Simplify FSM framework. Only model relevant states

base/fs/partitionmaps/abstract.py

@@ -1,25 +1,41 @@
 from abc import ABCMeta
 from abc import abstractmethod
 from common.tools import log_check_call
+from common.fsm_proxy import FSMProxy
 from ..exceptions import PartitionError
 
 
-class AbstractPartitionMap(object):
+class AbstractPartitionMap(FSMProxy):
 
 	__metaclass__ = ABCMeta
 
-	@abstractmethod
-	def __init__(self, data):
-		pass
+	events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'unmapped'},
+	          {'name': 'map', 'src': 'unmapped', 'dst': 'mapped'},
+	          {'name': 'unmap', 'src': 'mapped', 'dst': 'unmapped'},
+	          ]
+
+	def __init__(self):
+		cfg = {'initial': 'nonexistent', 'events': self.events, 'callbacks': {}}
+		super(AbstractPartitionMap, self).__init__(cfg)
+
+	def is_blocking(self):
+		return self.is_state('mapped')
 
 	def get_total_size(self):
 		return sum(p.size for p in self.partitions) + 1
 
-	@abstractmethod
 	def create(self, volume):
+		self.fsm.create(volume=volume)
+
+	@abstractmethod
+	def _before_create(self, event):
 		pass
 
 	def map(self, volume):
+		self.fsm.map(volume=volume)
+
+	def _before_map(self, event):
+		volume = event.volume
 		try:
 			mappings = log_check_call(['/sbin/kpartx', '-l', volume.device_path])
 			import re
@@ -38,35 +54,23 @@ class AbstractPartitionMap(object):
 				self.partitions[p_idx].map(partition_path)
 
 			for idx, partition in enumerate(self.partitions):
-				if not partition.state() in ['mapped', 'formatted']:
+				if not partition.is_state('mapped'):
 					raise PartitionError('kpartx did not map partition #{idx}'.format(idx=idx+1))
 
 		except PartitionError as e:
 			for partition in self.partitions:
-				if partition.state() in ['mapped', 'formatted']:
+				if not partition.is_state('mapped'):
 					partition.unmap()
 			log_check_call(['/sbin/kpartx', '-d', volume.device_path])
 			raise e
 
 	def unmap(self, volume):
+		self.fsm.unmap(volume=volume)
+
+	def _before_unmap(self, event):
+		volume = event.volume
 		for partition in self.partitions:
-			partition.unmap()
+			if partition.is_blocking():
+				msg = 'The partition {partition} prevents the unmap procedure'.format(partition=partition)
+				raise PartitionError(msg)
 		log_check_call(['/sbin/kpartx', '-d', volume.device_path])
-
-	def format(self):
-		for partition in self.partitions:
-			partition.format()
-
-	def mount_root(self, destination):
-		self.root.mount(destination)
-
-	def unmount_root(self):
-		self.root.unmount()
-
-	def mount_boot(self):
-		import os.path
-		destination = os.path.join(self.root.mount_dir, 'boot')
-		self.boot.mount(destination)
-
-	def unmount_boot(self):
-		self.boot.unmount()

base/fs/partitionmaps/gpt.py

@@ -20,7 +20,9 @@ class GPTPartitionMap(AbstractPartitionMap):
 			self.mount_points.append(('none', self.root))
 		self.partitions = filter(lambda p: p is not None, [self.boot, self.root, self.swap])
 
-	def create(self, volume):
+		super(GPTPartitionMap, self).__init__()
+
+	def _before_create(self, volume):
 		log_check_call(['/sbin/parted', '--script', '--align', 'none', volume.device_path,
 		                '--', 'mklabel', 'gpt'])
 		for partition in self.partitions:

base/fs/partitionmaps/mbr.py

@@ -20,7 +20,10 @@ class MBRPartitionMap(AbstractPartitionMap):
 			self.mount_points.append(('none', self.root))
 		self.partitions = filter(lambda p: p is not None, [self.boot, self.root, self.swap])
 
