std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& scriptPubKeyIn, bool fMineWitnessTx)
{
int64_t nTimeStart = GetTimeMicros();
resetBlock();
pblocktemplate.reset(new CBlockTemplate());
if(!pblocktemplate.get())
return nullptr;
pblock = &pblocktemplate->block; // pointer for convenience
// Add dummy coinbase tx as first transaction
pblock->vtx.emplace_back();
pblocktemplate->vTxFees.push_back(-1); // updated at end
pblocktemplate->vTxSigOpsCost.push_back(-1); // updated at end
LOCK2(cs_main, mempool.cs);
CBlockIndex* pindexPrev = chainActive.Tip();
assert(pindexPrev != nullptr);
nHeight = pindexPrev->nHeight + 1;
pblock->nVersion = ComputeBlockVersion(pindexPrev, chainparams.GetConsensus());
// -regtest only: allow overriding block.nVersion with
// -blockversion=N to test forking scenarios
if (chainparams.MineBlocksOnDemand())
pblock->nVersion = gArgs.GetArg("-blockversion", pblock->nVersion);
pblock->nTime = GetAdjustedTime();
const int64_t nMedianTimePast = pindexPrev->GetMedianTimePast();
nLockTimeCutoff = (STANDARD_LOCKTIME_VERIFY_FLAGS & LOCKTIME_MEDIAN_TIME_PAST)
? nMedianTimePast
: pblock->GetBlockTime();
// Decide whether to include witness transactions
// This is only needed in case the witness softfork activation is reverted
// (which would require a very deep reorganization) or when
// -promiscuousmempoolflags is used.
// TODO: replace this with a call to main to assess validity of a mempool
// transaction (which in most cases can be a no-op).
fIncludeWitness = IsWitnessEnabled(pindexPrev, chainparams.GetConsensus()) && fMineWitnessTx;
int nPackagesSelected = 0;
int nDescendantsUpdated = 0;
addPackageTxs(nPackagesSelected, nDescendantsUpdated);
int64_t nTime1 = GetTimeMicros();
nLastBlockTx = nBlockTx;
nLastBlockWeight = nBlockWeight;
// Create coinbase transaction.
CMutableTransaction coinbaseTx;
coinbaseTx.vin.resize(1);
coinbaseTx.vin[0].prevout.SetNull();
coinbaseTx.vout.resize(1);
coinbaseTx.vout[0].scriptPubKey = scriptPubKeyIn;
coinbaseTx.vout[0].nValue = nFees + GetBlockSubsidy(nHeight, chainparams.GetConsensus());
coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0;
pblock->vtx[0] = MakeTransactionRef(std::move(coinbaseTx));
pblocktemplate->vchCoinbaseCommitment = GenerateCoinbaseCommitment(*pblock, pindexPrev, chainparams.GetConsensus());
pblocktemplate->vTxFees[0] = -nFees;
LogPrintf("CreateNewBlock(): block weight: %u txs: %u fees: %ld sigops %d\n", GetBlockWeight(*pblock), nBlockTx, nFees, nBlockSigOpsCost);
// Fill in header
pblock->hashPrevBlock = pindexPrev->GetBlockHash();
UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());
pblock->nNonce = 0;
pblocktemplate->vTxSigOpsCost[0] = WITNESS_SCALE_FACTOR * GetLegacySigOpCount(*pblock->vtx[0]);
CValidationState state;
if (!TestBlockValidity(state, chainparams, *pblock, pindexPrev, false, false)) {
throw std::runtime_error(strprintf("%s: TestBlockValidity failed: %s", __func__, FormatStateMessage(state)));
}
int64_t nTime2 = GetTimeMicros();
LogPrint(BCLog::BENCH, "CreateNewBlock() packages: %.2fms (%d packages, %d updated descendants), validity: %.2fms (total %.2fms)\n", 0.001 * (nTime1 - nTimeStart), nPackagesSelected, nDescendantsUpdated, 0.001 * (nTime2 - nTime1), 0.001 * (nTime2 - nTimeStart));
return std::move(pblocktemplate);
}
static UniValue getblocktemplate(const JSONRPCRequest& request)
{
if (request.fHelp || request.params.size() > 1)
throw std::runtime_error(
"getblocktemplate ( TemplateRequest )\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"
"For full specification, see BIPs 22, 23, 9, and 145:\n"
" https://github.com/bitcoin/bips/blob/master/bip-0022.mediawiki\n"
" https://github.com/bitcoin/bips/blob/master/bip-0023.mediawiki\n"
" https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki#getblocktemplate_changes\n"
" https://github.com/bitcoin/bips/blob/master/bip-0145.mediawiki\n"
"\nArguments:\n"
"1. template_request (json object, optional) A json object in the following spec\n"
" {\n"
" \"mode\":\"template\" (string, optional) This must be set to \"template\", \"proposal\" (see BIP 23), 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"
" \"rules\":[ (array, optional) A list of strings\n"
" \"support\" (string) client side supported softfork deployment\n"
" ,...\n"
" ]\n"
" }\n"
"\n"
"\nResult:\n"
"{\n"
