// Copyright (c) 2010 Satoshi Nakamoto // Copyright (c) 2009-2014 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #include "amount.h" #include "chainparams.h" #include "core_io.h" #include "init.h" #include "net.h" #include "main.h" #include "miner.h" #include "pow.h" #include "rpcserver.h" #include "util.h" #include "validationinterface.h" #ifdef ENABLE_WALLET #include "wallet/db.h" #include "wallet/wallet.h" #endif #include #include #include "json/json_spirit_utils.h" #include "json/json_spirit_value.h" using namespace json_spirit; using namespace std; /** * Return average network hashes per second based on the last 'lookup' blocks, * or from the last difficulty change if 'lookup' is nonpositive. * If 'height' is nonnegative, compute the estimate at the time when a given block was found. */ Value GetNetworkHashPS(int lookup, int height) { CBlockIndex *pb = chainActive.Tip(); if (height >= 0 && height < chainActive.Height()) pb = chainActive[height]; if (pb == NULL || !pb->nHeight) return 0; // If lookup is -1, then use blocks since last difficulty change. if (lookup <= 0) lookup = pb->nHeight % Params().DifficultyAdjustmentInterval() + 1; // If lookup is larger than chain, then set it to chain length. if (lookup > pb->nHeight) lookup = pb->nHeight; CBlockIndex *pb0 = pb; int64_t minTime = pb0->GetBlockTime(); int64_t maxTime = minTime; for (int i = 0; i < lookup; i++) { pb0 = pb0->pprev; int64_t time = pb0->GetBlockTime(); minTime = std::min(time, minTime); maxTime = std::max(time, maxTime); } // In case there's a situation where minTime == maxTime, we don't want a divide by zero exception. if (minTime == maxTime) return 0; arith_uint256 workDiff = pb->nChainWork - pb0->nChainWork; int64_t timeDiff = maxTime - minTime; return (int64_t)(workDiff.getdouble() / timeDiff); } Value getnetworkhashps(const Array& params, bool fHelp) { if (fHelp || params.size() > 2) throw runtime_error( "getnetworkhashps ( blocks height )\n" "\nReturns the estimated network hashes per second based on the last n blocks.\n" "Pass in [blocks] to override # of blocks, -1 specifies since last difficulty change.\n" "Pass in [height] to estimate the network speed at the time when a certain block was found.\n" "\nArguments:\n" "1. blocks (numeric, optional, default=120) The number of blocks, or -1 for blocks since last difficulty change.\n" "2. height (numeric, optional, default=-1) To estimate at the time of the given height.\n" "\nResult:\n" "x (numeric) Hashes per second estimated\n" "\nExamples:\n" + HelpExampleCli("getnetworkhashps", "") + HelpExampleRpc("getnetworkhashps", "") ); LOCK(cs_main); return GetNetworkHashPS(params.size() > 0 ? params[0].get_int() : 120, params.size() > 1 ? params[1].get_int() : -1); } #ifdef ENABLE_WALLET Value getgenerate(const Array& params, bool fHelp) { if (fHelp || params.size() != 0) throw runtime_error( "getgenerate\n" "\nReturn if the server is set to generate coins or not. The default is false.\n" "It is set with the command line argument -gen (or bitcoin.conf setting gen)\n" "It can also be set with the setgenerate call.\n" "\nResult\n" "true|false (boolean) If the server is set to generate coins or not\n" "\nExamples:\n" + HelpExampleCli("getgenerate", "") + HelpExampleRpc("getgenerate", "") ); LOCK(cs_main); return GetBoolArg("-gen", false); } Value generate(const Array& params, bool fHelp) { if (fHelp || params.size() < 1 || params.size() > 1) throw runtime_error( "generate numblocks\n" "\nMine blocks immediately (before the RPC call returns)\n" "1. numblocks (numeric) How many blocks are generated immediately.