lbry-sdk/torba/util.py
Lex Berezhny b0bd0b1fc0 + reserving outpoints should no longer have race conditions
+ converted all comment type annotations to python 3 style syntax annotations
+ pylint & mypy
2018-07-28 20:52:54 -04:00

63 lines
1.2 KiB
Python

from binascii import unhexlify, hexlify
from typing import TypeVar, Sequence
T = TypeVar('T')
class ReadOnlyList(Sequence[T]):
def __init__(self, lst):
self.lst = lst
def __getitem__(self, key):
return self.lst[key]
def __len__(self) -> int:
return len(self.lst)
def subclass_tuple(name, base):
return type(name, (base,), {'__slots__': ()})
class cachedproperty:
def __init__(self, f):
self.f = f
def __get__(self, obj, objtype):
obj = obj or objtype
value = self.f(obj)
setattr(obj, self.f.__name__, value)
return value
def bytes_to_int(be_bytes):
""" Interprets a big-endian sequence of bytes as an integer. """
return int(hexlify(be_bytes), 16)
def int_to_bytes(value):
""" Converts an integer to a big-endian sequence of bytes. """
length = (value.bit_length() + 7) // 8
s = '%x' % value
return unhexlify(('0' * (len(s) % 2) + s).zfill(length * 2))
def rev_hex(s):
return hexlify(unhexlify(s)[::-1])
def int_to_hex(i, length=1):
s = hex(i)[2:].rstrip('L')
s = "0" * (2 * length - len(s)) + s
return rev_hex(s)
def hex_to_int(x):
return int(b'0x' + hexlify(x[::-1]), 16)
def hash_encode(x):
return hexlify(x[::-1])