qemu/scripts/qcow2-to-stdout.py

125 def write_features(cluster, offset, data_file_name):  argument
129         struct.pack_into(f">II{padded_name_len}s", cluster, offset,
148     struct.pack_into(">I", cluster, offset, QCOW2_FEATURE_NAME_TABLE)
149     struct.pack_into(">I", cluster, offset + 4, len(qcow2_features) * 48)
152         struct.pack_into(">BB46s", cluster, offset,
172         sys.exit("[Error] The image size is too large. Try using a larger cluster size.")
194             cluster = os.pread(fd, cluster_size, cluster_size * idx)
195             # If the last cluster is smaller than cluster_size pad it with zeroes
196             if len(cluster) < cluster_size:
197                 cluster += bytes(cluster_size - len(cluster))
198             # If a cluster has non-zero data then it must be allocated
200             if cluster != zero_cluster:
267     cluster = bytearray(cluster_size)
268     struct.pack_into(">4sIQIIQIIQQIIQQQQII", cluster, 0,
289     write_features(cluster, hdr_length, data_file_name)
291     sys.stdout.buffer.write(cluster)
297         cluster = bytearray(cluster_size)
301             struct.pack_into(">Q", cluster, idx * 8, cur_offset)
303         sys.stdout.buffer.write(cluster)
306 … remaining_refcount_block_entries = total_allocated_clusters # One entry for each allocated cluster
308         cluster = bytearray(cluster_size)
315                 struct.pack_into(">Q", cluster, idx * 8, 1)
317                 struct.pack_into(">L", cluster, idx * 4, 1)
319                 struct.pack_into(">H", cluster, idx * 2, 1)
321                 cluster[idx] = 1
323                 cluster[idx // 2] |= 1 << ((idx % 2) * 4)
325                 cluster[idx // 4] |= 1 << ((idx % 4) * 2)
327                 cluster[idx // 8] |= 1 << (idx % 8)
328         sys.stdout.buffer.write(cluster)
333         cluster = bytearray(cluster_size)
337                 struct.pack_into(">Q", cluster, idx * 8, cur_offset | QCOW_OFLAG_COPIED)
339         sys.stdout.buffer.write(cluster)
347             cluster = bytearray(cluster_size)
352                         struct.pack_into(">Q", cluster, idx * 8, cur_offset | QCOW_OFLAG_COPIED)
355 …              struct.pack_into(">Q", cluster, idx * 8, (l2_idx * cluster_size) | QCOW_OFLAG_COPIED)
356             sys.stdout.buffer.write(cluster)
361             cluster = os.pread(fd, cluster_size, cluster_size * idx)
362             # If the last cluster is smaller than cluster_size pad it with zeroes
363             if len(cluster) < cluster_size:
364                 cluster += bytes(cluster_size - len(cluster))
365             sys.stdout.buffer.write(cluster)
389         help=f"qcow2 cluster size (default: {QCOW2_DEFAULT_CLUSTER_SIZE})",
428         sys.exit("[Error] External data files require a larger cluster size")