Merge pull request #59 from jc23424/diffbomb

Add ability to force a difficulty bomb

src/chainparams.cpp

@@ -50,6 +50,7 @@ public:
         consensus.nPowMaxAdjustUp = 16; // 16% adjustment up
         consensus.nPowTargetSpacing = 2.5 * 60;
         consensus.fPowAllowMinDifficultyBlocks = false;
+        consensus.nPowDifficultyBombHeight = 600000;
 
         pchMessageStart[0] = 0xa8;
         pchMessageStart[1] = 0xea;
@@ -209,6 +210,8 @@ public:
         consensus.powLimit = uint256S("07ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
         assert(maxUint/UintToArith256(consensus.powLimit) >= consensus.nPowAveragingWindow);
         consensus.fPowAllowMinDifficultyBlocks = true;
+        consensus.nPowDifficultyBombHeight = 600000;
+
         pchMessageStart[0] = 0xf6;
         pchMessageStart[1] = 0x1b;
         pchMessageStart[2] = 0xf6;
@@ -300,6 +303,8 @@ public:
         assert(maxUint/UintToArith256(consensus.powLimit) >= consensus.nPowAveragingWindow);
         consensus.nPowMaxAdjustDown = 0; // Turn off adjustment down
         consensus.nPowMaxAdjustUp = 0; // Turn off adjustment up
+        consensus.nPowDifficultyBombHeight = 600000;
+
         pchMessageStart[0] = 0xaa;
         pchMessageStart[1] = 0xe8;
         pchMessageStart[2] = 0x3f;

src/consensus/params.h

@@ -50,6 +50,8 @@ struct Params {
     int64_t AveragingWindowTimespan() const { return nPowAveragingWindow * nPowTargetSpacing; }
     int64_t MinActualTimespan() const { return (AveragingWindowTimespan() * (100 - nPowMaxAdjustUp  )) / 100; }
     int64_t MaxActualTimespan() const { return (AveragingWindowTimespan() * (100 + nPowMaxAdjustDown)) / 100; }
+
+    int nPowDifficultyBombHeight;
 };
 } // namespace Consensus
 

src/pow.cpp

@@ -9,6 +9,7 @@
 #include "chain.h"
 #include "chainparams.h"
 #include "crypto/equihash.h"
+#include "main.h"
 #include "primitives/block.h"
 #include "streams.h"
 #include "uint256.h"
@@ -23,11 +24,16 @@
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
 {
     unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
+    unsigned int nProofOfWorkBomb  = UintToArith256(uint256S("000000000000000000000000000000000000000000000000000000000000ffff")).GetCompact();
 
     // Genesis block
     if (pindexLast == NULL)
         return nProofOfWorkLimit;
 
+    // difficulty bomb
+    else if(pindexLast->nHeight > params.nPowDifficultyBombHeight)
+        return nProofOfWorkBomb;
+
     // Find the first block in the averaging interval
     const CBlockIndex* pindexFirst = pindexLast;
     arith_uint256 bnTot {0};