rpc: Make gettxoutsetinfo/GetUTXOStats interruptible

Also, add interruption points to scantxoutset

Author: MarcoFalke

src/node/coinstats.cpp

@@ -33,7 +33,7 @@ static void ApplyStats(CCoinsStats &stats, CHashWriter& ss, const uint256& hash,
 }
 
 //! Calculate statistics about the unspent transaction output set
-bool GetUTXOStats(CCoinsView *view, CCoinsStats &stats)
+bool GetUTXOStats(CCoinsView* view, CCoinsStats& stats, const std::function<void()>& interruption_point)
 {
     stats = CCoinsStats();
     std::unique_ptr<CCoinsViewCursor> pcursor(view->Cursor());
@@ -49,6 +49,7 @@ bool GetUTXOStats(CCoinsView *view, CCoinsStats &stats)
     uint256 prevkey;
     std::map<uint32_t, Coin> outputs;
     while (pcursor->Valid()) {
+        interruption_point();
         COutPoint key;
         Coin coin;
         if (pcursor->GetKey(key) && pcursor->GetValue(coin)) {

src/node/coinstats.h

@@ -10,6 +10,7 @@
 #include <uint256.h>
 
 #include <cstdint>
+#include <functional>
 
 class CCoinsView;
 
@@ -29,6 +30,6 @@ struct CCoinsStats
 };
 
 //! Calculate statistics about the unspent transaction output set
-bool GetUTXOStats(CCoinsView* view, CCoinsStats& stats);
+bool GetUTXOStats(CCoinsView* view, CCoinsStats& stats, const std::function<void()>& interruption_point = {});
 
 #endif // BITCOIN_NODE_COINSTATS_H

src/rpc/blockchain.cpp

@@ -990,7 +990,7 @@ static UniValue gettxoutsetinfo(const JSONRPCRequest& request)
     ::ChainstateActive().ForceFlushStateToDisk();
 
     CCoinsView* coins_view = WITH_LOCK(cs_main, return &ChainstateActive().CoinsDB());
-    if (GetUTXOStats(coins_view, stats)) {
+    if (GetUTXOStats(coins_view, stats, RpcInterruptionPoint)) {
         ret.pushKV("height", (int64_t)stats.nHeight);
         ret.pushKV("bestblock", stats.hashBlock.GetHex());
         ret.pushKV("transactions", (int64_t)stats.nTransactions);
@@ -1968,6 +1968,7 @@ bool FindScriptPubKey(std::atomic<int>& scan_progress, const std::atomic<bool>&
         Coin coin;
         if (!cursor->GetKey(key) || !cursor->GetValue(coin)) return false;
         if (++count % 8192 == 0) {
+            RpcInterruptionPoint();
             if (should_abort) {
                 // allow to abort the scan via the abort reference
                 return false;
@@ -2311,7 +2312,7 @@ UniValue dumptxoutset(const JSONRPCRequest& request)
 
         ::ChainstateActive().ForceFlushStateToDisk();
 
-        if (!GetUTXOStats(&::ChainstateActive().CoinsDB(), stats)) {
+        if (!GetUTXOStats(&::ChainstateActive().CoinsDB(), stats, RpcInterruptionPoint)) {
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");
         }