def test_one_cluster(self, qcow2_compat):
with namedTemporaryDir() as tmpdir:
# Write full clusters so we dont fail when qemu change the
# implemention of writing partial cluster.
offset = 64 * KiB
length = 64 * KiB
size = MiB
image = os.path.join(tmpdir, "base.img")
op = qemuimg.create(image, size=size, format=self.FORMAT,
qcow2Compat=qcow2_compat)
op.run()
qemuio.write_pattern(
image,
self.FORMAT,
offset=offset,
len=length,
pattern=0xf0)
expected = [
# run 1 - empty
{
"start": 0,
"length": length,
"data": False,
"zero": True,
},
# run 2 - data
{
"start": offset,
"length": length,
"data": True,
"zero": False,
},
# run 3 - empty
{
"start": offset + length,
"length": size - offset - length,
"data": False,
"zero": True,
},
]
self.check_map(qemuimg.map(image), expected)
def test_empty_image(self, qcow2_compat):
with namedTemporaryDir() as tmpdir:
size = 1048576
image = os.path.join(tmpdir, "base.img")
op = qemuimg.create(image, size=size, format=self.FORMAT,
qcow2Compat=qcow2_compat)
op.run()
expected = [
# single run - empty
{
"start": 0,
"length": size,
"data": False,
"zero": True,
},
]
self.check_map(qemuimg.map(image), expected)
def estimate_size(filename):
"""
Estimate the required size of a new qcow2 file converted from source image
filename. Source image can be raw, qcow2, or compressed qcow2, on any
storage type.
"""
info = qemuimg.info(filename)
if "backingfile" in info:
raise ValueError("Estimate size not supported for images with "
"a backing file")
# Get used clusters and virtual size of destination volume.
virtual_size = info['virtualsize']
meta_size = _estimate_metadata_size(virtual_size)
runs = qemuimg.map(filename)
used_clusters = count_clusters(runs)
# Return the estimated size.
return meta_size + used_clusters * CLUSTER_SIZE
def test_one_block(self, offset, length, expected_length, qcow2_compat):
with namedTemporaryDir() as tmpdir:
size = 1048576
image = os.path.join(tmpdir, "base.img")
op = qemuimg.create(image, size=size, format=self.FORMAT,
qcow2Compat=qcow2_compat)
op.run()
qemuio.write_pattern(
image,
self.FORMAT,
offset=offset,
len=length,
pattern=0xf0)
expected = [
# run 1 - empty
{
"start": 0,
"length": offset,
"data": False,
"zero": True,
},
# run 2 - data
{
"start": offset,
"length": expected_length,
"data": True,
"zero": False,
},
# run 3 - empty
{
"start": offset + expected_length,
"length": size - offset - expected_length,
"data": False,
"zero": True,
},
]
self.check_map(qemuimg.map(image), expected)
