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comparison src/puppy/helpers.py @ 6:5f6d1a28051a

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add python package config files
author Dennis Concepcion Martin <dennisconcepcionmartin@gmail.com>
date Sun, 24 Oct 2021 15:18:54 +0200
parents src/helpers.py@1a8d94b500d8
children
comparison
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5:1a8d94b500d8 6:5f6d1a28051a
1 import hashlib
2
3
4 def __get_hash(buffer, bytes_order='backward'):
5 """
6 Compute hash from bytes
7 More info about bytes order: https://en.wikipedia.org/wiki/Endianness
8 :param buffer: bytes, required
9 :param bytes_order: string, 'backward' or 'forward', optional
10 :return: string
11 """
12
13 h = hashlib.sha256(buffer).digest()
14 h = hashlib.sha256(h).digest()
15
16 if bytes_order == 'backward':
17 h = h[::-1]
18
19 return h.hex()
20
21
22 def __get_variable_int(f):
23 """
24 Get variable int from transaction data
25 More info: https://learnmeabitcoin.com/technical/varint
26 :param f: buffer, required
27 :return: int
28 """
29
30 first_byte = f.read(1)
31
32 if first_byte == b'\xfd':
33 variable_int_bytes = f.read(2)[::-1]
34 elif first_byte == b'\xfe':
35 variable_int_bytes = f.read(4)[::-1]
36 elif first_byte == b'\xff':
37 variable_int_bytes = f.read(8)[::-1]
38 else:
39 variable_int_bytes = first_byte
40
41 return int.from_bytes(variable_int_bytes, 'little')