前言
在了解pow共識機制前，我們先了解下位元幣區塊的結構，下圖是位元幣區塊的結構圖：
從圖上可知，位元幣的結構分為區塊頭和區塊體，其中區塊頭細分為：
父區塊頭哈希值：前一區塊的哈希值，使用SHA256(SHA256(父區塊頭))計算，占32位元組
版本：區塊版本號，表示本區塊遵守的驗證規則 ，占4位元組
時間戳：該區塊產生的近似時間，精確到秒的UNIX時間戳，必須嚴格大于前11個區塊時間的中值，同時全節點也會拒絕那些超出自己2個小時時間戳的區塊，占4位元組
難度：該區塊作業量證明演算法的難度目標，已經使用特定演算法編碼，占4位元組
亂數（Nonce）：為了找到滿足難度目標所設定的亂數，為了解決32位亂數在算力飛升的情況下不夠用的問題，規定時間戳和coinbase交易資訊均可更改，以此擴展nonce的位數，占4位元組
Merkle根：該區塊中交易的Merkle樹根的哈希值，同樣采用SHA256(SHA256())計算，占32位元組
如此，細心的同學會發現，區塊頭總共占了80位元組，
區塊體除了籌幣交易記錄（由一棵Merkle二叉樹組成）外，還有一個交易計數，
位元幣的任何一個節點，想生成一個新的區塊，必須使用自己節點擁有的算力解算出pow問題，因此，我們先了解下pow作業量證明的三要素，
提示：以下是本篇文章正文內容，下面案例可供參考
PoW演算法在位元幣中的實作
原始碼如下：
位置：https://github.com/larryxiang/bitcoin/edit/master/src/rpc/mining.cpp
// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 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 <chain.h>
#include <chainparams.h>
#include <consensus/consensus.h>
#include <consensus/params.h>
#include <consensus/validation.h>
#include <core_io.h>
#include <key_io.h>
#include <miner.h>
#include <net.h>
#include <node/context.h>
#include <policy/fees.h>
#include <pow.h>
#include <rpc/blockchain.h>
#include <rpc/mining.h>
#include <rpc/server.h>
#include <rpc/util.h>
#include <script/descriptor.h>
#include <script/script.h>
#include <script/signingprovider.h>
#include <shutdown.h>
#include <txmempool.h>
#include <univalue.h>
#include <util/fees.h>
#include <util/strencodings.h>
#include <util/string.h>
#include <util/system.h>
#include <util/translation.h>
#include <validation.h>
#include <validationinterface.h>
#include <versionbitsinfo.h>
#include <warnings.h>
#include <memory>
#include <stdint.h>
/**
* 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.
*/
static UniValue GetNetworkHashPS(int lookup, int height) {
CBlockIndex *pb = ::ChainActive().Tip();
if (height >= 0 && height < ::ChainActive().Height())
pb = ::ChainActive()[height];
if (pb == nullptr || !pb->nHeight)
return 0;
// If lookup is -1, then use blocks since last difficulty change.
if (lookup <= 0)
lookup = pb->nHeight % Params().GetConsensus().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 workDiff.getdouble() / timeDiff;
}
static RPCHelpMan getnetworkhashps()
{
return RPCHelpMan{"getnetworkhashps",
"\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",
{
{"nblocks", RPCArg::Type::NUM, /* default */ "120", "The number of blocks, or -1 for blocks since last difficulty change."},
{"height", RPCArg::Type::NUM, /* default */ "-1", "To estimate at the time of the given height."},
},
RPCResult{
RPCResult::Type::NUM, "", "Hashes per second estimated"},
RPCExamples{
HelpExampleCli("getnetworkhashps", "")
+ HelpExampleRpc("getnetworkhashps", "")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
LOCK(cs_main);
return GetNetworkHashPS(!request.params[0].isNull() ? request.params[0].get_int() : 120, !request.params[1].isNull() ? request.params[1].get_int() : -1);
},
};
}
static bool GenerateBlock(ChainstateManager& chainman, CBlock& block, uint64_t& max_tries, unsigned int& extra_nonce, uint256& block_hash)
{
block_hash.SetNull();
{
LOCK(cs_main);
IncrementExtraNonce(&block, ::ChainActive().Tip(), extra_nonce);
}
CChainParams chainparams(Params());
while (max_tries > 0 && block.nNonce < std::numeric_limits<uint32_t>::max() && !CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus()) && !ShutdownRequested()) {
++block.nNonce;
--max_tries;
}
if (max_tries == 0 || ShutdownRequested()) {
return false;
}
if (block.nNonce == std::numeric_limits<uint32_t>::max()) {
return true;
}
std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(block);
if (!chainman.ProcessNewBlock(chainparams, shared_pblock, true, nullptr)) {
throw JSONRPCError(RPC_INTERNAL_ERROR, "ProcessNewBlock, block not accepted");
}
block_hash = block.GetHash();
return true;
}
static UniValue generateBlocks(ChainstateManager& chainman, const CTxMemPool& mempool, const CScript& coinbase_script, int nGenerate, uint64_t nMaxTries)
{
int nHeightEnd = 0;
int nHeight = 0;
{ // Don't keep cs_main locked
LOCK(cs_main);
nHeight = ::ChainActive().Height();
nHeightEnd = nHeight+nGenerate;
}
unsigned int nExtraNonce = 0;
UniValue blockHashes(UniValue::VARR);
while (nHeight < nHeightEnd && !ShutdownRequested())
{
std::unique_ptr<CBlockTemplate> pblocktemplate(BlockAssembler(mempool, Params()).CreateNewBlock(coinbase_script));
if (!pblocktemplate.get())
throw JSONRPCError(RPC_INTERNAL_ERROR, "Couldn't create new block");
CBlock *pblock = &pblocktemplate->block;
uint256 block_hash;
if (!GenerateBlock(chainman, *pblock, nMaxTries, nExtraNonce, block_hash)) {
break;
}
if (!block_hash.IsNull()) {
++nHeight;
blockHashes.push_back(block_hash.GetHex());
}
}
return blockHashes;
}
