ZCash ZEC information - Source

SUBMITTED BY: Hobbyistpool

DATE: Nov. 3, 2016, 5:22 p.m.

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  1. ZCASH Info
  3. https://www.worldcoinindex.com/coin/zcash
  4. https://www2.coinmine.pl/zec/index.php?page=dashboard
  5. https://github.com/zcash/zcash
  7. #include "chain.h"
  9. using namespace std;
  11. /**
  12. * CChain implementation
  13. */
  14. void CChain::SetTip(CBlockIndex *pindex) {
  15. if (pindex == NULL) {
  16. vChain.clear();
  17. return;
  18. }
  19. vChain.resize(pindex->nHeight + 1);
  20. while (pindex && vChain[pindex->nHeight] != pindex) {
  21. vChain[pindex->nHeight] = pindex;
  22. pindex = pindex->pprev;
  23. }
  24. }
  26. CBlockLocator CChain::GetLocator(const CBlockIndex *pindex) const {
  27. int nStep = 1;
  28. std::vector<uint256> vHave;
  29. vHave.reserve(32);
  31. if (!pindex)
  32. pindex = Tip();
  33. while (pindex) {
  34. vHave.push_back(pindex->GetBlockHash());
  35. // Stop when we have added the genesis block.
  36. if (pindex->nHeight == 0)
  37. break;
  38. // Exponentially larger steps back, plus the genesis block.
  39. int nHeight = std::max(pindex->nHeight - nStep, 0);
  40. if (Contains(pindex)) {
  41. // Use O(1) CChain index if possible.
  42. pindex = (*this)[nHeight];
  43. } else {
  44. // Otherwise, use O(log n) skiplist.
  45. pindex = pindex->GetAncestor(nHeight);
  46. }
  47. if (vHave.size() > 10)
  48. nStep *= 2;
  49. }
  51. return CBlockLocator(vHave);
  52. }
  54. const CBlockIndex *CChain::FindFork(const CBlockIndex *pindex) const {
  55. if (pindex->nHeight > Height())
  56. pindex = pindex->GetAncestor(Height());
  57. while (pindex && !Contains(pindex))
  58. pindex = pindex->pprev;
  59. return pindex;
  60. }
  62. /** Turn the lowest '1' bit in the binary representation of a number into a '0'. */
  63. int static inline InvertLowestOne(int n) { return n & (n - 1); }
  65. /** Compute what height to jump back to with the CBlockIndex::pskip pointer. */
  66. int static inline GetSkipHeight(int height) {
  67. if (height < 2)
  68. return 0;
  70. // Determine which height to jump back to. Any number strictly lower than height is acceptable,
  71. // but the following expression seems to perform well in simulations (max 110 steps to go back
  72. // up to 2**18 blocks).
  73. return (height & 1) ? InvertLowestOne(InvertLowestOne(height - 1)) + 1 : InvertLowestOne(height);
  74. }
  76. CBlockIndex* CBlockIndex::GetAncestor(int height)
  77. {
  78. if (height > nHeight || height < 0)
  79. return NULL;
  81. CBlockIndex* pindexWalk = this;
  82. int heightWalk = nHeight;
  83. while (heightWalk > height) {
  84. int heightSkip = GetSkipHeight(heightWalk);
  85. int heightSkipPrev = GetSkipHeight(heightWalk - 1);
  86. if (heightSkip == height ||
  87. (heightSkip > height && !(heightSkipPrev < heightSkip - 2 &&
  88. heightSkipPrev >= height))) {
  89. // Only follow pskip if pprev->pskip isn't better than pskip->pprev.
  90. pindexWalk = pindexWalk->pskip;
  91. heightWalk = heightSkip;
  92. } else {
  93. pindexWalk = pindexWalk->pprev;
  94. heightWalk--;
  95. }
  96. }
  97. return pindexWalk;
  98. }
  100. const CBlockIndex* CBlockIndex::GetAncestor(int height) const
  101. {
  102. return const_cast<CBlockIndex*>(this)->GetAncestor(height);
  103. }
  105. void CBlockIndex::BuildSkip()
  106. {
  107. if (pprev)
  108. pskip = pprev->GetAncestor(GetSkipHeight(nHeight));
  109. }
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