" \"version\" : n, (numeric) The preferred block version\n"
" \"rules\" : [ \"rulename\", ... ], (array of strings) specific block rules that are to be enforced\n"
" \"vbavailable\" : { (json object) set of pending, supported versionbit (BIP 9) softfork deployments\n"
" \"rulename\" : bitnumber (numeric) identifies the bit number as indicating acceptance and readiness for the named softfork rule\n"
" ,...\n"
" },\n"
" \"vbrequired\" : n, (numeric) bit mask of versionbits the server requires set in submissions\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"
" \"txid\" : \"xxxx\", (string) transaction id encoded in little-endian hexadecimal\n"
" \"hash\" : \"xxxx\", (string) hash encoded in little-endian hexadecimal (including witness data)\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 SigOps cost, as counted for purposes of block limits; if key is not present, sigop cost is unknown and clients MUST NOT assume it is zero\n"
" \"weight\" : n, (numeric) total transaction weight, as counted for purposes of block limits\n"
" }\n"
" ,...\n"
" ],\n"
" \"coinbaseaux\" : { (json object) data that should be included in the coinbase's scriptSig content\n"
" \"flags\" : \"xx\" (string) key name is to be ignored, and value included in scriptSig\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"
" \"weightlimit\" : n, (numeric) limit of block weight\n"
" \"curtime\" : ttt, (numeric) current timestamp in seconds since epoch (Jan 1 1970 GMT)\n"
" \"bits\" : \"xxxxxxxx\", (string) compressed target of next block\n"
" \"height\" : n (numeric) The height of the next block\n"
"}\n"
"\nExamples:\n"
+ HelpExampleCli("getblocktemplate", "{\"rules\": [\"segwit\"]}")
+ HelpExampleRpc("getblocktemplate", "{\"rules\": [\"segwit\"]}")
);
LOCK(cs_main);
std::string strMode = "template";
UniValue lpval = NullUniValue;
std::set<std::string> setClientRules;
int64_t nMaxVersionPreVB = -1;
if (!request.params[0].isNull())
{
const UniValue& oparam = request.params[0].get_obj();
const UniValue& modeval = find_value(oparam, "mode");
if (modeval.isStr())
strMode = modeval.get_str();
else if (modeval.isNull())
{
/* Do nothing */
}
else
throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode");
lpval = find_value(oparam, "longpollid");
if (strMode == "proposal")
{
const UniValue& dataval = find_value(oparam, "data");
if (!dataval.isStr())
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();
const CBlockIndex* pindex = LookupBlockIndex(hash);
if (pindex) {
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, Params(), block, pindexPrev, false, true);
return BIP22ValidationResult(state);
}
const UniValue& aClientRules = find_value(oparam, "rules");
if (aClientRules.isArray()) {
for (unsigned int i = 0; i < aClientRules.size(); ++i) {
const UniValue& v = aClientRules[i];
setClientRules.insert(v.get_str());
}
} else {
// NOTE: It is important that this NOT be read if versionbits is supported
const UniValue& uvMaxVersion = find_value(oparam, "maxversion");
if (uvMaxVersion.isNum()) {
nMaxVersionPreVB = uvMaxVersion.get_int64();
}
}
}
if (strMode != "template")
throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode");
if(!g_connman)
throw JSONRPCError(RPC_CLIENT_P2P_DISABLED, "Error: Peer-to-peer functionality missing or disabled");
if (g_connman->GetNodeCount(CConnman::CONNECTIONS_ALL) == 0)
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.isNull())
{
// Wait to respond until either the best block changes, OR a minute has passed and there are more transactions
uint256 hashWatchedChain;
std::chrono::steady_clock::time_point checktxtime;
unsigned int nTransactionsUpdatedLastLP;
if (lpval.isStr())
{
// Format: <hashBestChain><nTransactionsUpdatedLast>
std::string lpstr = lpval.get_str();
hashWatchedChain = ParseHashV(lpstr.substr(0, 64), "longpollid");
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 = std::chrono::steady_clock::now() + std::chrono::minutes(1);
WAIT_LOCK(g_best_block_mutex, lock);
while (g_best_block == hashWatchedChain && IsRPCRunning())
{
if (g_best_block_cv.wait_until(lock, checktxtime) == std::cv_status::timeout)
{
// Timeout: Check transactions for update
if (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLastLP)
break;
checktxtime += std::chrono::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?
