src/chain.h

@@ -226,6 +226,11 @@ public:
         return *phashBlock;
     }
 
+    uint256 GetBlockPoWHash() const
+    {
+        return GetBlockHeader().GetPoWHash();
+    }
+
     int64_t GetBlockTime() const
     {
         return (int64_t)nTime;

src/chainparams.cpp

@@ -59,15 +59,15 @@ static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesi
     genesis.hashMerkleRoot = genesis.ComputeMerkleRoot();
     genesis.hashClaimTrie = uint256S("0x0000000000000000000000000000000000000000000000000000000000000001");
 
-    /*bool found = false;
-    while (!found)
+    /*while (true)
     {
         genesis.nNonce += 1;
-        if (CheckProofOfWork2(genesis.GetHash(), nBits, consensus))
+        if (CheckProofOfWork2(genesis.GetPoWHash(), nBits, consensus))
         {
             std::cout << "nonce: " << genesis.nNonce << std::endl;
             std::cout << "hex: " << genesis.GetHash().GetHex() << std::endl;
-            found = true;
+            std::cout << "pow hash: " << genesis.GetPoWHash().GetHex() << std::endl;
+            break;
         }
     }*/
     return genesis;

src/hash.cpp

@@ -13,6 +13,15 @@ inline uint32_t ROTL32(uint32_t x, int8_t r)
     return (x << r) | (x >> (32 - r));
 }
 
+uint256 PoWHash(const std::vector<unsigned char>& input)
+{
+    CHash256 h;
+    h.Write(input.data(), input.size());
+    uint256 result;
+    h.Finalize((unsigned char*)&result);
+    return result;
+}
+
 unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash)
 {
     // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp

src/hash.h

@@ -159,6 +159,8 @@ uint256 SerializeHash(const T& obj, int nType=SER_GETHASH, int nVersion=PROTOCOL
     return ss.GetHash();
 }
 
+uint256 PoWHash(const std::vector<unsigned char>& input);
+
 unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash);
 
 void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]);

src/main.cpp

@@ -1074,7 +1074,7 @@ bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos)
     }
 
     // Check the header
-    if (!CheckProofOfWork(block.GetHash(), block.nBits, Params().GetConsensus()))
+    if (!CheckProofOfWork(block.GetPoWHash(), block.nBits, Params().GetConsensus()))
         return error("ReadBlockFromDisk: Errors in block header at %s", pos.ToString());
 
     return true;
@@ -2849,7 +2849,7 @@ bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigne
 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW)
 {
     // Check proof of work matches claimed amount
-    if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, Params().GetConsensus()))
+    if (fCheckPOW && !CheckProofOfWork(block.GetPoWHash(), block.nBits, Params().GetConsensus()))
         return state.DoS(50, error("CheckBlockHeader(): proof of work failed"),
                          REJECT_INVALID, "high-hash");
 

src/miner.cpp

@@ -504,39 +504,6 @@ void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned
 // Internal miner
 //
 
-//
-// ScanHash scans nonces looking for a hash with at least some zero bits.
-// The nonce is usually preserved between calls, but periodically or if the
-// nonce is 0xffff0000 or above, the block is rebuilt and nNonce starts over at
-// zero.
-//
-bool static ScanHash(const CBlockHeader *pblock, uint32_t& nNonce, uint256 *phash)
-{
-    // Write the first 108 bytes of the block header to a double-SHA256 state.
-    CHash256 hasher;
-    CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
-    ss << *pblock;
-    assert(ss.size() == 112);
-    hasher.Write((unsigned char*)&ss[0], 108);
-
-    while (true) {
-        nNonce++;
-
-        // Write the last 4 bytes of the block header (the nonce) to a copy of
-        // the double-SHA256 state, and compute the result.
-        CHash256(hasher).Write((unsigned char*)&nNonce, 4).Finalize((unsigned char*)phash);
-
-        // Return the nonce if the hash has at least some zero bits,
-        // caller will check if it has enough to reach the target
-        if (((uint16_t*)phash)[15] == 0)
-            return true;
-
-        // If nothing found after trying for a while, return -1
-        if ((nNonce & 0xfff) == 0)
-            return false;
-    }
-}
-
 static bool ProcessBlockFound(const CBlock* pblock, const CChainParams& chainparams)
 {
     LogPrintf("%s\n", pblock->ToString());
@@ -618,17 +585,17 @@ void static BitcoinMiner(const CChainParams& chainparams)
             int64_t nStart = GetTime();
             arith_uint256 hashTarget = arith_uint256().SetCompact(pblock->nBits);
             uint256 hash;
-            uint32_t nNonce = 0;
+            pblock->nNonce = 0;
+            bool found = false;
             while (true) {
                 // Check if something found
-                if (ScanHash(pblock, nNonce, &hash))
+                while (true)
                 {
-                    if (UintToArith256(hash) <= hashTarget)
+                    hash = pblock->GetPoWHash();
+                    if (((uint16_t*)&hash)[15] == 0 && UintToArith256(hash) <= hashTarget)
                     {
+                        found = true;
                         // Found a solution
-                        pblock->nNonce = nNonce;
-                        assert(hash == pblock->GetHash());
-
                         SetThreadPriority(THREAD_PRIORITY_NORMAL);
                         LogPrintf("LBRYcrdMiner:\n");
                         LogPrintf("proof-of-work found  \n  hash: %s  \ntarget: %s\n", hash.GetHex(), hashTarget.GetHex());
@@ -642,14 +609,19 @@ void static BitcoinMiner(const CChainParams& chainparams)
 
