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import logging
try:
from typing import List, Optional
except ImportError:
pass
from ..inventory import Device
from ..drive_group import DriveGroupSpec, DeviceSelection
from .filter import FilterGenerator
logger = logging.getLogger(__name__)
class DriveSelection(object):
def __init__(self,
spec, # type: DriveGroupSpec
disks, # type: List[Device]
existing_daemons=None, # type: Optional[int]
):
self.disks = disks.copy()
self.spec = spec
self.existing_daemons = existing_daemons or 0
self._data = self.assign_devices(self.spec.data_devices)
self._wal = self.assign_devices(self.spec.wal_devices)
self._db = self.assign_devices(self.spec.db_devices)
self._journal = self.assign_devices(self.spec.journal_devices)
def data_devices(self):
# type: () -> List[Device]
return self._data
def wal_devices(self):
# type: () -> List[Device]
return self._wal
def db_devices(self):
# type: () -> List[Device]
return self._db
def journal_devices(self):
# type: () -> List[Device]
return self._journal
def _limit_reached(self, device_filter, len_devices,
disk_path):
# type: (DeviceSelection, int, str) -> bool
""" Check for the <limit> property and apply logic
If a limit is set in 'device_attrs' we have to stop adding
disks at some point.
If limit is set (>0) and len(devices) >= limit
:param int len_devices: Length of the already populated device set/list
:param str disk_path: The disk identifier (for logging purposes)
:return: True/False if the device should be added to the list of devices
:rtype: bool
"""
limit = device_filter.limit or 0
if limit > 0 and (len_devices + self.existing_daemons >= limit):
logger.info("Refuse to add {} due to limit policy of <{}>".format(
disk_path, limit))
return True
return False
@staticmethod
def _has_mandatory_idents(disk):
# type: (Device) -> bool
""" Check for mandatory identification fields
"""
if disk.path:
logger.debug("Found matching disk: {}".format(disk.path))
return True
else:
raise Exception(
"Disk {} doesn't have a 'path' identifier".format(disk))
def assign_devices(self, device_filter):
# type: (Optional[DeviceSelection]) -> List[Device]
""" Assign drives based on used filters
Do not add disks when:
1) Filter didn't match
2) Disk doesn't have a mandatory identification item (path)
3) The set :limit was reached
After the disk was added we make sure not to re-assign this disk
for another defined type[wal/db/journal devices]
return a sorted(by path) list of devices
"""
if not device_filter:
logger.debug('device_filter is None')
return []
if not self.spec.data_devices:
logger.debug('data_devices is None')
return []
if device_filter.paths:
logger.debug('device filter is using explicit paths')
return device_filter.paths
devices = list() # type: List[Device]
for disk in self.disks:
logger.debug("Processing disk {}".format(disk.path))
if not self._has_mandatory_idents(disk):
logger.debug(
"Ignoring disk {}. Missing mandatory idents".format(
disk.path))
continue
# break on this condition.
if self._limit_reached(device_filter, len(devices), disk.path):
logger.debug("Ignoring disk {}. Limit reached".format(
disk.path))
break
if disk in devices:
continue
if self.spec.filter_logic == 'AND':
if not all(m.compare(disk) for m in FilterGenerator(device_filter)):
logger.debug(
"Ignoring disk {}. Not all filter did match the disk".format(
disk.path))
continue
if self.spec.filter_logic == 'OR':
if not any(m.compare(disk) for m in FilterGenerator(device_filter)):
logger.debug(
"Ignoring disk {}. No filter matched the disk".format(
disk.path))
continue
logger.debug('Adding disk {}'.format(disk.path))
devices.append(disk)
# This disk is already taken and must not be re-assigned.
for taken_device in devices:
if taken_device in self.disks:
self.disks.remove(taken_device)
return sorted([x for x in devices], key=lambda dev: dev.path)
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