-	def create(self, volume):
+		super(MBRPartitionMap, self).__init__()
+
+	def _before_create(self, event):
+		volume = event.volume
 		log_check_call(['/sbin/parted', '--script', '--align', 'none', volume.device_path,
 		                '--', 'mklabel', 'msdos'])
 		for partition in self.partitions:

base/fs/partitionmaps/none.py

@@ -1,7 +1,10 @@
 from ..partitions.single import SinglePartition
+from common.fsm_proxy import FSMProxy
 
 
-class NoPartitions(object):
+class NoPartitions(FSMProxy):
+
+	events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'created'}]
 
 	def __init__(self, data):
 		root = data['root']
@@ -9,17 +12,17 @@ class NoPartitions(object):
 		self.partitions = [self.root]
 		self.mount_points = [('/', self.root)]
 
+		cfg = {'initial': 'nonexistent', 'events': self.events, 'callbacks': {}}
+		super(NoPartitions, self).__init__(cfg)
+
+	def is_blocking(self):
+		return self.root.is_blocking()
+
 	def get_total_size(self):
 		return self.root.size
 
 	def create(self, volume):
-		self.root.create(volume)
+		self.fsm.create(volume=volume)
 
-	def format(self):
-		self.root.format()
-
-	def mount_root(self, destination):
-		self.root.mount(destination)
-
-	def unmount_root(self):
-		self.root.unmount()
+	def _before_create(self, event):
+		self.root.create(event.volume)

base/fs/partitions/abstract.py

@@ -1,10 +1,10 @@
 from abc import ABCMeta
 from abc import abstractmethod
 from common.tools import log_check_call
-from fysom import Fysom
+from common.fsm_proxy import FSMProxy
 
 
-class AbstractPartition(object):
+class AbstractPartition(FSMProxy):
 
 	__metaclass__ = ABCMeta
 
@@ -14,28 +14,16 @@ class AbstractPartition(object):
 	          {'name': 'unmount', 'src': 'mounted', 'dst': 'formatted'},
 	          ]
 
-	def __init__(self, size, filesystem, callbacks={}):
+	def __init__(self, size, filesystem):
 		self.size          = size
 		self.filesystem    = filesystem
 		self.device_path   = None
 
-		callbacks.update({'onbeforecreate': self._create,
-		                  'onbeforeformat': self._format,
-		                  'onbeforemount': self._mount,
-		                  'onbeforeunmount': self._unmount,
-		                  })
+		cfg = {'initial': 'nonexistent', 'events': self.events, 'callbacks': {}}
+		super(AbstractPartition, self).__init__(cfg)
 
-		self.fsm = Fysom({'initial': 'nonexistent',
-		                  'events': self.events,
-		                  'callbacks': callbacks})
-		from common.fsm import attach_proxy_methods
-		attach_proxy_methods(self, self.events, self.fsm)
-
-	def state(self):
-		return self.fsm.current
-
-	def force_state(self, state):
-		self.fsm.current = state
+	def is_blocking(self):
+		return self.is_state('mounted')
 
 	def get_uuid(self):
 		[uuid] = log_check_call(['/sbin/blkid', '-s', 'UUID', '-o', 'value', self.device_path])
@@ -45,20 +33,20 @@ class AbstractPartition(object):
 		self.fsm.create(volume=volume)
 
 	@abstractmethod
-	def _create(self, e):
+	def _before_create(self, e):
 		pass
 
-	def _format(self, e):
+	def _before_format(self, e):
 		mkfs = '/sbin/mkfs.{fs}'.format(fs=self.filesystem)
 		log_check_call([mkfs, self.device_path])
 
 	def mount(self, destination):
 		self.fsm.mount(destination=destination)
 
-	def _mount(self, e):
+	def _before_mount(self, e):
 		log_check_call(['/bin/mount', '--types', self.filesystem, self.device_path, e.destination])
 		self.mount_dir = e.destination
 