\n" "\nResult\n" "[ blockhashes ] (array) hashes of blocks generated\n" "\nExamples:\n" "\nGenerate 11 blocks\n" + HelpExampleCli("generate", "11") ); if (pwalletMain == NULL) throw JSONRPCError(RPC_METHOD_NOT_FOUND, "Method not found (disabled)"); int nHeightStart = 0; int nHeightEnd = 0; int nHeight = 0; int nGenerate = params[0].get_int(); { // Don't keep cs_main locked LOCK(cs_main); nHeightStart = chainActive.Height(); nHeight = nHeightStart; nHeightEnd = nHeightStart+nGenerate; } Array blockHashes; while (nHeight < nHeightEnd) { uint256 hash; if (!MineBlock(pwalletMain, hash)) throw JSONRPCError(RPC_INTERNAL_ERROR, "Wallet keypool empty"); ++nHeight; blockHashes.push_back(hash.GetHex()); } return blockHashes; } Value setgenerate(const Array& params, bool fHelp) { if (fHelp || params.size() < 1 || params.size() > 2) throw runtime_error( "setgenerate generate ( genproclimit )\n" "\nSet 'generate' true or false to turn generation on or off.\n" "Generation is limited to 'genproclimit' processors, -1 is unlimited.\n" "See the getgenerate call for the current setting.\n" "\nArguments:\n" "1. generate (boolean, required) Set to true to turn on generation, off to turn off.\n" "2. genproclimit (numeric, optional) Set the processor limit for when generation is on. Can be -1 for unlimited.\n" "\nExamples:\n" "\nSet the generation on with a limit of one processor\n" + HelpExampleCli("setgenerate", "true 1") + "\nCheck the setting\n" + HelpExampleCli("getgenerate", "") + "\nTurn off generation\n" + HelpExampleCli("setgenerate", "false") + "\nUsing json rpc\n" + HelpExampleRpc("setgenerate", "true, 1") ); if (pwalletMain == NULL) throw JSONRPCError(RPC_METHOD_NOT_FOUND, "Method not found (disabled)"); bool fGenerate = true; if (params.size() > 0) fGenerate = params[0].get_bool(); int nGenProcLimit = -1; if (params.size() > 1) { nGenProcLimit = params[1].get_int(); if (nGenProcLimit == 0) fGenerate = false; } mapArgs["-gen"] = (fGenerate ? "1" : "0"); mapArgs ["-genproclimit"] = itostr(nGenProcLimit); GenerateBitcoins(fGenerate, pwalletMain, nGenProcLimit); return Value::null; } #endif Value getmininginfo(const Array& params, bool fHelp) { if (fHelp || params.size() != 0) throw runtime_error( "getmininginfo\n" "\nReturns a json object containing mining-related information." "\nResult:\n" "{\n" " \"blocks\": nnn, (numeric) The current block\n" " \"currentblocksize\": nnn, (numeric) The last block size\n" " \"currentblocktx\": nnn, (numeric) The last block transaction\n" " \"difficulty\": xxx.xxxxx (numeric) The current difficulty\n" " \"errors\": \"...\" (string) Current errors\n" " \"generate\": true|false (boolean) If the generation is on or off (see getgenerate or setgenerate calls)\n" " \"genproclimit\": n (numeric) The processor limit for generation. -1 if no generation. (see getgenerate or setgenerate calls)\n" " \"pooledtx\": n (numeric) The size of the mem pool\n" " \"testnet\": true|false (boolean) If using testnet or not\n" " \"chain\": \"xxxx\", (string) current network name as defined in BIP70 (main, test, regtest)\n" "}\n" "\nExamples:\n" + HelpExampleCli("getmininginfo", "") + HelpExampleRpc("getmininginfo", "") ); LOCK(cs_main); Object obj; obj.push_back(Pair("blocks", (int)chainActive.Height())); obj.push_back(Pair("currentblocksize", (uint64_t)nLastBlockSize)); obj.push_back(Pair("currentblocktx", (uint64_t)nLastBlockTx)); obj.push_back(Pair("difficulty", (double)GetDifficulty())); obj.push_back(Pair("errors", GetWarnings("statusbar"))); obj.push_back(Pair("genproclimit", (int)GetArg("-genproclimit", -1))); obj.push_back(Pair("networkhashps", getnetworkhashps(params, false))); obj.push_back(Pair("pooledtx", (uint64_t)mempool.size())); obj.push_back(Pair("testnet", Params().TestnetToBeDeprecatedFieldRPC())); obj.push_back(Pair("chain", Params().NetworkIDString())); #ifdef ENABLE_WALLET obj.push_back(Pair("generate", getgenerate(params, false))); #endif return obj; } // NOTE: Unlike wallet RPC (which use BTC values), mining RPCs follow GBT (BIP 22) in using satoshi amounts Value prioritisetransaction(const Array& params, bool fHelp) { if (fHelp || params.size() != 3) throw runtime_error( "prioritisetransaction \n" "Accepts the transaction into mined blocks at a higher (or lower) priority\n" "\nArguments:\n" "1. \"txid\" (string, required) The transaction id.