                         break;
                     }
+                    pblock->nNonce += 1;
+                    if ((pblock->nNonce & 0xFF) == 0)
+                        break;
                 }
+                if (found)
+                    break;
 
                 // Check for stop or if block needs to be rebuilt
                 boost::this_thread::interruption_point();
                 // Regtest mode doesn't require peers
                 if (vNodes.empty() && chainparams.MiningRequiresPeers())
                     break;
-                if (nNonce >= 0xffff0000)
+                if (pblock->nNonce >= 0xffff0000)
                     break;
                 if (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLast && GetTime() - nStart > 60)
                     break;

src/primitives/block.cpp

@@ -9,12 +9,21 @@
 #include "tinyformat.h"
 #include "utilstrencodings.h"
 #include "crypto/common.h"
+#include "streams.h"
 
 uint256 CBlockHeader::GetHash() const
 {
     return SerializeHash(*this);
 }
 
+uint256 CBlockHeader::GetPoWHash() const
+{
+    CDataStream ds(SER_GETHASH, PROTOCOL_VERSION);
+    ds << *this;
+    std::vector<unsigned char> input(ds.begin(), ds.end());
+    return PoWHash(input);
+}
+
 uint256 CBlock::ComputeMerkleRoot(bool* fMutated) const
 {
     /* WARNING! If you're reading this because you're learning about crypto

src/primitives/block.h

@@ -67,6 +67,8 @@ public:
 
     uint256 GetHash() const;
 
+    uint256 GetPoWHash() const;
+
     int64_t GetBlockTime() const
     {
         return (int64_t)nTime;

src/rpcmining.cpp

@@ -165,7 +165,7 @@ UniValue generate(const UniValue& params, bool fHelp)
             LOCK(cs_main);
             IncrementExtraNonce(pblock, chainActive.Tip(), nExtraNonce);
         }
-        while (!CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
+        while (!CheckProofOfWork(pblock->GetPoWHash(), pblock->nBits, Params().GetConsensus())) {
             // Yes, there is a chance every nonce could fail to satisfy the -regtest
             // target -- 1 in 2^(2^32). That ain't gonna happen.
             ++pblock->nNonce;

src/test/claimtrie_tests.cpp

@@ -89,7 +89,7 @@ bool CreateBlock(CBlockTemplate* pblocktemplate)
     for (int i = 0; ; ++i)
     {
         pblock->nNonce = i;
-        if (CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus()))
+        if (CheckProofOfWork(pblock->GetPoWHash(), pblock->nBits, Params().GetConsensus()))
         {
             break;
         }

src/test/miner_tests.cpp

@@ -143,7 +143,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
         for (int j = 0; !fFound; j++)
         {
             pblock->nNonce = j;
-            if (CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus()))
+            if (CheckProofOfWork(pblock->GetPoWHash(), pblock->nBits, Params().GetConsensus()))
             {
                 fFound = true;
                 std::cout << pblock->nNonce << ",";

src/test/test_bitcoin.cpp

@@ -126,7 +126,7 @@ TestChain100Setup::CreateAndProcessBlock(const std::vector<CMutableTransaction>&
     unsigned int extraNonce = 0;
     IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
 
-    while (!CheckProofOfWork(block.GetHash(), block.nBits, Params(CBaseChainParams::REGTEST).GetConsensus())) ++block.nNonce;
+    while (!CheckProofOfWork(block.GetPoWHash(), block.nBits, Params(CBaseChainParams::REGTEST).GetConsensus())) ++block.nNonce;
 
     CValidationState state;
     ProcessNewBlock(state, NULL, &block, true, NULL);

src/txdb.cpp

@@ -204,7 +204,7 @@ bool CBlockTreeDB::LoadBlockIndexGuts()
                 pindexNew->nStatus        = diskindex.nStatus;
                 pindexNew->nTx            = diskindex.nTx;
 
-                if (!CheckProofOfWork(pindexNew->GetBlockHash(), pindexNew->nBits, Params().GetConsensus()))
+                if (!CheckProofOfWork(pindexNew->GetBlockPoWHash(), pindexNew->nBits, Params().GetConsensus()))
                     return error("LoadBlockIndex(): CheckProofOfWork failed: %s", pindexNew->ToString());
 
                 pcursor->Next();