static bool getScriptFromDescriptor(const std::string& descriptor, CScript& script, std::string& error)
{
FlatSigningProvider key_provider;
const auto desc = Parse(descriptor, key_provider, error, /* require_checksum = */ false);
if (desc) {
if (desc->IsRange()) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "Ranged descriptor not accepted. Maybe pass through deriveaddresses first?");
}
FlatSigningProvider provider;
std::vector<CScript> scripts;
if (!desc->Expand(0, key_provider, scripts, provider)) {
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Cannot derive script without private keys"));
}
// Combo descriptors can have 2 or 4 scripts, so we can't just check scripts.size() == 1
CHECK_NONFATAL(scripts.size() > 0 && scripts.size() <= 4);
if (scripts.size() == 1) {
script = scripts.at(0);
} else if (scripts.size() == 4) {
// For uncompressed keys, take the 3rd script, since it is p2wpkh
script = scripts.at(2);
} else {
// Else take the 2nd script, since it is p2pkh
script = scripts.at(1);
}
return true;
} else {
return false;
}
}
static RPCHelpMan generatetodescriptor()
{
return RPCHelpMan{
"generatetodescriptor",
"\nMine blocks immediately to a specified descriptor (before the RPC call returns)\n",
{
{"num_blocks", RPCArg::Type::NUM, RPCArg::Optional::NO, "How many blocks are generated immediately."},
{"descriptor", RPCArg::Type::STR, RPCArg::Optional::NO, "The descriptor to send the newly generated bitcoin to."},
{"maxtries", RPCArg::Type::NUM, /* default */ ToString(DEFAULT_MAX_TRIES), "How many iterations to try."},
},
RPCResult{
RPCResult::Type::ARR, "", "hashes of blocks generated",
{
{RPCResult::Type::STR_HEX, "", "blockhash"},
}
},
RPCExamples{
"\nGenerate 11 blocks to mydesc\n" + HelpExampleCli("generatetodescriptor", "11 \"mydesc\"")},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
const int num_blocks{request.params[0].get_int()};
const uint64_t max_tries{request.params[2].isNull() ? DEFAULT_MAX_TRIES : request.params[2].get_int()};
CScript coinbase_script;
std::string error;
if (!getScriptFromDescriptor(request.params[1].get_str(), coinbase_script, error)) {
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
}
const CTxMemPool& mempool = EnsureMemPool(request.context);
ChainstateManager& chainman = EnsureChainman(request.context);
return generateBlocks(chainman, mempool, coinbase_script, num_blocks, max_tries);
},
};
}
static RPCHelpMan generate()
{
return RPCHelpMan{"generate", "has been replaced by the -generate cli option. Refer to -help for more information.", {}, {}, RPCExamples{""}, [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue {
if (request.fHelp) {
throw std::runtime_error(self.ToString());
} else {
throw JSONRPCError(RPC_METHOD_NOT_FOUND, self.ToString());
}
}};
}
static RPCHelpMan generatetoaddress()
{
return RPCHelpMan{"generatetoaddress",
"\nMine blocks immediately to a specified address (before the RPC call returns)\n",
{
{"nblocks", RPCArg::Type::NUM, RPCArg::Optional::NO, "How many blocks are generated immediately."},
{"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The address to send the newly generated bitcoin to."},
{"maxtries", RPCArg::Type::NUM, /* default */ ToString(DEFAULT_MAX_TRIES), "How many iterations to try."},
},
RPCResult{
RPCResult::Type::ARR, "", "hashes of blocks generated",
{
{RPCResult::Type::STR_HEX, "", "blockhash"},
}},
RPCExamples{
"\nGenerate 11 blocks to myaddress\n"
+ HelpExampleCli("generatetoaddress", "11 \"myaddress\"")
+ "If you are using the " PACKAGE_NAME " wallet, you can get a new address to send the newly generated bitcoin to with:\n"
+ HelpExampleCli("getnewaddress", "")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
const int num_blocks{request.params[0].get_int()};
const uint64_t max_tries{request.params[2].isNull() ? DEFAULT_MAX_TRIES : request.params[2].get_int()};
CTxDestination destination = DecodeDestination(request.params[1].get_str());
if (!IsValidDestination(destination)) {
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Error: Invalid address");
}
const CTxMemPool& mempool = EnsureMemPool(request.context);
ChainstateManager& chainman = EnsureChainman(request.context);
CScript coinbase_script = GetScriptForDestination(destination);
return generateBlocks(chainman, mempool, coinbase_script, num_blocks, max_tries);
},
};
}
static RPCHelpMan generateblock()
{
return RPCHelpMan{"generateblock",
"\nMine a block with a set of ordered transactions immediately to a specified address or descriptor (before the RPC call returns)\n",
{
{"output", RPCArg::Type::STR, RPCArg::Optional::NO, "The address or descriptor to send the newly generated bitcoin to."},