}
const struct VBDeploymentInfo& segwit_info = VersionBitsDeploymentInfo[Consensus::DEPLOYMENT_SEGWIT];
// If the caller is indicating segwit support, then allow CreateNewBlock()
// to select witness transactions, after segwit activates (otherwise
// don't).
bool fSupportsSegwit = setClientRules.find(segwit_info.name) != setClientRules.end();
// Update block
static CBlockIndex* pindexPrev;
static int64_t nStart;
static std::unique_ptr<CBlockTemplate> pblocktemplate;
// Cache whether the last invocation was with segwit support, to avoid returning
// a segwit-block to a non-segwit caller.
static bool fLastTemplateSupportsSegwit = true;
if (pindexPrev != chainActive.Tip() ||
(mempool.GetTransactionsUpdated() != nTransactionsUpdatedLast && GetTime() - nStart > 5) ||
fLastTemplateSupportsSegwit != fSupportsSegwit)
{
// Clear pindexPrev so future calls make a new block, despite any failures from here on
pindexPrev = nullptr;
// Store the pindexBest used before CreateNewBlock, to avoid races
nTransactionsUpdatedLast = mempool.GetTransactionsUpdated();
CBlockIndex* pindexPrevNew = chainActive.Tip();
nStart = GetTime();
fLastTemplateSupportsSegwit = fSupportsSegwit;
// Create new block
CScript scriptDummy = CScript() << OP_TRUE;
pblocktemplate = BlockAssembler(Params()).CreateNewBlock(scriptDummy, fSupportsSegwit);
if (!pblocktemplate)
throw JSONRPCError(RPC_OUT_OF_MEMORY, "Out of memory");
// Need to update only after we know CreateNewBlock succeeded
pindexPrev = pindexPrevNew;
}
assert(pindexPrev);
CBlock* pblock = &pblocktemplate->block; // pointer for convenience
const Consensus::Params& consensusParams = Params().GetConsensus();
// Update nTime
UpdateTime(pblock, consensusParams, pindexPrev);
pblock->nNonce = 0;
// NOTE: If at some point we support pre-segwit miners post-segwit-activation, this needs to take segwit support into consideration
const bool fPreSegWit = (ThresholdState::ACTIVE != VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT, versionbitscache));
UniValue aCaps(UniValue::VARR); aCaps.push_back("proposal");
UniValue transactions(UniValue::VARR);
std::map<uint256, int64_t> setTxIndex;
int i = 0;
for (const auto& it : pblock->vtx) {
const CTransaction& tx = *it;
uint256 txHash = tx.GetHash();
setTxIndex[txHash] = i++;
if (tx.IsCoinBase())
continue;
UniValue entry(UniValue::VOBJ);
entry.pushKV("data", EncodeHexTx(tx));
entry.pushKV("txid", txHash.GetHex());
entry.pushKV("hash", tx.GetWitnessHash().GetHex());
UniValue deps(UniValue::VARR);
for (const CTxIn &in : tx.vin)
{
if (setTxIndex.count(in.prevout.hash))
deps.push_back(setTxIndex[in.prevout.hash]);
}
entry.pushKV("depends", deps);
int index_in_template = i - 1;
entry.pushKV("fee", pblocktemplate->vTxFees[index_in_template]);
int64_t nTxSigOps = pblocktemplate->vTxSigOpsCost[index_in_template];
if (fPreSegWit) {
assert(nTxSigOps % WITNESS_SCALE_FACTOR == 0);
nTxSigOps /= WITNESS_SCALE_FACTOR;
}
entry.pushKV("sigops", nTxSigOps);
entry.pushKV("weight", GetTransactionWeight(tx));
transactions.push_back(entry);
}
UniValue aux(UniValue::VOBJ);
aux.pushKV("flags", HexStr(COINBASE_FLAGS.begin(), COINBASE_FLAGS.end()));
arith_uint256 hashTarget = arith_uint256().SetCompact(pblock->nBits);
UniValue aMutable(UniValue::VARR);
aMutable.push_back("time");
aMutable.push_back("transactions");
aMutable.push_back("prevblock");
UniValue result(UniValue::VOBJ);
result.pushKV("capabilities", aCaps);
UniValue aRules(UniValue::VARR);
UniValue vbavailable(UniValue::VOBJ);
for (int j = 0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
Consensus::DeploymentPos pos = Consensus::DeploymentPos(j);
ThresholdState state = VersionBitsState(pindexPrev, consensusParams, pos, versionbitscache);
switch (state) {
case ThresholdState::DEFINED:
case ThresholdState::FAILED:
// Not exposed to GBT at all
break;
case ThresholdState::LOCKED_IN:
// Ensure bit is set in block version
pblock->nVersion |= VersionBitsMask(consensusParams, pos);
// FALL THROUGH to get vbavailable set...