-	def _unmount(self, e):
+	def _before_unmount(self, e):
 		log_check_call(['/bin/umount', self.mount_dir])
 		del self.mount_dir

base/fs/partitions/base.py

@@ -5,20 +5,21 @@ class BasePartition(AbstractPartition):
 
 	events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'unmapped'},
 	          {'name': 'map', 'src': 'unmapped', 'dst': 'mapped'},
-	          {'name': 'map', 'src': 'unmapped_fmt', 'dst': 'formatted'},
 	          {'name': 'format', 'src': 'mapped', 'dst': 'formatted'},
 	          {'name': 'mount', 'src': 'formatted', 'dst': 'mounted'},
 	          {'name': 'unmount', 'src': 'mounted', 'dst': 'formatted'},
 	          {'name': 'unmap', 'src': 'formatted', 'dst': 'unmapped_fmt'},
+
+	          {'name': 'map', 'src': 'unmapped_fmt', 'dst': 'formatted'},
 	          {'name': 'unmap', 'src': 'mapped', 'dst': 'unmapped'},
 	          ]
 
-	def __init__(self, size, filesystem, previous, callbacks={}):
+	def __init__(self, size, filesystem, previous):
 		self.previous = previous
-		callbacks.update({'onbeforemap': self._map,
-		                  'onbeforeunmap': self._unmap,
-		                  })
-		super(BasePartition, self).__init__(size, filesystem, callbacks=callbacks)
+		super(BasePartition, self).__init__(size, filesystem)
+
+	def is_blocking(self):
+		return self.get_state() in ['mapped', 'mounted', 'formatted']
 
 	def get_index(self):
 		if self.previous is None:
@@ -35,8 +36,8 @@ class BasePartition(AbstractPartition):
 	def map(self, device_path):
 		self.fsm.map(device_path=device_path)
 
-	def _map(self, e):
+	def _before_map(self, e):
 		self.device_path = e.device_path
 
-	def _unmap(self, e):
+	def _before_unmap(self, e):
 		self.device_path = None

base/fs/partitions/gpt.py

@@ -4,11 +4,11 @@ from base import BasePartition
 
 class GPTPartition(BasePartition):
 
-	def __init__(self, size, filesystem, name, previous, callbacks={}):
+	def __init__(self, size, filesystem, name, previous):
 		self.name = name
-		super(GPTPartition, self).__init__(size, filesystem, previous, callbacks=callbacks)
+		super(GPTPartition, self).__init__(size, filesystem, previous)
 
-	def _create(self, e):
+	def _before_create(self, e):
 		start = self.get_start()
 		# {name} only works for gpt, for msdos that becomes the part-type (primary, extended, logical)
 		parted_command = ('mkpart primary {start}MiB {end}MiB'

base/fs/partitions/gpt_swap.py

@@ -7,5 +7,5 @@ class GPTSwapPartition(GPTPartition):
 	def __init__(self, size, previous):
 		super(GPTSwapPartition, self).__init__(size, 'swap', 'swap', previous)
 
-	def _format(self, e):
+	def _before_format(self, e):
 		log_check_call(['/sbin/mkswap', self.device_path])

base/fs/partitions/mbr.py

@@ -4,7 +4,7 @@ from base import BasePartition
 
 class MBRPartition(BasePartition):
 
-	def _create(self, e):
+	def _before_create(self, e):
 		start = self.get_start()
 		parted_command = ('mkpart primary {start}MiB {end}MiB'
 		                  .format(start=str(start),

base/fs/partitions/mbr_swap.py

@@ -7,5 +7,5 @@ class MBRSwapPartition(MBRPartition):
 	def __init__(self, size, previous):
 		super(MBRSwapPartition, self).__init__(size, 'swap', previous)
 
-	def _format(self, e):
+	def _before_format(self, e):
 		log_check_call(['/sbin/mkswap', self.device_path])

base/fs/partitions/single.py

@@ -3,11 +3,5 @@ from abstract import AbstractPartition
 
 class SinglePartition(AbstractPartition):
 
-	events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'created'},
-	          {'name': 'format', 'src': 'created', 'dst': 'formatted'},
-	          {'name': 'mount', 'src': 'formatted', 'dst': 'mounted'},
-	          {'name': 'unmount', 'src': 'mounted', 'dst': 'formatted'},
-	          ]
-
-	def _create(self, e):
+	def _before_create(self, e):
 		self.device_path = e.volume.device_path

base/fs/volume.py

@@ -1,138 +1,48 @@
 from abc import ABCMeta
-from fysom import Fysom
+from common.fsm_proxy import FSMProxy
+from common.tools import log_check_call
+from exceptions import VolumeError
 