\n" "2. priority delta (numeric, required) The priority to add or subtract.\n" " The transaction selection algorithm considers the tx as it would have a higher priority.\n" " (priority of a transaction is calculated: coinage * value_in_satoshis / txsize) \n" "3. fee delta (numeric, required) The fee value (in satoshis) to add (or subtract, if negative).\n" " The fee is not actually paid, only the algorithm for selecting transactions into a block\n" " considers the transaction as it would have paid a higher (or lower) fee.\n" "\nResult\n" "true (boolean) Returns true\n" "\nExamples:\n" + HelpExampleCli("prioritisetransaction", "\"txid\" 0.0 10000") + HelpExampleRpc("prioritisetransaction", "\"txid\", 0.0, 10000") ); LOCK(cs_main); uint256 hash = ParseHashStr(params[0].get_str(), "txid"); CAmount nAmount = params[2].get_int64(); mempool.PrioritiseTransaction(hash, params[0].get_str(), params[1].get_real(), nAmount); return true; } // NOTE: Assumes a conclusive result; if result is inconclusive, it must be handled by caller static Value BIP22ValidationResult(const CValidationState& state) { if (state.IsValid()) return Value::null; std::string strRejectReason = state.GetRejectReason(); if (state.IsError()) throw JSONRPCError(RPC_VERIFY_ERROR, strRejectReason); if (state.IsInvalid()) { if (strRejectReason.empty()) return "rejected"; return strRejectReason; } // Should be impossible return "valid?"; } Value getblocktemplate(const Array& params, bool fHelp) { if (fHelp || params.size() > 1) throw runtime_error( "getblocktemplate ( \"jsonrequestobject\" )\n" "\nIf the request parameters include a 'mode' key, that is used to explicitly select between the default 'template' request or a 'proposal'.\n" "It returns data needed to construct a block to work on.\n" "See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n" "\nArguments:\n" "1. \"jsonrequestobject\" (string, optional) A json object in the following spec\n" " {\n" " \"mode\":\"template\" (string, optional) This must be set to \"template\" or omitted\n" " \"capabilities\":[ (array, optional) A list of strings\n" " \"support\" (string) client side supported feature, 'longpoll', 'coinbasetxn', 'coinbasevalue', 'proposal', 'serverlist', 'workid'\n" " ,...\n" " ]\n" " }\n" "\n" "\nResult:\n" "{\n" " \"version\" : n, (numeric) The block version\n" " \"previousblockhash\" : \"xxxx\", (string) The hash of current highest block\n" " \"transactions\" : [ (array) contents of non-coinbase transactions that should be included in the next block\n" " {\n" " \"data\" : \"xxxx\", (string) transaction data encoded in hexadecimal (byte-for-byte)\n" " \"hash\" : \"xxxx\", (string) hash/id encoded in little-endian hexadecimal\n" " \"depends\" : [ (array) array of numbers \n" " n (numeric) transactions before this one (by 1-based index in 'transactions' list) that must be present in the final block if this one is\n" " ,...\n" " ],\n" " \"fee\": n, (numeric) difference in value between transaction inputs and outputs (in Satoshis); for coinbase transactions, this is a negative Number of the total collected block fees (ie, not including the block subsidy); if key is not present, fee is unknown and clients MUST NOT assume there isn't one\n" " \"sigops\" : n, (numeric) total number of SigOps, as counted for purposes of block limits; if key is not present, sigop count is unknown and clients MUST NOT assume there aren't any\n" " \"required\" : true|false (boolean) if provided and true, this transaction must be in the final block\n" " }\n" " ,...