{"transactions", RPCArg::Type::ARR, RPCArg::Optional::NO, "An array of hex strings which are either txids or raw transactions.\n"
"Txids must reference transactions currently in the mempool.\n"
"All transactions must be valid and in valid order, otherwise the block will be rejected.",
{
{"rawtx/txid", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
},
},
},
RPCResult{
RPCResult::Type::OBJ, "", "",
{
{RPCResult::Type::STR_HEX, "hash", "hash of generated block"},
}
},
RPCExamples{
"\nGenerate a block to myaddress, with txs rawtx and mempool_txid\n"
+ HelpExampleCli("generateblock", R"("myaddress" '["rawtx", "mempool_txid"]')")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
const auto address_or_descriptor = request.params[0].get_str();
CScript coinbase_script;
std::string error;
if (!getScriptFromDescriptor(address_or_descriptor, coinbase_script, error)) {
const auto destination = DecodeDestination(address_or_descriptor);
if (!IsValidDestination(destination)) {
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Error: Invalid address or descriptor");
}
coinbase_script = GetScriptForDestination(destination);
}
const CTxMemPool& mempool = EnsureMemPool(request.context);
std::vector<CTransactionRef> txs;
const auto raw_txs_or_txids = request.params[1].get_array();
for (size_t i = 0; i < raw_txs_or_txids.size(); i++) {
const auto str(raw_txs_or_txids[i].get_str());
uint256 hash;
CMutableTransaction mtx;
if (ParseHashStr(str, hash)) {
const auto tx = mempool.get(hash);
if (!tx) {
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Transaction %s not in mempool.", str));
}
txs.emplace_back(tx);
} else if (DecodeHexTx(mtx, str)) {
txs.push_back(MakeTransactionRef(std::move(mtx)));
} else {
throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("Transaction decode failed for %s. Make sure the tx has at least one input.", str));
}
}
CChainParams chainparams(Params());
CBlock block;
{
LOCK(cs_main);
CTxMemPool empty_mempool;
std::unique_ptr<CBlockTemplate> blocktemplate(BlockAssembler(empty_mempool, chainparams).CreateNewBlock(coinbase_script));
if (!blocktemplate) {
throw JSONRPCError(RPC_INTERNAL_ERROR, "Couldn't create new block");
}
block = blocktemplate->block;
}
CHECK_NONFATAL(block.vtx.size() == 1);
// Add transactions
block.vtx.insert(block.vtx.end(), txs.begin(), txs.end());
RegenerateCommitments(block);
{
LOCK(cs_main);
BlockValidationState state;
if (!TestBlockValidity(state, chainparams, block, LookupBlockIndex(block.hashPrevBlock), false, false)) {
throw JSONRPCError(RPC_VERIFY_ERROR, strprintf("TestBlockValidity failed: %s", state.ToString()));
}
}
uint256 block_hash;
uint64_t max_tries{DEFAULT_MAX_TRIES};
unsigned int extra_nonce{0};
if (!GenerateBlock(EnsureChainman(request.context), block, max_tries, extra_nonce, block_hash) || block_hash.IsNull()) {
throw JSONRPCError(RPC_MISC_ERROR, "Failed to make block.");
}
UniValue obj(UniValue::VOBJ);
obj.pushKV("hash", block_hash.GetHex());
return obj;
},
};
}
static RPCHelpMan getmininginfo()
{
return RPCHelpMan{"getmininginfo",
"\nReturns a json object containing mining-related information.",
{},
RPCResult{
RPCResult::Type::OBJ, "", "",
{
{RPCResult::Type::NUM, "blocks", "The current block"},
{RPCResult::Type::NUM, "currentblockweight", /* optional */ true, "The block weight of the last assembled block (only present if a block was ever assembled)"},
{RPCResult::Type::NUM, "currentblocktx", /* optional */ true, "The number of block transactions of the last assembled block (only present if a block was ever assembled)"},
{RPCResult::Type::NUM, "difficulty", "The current difficulty"},
{RPCResult::Type::NUM, "networkhashps", "The network hashes per second"},
{RPCResult::Type::NUM, "pooledtx", "The size of the mempool"},
{RPCResult::Type::STR, "chain", "current network name (main, test, regtest)"},
{RPCResult::Type::STR, "warnings", "any network and blockchain warnings"},
}},
RPCExamples{
HelpExampleCli("getmininginfo", "")
+ HelpExampleRpc("getmininginfo", "")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
LOCK(cs_main);
const CTxMemPool& mempool = EnsureMemPool(request.context);
UniValue obj(UniValue::VOBJ);
obj.pushKV("blocks", (int)::ChainActive().Height());
if (BlockAssembler::m_last_block_weight) obj.pushKV("currentblockweight", *BlockAssembler::m_last_block_weight);
if (BlockAssembler::m_last_block_num_txs) obj.pushKV("currentblocktx", *BlockAssembler::m_last_block_num_txs);
obj.pushKV("difficulty", (double)GetDifficulty(::ChainActive().Tip()));
obj.pushKV("networkhashps", getnetworkhashps().HandleRequest(request));
obj.pushKV("pooledtx", (uint64_t)mempool.size());
obj.pushKV("chain", Params().NetworkIDString());
obj.pushKV("warnings", GetWarnings(false).original);