 
-class Volume(object):
+class Volume(FSMProxy):
 
 	__metaclass__ = ABCMeta
 
 	events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'detached'},
 	          {'name': 'attach', 'src': 'detached', 'dst': 'attached'},
-	          {'name': 'partition', 'src': 'attached', 'dst': 'partitioned'},
-	          {'name': 'map', 'src': 'partitioned', 'dst': 'mapped'},
-	          {'name': 'format', 'src': 'mapped', 'dst': 'formatted'},
-	          {'name': 'mount', 'src': ['formatted', 'mounted'], 'dst': 'mounted'},
-	          {'name': 'unmount', 'src': 'mounted', 'dst': 'formatted'},
-	          {'name': 'unmap', 'src': 'formatted', 'dst': 'partitioned_fmt'},
-	          {'name': 'detach', 'src': 'partitioned_fmt', 'dst': 'detached_fmt'},
-	          {'name': 'delete', 'src': ['detached', 'detached_prt', 'detached_fmt'], 'dst': 'deleted'},
-
-	          {'name': 'attach', 'src': 'detached_fmt', 'dst': 'partitioned_fmt'},
-	          {'name': 'map', 'src': 'partitioned_fmt', 'dst': 'formatted'},
-
-	          {'name': 'attach', 'src': 'detached_prt', 'dst': 'partitioned'},
-	          {'name': 'detach', 'src': 'partitioned', 'dst': 'detached_prt'},
-
+	          {'name': 'mount_specials', 'src': 'attached', 'dst': 'specials_mounted'},
+	          {'name': 'unmount_specials', 'src': 'specials_mounted', 'dst': 'attached'},
 	          {'name': 'detach', 'src': 'attached', 'dst': 'detached'},
-	          {'name': 'unmap', 'src': 'mapped', 'dst': 'partitioned'},
+	          {'name': 'delete', 'src': 'detached', 'dst': 'deleted'},
 	          ]
 
-	mount_events = [{'name': 'mount_root', 'src': 'unmounted', 'dst': 'root_mounted'},
-	                {'name': 'mount_boot', 'src': 'root_mounted', 'dst': 'boot_mounted'},
-	                {'name': 'mount_specials', 'src': 'boot_mounted', 'dst': 'specials_mounted'},
-	                {'name': 'unmount_specials', 'src': 'specials_mounted', 'dst': 'boot_mounted'},
-	                {'name': 'unmount_boot', 'src': 'boot_mounted', 'dst': 'root_mounted'},
-	                {'name': 'unmount_root', 'src': 'root_mounted', 'dst': 'unmounted'},
-
-	                {'name': 'mount_specials', 'src': 'root_mounted', 'dst': 'specials_mounted_no_boot'},
-	                {'name': 'mount_boot', 'src': 'specials_mounted_no_boot', 'dst': 'specials_mounted'},
-	                {'name': 'unmount_specials', 'src': 'specials_mounted_no_boot', 'dst': 'root_mounted'},
-	                {'name': 'unmount_boot', 'src': 'specials_mounted', 'dst': 'specials_mounted_no_boot'},
-	                ]
-
-	def __init__(self, partition_map, callbacks={}):
+	def __init__(self, partition_map):
 		self.device_path = None
 		self.partition_map = partition_map
 		self.size = self.partition_map.get_total_size()
 
-		callbacks.update({'onbeforepartition': self._partition,
-		                  'onbeforemap': self._map,
-		                  'onbeforeunmap': self._unmap,
-		                  'onbeforeformat': self._format,
-		                  'onbeforeunmount': self._unmount,
-		                  })
+		callbacks = {'onbeforedetach': self._check_blocking}
+		from partitionmaps.none import NoPartitions
+		if isinstance(self.partition_map, NoPartitions):
+			callbacks['onafterattach'] = lambda e: self.partition_map.create(self)
 