\n" " ],\n" " \"coinbaseaux\" : { (json object) data that should be included in the coinbase's scriptSig content\n" " \"flags\" : \"flags\" (string) \n" " },\n" " \"coinbasevalue\" : n, (numeric) maximum allowable input to coinbase transaction, including the generation award and transaction fees (in Satoshis)\n" " \"coinbasetxn\" : { ... }, (json object) information for coinbase transaction\n" " \"target\" : \"xxxx\", (string) The hash target\n" " \"mintime\" : xxx, (numeric) The minimum timestamp appropriate for next block time in seconds since epoch (Jan 1 1970 GMT)\n" " \"mutable\" : [ (array of string) list of ways the block template may be changed \n" " \"value\" (string) A way the block template may be changed, e.g. 'time', 'transactions', 'prevblock'\n" " ,...\n" " ],\n" " \"noncerange\" : \"00000000ffffffff\", (string) A range of valid nonces\n" " \"sigoplimit\" : n, (numeric) limit of sigops in blocks\n" " \"sizelimit\" : n, (numeric) limit of block size\n" " \"curtime\" : ttt, (numeric) current timestamp in seconds since epoch (Jan 1 1970 GMT)\n" " \"bits\" : \"xxx\", (string) compressed target of next block\n" " \"height\" : n (numeric) The height of the next block\n" "}\n" "\nExamples:\n" + HelpExampleCli("getblocktemplate", "") + HelpExampleRpc("getblocktemplate", "") ); LOCK(cs_main); std::string strMode = "template"; Value lpval = Value::null; if (params.size() > 0) { const Object& oparam = params[0].get_obj(); const Value& modeval = find_value(oparam, "mode"); if (modeval.type() == str_type) strMode = modeval.get_str(); else if (modeval.type() == null_type) { /* Do nothing */ } else throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode"); lpval = find_value(oparam, "longpollid"); if (strMode == "proposal") { const Value& dataval = find_value(oparam, "data"); if (dataval.type() != str_type) throw JSONRPCError(RPC_TYPE_ERROR, "Missing data String key for proposal"); CBlock block; if (!DecodeHexBlk(block, dataval.get_str())) throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed"); uint256 hash = block.GetHash(); BlockMap::iterator mi = mapBlockIndex.find(hash); if (mi != mapBlockIndex.end()) { CBlockIndex *pindex = mi->second; if (pindex->IsValid(BLOCK_VALID_SCRIPTS)) return "duplicate"; if (pindex->nStatus & BLOCK_FAILED_MASK) return "duplicate-invalid"; return "duplicate-inconclusive"; } CBlockIndex* const pindexPrev = chainActive.Tip(); // TestBlockValidity only supports blocks built on the current Tip if (block.hashPrevBlock != pindexPrev->GetBlockHash()) return "inconclusive-not-best-prevblk"; CValidationState state; TestBlockValidity(state, block, pindexPrev, false, true); return BIP22ValidationResult(state); } } if (strMode != "template") throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode"); if (vNodes.empty()) throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, "Bitcoin is not connected!"); if (IsInitialBlockDownload()) throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Bitcoin is downloading blocks..."); static unsigned int nTransactionsUpdatedLast; if (lpval.type() != null_type) { // Wait to respond until either the best block changes, OR a minute has passed and there are more transactions uint256 hashWatchedChain; boost::system_time checktxtime; unsigned int nTransactionsUpdatedLastLP; if (lpval.type() == str_type) { // Format: std::string lpstr = lpval.get_str(); hashWatchedChain.SetHex(lpstr.substr(0, 64)); nTransactionsUpdatedLastLP = atoi64(lpstr.substr(64)); } else { // NOTE: Spec does not specify behaviour for non-string longpollid, but this makes testing easier