case ThresholdState::STARTED:
{
const struct VBDeploymentInfo& vbinfo = VersionBitsDeploymentInfo[pos];
vbavailable.pushKV(gbt_vb_name(pos), consensusParams.vDeployments[pos].bit);
if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
if (!vbinfo.gbt_force) {
// If the client doesn't support this, don't indicate it in the [default] version
pblock->nVersion &= ~VersionBitsMask(consensusParams, pos);
}
}
break;
}
case ThresholdState::ACTIVE:
{
// Add to rules only
const struct VBDeploymentInfo& vbinfo = VersionBitsDeploymentInfo[pos];
aRules.push_back(gbt_vb_name(pos));
if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
// Not supported by the client; make sure it's safe to proceed
if (!vbinfo.gbt_force) {
// If we do anything other than throw an exception here, be sure version/force isn't sent to old clients
throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Support for '%s' rule requires explicit client support", vbinfo.name));
}
}
break;
}
}
}
result.pushKV("version", pblock->nVersion);
result.pushKV("rules", aRules);
result.pushKV("vbavailable", vbavailable);
result.pushKV("vbrequired", int(0));
if (nMaxVersionPreVB >= 2) {
// If VB is supported by the client, nMaxVersionPreVB is -1, so we won't get here
// Because BIP 34 changed how the generation transaction is serialized, we can only use version/force back to v2 blocks
// This is safe to do [otherwise-]unconditionally only because we are throwing an exception above if a non-force deployment gets activated
// Note that this can probably also be removed entirely after the first BIP9 non-force deployment (ie, probably segwit) gets activated
aMutable.push_back("version/force");
}
result.pushKV("previousblockhash", pblock->hashPrevBlock.GetHex());
result.pushKV("transactions", transactions);
result.pushKV("coinbaseaux", aux);
result.pushKV("coinbasevalue", (int64_t)pblock->vtx[0]->vout[0].nValue);
result.pushKV("longpollid", chainActive.Tip()->GetBlockHash().GetHex() + i64tostr(nTransactionsUpdatedLast));
result.pushKV("target", hashTarget.GetHex());
result.pushKV("mintime", (int64_t)pindexPrev->GetMedianTimePast()+1);
result.pushKV("mutable", aMutable);
result.pushKV("noncerange", "00000000ffffffff");
int64_t nSigOpLimit = MAX_BLOCK_SIGOPS_COST;
int64_t nSizeLimit = MAX_BLOCK_SERIALIZED_SIZE;
if (fPreSegWit) {
assert(nSigOpLimit % WITNESS_SCALE_FACTOR == 0);
nSigOpLimit /= WITNESS_SCALE_FACTOR;
assert(nSizeLimit % WITNESS_SCALE_FACTOR == 0);
nSizeLimit /= WITNESS_SCALE_FACTOR;
}
result.pushKV("sigoplimit", nSigOpLimit);
result.pushKV("sizelimit", nSizeLimit);
if (!fPreSegWit) {
result.pushKV("weightlimit", (int64_t)MAX_BLOCK_WEIGHT);
}
result.pushKV("curtime", pblock->GetBlockTime());
result.pushKV("bits", strprintf("%08x", pblock->nBits));
result.pushKV("height", (int64_t)(pindexPrev->nHeight+1));
if (!pblocktemplate->vchCoinbaseCommitment.empty() && fSupportsSegwit) {
result.pushKV("default_witness_commitment", HexStr(pblocktemplate->vchCoinbaseCommitment.begin(), pblocktemplate->vchCoinbaseCommitment.end()));
}
return result;
}
UniValue getblocktemplate(const JSONRPCRequest& request)
{
if (request.fHelp || request.params.size() > 1)
throw std::runtime_error(
"getblocktemplate ( TemplateRequest )\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"
"For full specification, see BIPs 22, 23, and 9:\n"
" https://github.com/bitcoin/bips/blob/master/bip-0022.mediawiki\n"
" https://github.com/bitcoin/bips/blob/master/bip-0023.mediawiki\n"
" https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki#getblocktemplate_changes\n"
"\nArguments:\n"
"1. template_request (json object, optional) A json object in the following spec\n"
" {\n"
" \"mode\":\"template\" (string, optional) This must be set to \"template\", \"proposal\" (see BIP 23), 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"
