donau

commit 1d9fa76053c5523de38c1cf58f3887ed33fae4dc
parent 736e6a16715b4e43fcb79596a65cfebabda35c59
Author: Christian Grothoff <christian@grothoff.org>
Date:   Fri,  7 Aug 2026 00:15:20 +0200

handle soft error with retries

Diffstat:
M
src/donau/donau-httpd_post-batch-issue-CHARITY_ID.c
 | 
42
+++++++++++++++++++++++++++++++-----------
M
src/donau/donau-httpd_post-batch-submit.c
 | 
25
++++++++++++++++++++-----

2 files changed, 51 insertions(+), 16 deletions(-)
diff --git a/src/donau/donau-httpd_post-batch-issue-CHARITY_ID.c b/src/donau/donau-httpd_post-batch-issue-CHARITY_ID.c
@@ -485,20 +485,40 @@ start:
                 "made blind signatures!\n");
 
     /* save new receipts to date and save receipts Request (blinded signatures,
-     * charity id, amount, hash over bkps) to make it idempotent*/
-    qs_insert_ir
-      = DONAUDB_do_insert_receipt_issued (DH_context,
-                                          year,
-                                          num_bkps,
-                                          du_sigs,
-                                          (uint64_t) charity_id,
-                                          &h_receipts,
-                                          &receipts_sum,
-                                          &smaller_than_max_per_year);
+     * charity id, amount, hash over bkps) to make it idempotent.
+     * Two concurrent requests for the same charity update the same
+     * `charities' row and thus serialize against each other; the database
+     * reports that as a soft error, which means "retry me". */
+    for (unsigned int retries = 0;
+         retries < MAX_TRANSACTION_COMMIT_RETRIES;
+         retries++)
+    {
+      qs_insert_ir
+        = DONAUDB_do_insert_receipt_issued (DH_context,
+                                            year,
+                                            num_bkps,
+                                            du_sigs,
+                                            (uint64_t) charity_id,
+                                            &h_receipts,
+                                            &receipts_sum,
+                                            &smaller_than_max_per_year);
+      if (GNUNET_DB_STATUS_SOFT_ERROR != qs_insert_ir)
+        break;
+    }
     switch (qs_insert_ir)
     {
-    case GNUNET_DB_STATUS_HARD_ERROR:
     case GNUNET_DB_STATUS_SOFT_ERROR:
+      /* still failing after MAX_TRANSACTION_COMMIT_RETRIES attempts */
+      free_bkps (num_bkps,
+                 bkps);
+      json_decref (blind_signatures);
+      for (unsigned int i = 0; i<num_bkps; i++)
+        GNUNET_CRYPTO_blinded_sig_decref (du_sigs[i].blinded_sig);
+      return TALER_MHD_reply_with_error (rc->connection,
+                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                         TALER_EC_GENERIC_DB_SOFT_FAILURE,
+                                         NULL);
+    case GNUNET_DB_STATUS_HARD_ERROR:
       GNUNET_break (0);
       free_bkps (num_bkps,
                  bkps);
diff --git a/src/donau/donau-httpd_post-batch-submit.c b/src/donau/donau-httpd_post-batch-submit.c
@@ -27,6 +27,7 @@
 #include "taler/taler_mhd_lib.h"
 #include "taler/taler_signatures.h"
 #include "donau-httpd_post-batch-submit.h"
+#include "donau-httpd_db.h"
 #include "donau-httpd_get-keys.h"
 #include "donau-database/insert_receipts_submitted.h"
 
@@ -246,12 +247,26 @@ DH_handler_post_batch_submit (struct DH_RequestContext *rc,
   {
     enum GNUNET_DB_QueryStatus qs;
 
-    qs = DONAUDB_insert_receipts_submitted (DH_context,
-                                            &irc.h_donor_tax_id,
-                                            num_dr,
-                                            irc.donation_receipts,
-                                            irc.donation_year);
+    /* Concurrent submissions can serialize against each other; the
+       database reports that as a soft error, which means "retry me". */
+    for (unsigned int retries = 0;
+         retries < MAX_TRANSACTION_COMMIT_RETRIES;
+         retries++)
+    {
+      qs = DONAUDB_insert_receipts_submitted (DH_context,
+                                              &irc.h_donor_tax_id,
+                                              num_dr,
+                                              irc.donation_receipts,
+                                              irc.donation_year);
+      if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
+        break;
+    }
     free_irc (&irc);
+    if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
+      return TALER_MHD_reply_with_error (rc->connection,
+                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                         TALER_EC_GENERIC_DB_SOFT_FAILURE,
+                                         "insert_receipts_submitted");
     if (qs < 0)
     {
       GNUNET_break (0);