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#!/usr/bin/python3
"""
Copyright (C) 2023 Michael Ablassmeier <abi@grinser.de>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
import logging
import pprint
from argparse import Namespace
from libvirtnbdbackup import chunk
from libvirtnbdbackup import lz4
from libvirtnbdbackup import common as lib
from libvirtnbdbackup.sparsestream import types
from libvirtnbdbackup.sparsestream import streamer
from libvirtnbdbackup.sparsestream.exceptions import StreamFormatException
from libvirtnbdbackup.exceptions import RestoreError
from libvirtnbdbackup.exceptions import UntilCheckpointReached
def restore(
args: Namespace,
stream: streamer.SparseStream,
disk: str,
targetFile: str,
connection,
) -> bool:
"""Restore the data stream to the target file"""
diskState = False
diskState = _write(args, stream, disk, targetFile, connection)
# no data has been processed
if diskState is None:
diskState = True
return diskState
def _write( # pylint: disable=too-many-branches,too-many-locals,too-many-statements
args: Namespace,
stream: streamer.SparseStream,
dataFile: str,
targetFile: str,
connection,
) -> bool:
"""Restore data for disk"""
sTypes = types.SparseStreamTypes()
try:
# pylint: disable=consider-using-with
reader = open(dataFile, "rb")
except OSError as errmsg:
logging.error("Failed to open backup file for reading: [%s].", errmsg)
raise RestoreError from errmsg
try:
kind, start, length = stream.readFrame(reader)
meta = stream.loadMetadata(reader.read(length))
except StreamFormatException as errmsg:
logging.fatal(errmsg)
raise RestoreError from errmsg
trailer = None
if lib.isCompressed(meta) is True:
trailer = stream.readCompressionTrailer(reader)
logging.info("Found compression trailer.")
logging.debug("%s", trailer)
if meta["dataSize"] == 0:
logging.info("File [%s] contains no dirty blocks, skipping.", dataFile)
if meta["checkpointName"] == args.until:
logging.info("Reached checkpoint [%s], stopping", args.until)
raise UntilCheckpointReached
return True
logging.info(
"Applying data from backup file [%s] to target file [%s].", dataFile, targetFile
)
pprint.pprint(meta)
assert reader.read(len(sTypes.TERM)) == sTypes.TERM
progressBar = lib.progressBar(
meta["dataSize"], f"restoring disk [{meta['diskName']}]", args
)
dataSize: int = 0
dataBlockCnt: int = 0
while True:
try:
kind, start, length = stream.readFrame(reader)
except StreamFormatException as err:
logging.error("Can't read stream at pos: [%s]: [%s]", reader.tell(), err)
raise RestoreError from err
if kind == sTypes.ZERO:
logging.debug("Zero segment from [%s] length: [%s]", start, length)
elif kind == sTypes.DATA:
logging.debug(
"Processing data segment from [%s] length: [%s]", start, length
)
originalSize = length
if trailer:
logging.debug("Block: [%s]", dataBlockCnt)
logging.debug("Original block size: [%s]", length)
length = trailer[dataBlockCnt]
logging.debug("Compressed block size: [%s]", length)
if originalSize >= connection.maxRequestSize:
logging.debug(
"Chunked read/write, start: [%s], len: [%s]", start, length
)
try:
written = chunk.read(
reader,
start,
length,
connection,
lib.isCompressed(meta),
progressBar,
)
except Exception as e:
logging.exception(e)
raise RestoreError from e
logging.debug("Wrote: [%s]", written)
else:
try:
data = reader.read(length)
if lib.isCompressed(meta):
data = lz4.decompressFrame(data)
connection.nbd.pwrite(data, start)
written = len(data)
except Exception as e:
logging.exception(e)
raise RestoreError from e
progressBar.update(written)
assert reader.read(len(sTypes.TERM)) == sTypes.TERM
dataSize += originalSize
dataBlockCnt += 1
elif kind == sTypes.STOP:
progressBar.close()
if dataSize != meta["dataSize"]:
logging.error(
"Restored data size does not match [%s] != [%s]",
dataSize,
meta["dataSize"],
)
raise RestoreError("Data size mismatch")
break
logging.info("End of stream, [%s] of data processed", lib.humanize(dataSize))
if meta["checkpointName"] == args.until:
logging.info("Reached checkpoint [%s], stopping", args.until)
raise UntilCheckpointReached
if connection.nbd.can_flush() is True:
logging.debug("Flushing NBD connection handle")
connection.nbd.flush()
return True
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