" \"rules\":[ (array, optional) A list of strings\n"
" \"support\" (string) client side supported softfork deployment\n"
" ,...\n"
" ]\n"
" }\n"
"\n"
"\nResult:\n"
"{\n"
" \"capabilities\" : [ \"capability\", ... ], (array of strings) specific client side supported features\n"
" \"version\" : n, (numeric) The preferred block version\n"
" \"rules\" : [ \"rulename\", ... ], (array of strings) specific block rules that are to be enforced\n"
" \"vbavailable\" : { (json object) set of pending, supported versionbit (BIP 9) softfork deployments\n"
" \"rulename\" : bitnumber (numeric) identifies the bit number as indicating acceptance and readiness for the named softfork rule\n"
" ,...\n"
" },\n"
" \"vbrequired\" : n, (numeric) bit mask of versionbits the server requires set in submissions\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 duffs); 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\" : \"xx\" (string) key name is to be ignored, and value included in scriptSig\n"
" },\n"
" \"coinbasevalue\" : n, (numeric) maximum allowable input to coinbase transaction, including the generation award and transaction fees (in duffs)\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\" : \"xxxxxxxx\", (string) compressed target of next block\n"
" \"previousbits\" : \"xxxxxxxx\", (string) compressed target of current highest block\n"
" \"height\" : n (numeric) The height of the next block\n"
" \"masternode\" : [ (array) required masternode payments that must be included in the next block\n"
" {\n"
" \"payee\" : \"xxxx\", (string) payee address\n"
" \"script\" : \"xxxx\", (string) payee scriptPubKey\n"
" \"amount\": n (numeric) required amount to pay\n"
" }\n"
" },\n"
" \"masternode_payments_started\" : true|false, (boolean) true, if masternode payments started\n"
" \"masternode_payments_enforced\" : true|false, (boolean) true, if masternode payments are enforced\n"
" \"superblock\" : [ (array) required superblock payees that must be included in the next block\n"
" {\n"
" \"payee\" : \"xxxx\", (string) payee address\n"
" \"script\" : \"xxxx\", (string) payee scriptPubKey\n"
" \"amount\": n (numeric) required amount to pay\n"
" }\n"
" ,...\n"
" ],\n"
" \"superblocks_started\" : true|false, (boolean) true, if superblock payments started\n"
" \"superblocks_enabled\" : true|false, (boolean) true, if superblock payments are enabled\n"
" \"coinbase_payload\" : \"xxxxxxxx\" (string) coinbase transaction payload data encoded in hexadecimal\n"
"}\n"
"\nExamples:\n"
+ HelpExampleCli("getblocktemplate", "")
+ HelpExampleRpc("getblocktemplate", "")
);
LOCK(cs_main);
std::string strMode = "template";
UniValue lpval = NullUniValue;
std::set<std::string> setClientRules;
int64_t nMaxVersionPreVB = -1;
if (request.params.size() > 0)
{
const UniValue& oparam = request.params[0].get_obj();
const UniValue& modeval = find_value(oparam, "mode");
if (modeval.isStr())
strMode = modeval.get_str();
else if (modeval.isNull())
{
/* Do nothing */
}
else
throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode");
lpval = find_value(oparam, "longpollid");
if (strMode == "proposal")
{
const UniValue& dataval = find_value(oparam, "data");
if (!dataval.isStr())
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, Params(), block, pindexPrev, false, true);
return BIP22ValidationResult(state);
}
const UniValue& aClientRules = find_value(oparam, "rules");
if (aClientRules.isArray()) {
for (unsigned int i = 0; i < aClientRules.size(); ++i) {
const UniValue& v = aClientRules[i];
setClientRules.insert(v.get_str());
}
} else {
// NOTE: It is important that this NOT be read if versionbits is supported
const UniValue& uvMaxVersion = find_value(oparam, "maxversion");
if (uvMaxVersion.isNum()) {