hashWatchedChain = chainActive.Tip()->GetBlockHash(); nTransactionsUpdatedLastLP = nTransactionsUpdatedLast; } // Release the wallet and main lock while waiting LEAVE_CRITICAL_SECTION(cs_main); { checktxtime = boost::get_system_time() + boost::posix_time::minutes(1); boost::unique_lock lock(csBestBlock); while (chainActive.Tip()->GetBlockHash() == hashWatchedChain && IsRPCRunning()) { if (!cvBlockChange.timed_wait(lock, checktxtime)) { // Timeout: Check transactions for update if (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLastLP) break; checktxtime += boost::posix_time::seconds(10); } } } ENTER_CRITICAL_SECTION(cs_main); if (!IsRPCRunning()) throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, "Shutting down"); // TODO: Maybe recheck connections/IBD and (if something wrong) send an expires-immediately template to stop miners? } // Update block static CBlockIndex* pindexPrev; static int64_t nStart; static CBlockTemplate* pblocktemplate; if (pindexPrev != chainActive.Tip() || (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLast && GetTime() - nStart > 5)) { // Clear pindexPrev so future calls make a new block, despite any failures from here on pindexPrev = NULL; // Store the pindexBest used before CreateNewBlock, to avoid races nTransactionsUpdatedLast = mempool.GetTransactionsUpdated(); CBlockIndex* pindexPrevNew; nStart = GetTime(); // Create new block if(pblocktemplate) { delete pblocktemplate; pblocktemplate = NULL; } CScript scriptDummy = CScript() << OP_TRUE; pblocktemplate = CreateNewBlock(scriptDummy, pindexPrevNew); if (!pblocktemplate) throw JSONRPCError(RPC_OUT_OF_MEMORY, "Out of memory"); // Need to update only after we know CreateNewBlock succeeded pindexPrev = pindexPrevNew; } CBlock* pblock = &pblocktemplate->block; // pointer for convenience // Update nTime UpdateTime(pblock, pindexPrev); pblock->nNonce = 0; static const Array aCaps = boost::assign::list_of("proposal"); Array transactions; map setTxIndex; int i = 0; BOOST_FOREACH (CTransaction& tx, pblock->vtx) { uint256 txHash = tx.GetHash(); setTxIndex[txHash] = i++; if (tx.IsCoinBase()) continue; Object entry; entry.push_back(Pair("data", EncodeHexTx(tx))); entry.push_back(Pair("hash", txHash.GetHex())); Array deps; BOOST_FOREACH (const CTxIn &in, tx.vin) { if (setTxIndex.count(in.prevout.hash)) deps.push_back(setTxIndex[in.prevout.hash]); } entry.push_back(Pair("depends", deps)); int index_in_template = i - 1; entry.push_back(Pair("fee", pblocktemplate->vTxFees[index_in_template])); entry.push_back(Pair("sigops", pblocktemplate->vTxSigOps[index_in_template])); transactions.push_back(entry); } Object aux; aux.push_back(Pair("flags", HexStr(COINBASE_FLAGS.begin(), COINBASE_FLAGS.end()))); arith_uint256 hashTarget = arith_uint256().SetCompact(pblock->nBits); static Array aMutable; if (aMutable.empty()) { aMutable.push_back("time"); aMutable.push_back("transactions"); aMutable.push_back("prevblock"); } Object result; result.push_back(Pair("capabilities", aCaps)); result.push_back(Pair("version", pblock->nVersion)); result.push_back(Pair("previousblockhash", pblock->hashPrevBlock.GetHex())); result.push_back(Pair("transactions", transactions)); result.push_back(Pair("coinbaseaux", aux)); result.push_back(Pair("coinbasevalue", (int64_t)pblock->vtx[0].vout[0].nValue)); result.push_back(Pair("longpollid", chainActive.Tip()->GetBlockHash().GetHex() + i64tostr(nTransactionsUpdatedLast))); result.push_back(Pair("target", hashTarget.GetHex())); result.push_back(Pair("mintime", (int64_t)pindexPrev->GetMedianTimePast()+1)); result.push_back(Pair("mutable", aMutable)); result.push_back(Pair("noncerange", "00000000ffffffff")); result.push_back(Pair("sigoplimit", (int64_t)MAX_BLOCK_SIGOPS)); result.push_back(Pair("sizelimit", (int64_t)MAX_BLOCK_SIZE)); result.push_back(Pair("curtime", pblock->GetBlockTime())); result.push_back(Pair("bits", strprintf("%08x", pblock->nBits))); result.push_back(Pair("height", (int64_t)(pindexPrev->nHeight+1))); return