From e86756193ebdbf71504e2a1a8db43e38d57f9673 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jorge=20Tim=C3=B3n?= <jtimon@jtimon.cc>
Date: Mon, 30 Nov 2015 00:46:49 +0100
Subject: [PATCH] MOVEONLY: non-consensus: from pow to chain:

- GetBlockProof
- GetBlockProofEquivalentTime
---
 src/chain.cpp | 32 ++++++++++++++++++++++++++++++++
 src/chain.h   |  4 ++++
 src/pow.cpp   | 32 --------------------------------
 src/pow.h     |  5 -----
 4 files changed, 36 insertions(+), 37 deletions(-)

diff --git a/src/chain.cpp b/src/chain.cpp
index 3450ed6c3f3..32f6480f849 100644
--- a/src/chain.cpp
+++ b/src/chain.cpp
@@ -110,3 +110,35 @@ void CBlockIndex::BuildSkip()
     if (pprev)
         pskip = pprev->GetAncestor(GetSkipHeight(nHeight));
 }
+
+arith_uint256 GetBlockProof(const CBlockIndex& block)
+{
+    arith_uint256 bnTarget;
+    bool fNegative;
+    bool fOverflow;
+    bnTarget.SetCompact(block.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 arith_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;
+}
+
+int64_t GetBlockProofEquivalentTime(const CBlockIndex& to, const CBlockIndex& from, const CBlockIndex& tip, const Consensus::Params& params)
+{
+    arith_uint256 r;
+    int sign = 1;
+    if (to.nChainWork > from.nChainWork) {
+        r = to.nChainWork - from.nChainWork;
+    } else {
+        r = from.nChainWork - to.nChainWork;
+        sign = -1;
+    }
+    r = r * arith_uint256(params.nPowTargetSpacing) / GetBlockProof(tip);
+    if (r.bits() > 63) {
+        return sign * std::numeric_limits<int64_t>::max();
+    }
+    return sign * r.GetLow64();
+}
diff --git a/src/chain.h b/src/chain.h
index 01be2d6e5c9..0c152a5ea91 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -282,6 +282,10 @@ public:
     const CBlockIndex* GetAncestor(int height) const;
 };
 
+arith_uint256 GetBlockProof(const CBlockIndex& block);
+/** Return the time it would take to redo the work difference between from and to, assuming the current hashrate corresponds to the difficulty at tip, in seconds. */
+int64_t GetBlockProofEquivalentTime(const CBlockIndex& to, const CBlockIndex& from, const CBlockIndex& tip, const Consensus::Params&);
+
 /** Used to marshal pointers into hashes for db storage. */
 class CDiskBlockIndex : public CBlockIndex
 {
diff --git a/src/pow.cpp b/src/pow.cpp
index 5ace3fbc9b5..dc58e21e122 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -102,35 +102,3 @@ bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params&
 
     return true;
 }
-
-arith_uint256 GetBlockProof(const CBlockIndex& block)
-{
-    arith_uint256 bnTarget;
-    bool fNegative;
-    bool fOverflow;
-    bnTarget.SetCompact(block.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 arith_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;
-}
-
-int64_t GetBlockProofEquivalentTime(const CBlockIndex& to, const CBlockIndex& from, const CBlockIndex& tip, const Consensus::Params& params)
-{
-    arith_uint256 r;
-    int sign = 1;
-    if (to.nChainWork > from.nChainWork) {
-        r = to.nChainWork - from.nChainWork;
-    } else {
-        r = from.nChainWork - to.nChainWork;
-        sign = -1;
-    }
-    r = r * arith_uint256(params.nPowTargetSpacing) / GetBlockProof(tip);
-    if (r.bits() > 63) {
-        return sign * std::numeric_limits<int64_t>::max();
-    }
-    return sign * r.GetLow64();
-}
diff --git a/src/pow.h b/src/pow.h
index e864a474ccd..a80a3351758 100644
--- a/src/pow.h
+++ b/src/pow.h
@@ -13,16 +13,11 @@
 class CBlockHeader;
 class CBlockIndex;
 class uint256;
-class arith_uint256;
 
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params&);
 unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params&);
 
 /** Check whether a block hash satisfies the proof-of-work requirement specified by nBits */
 bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params&);
-arith_uint256 GetBlockProof(const CBlockIndex& block);
-
-/** Return the time it would take to redo the work difference between from and to, assuming the current hashrate corresponds to the difficulty at tip, in seconds. */
-int64_t GetBlockProofEquivalentTime(const CBlockIndex& to, const CBlockIndex& from, const CBlockIndex& tip, const Consensus::Params&);
 
 #endif // BITCOIN_POW_H