nMaxVersionPreVB = uvMaxVersion.get_int64();
}
}
}
if (strMode != "template")
throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode");
if(!g_connman)
throw JSONRPCError(RPC_CLIENT_P2P_DISABLED, "Error: Peer-to-peer functionality missing or disabled");
if (Params().MiningRequiresPeers()) {
if (g_connman->GetNodeCount(CConnman::CONNECTIONS_ALL) == 0)
throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, "Dash Core is not connected!");
if (IsInitialBlockDownload())
throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Dash Core is downloading blocks...");
}
// when enforcement is on we need information about a masternode payee or otherwise our block is going to be orphaned by the network
std::vector<CTxOut> voutMasternodePayments;
if (sporkManager.IsSporkActive(SPORK_8_MASTERNODE_PAYMENT_ENFORCEMENT)
&& !masternodeSync.IsWinnersListSynced()
&& !mnpayments.GetBlockTxOuts(chainActive.Height() + 1, 0, voutMasternodePayments))
throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Dash Core is downloading masternode winners...");
// next bock is a superblock and we need governance info to correctly construct it
if (sporkManager.IsSporkActive(SPORK_9_SUPERBLOCKS_ENABLED)
&& !masternodeSync.IsSynced()
&& CSuperblock::IsValidBlockHeight(chainActive.Height() + 1))
throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Dash Core is syncing with network...");
static unsigned int nTransactionsUpdatedLast;
if (!lpval.isNull())
{
// 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.isStr())
{
// Format: <hashBestChain><nTransactionsUpdatedLast>
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<boost::mutex> 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 std::unique_ptr<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 = nullptr;
// Store the chainActive.Tip() used before CreateNewBlock, to avoid races
nTransactionsUpdatedLast = mempool.GetTransactionsUpdated();
CBlockIndex* pindexPrevNew = chainActive.Tip();
nStart = GetTime();
// Create new block
CScript scriptDummy = CScript() << OP_TRUE;
pblocktemplate = BlockAssembler(Params()).CreateNewBlock(scriptDummy);
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
const Consensus::Params& consensusParams = Params().GetConsensus();
// Update nTime
UpdateTime(pblock, consensusParams, pindexPrev);
pblock->nNonce = 0;
UniValue aCaps(UniValue::VARR); aCaps.push_back("proposal");
UniValue transactions(UniValue::VARR);
std::map<uint256, int64_t> setTxIndex;
int i = 0;
for (const auto& it : pblock->vtx) {
const CTransaction& tx = *it;
uint256 txHash = tx.GetHash();
setTxIndex[txHash] = i++;
if (tx.IsCoinBase())
continue;
UniValue entry(UniValue::VOBJ);
entry.push_back(Pair("data", EncodeHexTx(tx)));
entry.push_back(Pair("hash", txHash.GetHex()));
UniValue deps(UniValue::VARR);
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);
}
UniValue aux(UniValue::VOBJ);
aux.push_back(Pair("flags", HexStr(COINBASE_FLAGS.begin(), COINBASE_FLAGS.end())));
arith_uint256 hashTarget = arith_uint256().SetCompact(pblock->nBits);
UniValue aMutable(UniValue::VARR);
aMutable.push_back("time");
aMutable.push_back("transactions");
aMutable.push_back("prevblock");
UniValue result(UniValue::VOBJ);
result.push_back(Pair("capabilities", aCaps));
UniValue aRules(UniValue::VARR);
UniValue vbavailable(UniValue::VOBJ);
for (int j = 0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
Consensus::DeploymentPos pos = Consensus::DeploymentPos(j);
ThresholdState state = VersionBitsState(pindexPrev, consensusParams, pos, versionbitscache);
switch (state) {
case THRESHOLD_DEFINED:
case THRESHOLD_FAILED:
// Not exposed to GBT at all
break;
case THRESHOLD_LOCKED_IN:
// Ensure bit is set in block version
pblock->nVersion |= VersionBitsMask(consensusParams, pos);
// FALL THROUGH to get vbavailable set...
