def get_target_from_timespans(self, bits, nActualTimespan, nTargetTimespan):
# convert to bignum
MM = 256*256*256
a = bits%MM
if a < 0x8000:
a *= 256
target = (a) * pow(2, 8 * (bits/MM - 3))
# new target
new_target = min( max_target, cdiv(target * nActualTimespan, nTargetTimespan) )
# convert it to bits
c = ("%064X"%new_target)[2:]
i = 31
while c[0:2]=="00":
c = c[2:]
i -= 1
c = int('0x'+c[0:6],16)
if c >= 0x800000:
c /= 256
i += 1
new_bits = c + MM * i
#print 'new target: ', hex(new_target)
return new_bits, new_target
def get_target_from_timespans(self, bits, nActualTimespan,
nTargetTimespan):
# convert to bignum
MM = 256 * 256 * 256
a = bits % MM
if a < 0x8000:
a *= 256
target = (a) * pow(2, 8 * (bits / MM - 3))
# new target
new_target = min(max_target,
cdiv(target * nActualTimespan, nTargetTimespan))
# convert it to bits
c = ("%064X" % new_target)[2:]
i = 31
while c[0:2] == "00":
c = c[2:]
i -= 1
c = int('0x' + c[0:6], 16)
if c >= 0x800000:
c /= 256
i += 1
new_bits = c + MM * i
#print 'new target: ', hex(new_target)
return new_bits, new_target
def get_target(self, height, chain=None):
if chain is None:
chain = [] # Do not use mutables as default values!
if height < 240: return 0x1e0ffff0, 0x00000FFFF0000000000000000000000000000000000000000000000000000000
nTargetTimespan = 4*60*60 #dogecoin: every 4 hours
nTargetTimespanNEW = 60 #dogecoin: every 1 minute
nTargetSpacing = 60 #dogecoin: 1 minute
nInterval = nTargetTimespan / nTargetSpacing #240
retargetTimespan = nTargetTimespan
retargetInterval = nInterval
if height > digishield_start:
retargetInterval = nTargetTimespanNEW / nTargetSpacing #1
retargetTimespan = nTargetTimespanNEW
blockstogoback = retargetInterval - 1
if (height != retargetInterval):
blockstogoback = retargetInterval
latest_retarget_height = (height / retargetInterval) * retargetInterval
#print 'latest_retarget_height', latest_retarget_height
last_height = latest_retarget_height - 1
first_height = last_height - blockstogoback
#print 'first height', first_height
#print 'last height', last_height
first = self.read_header(first_height)
last = self.read_header(last_height)
#print 'first'
#print first
#print 'last'
#print last
if first is None:
for h in chain:
if h.get('block_height') == first_height:
first = h
if last is None:
for h in chain:
if h.get('block_height') == last_height:
last = h
nActualTimespan = last.get('timestamp') - first.get('timestamp')
nModulatedTimespan = nActualTimespan
if height <= 5000:
nModulatedTimespan = max(nModulatedTimespan, cdiv(nTargetTimespan, 16))
nModulatedTimespan = min(nModulatedTimespan, nTargetTimespan*4)
elif height <= 10000:
nModulatedTimespan = max(nModulatedTimespan, cdiv(nTargetTimespan, 8))
nModulatedTimespan = min(nModulatedTimespan, nTargetTimespan*4)
elif height <= digishield_start:
nModulatedTimespan = max(nModulatedTimespan, cdiv(nTargetTimespan, 4))
nModulatedTimespan = min(nModulatedTimespan, nTargetTimespan*4)
# digishield
# https://github.com/dogecoin/dogecoin/blob/master/src/main.cpp#L1354
else:
nModulatedTimespan = retargetTimespan + cdiv(nModulatedTimespan - retargetTimespan, 8)
nModulatedTimespan = max(nModulatedTimespan, retargetTimespan - cdiv(retargetTimespan, 4))
nModulatedTimespan = min(nModulatedTimespan, retargetTimespan + cdiv(retargetTimespan, 2))
bits = last.get('bits')
#print 'before', hex(bits)
#print 'nActualTimespan', nActualTimespan
#print 'nTargetTimespan', nTargetTimespan
#print 'retargetTimespan', retargetTimespan
#print 'nModulatedTimespan', nModulatedTimespan
return self.get_target_from_timespans(bits, nModulatedTimespan, retargetTimespan)
def get_target(self, height, chain=None):
if chain is None:
chain = [] # Do not use mutables as default values!
if height < 240:
return 0x1e0ffff0, 0x00000FFFF0000000000000000000000000000000000000000000000000000000
nTargetTimespan = 4 * 60 * 60 #dogecoin: every 4 hours
nTargetTimespanNEW = 60 #dogecoin: every 1 minute
nTargetSpacing = 60 #dogecoin: 1 minute
nInterval = nTargetTimespan / nTargetSpacing #240
retargetTimespan = nTargetTimespan
retargetInterval = nInterval
if height > digishield_start:
retargetInterval = nTargetTimespanNEW / nTargetSpacing #1
retargetTimespan = nTargetTimespanNEW
blockstogoback = retargetInterval - 1
if (height != retargetInterval):
blockstogoback = retargetInterval
latest_retarget_height = (height / retargetInterval) * retargetInterval
#print 'latest_retarget_height', latest_retarget_height
last_height = latest_retarget_height - 1
first_height = last_height - blockstogoback
#print 'first height', first_height
#print 'last height', last_height
first = self.read_header(first_height)
last = self.read_header(last_height)
#print 'first'
#print first
#print 'last'
#print last
if first is None:
for h in chain:
if h.get('block_height') == first_height:
first = h
if last is None:
for h in chain:
if h.get('block_height') == last_height:
last = h
nActualTimespan = last.get('timestamp') - first.get('timestamp')
nModulatedTimespan = nActualTimespan
if height <= 5000:
nModulatedTimespan = max(nModulatedTimespan,
cdiv(nTargetTimespan, 16))
nModulatedTimespan = min(nModulatedTimespan, nTargetTimespan * 4)
elif height <= 10000:
nModulatedTimespan = max(nModulatedTimespan,
cdiv(nTargetTimespan, 8))
nModulatedTimespan = min(nModulatedTimespan, nTargetTimespan * 4)
elif height <= digishield_start:
nModulatedTimespan = max(nModulatedTimespan,
cdiv(nTargetTimespan, 4))
nModulatedTimespan = min(nModulatedTimespan, nTargetTimespan * 4)
# digishield
# https://github.com/dogecoin/dogecoin/blob/master/src/main.cpp#L1354
else:
nModulatedTimespan = retargetTimespan + cdiv(
nModulatedTimespan - retargetTimespan, 8)
nModulatedTimespan = max(
nModulatedTimespan,
retargetTimespan - cdiv(retargetTimespan, 4))
nModulatedTimespan = min(
nModulatedTimespan,
retargetTimespan + cdiv(retargetTimespan, 2))
bits = last.get('bits')
#print 'before', hex(bits)
#print 'nActualTimespan', nActualTimespan
#print 'nTargetTimespan', nTargetTimespan
#print 'retargetTimespan', retargetTimespan
#print 'nModulatedTimespan', nModulatedTimespan
return self.get_target_from_timespans(bits, nModulatedTimespan,
retargetTimespan)