiate DONAU_charity_get() for `%s'\n",
                 fcc->donau_url);
-    /* we do NOT retry here – simply finish the (failed) inquiry */
-    end_inquiry ();
+    /* no inquiry was started, so we must not call end_inquiry() here;
+       retry with exponential backoff instead */
+    fcc->retry_delay
+      = GNUNET_TIME_STD_BACKOFF (fcc->retry_delay);
+    fcc->retry_task
+      = GNUNET_SCHEDULER_add_delayed (fcc->retry_delay,
+                                      &download_charity_id,
+                                      fcc);
   }
 }
 
@@ -780,6 +835,12 @@ force_donau_charity_id (void *cls,
                   fcc->donau_url);
       return;
     }
+    if (NULL != fcc->retry_task)
+    {
+      GNUNET_SCHEDULER_cancel (fcc->retry_task);
+      fcc->retry_task = NULL;
+    }
+    fcc->charity_id = charity_id;
   }
   download_charity_id (fcc);
 }
@@ -894,6 +955,26 @@ shutdown_task (void *cls)
                                  d);
     GNUNET_free (d);
   }
+  while (NULL != fcc_head)
+  {
+    struct ForceCharityCtx *fcc = fcc_head;
+
+    if (NULL != fcc->h)
+    {
+      DONAU_charity_get_cancel (fcc->h);
+      fcc->h = NULL;
+    }
+    if (NULL != fcc->retry_task)
+    {
+      GNUNET_SCHEDULER_cancel (fcc->retry_task);
+      fcc->retry_task = NULL;
+    }
+    GNUNET_CONTAINER_DLL_remove (fcc_head,
+                                 fcc_tail,
+                                 fcc);
+    GNUNET_free (fcc->donau_url);
+    GNUNET_free (fcc);
+  }
   if (NULL != eh)
   {
     TALER_MERCHANTDB_event_listen_cancel (eh);