forked from LBRYCommunity/lbry-sdk
83 lines
3.2 KiB
Python
83 lines
3.2 KiB
Python
import struct
|
|
from typing import Optional
|
|
from binascii import hexlify, unhexlify
|
|
|
|
from torba.baseheader import BaseHeaders, ArithUint256
|
|
from torba.hash import sha512, double_sha256, ripemd160
|
|
|
|
|
|
class Headers(BaseHeaders):
|
|
|
|
header_size = 112
|
|
chunk_size = 10**16
|
|
|
|
max_target = 0x0000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
|
|
genesis_hash = b'9c89283ba0f3227f6c03b70216b9f665f0118d5e0fa729cedf4fb34d6a34f463'
|
|
target_timespan = 150
|
|
|
|
@property
|
|
def claim_trie_root(self):
|
|
return self[self.height]['claim_trie_root']
|
|
|
|
@staticmethod
|
|
def serialize(header):
|
|
return b''.join([
|
|
struct.pack('<I', header['version']),
|
|
unhexlify(header['prev_block_hash'])[::-1],
|
|
unhexlify(header['merkle_root'])[::-1],
|
|
unhexlify(header['claim_trie_root'])[::-1],
|
|
struct.pack('<III', header['timestamp'], header['bits'], header['nonce'])
|
|
])
|
|
|
|
@staticmethod
|
|
def deserialize(height, header):
|
|
version, = struct.unpack('<I', header[:4])
|
|
timestamp, bits, nonce = struct.unpack('<III', header[100:112])
|
|
return {
|
|
'version': version,
|
|
'prev_block_hash': hexlify(header[4:36][::-1]),
|
|
'merkle_root': hexlify(header[36:68][::-1]),
|
|
'claim_trie_root': hexlify(header[68:100][::-1]),
|
|
'timestamp': timestamp,
|
|
'bits': bits,
|
|
'nonce': nonce,
|
|
'block_height': height,
|
|
}
|
|
|
|
def get_next_block_target(self, max_target: ArithUint256, previous: Optional[dict],
|
|
current: Optional[dict]) -> ArithUint256:
|
|
# https://github.com/lbryio/lbrycrd/blob/master/src/lbry.cpp
|
|
if previous is None and current is None:
|
|
return max_target
|
|
if previous is None:
|
|
previous = current
|
|
actual_timespan = current['timestamp'] - previous['timestamp']
|
|
modulated_timespan = self.target_timespan + int((actual_timespan - self.target_timespan) / 8)
|
|
minimum_timespan = self.target_timespan - int(self.target_timespan / 8) # 150 - 18 = 132
|
|
maximum_timespan = self.target_timespan + int(self.target_timespan / 2) # 150 + 75 = 225
|
|
clamped_timespan = max(minimum_timespan, min(modulated_timespan, maximum_timespan))
|
|
target = ArithUint256.from_compact(current['bits'])
|
|
new_target = min(max_target, (target * clamped_timespan) / self.target_timespan)
|
|
return new_target
|
|
|
|
@classmethod
|
|
def get_proof_of_work(cls, header_hash: bytes):
|
|
return super().get_proof_of_work(
|
|
cls.header_hash_to_pow_hash(header_hash)
|
|
)
|
|
|
|
@staticmethod
|
|
def header_hash_to_pow_hash(header_hash: bytes):
|
|
header_hash_bytes = unhexlify(header_hash)[::-1]
|
|
h = sha512(header_hash_bytes)
|
|
pow_hash = double_sha256(
|
|
ripemd160(h[:len(h) // 2]) +
|
|
ripemd160(h[len(h) // 2:])
|
|
)
|
|
return hexlify(pow_hash[::-1])
|
|
|
|
|
|
class UnvalidatedHeaders(Headers):
|
|
validate_difficulty = False
|
|
max_target = 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
|
|
genesis_hash = b'6e3fcf1299d4ec5d79c3a4c91d624a4acf9e2e173d95a1a0504f677669687556'
|