Merge #10208: [wallet] Rescan abortability

9141622 [rpc] Add abortrescan command to RPC interface. (Kalle Alm)
75a08e7 [wallet] Add support for aborting wallet transaction rescans. (Kalle Alm)

Tree-SHA512: 18545a1dc48c6dc112993f971f3adc7c0341fa621186c6d70bef1052e1d127ca116c5769595d721a209d502ca2019f2ad33876fe35d2b17216393404607a6c76

src/wallet/rpcdump.cpp

@@ -156,6 +156,31 @@ UniValue importprivkey(const JSONRPCRequest& request)
     return NullUniValue;
 }
 
+UniValue abortrescan(const JSONRPCRequest& request)
+{
+    CWallet* const pwallet = GetWalletForJSONRPCRequest(request);
+    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
+        return NullUniValue;
+    }
+
+    if (request.fHelp || request.params.size() > 0)
+        throw std::runtime_error(
+            "abortrescan\n"
+            "\nStops current wallet rescan triggered e.g. by an importprivkey call.\n"
+            "\nExamples:\n"
+            "\nImport a private key\n"
+            + HelpExampleCli("importprivkey", "\"mykey\"") +
+            "\nAbort the running wallet rescan\n"
+            + HelpExampleCli("abortrescan", "") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("abortrescan", "")
+        );
+
+    if (!pwallet->IsScanning() || pwallet->IsAbortingRescan()) return false;
+    pwallet->AbortRescan();
+    return true;
+}
+
 void ImportAddress(CWallet*, const CBitcoinAddress& address, const std::string& strLabel);
 void ImportScript(CWallet* const pwallet, const CScript& script, const std::string& strLabel, bool isRedeemScript)
 {

src/wallet/rpcwallet.cpp

@@ -2914,6 +2914,7 @@ UniValue bumpfee(const JSONRPCRequest& request)
     return result;
 }
 
+extern UniValue abortrescan(const JSONRPCRequest& request); // in rpcdump.cpp
 extern UniValue dumpprivkey(const JSONRPCRequest& request); // in rpcdump.cpp
 extern UniValue importprivkey(const JSONRPCRequest& request);
 extern UniValue importaddress(const JSONRPCRequest& request);
@@ -2930,6 +2931,7 @@ static const CRPCCommand commands[] =
     { "rawtransactions",    "fundrawtransaction",       &fundrawtransaction,       false,  {"hexstring","options"} },
     { "hidden",             "resendwallettransactions", &resendwallettransactions, true,   {} },
     { "wallet",             "abandontransaction",       &abandontransaction,       false,  {"txid"} },
+    { "wallet",             "abortrescan",              &abortrescan,              false,  {} },
     { "wallet",             "addmultisigaddress",       &addmultisigaddress,       true,   {"nrequired","keys","account"} },
     { "wallet",             "addwitnessaddress",        &addwitnessaddress,        true,   {"address"} },
     { "wallet",             "backupwallet",             &backupwallet,             true,   {"destination"} },

src/wallet/wallet.cpp

@@ -1554,6 +1554,8 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool f
     CBlockIndex* pindex = pindexStart;
     {
         LOCK2(cs_main, cs_wallet);
+        fAbortRescan = false;
+        fScanningWallet = true;
 
         // no need to read and scan block, if block was created before
         // our wallet birthday (as adjusted for block time variability)
@@ -1563,7 +1565,7 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool f
         ShowProgress(_("Rescanning..."), 0); // show rescan progress in GUI as dialog or on splashscreen, if -rescan on startup
         double dProgressStart = GuessVerificationProgress(chainParams.TxData(), pindex);
         double dProgressTip = GuessVerificationProgress(chainParams.TxData(), chainActive.Tip());
-        while (pindex)
+        while (pindex && !fAbortRescan)
         {
             if (pindex->nHeight % 100 == 0 && dProgressTip - dProgressStart > 0.0)
                 ShowProgress(_("Rescanning..."), std::max(1, std::min(99, (int)((GuessVerificationProgress(chainParams.TxData(), pindex) - dProgressStart) / (dProgressTip - dProgressStart) * 100))));
@@ -1585,7 +1587,12 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool f
                 LogPrintf("Still rescanning. At block %d. Progress=%f\n", pindex->nHeight, GuessVerificationProgress(chainParams.TxData(), pindex));
             }
         }
+        if (pindex && fAbortRescan) {
+            LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight, GuessVerificationProgress(chainParams.TxData(), pindex));
+        }
         ShowProgress(_("Rescanning..."), 100); // hide progress dialog in GUI
+
+        fScanningWallet = false;
     }
     return ret;
 }

src/wallet/wallet.h

@@ -651,6 +651,8 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
 {
 private:
     static std::atomic<bool> fFlushScheduled;
+    std::atomic<bool> fAbortRescan;
+    std::atomic<bool> fScanningWallet;
 
     /**
      * Select a set of coins such that nValueRet >= nTargetValue and at least
@@ -779,6 +781,8 @@ public:
         nTimeFirstKey = 0;
         fBroadcastTransactions = false;
         nRelockTime = 0;
+        fAbortRescan = false;
+        fScanningWallet = false;
     }
 
     std::map<uint256, CWalletTx> mapWallet;
@@ -823,6 +827,13 @@ public:
     void UnlockAllCoins();
     void ListLockedCoins(std::vector<COutPoint>& vOutpts);
 
+    /*
+     * Rescan abort properties
+     */
+    void AbortRescan() { fAbortRescan = true; }
+    bool IsAbortingRescan() { return fAbortRescan; }
+    bool IsScanning() { return fScanningWallet; }
+
     /**
      * keystore implementation
      * Generate a new key