Move CBlockIndex::GetBlockWork() to pow::GetProofIncrement(nBits)

pull/4377/head
jtimon 11 years ago
parent c2c02f3fa9
commit b343c1a1e3

@ -14,6 +14,7 @@
#include "coins.h" #include "coins.h"
#include "core.h" #include "core.h"
#include "net.h" #include "net.h"
#include "pow.h"
#include "script.h" #include "script.h"
#include "sync.h" #include "sync.h"
#include "txmempool.h" #include "txmempool.h"
@ -792,17 +793,7 @@ public:
uint256 GetBlockWork() const uint256 GetBlockWork() const
{ {
uint256 bnTarget; return GetProofIncrement(nBits);
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;
} }
enum { nMedianTimeSpan=11 }; enum { nMedianTimeSpan=11 };

@ -127,3 +127,18 @@ void UpdateTime(CBlockHeader* pblock, const CBlockIndex* pindexPrev)
if (Params().AllowMinDifficultyBlocks()) if (Params().AllowMinDifficultyBlocks())
pblock->nBits = GetNextWorkRequired(pindexPrev, pblock); 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;
}

@ -22,4 +22,6 @@ unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime);
void UpdateTime(CBlockHeader* block, const CBlockIndex* pindexPrev); void UpdateTime(CBlockHeader* block, const CBlockIndex* pindexPrev);
uint256 GetProofIncrement(unsigned int nBits);
#endif #endif

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