return obj;
},
};
}
// NOTE: Unlike wallet RPC (which use BTC values), mining RPCs follow GBT (BIP 22) in using satoshi amounts
static RPCHelpMan prioritisetransaction()
{
return RPCHelpMan{"prioritisetransaction",
"Accepts the transaction into mined blocks at a higher (or lower) priority\n",
{
{"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id."},
{"dummy", RPCArg::Type::NUM, RPCArg::Optional::OMITTED_NAMED_ARG, "API-Compatibility for previous API. Must be zero or null.\n"
" DEPRECATED. For forward compatibility use named arguments and omit this parameter."},
{"fee_delta", RPCArg::Type::NUM, RPCArg::Optional::NO, "The fee value (in satoshis) to add (or subtract, if negative).\n"
" Note, that this value is not a fee rate. It is a value to modify absolute fee of the TX.\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."},
},
RPCResult{
RPCResult::Type::BOOL, "", "Returns true"},
RPCExamples{
HelpExampleCli("prioritisetransaction", "\"txid\" 0.0 10000")
+ HelpExampleRpc("prioritisetransaction", "\"txid\", 0.0, 10000")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
LOCK(cs_main);
uint256 hash(ParseHashV(request.params[0], "txid"));
CAmount nAmount = request.params[2].get_int64();
if (!(request.params[1].isNull() || request.params[1].get_real() == 0)) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "Priority is no longer supported, dummy argument to prioritisetransaction must be 0.");
}
EnsureMemPool(request.context).PrioritiseTransaction(hash, nAmount);
return true;
},
};
}
// NOTE: Assumes a conclusive result; if result is inconclusive, it must be handled by caller
static UniValue BIP22ValidationResult(const BlockValidationState& state)
{
if (state.IsValid())
return NullUniValue;
if (state.IsError())
throw JSONRPCError(RPC_VERIFY_ERROR, state.ToString());
if (state.IsInvalid())
{
std::string strRejectReason = state.GetRejectReason();
if (strRejectReason.empty())
return "rejected";
return strRejectReason;
}
// Should be impossible
return "valid?";
}
static std::string gbt_vb_name(const Consensus::DeploymentPos pos) {
const struct VBDeploymentInfo& vbinfo = VersionBitsDeploymentInfo[pos];
std::string s = vbinfo.name;
if (!vbinfo.gbt_force) {
s.insert(s.begin(), '!');
}
return s;
}
static RPCHelpMan getblocktemplate()
{
return RPCHelpMan{"getblocktemplate",
"\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",
{
{"template_request", RPCArg::Type::OBJ, "{}", "Format of the template",
{
{"mode", RPCArg::Type::STR, /* treat as named arg */ RPCArg::Optional::OMITTED_NAMED_ARG, "This must be set to \"template\", \"proposal\" (see BIP 23), or omitted"},
{"capabilities", RPCArg::Type::ARR, /* treat as named arg */ RPCArg::Optional::OMITTED_NAMED_ARG, "A list of strings",
{
{"str", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "client side supported feature, 'longpoll', 'coinbasevalue', 'proposal', 'serverlist', 'workid'"},
},
},
{"rules", RPCArg::Type::ARR, RPCArg::Optional::NO, "A list of strings",
{
{"segwit", RPCArg::Type::STR, RPCArg::Optional::NO, "(literal) indicates client side segwit support"},
{"str", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "other client side supported softfork deployment"},
},
},
},
"\"template_request\""},
},
RPCResult{
RPCResult::Type::OBJ, "", "",
{
{RPCResult::Type::NUM, "version", "The preferred block version"},
{RPCResult::Type::ARR, "rules", "specific block rules that are to be enforced",
{
{RPCResult::Type::STR, "", "name of a rule the client must understand to some extent; see BIP 9 for format"},
}},
{RPCResult::Type::OBJ_DYN, "vbavailable", "set of pending, supported versionbit (BIP 9) softfork deployments",
{
{RPCResult::Type::NUM, "rulename", "identifies the bit number as indicating acceptance and readiness for the named softfork rule"},
}},
{RPCResult::Type::NUM, "vbrequired", "bit mask of versionbits the server requires set in submissions"},
{RPCResult::Type::STR, "previousblockhash", "The hash of current highest block"},
{RPCResult::Type::ARR, "transactions", "contents of non-coinbase transactions that should be included in the next block",
{
{RPCResult::Type::OBJ, "", "",
{
{RPCResult::Type::STR_HEX, "data", "transaction data encoded in hexadecimal (byte-for-byte)"},
{RPCResult::Type::STR_HEX, "txid", "transaction id encoded in little-endian hexadecimal"},
{RPCResult::Type::STR_HEX, "hash", "hash encoded in little-endian hexadecimal (including witness data)"},
{RPCResult::Type::ARR, "depends", "array of numbers",
{
{RPCResult::Type::NUM, "", "transactions before this one (by 1-based index in 'transactions' list) that must be present in the final block if this one is"},
}},