-		mount_callbacks = {'onbeforemount_root': self._mount_root,
-		                   'onbeforemount_boot': self._mount_boot,
-		                   'onbeforemount_specials': self._mount_specials,
-		                   'onbeforeunmount_root': self._unmount_root,
-		                   'onbeforeunmount_boot': self._unmount_boot,
-		                   'onbeforeunmount_specials': self._unmount_specials,
-		                   }
-		self.fsm = Fysom({'initial': 'nonexistent',
-		                  'events': self.events,
-		                  'callbacks': callbacks})
+		cfg = {'initial': 'nonexistent', 'events': self.events, 'callbacks': callbacks}
+		super(Volume, self).__init__(cfg)
 
-		self.mount_fsm = Fysom({'initial': 'unmounted',
-		                        'events': self.mount_events,
-		                        'callbacks': mount_callbacks})
-
-		from common.fsm import attach_proxy_methods
-		attach_proxy_methods(self, self.events, self.fsm)
-		attach_proxy_methods(self, self.mount_events, self.mount_fsm)
-
-	def state(self):
-		return self.fsm.current
-
-	def force_state(self, state):
-		self.fsm.current = state
-
-	def _partition(self, e):
-		self.partition_map.create(self)
-
-	def _map(self, e):
-		self.partition_map.map(self)
-
-	def _unmap(self, e):
-		self.partition_map.unmap(self)
-
-	def _format(self, e):
-		self.partition_map.format()
-
-	def _unmount(self, e):
-		if self.mount_fsm.current is 'specials_mounted':
-			self.unmount_specials()
-		if self.mount_fsm.current is 'specials_mounted_no_boot':
-			self.unmount_specials()
-		if self.mount_fsm.current is 'boot_mounted':
-			self.unmount_boot()
-		if self.mount_fsm.current is 'root_mounted':
-			self.unmount_root()
-
-	def mount_root(self, destination):
-		self.mount_fsm.mount_root(destination=destination)
-
-	def unmount_root(self):
-		self.mount_fsm.unmount_root()
-		self.fsm.unmount()
-
-	def _mount_root(self, e):
-		self.mount()
-		self.partition_map.mount_root(e.destination)
-
-	def _unmount_root(self, e):
-		self.partition_map.unmount_root()
-
-	def _mount_boot(self, e):
-		self.mount()
-		self.partition_map.mount_boot()
-
-	def _unmount_boot(self, e):
-		self.partition_map.unmount_boot()
-
-	def _mount_specials(self, e):
-		self.mount()
-		from common.tools import log_check_call
+	def _before_mount_specials(self, e):
 		root = self.partition_map.root.mount_dir
 		log_check_call(['/bin/mount', '--bind', '/dev', '{root}/dev'.format(root=root)])
 		log_check_call(['/usr/sbin/chroot', root, '/bin/mount', '--types', 'proc', 'none', '/proc'])
 		log_check_call(['/usr/sbin/chroot', root, '/bin/mount', '--types', 'sysfs', 'none', '/sys'])
 		log_check_call(['/usr/sbin/chroot', root, '/bin/mount', '--types', 'devpts', 'none', '/dev/pts'])
 
-	def _unmount_specials(self, e):
-		from common.tools import log_check_call
+	def _before_unmount_specials(self, e):
 		root = self.partition_map.root.mount_dir
 		log_check_call(['/usr/sbin/chroot', root, '/bin/umount', '/dev/pts'])
 		log_check_call(['/usr/sbin/chroot', root, '/bin/umount', '/sys'])
 		log_check_call(['/usr/sbin/chroot', root, '/bin/umount', '/proc'])
 		log_check_call(['/bin/umount', '{root}/dev'.format(root=root)])
+
+	def _check_blocking(self, e):
+		if self.partition_map.is_blocking():
+			raise VolumeError('The partitionmap prevents the detach procedure')

common/fs/loopbackvolume.py

@@ -9,45 +9,31 @@ from base.fs.exceptions import VolumeError
 
 class LoopbackVolume(Volume):
 
