firmware/shared/utils.py
Peter D. Gray f2bee804cd
Whitespace
2019-05-31 14:44:31 -04:00

136 lines
3.5 KiB
Python

# (c) Copyright 2018 by Coinkite Inc. This file is part of Coldcard <coldcardwallet.com>
# and is covered by GPLv3 license found in COPYING.
#
# utils.py - Misc utils. My favourite kind of source file.
#
import gc, sys
class imported:
# Context manager that temporarily imports
# a list of modules.
# LATER: doubtful this saves any memory when all the code is frozen.
def __init__(self, *modules):
self.modules = modules
def __enter__(self):
# import everything required
rv = tuple(__import__(n) for n in self.modules)
return rv[0] if len(self.modules) == 1 else rv
def __exit__(self, exc_type, exc_value, traceback):
for n in self.modules:
if n in sys.modules:
del sys.modules[n]
# recovery that tasty memory.
gc.collect()
# class min_dramatic_pause:
# # insure that something takes at least N ms
# def __init__(self, min_time):
# import utime
#
# self.min_time = min_time
# self.start_time = utime.ticks_ms()
#
# def __enter__(self):
# pass
#
# def __exit__(self, exc_type, exc_value, traceback):
# import utime
#
# if exc_type is not None: return
#
# actual = utime.ticks_ms() - self.start_time
# if actual < self.min_time:
# utime.sleep_ms(self.min_time - actual)
#
def pretty_delay(n):
# decode # of seconds into various ranges, need not be precise.
if n < 120:
return '%d seconds' % n
n /= 60
if n < 60:
return '%d minutes' % n
n /= 60
if n < 48:
return '%.1f hours' % n
n /= 24
return 'about %d days' % n
def pop_count(i):
# 32-bit population count for integers
# from <https://stackoverflow.com/questions/9829578>
i = i - ((i >> 1) & 0x55555555)
i = (i & 0x33333333) + ((i >> 2) & 0x33333333)
return (((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) & 0xffffffff) >> 24
def get_filesize(fn):
# like os.path.getsize()
import uos
return uos.stat(fn)[6]
class HexWriter:
# Emulate a file/stream but convert binary to hex as they write
def __init__(self, fd):
self.fd = fd
def __enter__(self):
self.fd.__enter__()
return self
def __exit__(self, *a, **k):
self.fd.write('\r\n')
return self.fd.__exit__(*a, **k)
def write(self, b):
for ch in b:
self.fd.write('%02x' % ch)
def swab32(n):
# endian swap: 32 bits
import ustruct
return ustruct.unpack('>I', ustruct.pack('<I', n))[0]
def xfp2str(xfp):
# Standardized way to show an xpub's fingerprint... it's a 4-byte string
# and not really an integer. Used to show as '0x%08x' but that's wrong endian.
import ustruct
from ubinascii import hexlify as b2a_hex
return b2a_hex(ustruct.pack('>I', xfp)).decode().upper()
def problem_file_line(exc):
# return a string of just the filename.py and line number where
# an exception occured. Best used on AssertionError.
import uio, sys, ure
tmp = uio.StringIO()
sys.print_exception(exc, tmp)
lines = tmp.getvalue().split('\n')[-3:]
del tmp
# convert:
# File "main.py", line 63, in interact
# into just:
# main.py:63
#
# on simulator, huge path is included, remove that too
rv = None
for ln in lines:
mat = ure.match(r'.*"(/.*/)(.*)", line (.*), ', ln)
if mat:
try:
rv = mat.group(2) + ':' + mat.group(3)
except: pass
return rv or str(exc) or 'Exception'
# EOF