result; } class submitblock_StateCatcher : public CValidationInterface { public: uint256 hash; bool found; CValidationState state; submitblock_StateCatcher(const uint256 &hashIn) : hash(hashIn), found(false), state() {}; protected: virtual void BlockChecked(const CBlock& block, const CValidationState& stateIn) { if (block.GetHash() != hash) return; found = true; state = stateIn; }; }; Value submitblock(const Array& params, bool fHelp) { if (fHelp || params.size() < 1 || params.size() > 2) throw runtime_error( "submitblock \"hexdata\" ( \"jsonparametersobject\" )\n" "\nAttempts to submit new block to network.\n" "The 'jsonparametersobject' parameter is currently ignored.\n" "See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n" "\nArguments\n" "1. \"hexdata\" (string, required) the hex-encoded block data to submit\n" "2. \"jsonparametersobject\" (string, optional) object of optional parameters\n" " {\n" " \"workid\" : \"id\" (string, optional) if the server provided a workid, it MUST be included with submissions\n" " }\n" "\nResult:\n" "\nExamples:\n" + HelpExampleCli("submitblock", "\"mydata\"") + HelpExampleRpc("submitblock", "\"mydata\"") ); CBlock block; if (!DecodeHexBlk(block, params[0].get_str())) throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed"); uint256 hash = block.GetHash(); BlockMap::iterator mi = mapBlockIndex.find(hash); if (mi != mapBlockIndex.end()) { CBlockIndex *pindex = mi->second; if (pindex->IsValid(BLOCK_VALID_SCRIPTS)) return "duplicate"; if (pindex->nStatus & BLOCK_FAILED_MASK) return "duplicate-invalid"; // Otherwise, we might only have the header - process the block before returning } CValidationState state; submitblock_StateCatcher sc(block.GetHash()); RegisterValidationInterface(&sc); bool fAccepted = ProcessNewBlock(state, NULL, &block); UnregisterValidationInterface(&sc); if (mi != mapBlockIndex.end()) { if (fAccepted && !sc.found) return "duplicate-inconclusive"; return "duplicate"; } if (fAccepted) { if (!sc.found) return "inconclusive"; state = sc.state; } return BIP22ValidationResult(state); } Value estimatefee(const Array& params, bool fHelp) { if (fHelp || params.size() != 1) throw runtime_error( "estimatefee nblocks\n" "\nEstimates the approximate fee per kilobyte\n" "needed for a transaction to begin confirmation\n" "within nblocks blocks.\n" "\nArguments:\n" "1. nblocks (numeric)\n" "\nResult:\n" "n : (numeric) estimated fee-per-kilobyte\n" "\n" "-1.0 is returned if not enough transactions and\n" "blocks have been observed to make an estimate.\n" "\nExample:\n" + HelpExampleCli("estimatefee", "6") ); RPCTypeCheck(params, boost::assign::list_of(int_type)); int nBlocks = params[0].get_int(); if (nBlocks < 1) nBlocks = 1; CFeeRate feeRate = mempool.estimateFee(nBlocks); if (feeRate == CFeeRate(0)) return -1.0; return ValueFromAmount(feeRate.GetFeePerK()); } Value estimatepriority(const Array& params, bool fHelp) { if (fHelp || params.size() != 1) throw runtime_error( "estimatepriority nblocks\n" "\nEstimates the approximate priority\n" "a zero-fee transaction needs to begin confirmation\n" "within nblocks blocks.\n" "\nArguments:\n" "1. nblocks (numeric)\n" "\nResult:\n" "n : (numeric) estimated priority\n" "\n" "-1.0 is returned if not enough transactions and\n" "blocks have been observed to make an estimate.\n" "\nExample:\n" + HelpExampleCli("estimatepriority", "6") ); RPCTypeCheck(params, boost::assign::list_of(int_type)); int nBlocks = params[0].get_int(); if (nBlocks < 1) nBlocks = 1; return mempool.estimatePriority(nBlocks); }