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#!/usr/bin/env python3
# Copyright 2020 Red Hat, Inc
# All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""This is a helper tool to test Glance's stream-based format inspection."""
# Example usage:
# -f qcow2 -v -i ~/cirros-0.5.1-x86_64-disk.img
import argparse
import logging
import sys
from oslo_utils import units
from glance.common import format_inspector
from glance.tests.unit.common import test_format_inspector
def main():
formats = ['raw', 'qcow2', 'vhd', 'vhdx', 'vmdk', 'vdi']
parser = argparse.ArgumentParser()
parser.add_argument('-d', '--debug', action='store_true')
parser.add_argument('-f', '--format', default='raw',
help='Format (%s)' % ','.join(sorted(formats)))
parser.add_argument('-b', '--block-size', default=65536, type=int,
help='Block read size')
parser.add_argument('--context-limit', default=(1 * 1024), type=int,
help='Maximum memory footprint (KiB)')
parser.add_argument('-i', '--input', default=None,
help='Input file. Defaults to stdin')
parser.add_argument('-v', '--verify', action='store_true',
help=('Verify our number with qemu-img '
'(requires --input)'))
args = parser.parse_args()
if args.debug:
fmt = format_inspector.get_inspector(args.format)(tracing=args.debug)
if args.input:
input_stream = open(args.input, 'rb')
input_stream = sys.stdin.buffer
stream = format_inspector.InfoWrapper(input_stream, fmt)
count = 0
found_size = False
while True:
chunk =
# This could stream to an output destination or stdin for testing
# sys.stdout.write(chunk)
if not chunk:
count += len(chunk)
if args.format != 'raw' and not found_size and fmt.virtual_size != 0:
# Print the point at which we've seen enough of the file to
# know what the virtual size is. This is almost always less
# than the raw_size
print('Determined virtual size at byte %i' % count)
found_size = True
if fmt.format_match:
print('Source was %s file, virtual size %i MiB (%i bytes)' % (
fmt, fmt.virtual_size / units.Mi, fmt.virtual_size))
print('*** Format inspector did not detect file as %s' % args.format)
print('Raw size %i MiB (%i bytes)' % (fmt.actual_size / units.Mi,
print('Required contexts: %s' % str(fmt.context_info))
mem_total = sum(fmt.context_info.values())
print('Total memory footprint: %i bytes' % mem_total)
# To make sure we're not storing the whole image, complain if the
# format inspector stored more than context_limit data
if mem_total > args.context_limit * 1024:
print('*** ERROR: Memory footprint exceeded!')
if args.verify and args.input:
size = test_format_inspector.get_size_from_qemu_img(args.input)
if size != fmt.virtual_size:
print('*** QEMU disagrees with our size of %i: %i' % (
fmt.virtual_size, size))
print('Confirmed size with qemu-img')
if __name__ == '__main__':