{RPCResult::Type::NUM, "fee", "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"},
{RPCResult::Type::NUM, "sigops", "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"},
{RPCResult::Type::NUM, "weight", "total transaction weight, as counted for purposes of block limits"},
}},
}},
{RPCResult::Type::OBJ_DYN, "coinbaseaux", "data that should be included in the coinbase's scriptSig content",
{
{RPCResult::Type::STR_HEX, "key", "values must be in the coinbase (keys may be ignored)"},
}},
{RPCResult::Type::NUM, "coinbasevalue", "maximum allowable input to coinbase transaction, including the generation award and transaction fees (in satoshis)"},
{RPCResult::Type::STR, "longpollid", "an id to include with a request to longpoll on an update to this template"},
{RPCResult::Type::STR, "target", "The hash target"},
{RPCResult::Type::NUM_TIME, "mintime", "The minimum timestamp appropriate for the next block time, expressed in " + UNIX_EPOCH_TIME},
{RPCResult::Type::ARR, "mutable", "list of ways the block template may be changed",
{
{RPCResult::Type::STR, "value", "A way the block template may be changed, e.g. 'time', 'transactions', 'prevblock'"},
}},
{RPCResult::Type::STR_HEX, "noncerange", "A range of valid nonces"},
{RPCResult::Type::NUM, "sigoplimit", "limit of sigops in blocks"},
{RPCResult::Type::NUM, "sizelimit", "limit of block size"},
{RPCResult::Type::NUM, "weightlimit", "limit of block weight"},
{RPCResult::Type::NUM_TIME, "curtime", "current timestamp in " + UNIX_EPOCH_TIME},
{RPCResult::Type::STR, "bits", "compressed target of next block"},
{RPCResult::Type::NUM, "height", "The height of the next block"},
{RPCResult::Type::STR, "default_witness_commitment", /* optional */ true, "a valid witness commitment for the unmodified block template"}
}},
RPCExamples{
HelpExampleCli("getblocktemplate", "'{\"rules\": [\"segwit\"]}'")
+ HelpExampleRpc("getblocktemplate", "{\"rules\": [\"segwit\"]}")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
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";
BlockValidationState 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");
NodeContext& node = EnsureNodeContext(request.context);
if(!node.connman)
throw JSONRPCError(RPC_CLIENT_P2P_DISABLED, "Error: Peer-to-peer functionality missing or disabled");
if (node.connman->GetNodeCount(CConnman::CONNECTIONS_ALL) == 0)
throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, PACKAGE_NAME " is not connected!");
if (::ChainstateActive().IsInitialBlockDownload())
throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, PACKAGE_NAME " is in initial sync and waiting for blocks...");
static unsigned int nTransactionsUpdatedLast;
const CTxMemPool& mempool = EnsureMemPool(request.context);
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 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
// without holding the mempool lock to avoid deadlocks
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?
}
// GBT must be called with 'segwit' set in the rules
if (setClientRules.count("segwit") != 1) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "getblocktemplate must be called with the segwit rule set (call with {\"rules\": [\"segwit\"]})");
}
// 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 pindexBest 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(mempool, 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;
}
CHECK_NONFATAL(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 = (pindexPrev->nHeight + 1 < consensusParams.SegwitHeight);
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) {
CHECK_NONFATAL(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);
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);
aRules.push_back("csv");
if (!fPreSegWit) aRules.push_back("!segwit");
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() + ToString(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) {
CHECK_NONFATAL(nSigOpLimit % WITNESS_SCALE_FACTOR == 0);
nSigOpLimit /= WITNESS_SCALE_FACTOR;
CHECK_NONFATAL(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()) {
result.pushKV("default_witness_commitment", HexStr(pblocktemplate->vchCoinbaseCommitment));
}
return result;
},
};
}
class submitblock_StateCatcher final : public CValidationInterface
{
public:
uint256 hash;
bool found;
BlockValidationState state;
explicit submitblock_StateCatcher(const uint256 &hashIn) : hash(hashIn), found(false), state() {}
protected:
void BlockChecked(const CBlock& block, const BlockValidationState& stateIn) override {
if (block.GetHash() != hash)
return;
found = true;
state = stateIn;
}
};
static RPCHelpMan submitblock()
{
// We allow 2 arguments for compliance with BIP22. Argument 2 is ignored.
return RPCHelpMan{"submitblock",
"\nAttempts to submit new block to network.\n"
"See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n",
{
{"hexdata", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "the hex-encoded block data to submit"},
{"dummy", RPCArg::Type::STR, /* default */ "ignored", "dummy value, for compatibility with BIP22. This value is ignored."},
},
RPCResult{RPCResult::Type::NONE, "", "Returns JSON Null when valid, a string according to BIP22 otherwise"},
RPCExamples{
HelpExampleCli("submitblock", "\"mydata\"")
+ HelpExampleRpc("submitblock", "\"mydata\"")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
std::shared_ptr<CBlock> blockptr = std::make_shared<CBlock>();
CBlock& block = *blockptr;
if (!DecodeHexBlk(block, request.params[0].get_str())) {
throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");
}
if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) {
throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block does not start with a coinbase");
}
uint256 hash = block.GetHash();
{
LOCK(cs_main);
const CBlockIndex* pindex = LookupBlockIndex(hash);
if (pindex) {
if (pindex->IsValid(BLOCK_VALID_SCRIPTS)) {
return "duplicate";
}
if (pindex->nStatus & BLOCK_FAILED_MASK) {
return "duplicate-invalid";
}
}
}
{
LOCK(cs_main);
const CBlockIndex* pindex = LookupBlockIndex(block.hashPrevBlock);
if (pindex) {
UpdateUncommittedBlockStructures(block, pindex, Params().GetConsensus());
}
}
bool new_block;
auto sc = std::make_shared<submitblock_StateCatcher>(block.GetHash());
RegisterSharedValidationInterface(sc);
bool accepted = EnsureChainman(request.context).ProcessNewBlock(Params(), blockptr, /* fForceProcessing */ true, /* fNewBlock */ &new_block);
UnregisterSharedValidationInterface(sc);
if (!new_block && accepted) {
return "duplicate";
}
if (!sc->found) {
return "inconclusive";
}
return BIP22ValidationResult(sc->state);
},
};
}
static RPCHelpMan submitheader()
{
return RPCHelpMan{"submitheader",
"\nDecode the given hexdata as a header and submit it as a candidate chain tip if valid."
"\nThrows when the header is invalid.\n",
{
{"hexdata", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "the hex-encoded block header data"},
},
RPCResult{
RPCResult::Type::NONE, "", "None"},
RPCExamples{
HelpExampleCli("submitheader", "\"aabbcc\"") +
HelpExampleRpc("submitheader", "\"aabbcc\"")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
CBlockHeader h;
if (!DecodeHexBlockHeader(h, request.params[0].get_str())) {
throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block header decode failed");
}
{
LOCK(cs_main);
if (!LookupBlockIndex(h.hashPrevBlock)) {
throw JSONRPCError(RPC_VERIFY_ERROR, "Must submit previous header (" + h.hashPrevBlock.GetHex() + ") first");
}
}
BlockValidationState state;
EnsureChainman(request.context).ProcessNewBlockHeaders({h}, state, Params());
if (state.IsValid()) return NullUniValue;
if (state.IsError()) {
throw JSONRPCError(RPC_VERIFY_ERROR, state.ToString());
}
throw JSONRPCError(RPC_VERIFY_ERROR, state.GetRejectReason());
},
};
}
static RPCHelpMan estimatesmartfee()
{
return RPCHelpMan{"estimatesmartfee",
"\nEstimates the approximate fee per kilobyte needed for a transaction to begin\n"
"confirmation within conf_target blocks if possible and return the number of blocks\n"
"for which the estimate is valid. Uses virtual transaction size as defined\n"
"in BIP 141 (witness data is discounted).\n",
{
{"conf_target", RPCArg::Type::NUM, RPCArg::Optional::NO, "Confirmation target in blocks (1 - 1008)"},
{"estimate_mode", RPCArg::Type::STR, /* default */ "CONSERVATIVE", "The fee estimate mode.\n"
" Whether to return a more conservative estimate which also satisfies\n"
" a longer history. A conservative estimate potentially returns a\n"
" higher feerate and is more likely to be sufficient for the desired\n"
" target, but is not as responsive to short term drops in the\n"
" prevailing fee market. Must be one of:\n"
" \"UNSET\"\n"
" \"ECONOMICAL\"\n"
" \"CONSERVATIVE\""},
},
RPCResult{
RPCResult::Type::OBJ, "", "",
{
{RPCResult::Type::NUM, "feerate", /* optional */ true, "estimate fee rate in " + CURRENCY_UNIT + "/kB (only present if no errors were encountered)"},
{RPCResult::Type::ARR, "errors", /* optional */ true, "Errors encountered during processing (if there are any)",
{
{RPCResult::Type::STR, "", "error"},
}},
{RPCResult::Type::NUM, "blocks", "block number where estimate was found\n"
"The request target will be clamped between 2 and the highest target\n"
"fee estimation is able to return based on how long it has been running.\n"
"An error is returned if not enough transactions and blocks\n"
"have been observed to make an estimate for any number of blocks."},
}},
RPCExamples{
HelpExampleCli("estimatesmartfee", "6")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
RPCTypeCheck(request.params, {UniValue::VNUM, UniValue::VSTR});
RPCTypeCheckArgument(request.params[0], UniValue::VNUM);
unsigned int max_target = ::feeEstimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
unsigned int conf_target = ParseConfirmTarget(request.params[0], max_target);
bool conservative = true;
if (!request.params[1].isNull()) {
FeeEstimateMode fee_mode;
if (!FeeModeFromString(request.params[1].get_str(), fee_mode)) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid estimate_mode parameter");
}
if (fee_mode == FeeEstimateMode::ECONOMICAL) conservative = false;
}
UniValue result(UniValue::VOBJ);
UniValue errors(UniValue::VARR);
FeeCalculation feeCalc;
CFeeRate feeRate = ::feeEstimator.estimateSmartFee(conf_target, &feeCalc, conservative);
if (feeRate != CFeeRate(0)) {
result.pushKV("feerate", ValueFromAmount(feeRate.GetFeePerK()));
} else {
errors.push_back("Insufficient data or no feerate found");
result.pushKV("errors", errors);
}
result.pushKV("blocks", feeCalc.returnedTarget);
return result;
},
};
}
static RPCHelpMan estimaterawfee()
{
return RPCHelpMan{"estimaterawfee",
"\nWARNING: This interface is unstable and may disappear or change!\n"
"\nWARNING: This is an advanced API call that is tightly coupled to the specific\n"
" implementation of fee estimation. The parameters it can be called with\n"
" and the results it returns will change if the internal implementation changes.\n"
"\nEstimates the approximate fee per kilobyte needed for a transaction to begin\n"
"confirmation within conf_target blocks if possible. Uses virtual transaction size as\n"
"defined in BIP 141 (witness data is discounted).\n",
{
{"conf_target", RPCArg::Type::NUM, RPCArg::Optional::NO, "Confirmation target in blocks (1 - 1008)"},
{"threshold", RPCArg::Type::NUM, /* default */ "0.95", "The proportion of transactions in a given feerate range that must have been\n"
" confirmed within conf_target in order to consider those feerates as high enough and proceed to check\n"
" lower buckets."},
},
RPCResult{
RPCResult::Type::OBJ, "", "Results are returned for any horizon which tracks blocks up to the confirmation target",
{
{RPCResult::Type::OBJ, "short", /* optional */ true, "estimate for short time horizon",
{
{RPCResult::Type::NUM, "feerate", /* optional */ true, "estimate fee rate in " + CURRENCY_UNIT + "/kB"},
{RPCResult::Type::NUM, "decay", "exponential decay (per block) for historical moving average of confirmation data"},
{RPCResult::Type::NUM, "scale", "The resolution of confirmation targets at this time horizon"},
{RPCResult::Type::OBJ, "pass", /* optional */ true, "information about the lowest range of feerates to succeed in meeting the threshold",
{
{RPCResult::Type::NUM, "startrange", "start of feerate range"},
{RPCResult::Type::NUM, "endrange", "end of feerate range"},
{RPCResult::Type::NUM, "withintarget", "number of txs over history horizon in the feerate range that were confirmed within target"},
{RPCResult::Type::NUM, "totalconfirmed", "number of txs over history horizon in the feerate range that were confirmed at any point"},
{RPCResult::Type::NUM, "inmempool", "current number of txs in mempool in the feerate range unconfirmed for at least target blocks"},
{RPCResult::Type::NUM, "leftmempool", "number of txs over history horizon in the feerate range that left mempool unconfirmed after target"},
}},
{RPCResult::Type::OBJ, "fail", /* optional */ true, "information about the highest range of feerates to fail to meet the threshold",
{
{RPCResult::Type::ELISION, "", ""},
}},
{RPCResult::Type::ARR, "errors", /* optional */ true, "Errors encountered during processing (if there are any)",
{
{RPCResult::Type::STR, "error", ""},
}},
}},
{RPCResult::Type::OBJ, "medium", /* optional */ true, "estimate for medium time horizon",
{
{RPCResult::Type::ELISION, "", ""},
}},
{RPCResult::Type::OBJ, "long", /* optional */ true, "estimate for long time horizon",
{
{RPCResult::Type::ELISION, "", ""},
}},
}},
RPCExamples{
HelpExampleCli("estimaterawfee", "6 0.9")
},
[&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
RPCTypeCheck(request.params, {UniValue::VNUM, UniValue::VNUM}, true);
RPCTypeCheckArgument(request.params[0], UniValue::VNUM);
unsigned int max_target = ::feeEstimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
unsigned int conf_target = ParseConfirmTarget(request.params[0], max_target);
double threshold = 0.95;
if (!request.params[1].isNull()) {
threshold = request.params[1].get_real();
}
if (threshold < 0 || threshold > 1) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid threshold");
}
UniValue result(UniValue::VOBJ);
for (const FeeEstimateHorizon horizon : {FeeEstimateHorizon::SHORT_HALFLIFE, FeeEstimateHorizon::MED_HALFLIFE, FeeEstimateHorizon::LONG_HALFLIFE}) {
CFeeRate feeRate;
EstimationResult buckets;
// Only output results for horizons which track the target
if (conf_target > ::feeEstimator.HighestTargetTracked(horizon)) continue;
feeRate = ::feeEstimator.estimateRawFee(conf_target, threshold, horizon, &buckets);
UniValue horizon_result(UniValue::VOBJ);
UniValue errors(UniValue::VARR);
UniValue passbucket(UniValue::VOBJ);
passbucket.pushKV("startrange", round(buckets.pass.start));
passbucket.pushKV("endrange", round(buckets.pass.end));
passbucket.pushKV("withintarget", round(buckets.pass.withinTarget * 100.0) / 100.0);
passbucket.pushKV("totalconfirmed", round(buckets.pass.totalConfirmed * 100.0) / 100.0);
passbucket.pushKV("inmempool", round(buckets.pass.inMempool * 100.0) / 100.0);
passbucket.pushKV("leftmempool", round(buckets.pass.leftMempool * 100.0) / 100.0);
UniValue failbucket(UniValue::VOBJ);
failbucket.pushKV("startrange", round(buckets.fail.start));
failbucket.pushKV("endrange", round(buckets.fail.end));
failbucket.pushKV("withintarget", round(buckets.fail.withinTarget * 100.0) / 100.0);
failbucket.pushKV("totalconfirmed", round(buckets.fail.totalConfirmed * 100.0) / 100.0);
failbucket.pushKV("inmempool", round(buckets.fail.inMempool * 100.0) / 100.0);
failbucket.pushKV("leftmempool", round(buckets.fail.leftMempool * 100.0) / 100.0);
// CFeeRate(0) is used to indicate error as a return value from estimateRawFee
if (feeRate != CFeeRate(0)) {
horizon_result.pushKV("feerate", ValueFromAmount(feeRate.GetFeePerK()));
horizon_result.pushKV("decay", buckets.decay);
horizon_result.pushKV("scale", (int)buckets.scale);
horizon_result.pushKV("pass", passbucket);
// buckets.fail.start == -1 indicates that all buckets passed, there is no fail bucket to output
if (buckets.fail.start != -1) horizon_result.pushKV("fail", failbucket);
} else {
// Output only information that is still meaningful in the event of error
horizon_result.pushKV("decay", buckets.decay);
horizon_result.pushKV("scale", (int)buckets.scale);
horizon_result.pushKV("fail", failbucket);
errors.push_back("Insufficient data or no feerate found which meets threshold");
horizon_result.pushKV("errors",errors);
}
result.pushKV(StringForFeeEstimateHorizon(horizon), horizon_result);
}
return result;
},
};
}
void RegisterMiningRPCCommands(CRPCTable &t)
{
// clang-format off
static const CRPCCommand commands[] =
{ // category name actor (function) argNames
// --------------------- ------------------------ ----------------------- ----------
{ "mining", "getnetworkhashps", &getnetworkhashps, {"nblocks","height"} },
{ "mining", "getmininginfo", &getmininginfo, {} },
{ "mining", "prioritisetransaction", &prioritisetransaction, {"txid","dummy","fee_delta"} },
{ "mining", "getblocktemplate", &getblocktemplate, {"template_request"} },
{ "mining", "submitblock", &submitblock, {"hexdata","dummy"} },
{ "mining", "submitheader", &submitheader, {"hexdata"} },
{ "generating", "generatetoaddress", &generatetoaddress, {"nblocks","address","maxtries"} },
{ "generating", "generatetodescriptor", &generatetodescriptor, {"num_blocks","descriptor","maxtries"} },
{ "generating", "generateblock", &generateblock, {"output","transactions"} },
{ "util", "estimatesmartfee", &estimatesmartfee, {"conf_target", "estimate_mode"} },
{ "hidden", "estimaterawfee", &estimaterawfee, {"conf_target", "threshold"} },
{ "hidden", "generate", &generate, {} },
};
// clang-format on
for (const auto& c : commands) {
t.appendCommand(c.name, &c);
}
}
pow作業量證明流程:
在位元幣系統中，PoW演算法的程序可理解為不斷調整Nonce值，調整Nonce值就是對區塊頭做雙重SHA-256哈希運算，使得結果滿足給定數量前導0的哈希值的程序，其中前導0的個數，取決于挖礦難度，前導0的個數越多，挖礦難度越大，
具體的處理邏輯如下，
1）生成鑄幣交易，然后與其他所有準備打包進區塊的交易一起組成交易串列，隨后基于交易串列中的資料生成 Merkle樹，并計算Merkle樹根節點的哈希值，
2）將Merkle樹根節點的哈希值與其他欄位（如區塊高度、時間戳等)組成區塊頭，將80位元組長度的區塊頭作為PoW演算法的輸入，
3）不斷變更區塊頭中的亂數Nonce，對變更后的區塊頭做雙重SHA-256哈希運算，將得到的結果與當前難度的目標值做比對，如果小于目標難度，即PoW演算法完成，
在一定時間段內率先完成PoW演算法的區塊向全網廣播，其他節點驗證其是否符合規則，如果驗證有效，其他節點將接收此區塊，并附加在已有區塊鏈之后，隨后開啟下一輪挖礦，
目前位元幣系統已經吸引了全球大部分的算力，其他在基于PoW共識機制的區塊鏈公鏈應用很難獲得相同的算力來保障期自身的安全，此外，共識達成的周期較長,挖礦造成大量的電力和計算資源的浪費使其不適合商業應用，
參考：https://www.jianshu.com/p/1026fb3c566f
總結
POW的優點是：演算法簡單，采用大家認可的數學邏輯（找尋亂數），容易實作，安全系數最高，破壞整個系統，需要投入巨大成本，
POW的缺點是：大部分耗費大量電力，處理效率低（每秒只能處理7筆交易），以及算力集中問題，51%攻擊隱患，如果有人算力超過50%，那么就可能會發生51%攻擊，從而破壞/篡改區塊鏈網路，
轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/236648.html
標籤：區塊鏈
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