case THRESHOLD_STARTED:
{
const struct BIP9DeploymentInfo& vbinfo = VersionBitsDeploymentInfo[pos];
vbavailable.push_back(Pair(gbt_vb_name(pos), consensusParams.vDeployments[pos].bit));
if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
if (!vbinfo.gbt_force) {
// If the client doesn't support this, don't indicate it in the [default] version
pblock->nVersion &= ~VersionBitsMask(consensusParams, pos);
}
}
break;
}
case THRESHOLD_ACTIVE:
{
// Add to rules only
const struct BIP9DeploymentInfo& vbinfo = VersionBitsDeploymentInfo[pos];
aRules.push_back(gbt_vb_name(pos));
if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
// Not supported by the client; make sure it's safe to proceed
if (!vbinfo.gbt_force) {
// If we do anything other than throw an exception here, be sure version/force isn't sent to old clients
throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Support for '%s' rule requires explicit client support", vbinfo.name));
}
}
break;
}
}
}
result.push_back(Pair("version", pblock->nVersion));
result.push_back(Pair("rules", aRules));
result.push_back(Pair("vbavailable", vbavailable));
result.push_back(Pair("vbrequired", int(0)));
if (nMaxVersionPreVB >= 2) {
// If VB is supported by the client, nMaxVersionPreVB is -1, so we won't get here
// Because BIP 34 changed how the generation transaction is serialized, we can only use version/force back to v2 blocks
// This is safe to do [otherwise-]unconditionally only because we are throwing an exception above if a non-force deployment gets activated
// Note that this can probably also be removed entirely after the first BIP9 non-force deployment (ie, probably segwit) gets activated
aMutable.push_back("version/force");
}
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]->GetValueOut()));
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)MaxBlockSigOps(fDIP0001ActiveAtTip)));
result.push_back(Pair("sizelimit", (int64_t)MaxBlockSize(fDIP0001ActiveAtTip)));
result.push_back(Pair("curtime", pblock->GetBlockTime()));
result.push_back(Pair("bits", strprintf("%08x", pblock->nBits)));
result.push_back(Pair("previousbits", strprintf("%08x", pblocktemplate->nPrevBits)));
result.push_back(Pair("height", (int64_t)(pindexPrev->nHeight+1)));
UniValue masternodeObj(UniValue::VARR);
for (const auto& txout : pblocktemplate->voutMasternodePayments) {
CTxDestination address1;
ExtractDestination(txout.scriptPubKey, address1);
CBitcoinAddress address2(address1);
UniValue obj(UniValue::VOBJ);
obj.push_back(Pair("payee", address2.ToString().c_str()));
obj.push_back(Pair("script", HexStr(txout.scriptPubKey)));
obj.push_back(Pair("amount", txout.nValue));
masternodeObj.push_back(obj);
}
result.push_back(Pair("masternode", masternodeObj));
result.push_back(Pair("masternode_payments_started", pindexPrev->nHeight + 1 > consensusParams.nMasternodePaymentsStartBlock));
result.push_back(Pair("masternode_payments_enforced", deterministicMNManager->IsDeterministicMNsSporkActive() || sporkManager.IsSporkActive(SPORK_8_MASTERNODE_PAYMENT_ENFORCEMENT)));
UniValue superblockObjArray(UniValue::VARR);
if(pblocktemplate->voutSuperblockPayments.size()) {
for (const auto& txout : pblocktemplate->voutSuperblockPayments) {
UniValue entry(UniValue::VOBJ);
CTxDestination address1;
ExtractDestination(txout.scriptPubKey, address1);
CBitcoinAddress address2(address1);
entry.push_back(Pair("payee", address2.ToString().c_str()));
entry.push_back(Pair("script", HexStr(txout.scriptPubKey)));
entry.push_back(Pair("amount", txout.nValue));
superblockObjArray.push_back(entry);
}
}
result.push_back(Pair("superblock", superblockObjArray));
result.push_back(Pair("superblocks_started", pindexPrev->nHeight + 1 > consensusParams.nSuperblockStartBlock));
result.push_back(Pair("superblocks_enabled", sporkManager.IsSporkActive(SPORK_9_SUPERBLOCKS_ENABLED)));
result.push_back(Pair("coinbase_payload", HexStr(pblock->vtx[0]->vExtraPayload)));
return result;
}