private static void darkGravityWave3Check(
StoredBlock prevBlock, Block added, BlockStore store, NetworkParameters params) {
StoredBlock blockReading = prevBlock;
long actualTimespan = 0;
long lastBlockTime = 0;
long pastBlocksMin = 24;
long pastBlocksMax = 24;
long countBlocks = 0;
BigInteger pastDifficultyAverage = BigInteger.ZERO;
BigInteger pastDifficultyAveragePrev = BigInteger.ZERO;
if (prevBlock == null || prevBlock.getHeight() == 0 || prevBlock.getHeight() < pastBlocksMin) {
verifyDifficulty(prevBlock, added, params.getMaxTarget(), params);
return;
}
for (int i = 1; blockReading.getHeight() > 0; i++) {
if (i > pastBlocksMax) {
break;
}
countBlocks++;
if (countBlocks <= pastBlocksMin) {
if (countBlocks == 1) {
pastDifficultyAverage = blockReading.getHeader().getDifficultyTargetAsInteger();
} else {
pastDifficultyAverage =
pastDifficultyAveragePrev
.multiply(BigInteger.valueOf(countBlocks))
.add(blockReading.getHeader().getDifficultyTargetAsInteger())
.divide(BigInteger.valueOf(countBlocks + 1));
}
pastDifficultyAveragePrev = pastDifficultyAverage;
}
if (lastBlockTime > 0) {
actualTimespan += (lastBlockTime - blockReading.getHeader().getTimeSeconds());
}
lastBlockTime = blockReading.getHeader().getTimeSeconds();
try {
blockReading = store.get(blockReading.getHeader().getPrevBlockHash());
if (blockReading == null) {
return;
}
} catch (BlockStoreException ex) {
log.warn("Dark gravity wave 3 descended to start of the chain");
return;
}
}
BigInteger bnNew = pastDifficultyAverage;
long targetTimespan =
countBlocks * params.getTargetSpacing(prevBlock.getHeader(), prevBlock.getHeight());
if (actualTimespan < targetTimespan / 3) {
actualTimespan = targetTimespan / 3;
}
if (actualTimespan > targetTimespan * 3) {
actualTimespan = targetTimespan * 3;
}
// Retarget
bnNew = bnNew.multiply(BigInteger.valueOf(actualTimespan));
bnNew = bnNew.divide(BigInteger.valueOf(targetTimespan));
verifyDifficulty(prevBlock, added, bnNew, params);
}
private static void darkGravityWaveCheck(
StoredBlock prevBlock, Block added, BlockStore store, NetworkParameters params) {
StoredBlock blockReading = prevBlock;
long blockTimeAverage = 0;
long blockTimeAveragePrev = 0;
long blockTimeCount = 0;
long blockTimeSum2 = 0;
long blockTimeCount2 = 0;
long lastBlockTime = 0;
long pastBlocksMin = 14;
long pastBlocksMax = 140;
long countBlocks = 0;
BigInteger pastDifficultyAverage = BigInteger.valueOf(0);
BigInteger pastDifficultyAveragePrev = BigInteger.valueOf(0);
if (prevBlock == null || prevBlock.getHeight() == 0 || prevBlock.getHeight() < pastBlocksMin) {
verifyDifficulty(prevBlock, added, params.getMaxTarget(), params);
return;
}
for (int i = 1; blockReading.getHeight() > 0; i++) {
if (i > pastBlocksMax) {
break;
}
countBlocks++;
if (countBlocks <= pastBlocksMin) {
if (countBlocks == 1) {
pastDifficultyAverage = blockReading.getHeader().getDifficultyTargetAsInteger();
} else {
pastDifficultyAverage =
blockReading
.getHeader()
.getDifficultyTargetAsInteger()
.subtract(pastDifficultyAveragePrev)
.divide(BigInteger.valueOf(countBlocks))
.add(pastDifficultyAveragePrev);
}
pastDifficultyAveragePrev = pastDifficultyAverage;
}
if (lastBlockTime > 0) {
long diff = lastBlockTime - blockReading.getHeader().getTimeSeconds();
if (blockTimeCount <= pastBlocksMin) {
blockTimeCount++;
if (blockTimeCount == 1) {
blockTimeAverage = diff;
} else {
blockTimeAverage =
(diff - blockTimeAveragePrev) / blockTimeCount + blockTimeAveragePrev;
}
blockTimeAveragePrev = blockTimeAverage;
}
blockTimeCount2++;
blockTimeSum2 += diff;
}
lastBlockTime = blockReading.getHeader().getTimeSeconds();
try {
blockReading = store.get(blockReading.getHeader().getPrevBlockHash());
if (blockReading == null) {
return;
}
} catch (BlockStoreException ex) {
log.warn("Dark gravity wave 3 descended to start of the chain");
return;
}
}
BigInteger bnNew = pastDifficultyAverage;
if (blockTimeCount != 0 && blockTimeCount2 != 0) {
double smartAverage =
((double) blockTimeAverage) * 0.7
+ ((double) blockTimeSum2 / (double) blockTimeCount2) * 0.3;
if (smartAverage < 1) smartAverage = 1;
final int targetSpacing =
params.getTargetSpacing(prevBlock.getHeader(), prevBlock.getHeight());
final double shift = targetSpacing / smartAverage;
final double dCountBlocks = (double) countBlocks;
double actualTimespan = dCountBlocks * ((double) targetSpacing) / shift;
double targetTimespan = dCountBlocks * targetSpacing;
if (actualTimespan < targetTimespan / 3) actualTimespan = targetTimespan / 3;
if (actualTimespan > targetTimespan * 3) actualTimespan = targetTimespan * 3;
// Retarget
bnNew = bnNew.multiply(BigInteger.valueOf((long) actualTimespan));
bnNew = bnNew.divide(BigInteger.valueOf((long) targetTimespan));
}
verifyDifficulty(prevBlock, added, bnNew, params);
}