rpc: Block until synced if coinstatsindex is used in gettxoutsetinfo

During initial sync after startup the gettxoutsetinfo RPC will still return an error while catching up. However, after the initial sync the index will not error immediately anymore when it's in the process of syncing to the tip while being called. Instead it will block until synced and then return the response.

1 files changed, 12 insertions, 7 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 86f6a4320e..2347fcbb73 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1175,6 +1175,18 @@ static RPCHelpMan gettxoutsetinfo()
         pindex = ParseHashOrHeight(request.params[1], chainman);
     }
 
+    if (stats.index_requested && g_coin_stats_index) {
+        if (!g_coin_stats_index->BlockUntilSyncedToCurrentChain()) {
+            const IndexSummary summary{g_coin_stats_index->GetSummary()};
+
+            // If a specific block was requested and the index has already synced past that height, we can return the
+            // data already even though the index is not fully synced yet.
+            if (pindex->nHeight > summary.best_block_height) {
+                throw JSONRPCError(RPC_INTERNAL_ERROR, strprintf("Unable to get data because coinstatsindex is still syncing. Current height: %d", summary.best_block_height));
+            }
+        }
+    }
+
     if (GetUTXOStats(coins_view, *blockman, stats, node.rpc_interruption_point, pindex)) {
         ret.pushKV("height", (int64_t)stats.nHeight);
         ret.pushKV("bestblock", stats.hashBlock.GetHex());
@@ -1215,13 +1227,6 @@ static RPCHelpMan gettxoutsetinfo()
             ret.pushKV("block_info", block_info);
         }
     } else {
-        if (g_coin_stats_index) {
-            const IndexSummary summary{g_coin_stats_index->GetSummary()};
-
-            if (!summary.synced) {
-                throw JSONRPCError(RPC_INTERNAL_ERROR, strprintf("Unable to read UTXO set because coinstatsindex is still syncing. Current height: %d", summary.best_block_height));
-            }
-        }
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");
     }
     return ret;