X-Git-Url: https://code.grnet.gr/git/snf-image-creator/blobdiff_plain/42ace959b13633144426e80ccf4a8e991e5206a8..03eb7dc84276e1b6504fbe4c91d30eac11359a3b:/image_creator/util.py diff --git a/image_creator/util.py b/image_creator/util.py index efccabb..61a97e9 100644 --- a/image_creator/util.py +++ b/image_creator/util.py @@ -31,103 +31,82 @@ # interpreted as representing official policies, either expressed # or implied, of GRNET S.A. -import sys -import pbs +import sh import hashlib -from colors import red, green, yellow -from progress.bar import Bar +import time +import os class FatalError(Exception): + """Fatal Error exception of snf-image-creator""" pass -silent = False - - def get_command(command): + """Return a file system binary command""" def find_sbin_command(command, exception): search_paths = ['/usr/local/sbin', '/usr/sbin', '/sbin'] for fullpath in map(lambda x: "%s/%s" % (x, command), search_paths): if os.path.exists(fullpath) and os.access(fullpath, os.X_OK): - return pbs.Command(fullpath) + return sh.Command(fullpath) raise exception try: - return pbs.__getattr__(command) - except pbs.CommadNotFount as e: + return sh.__getattr__(command) + except sh.CommandNotFound as e: return find_sbin_command(command, e) -def error(msg, new_line=True): - nl = "\n" if new_line else '' - sys.stderr.write(red('Error: %s' % msg) + nl) - - -def warn(msg, new_line=True): - if not silent: - nl = "\n" if new_line else '' - sys.stderr.write(yellow("Warning: %s" % msg) + nl) - - -def success(msg, new_line=True): - if not silent: - nl = "\n" if new_line else '' - sys.stdout.write(green(msg) + nl) - if not nl: - sys.stdout.flush() - - -def output(msg="", new_line=True): - if not silent: - nl = "\n" if new_line else '' - sys.stdout.write(msg + nl) - if not nl: - sys.stdout.flush() - - -def progress(message='', bar_type="default"): - - MESSAGE_LENGTH = 30 - - suffix = { - 'default': '%(index)d/%(max)d', - 'percent': '%(percent)d%%', - 'b': '%(index)d/%(max)d B', - 'kb': '%(index)d/%(max)d KB', - 'mb': '%(index)d/%(max)d MB' - } - - bar = Bar() - bar.message = message.ljust(MESSAGE_LENGTH) - bar.fill = '#' - bar.suffix = suffix[bar_type] - bar.bar_prefix = ' [' - bar.bar_suffix = '] ' - - return bar - - -def md5(filename, size): - - BLOCKSIZE = 2 ** 22 # 4MB - - progressbar = progress("Calculating md5sum:", 'mb') - progressbar.max = (size // (2 ** 20)) - md5 = hashlib.md5() - with open(filename, "r") as src: - left = size - while left > 0: - length = min(left, BLOCKSIZE) - data = src.read(length) - md5.update(data) - left -= length - progressbar.goto((size - left) // (2 ** 20)) - - checksum = md5.hexdigest() - output("\rCalculating md5sum...\033[K", False) - success(checksum) - - return checksum +def try_fail_repeat(command, *args): + """Execute a command multiple times until it succeeds""" + times = (0.1, 0.5, 1, 2) + i = iter(times) + while True: + try: + command(*args) + return + except sh.ErrorReturnCode: + try: + wait = i.next() + except StopIteration: + break + time.sleep(wait) + + raise FatalError("Command: `%s %s' failed" % (command, " ".join(args))) + + +def free_space(dirname): + """Compute the free space in a directory""" + stat = os.statvfs(dirname) + return stat.f_bavail * stat.f_frsize + + +class MD5: + """Represents MD5 computations""" + def __init__(self, output): + """Create an MD5 instance""" + self.out = output + + def compute(self, filename, size): + """Compute the MD5 checksum of a file""" + MB = 2 ** 20 + BLOCKSIZE = 4 * MB # 4MB + + prog_size = ((size + MB - 1) // MB) # in MB + progressbar = self.out.Progress(prog_size, "Calculating md5sum", 'mb') + md5 = hashlib.md5() + with open(filename, "r") as src: + left = size + while left > 0: + length = min(left, BLOCKSIZE) + data = src.read(length) + md5.update(data) + left -= length + progressbar.goto((size - left) // MB) + + checksum = md5.hexdigest() + progressbar.success(checksum) + + return checksum # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :