From c6e929c756ddb121c73efc8daa5699f7d0ee60d2 Mon Sep 17 00:00:00 2001
From: myriadcoin <myriadcoin>
Date: Sun, 7 Dec 2014 11:00:08 +0200
Subject: [PATCH] Proposed change to add decay to block work

---
 src/main.h | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/main.h b/src/main.h
index 5d04d1a0..524bfb17 100644
--- a/src/main.h
+++ b/src/main.h
@@ -689,6 +689,7 @@ enum BlockStatus {
 
 const int64_t nBlockAlgoWorkWeightStart = 142000; // block where algo work weighting starts
 const int64_t nBlockAlgoNormalisedWorkStart = 740000; // block where algo combined weight starts
+const int64_t nBlockAlgoNormalisedWorkStart2 = 99990000; // block where algo combined weight starts with decay
 const int64_t nBlockSequentialAlgoRuleStart = 740000; // block where sequential algo rule starts
 const int64_t nBlockSequentialAlgoRuleStart2 = 766000; // block where sequential algo rule starts
 const int nBlockSequentialAlgoMaxCount = 6; // maximum sequential blocks of same algo
@@ -833,7 +834,6 @@ public:
 
     CBigNum GetPrevWorkForAlgo(int algo) const
     {
-        CBigNum nWork;
         CBlockIndex* pindex = this->pprev;
         while (pindex)
         {
@@ -846,6 +846,30 @@ public:
         return Params().ProofOfWorkLimit(algo);
     }
 
+    CBigNum GetPrevWorkForAlgoWithDecay(int algo) const
+    {
+        int nDistance = 0;
+        CBigNum nWork;
+        CBlockIndex* pindex = this->pprev;
+        while (pindex)
+        {
+            if (nDistance > 32)
+            {
+                return Params().ProofOfWorkLimit(algo);
+            }
+            if (pindex->GetAlgo() == algo)
+            {
+                CBigNum nWork = pindex->GetBlockWork();
+                nWork = nWork * (32 - nDistance);
+                nWork = nWork / 32;
+                return nWork;
+            }
+            pindex = pindex->pprev;
+            nDistance++;
+        }
+        return Params().ProofOfWorkLimit(algo);
+    }
+
     CBigNum GetBlockWork() const
     {
         CBigNum bnTarget;
@@ -897,7 +921,10 @@ public:
             {
                 if (algo != nAlgo)
                 {
-                    nBlockWork += GetPrevWorkForAlgo(algo);
+                    if (nHeight >= nBlockAlgoNormalisedWorkStart2)
+                        nBlockWork += GetPrevWorkForAlgoWithDecay(algo);
+                    else
+                        nBlockWork += GetPrevWorkForAlgo(algo);
                 }
             }
             bnRes = nBlockWork / NUM_ALGOS;