From c2c02f3fa99385f5a5be722fda6f71522c93bdaa Mon Sep 17 00:00:00 2001
From: jtimon <jtimon@monetize.io>
Date: Sat, 28 Jun 2014 14:03:06 +0200
Subject: Move UpdateTime to pow

---
 src/pow.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'src/pow.cpp')

diff --git a/src/pow.cpp b/src/pow.cpp
index c0d0a7ca2..a99c582d7 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -8,6 +8,7 @@
 #include "chainparams.h"
 #include "core.h"
 #include "main.h"
+#include "timedata.h"
 #include "uint256.h"
 
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock)
@@ -117,3 +118,12 @@ unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime)
         bnResult = bnLimit;
     return bnResult.GetCompact();
 }
+
+void UpdateTime(CBlockHeader* pblock, const CBlockIndex* pindexPrev)
+{
+    pblock->nTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+
+    // Updating time can change work required on testnet:
+    if (Params().AllowMinDifficultyBlocks())
+        pblock->nBits = GetNextWorkRequired(pindexPrev, pblock);
+}
-- 
cgit v1.2.3


From b343c1a1e34f851e70649ad1f49855a7d878f9ef Mon Sep 17 00:00:00 2001
From: jtimon <jtimon@monetize.io>
Date: Sat, 5 Jul 2014 12:05:33 +0200
Subject: Move CBlockIndex::GetBlockWork() to pow::GetProofIncrement(nBits)

---
 src/pow.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'src/pow.cpp')

diff --git a/src/pow.cpp b/src/pow.cpp
index a99c582d7..d76928bda 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -127,3 +127,18 @@ void UpdateTime(CBlockHeader* pblock, const CBlockIndex* pindexPrev)
     if (Params().AllowMinDifficultyBlocks())
         pblock->nBits = GetNextWorkRequired(pindexPrev, pblock);
 }
+
+uint256 GetProofIncrement(unsigned int nBits)
+{
+    uint256 bnTarget;
+    bool fNegative;
+    bool fOverflow;
+    bnTarget.SetCompact(nBits, &fNegative, &fOverflow);
+    if (fNegative || fOverflow || bnTarget == 0)
+        return 0;
+    // We need to compute 2**256 / (bnTarget+1), but we can't represent 2**256
+    // as it's too large for a uint256. However, as 2**256 is at least as large
+    // as bnTarget+1, it is equal to ((2**256 - bnTarget - 1) / (bnTarget+1)) + 1,
+    // or ~bnTarget / (nTarget+1) + 1.
+    return (~bnTarget / (bnTarget + 1)) + 1;
+}
-- 
cgit v1.2.3


From 654871d43677947d124673c9e0dd2984f0d3ca61 Mon Sep 17 00:00:00 2001
From: jtimon <jtimon@monetize.io>
Date: Fri, 20 Jun 2014 20:55:42 +0200
Subject: replace ComputeMinWork with CheckMinWork

---
 src/pow.cpp | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

(limited to 'src/pow.cpp')

diff --git a/src/pow.cpp b/src/pow.cpp
index d76928bda..1d2b743b4 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -94,29 +94,36 @@ bool CheckProofOfWork(uint256 hash, unsigned int nBits)
 }
 
 //
-// minimum amount of work that could possibly be required nTime after
-// minimum work required was nBase
+// true if nBits is greater than the minimum amount of work that could
+// possibly be required deltaTime after minimum work required was nBase
 //
-unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime)
+bool CheckMinWork(unsigned int nBits, unsigned int nBase, int64_t deltaTime)
 {
+    bool fOverflow = false;
+    uint256 bnNewBlock;
+    bnNewBlock.SetCompact(nBits, NULL, &fOverflow);
+    if (fOverflow)
+        return false;
+
     const uint256 &bnLimit = Params().ProofOfWorkLimit();
     // Testnet has min-difficulty blocks
     // after Params().TargetSpacing()*2 time between blocks:
-    if (Params().AllowMinDifficultyBlocks() && nTime > Params().TargetSpacing()*2)
-        return bnLimit.GetCompact();
+    if (Params().AllowMinDifficultyBlocks() && deltaTime > Params().TargetSpacing()*2)
+        return bnNewBlock <= bnLimit;
 
     uint256 bnResult;
     bnResult.SetCompact(nBase);
-    while (nTime > 0 && bnResult < bnLimit)
+    while (deltaTime > 0 && bnResult < bnLimit)
     {
         // Maximum 400% adjustment...
         bnResult *= 4;
         // ... in best-case exactly 4-times-normal target time
-        nTime -= Params().TargetTimespan()*4;
+        deltaTime -= Params().TargetTimespan()*4;
     }
     if (bnResult > bnLimit)
         bnResult = bnLimit;
-    return bnResult.GetCompact();
+
+    return bnNewBlock <= bnResult;
 }
 
 void UpdateTime(CBlockHeader* pblock, const CBlockIndex* pindexPrev)
-- 
cgit v1.2.3