-	link_dm_events = [{'name': 'link_dm_node', 'src': 'partitioned', 'dst': 'linked'},
-	                  {'name': 'map', 'src': 'linked', 'dst': 'mapped_lnk'},
-	                  {'name': 'format', 'src': 'mapped_lnk', 'dst': 'formatted_lnk'},
-	                  {'name': 'mount', 'src': ['formatted_lnk', 'mounted_lnk'], 'dst': 'mounted_lnk'},
-	                  {'name': 'unmount', 'src': 'mounted_lnk', 'dst': 'formatted_lnk'},
-	                  {'name': 'unmap', 'src': 'formatted_lnk', 'dst': 'partitioned_fmt_lnk'},
-	                  {'name': 'unlink_dm_node', 'src': 'partitioned_fmt_lnk', 'dst': 'partitioned_fmt'},
-
-	                  {'name': 'link_dm_node', 'src': 'partitioned_fmt', 'dst': 'partitioned_fmt_lnk'},
-	                  {'name': 'map', 'src': 'partitioned_fmt_lnk', 'dst': 'formatted_lnk'},
-	                  {'name': 'unmap', 'src': 'mapped_lnk', 'dst': 'linked'},
-	                  {'name': 'unlink_dm_node', 'src': 'linked', 'dst': 'partitioned'},
-	                  ]
+	events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'detached'},
+	          {'name': 'attach', 'src': 'detached', 'dst': 'attached'},
+	          {'name': 'link_dm_node', 'src': 'attached', 'dst': 'linked'},
+            {'name': 'unlink_dm_node', 'src': 'linked', 'dst': 'attached'},
+	          {'name': 'detach', 'src': 'attached', 'dst': 'detached'},
+	          {'name': 'delete', 'src': 'detached', 'dst': 'deleted'},
+	          ]
 
 	extension = 'raw'
 
-	def __init__(self, partition_map, callbacks={}):
-		callbacks.update({'onbeforecreate': self._create,
-		                  'onbeforeattach': self._attach,
-		                  'onbeforedetach': self._detach,
-		                  'onbeforedelete': self._delete,
-		                  'onbeforelink_dm_node': self._link_dm_node,
-		                  'onbeforeunlink_dm_node': self._unlink_dm_node,
-		                  })
-		self.events.extend(self.link_dm_events)
-		super(LoopbackVolume, self).__init__(partition_map, callbacks=callbacks)
+	def __init__(self, partition_map):
+		super(LoopbackVolume, self).__init__(partition_map)
 
 	def create(self, image_path):
 		self.fsm.create(image_path=image_path)
 
-	def _create(self, e):
+	def _before_create(self, e):
 		self.image_path = e.image_path
 		log_check_call(['/usr/bin/qemu-img', 'create', '-f', 'raw', self.image_path, str(self.size) + 'M'])
 
-	def _attach(self, e):
+	def _before_attach(self, e):
 		[self.loop_device_path] = log_check_call(['/sbin/losetup', '--show', '--find', self.image_path])
 		self.device_path = self.loop_device_path
 
-	def _link_dm_node(self, e):
+	def _before_link_dm_node(self, e):
 		import os.path
 		from . import get_partitions
 		proc_partitions = get_partitions()
@@ -77,18 +63,18 @@ class LoopbackVolume(Volume):
 		log_check_call(['/sbin/dmsetup', 'create', self.dm_node_name], table)
 		self.device_path = self.dm_node_path
 
-	def _unlink_dm_node(self, e):
+	def _before_unlink_dm_node(self, e):
 		log_check_call(['/sbin/dmsetup', 'remove', self.dm_node_name])
 		del self.dm_node_name
 		del self.dm_node_path
 		self.device_path = self.loop_device_path
 
-	def _detach(self, e):
+	def _before_detach(self, e):
 		log_check_call(['/sbin/losetup', '--detach', self.loop_device_path])
 		del self.loop_device_path
 		del self.device_path
 
-	def _delete(self, e):
+	def _before_delete(self, e):
 		from os import remove
 		remove(self.image_path)
 		del self.image_path

common/fsm.py

@@ -1,7 +0,0 @@
-
-
-def attach_proxy_methods(obj, events, fsm):
-	methods = set([e['name'] for e in events])
-	for event in methods:
-		if not hasattr(obj, event):
-			setattr(obj, event, lambda e=event: getattr(fsm, e)())

common/fsm_proxy.py

@@ -0,0 +1,51 @@
+
+
+class FSMProxy(object):
+
+	def __init__(self, cfg):
+		from fysom import Fysom
+		events = set([event['name'] for event in cfg['events']])
+		cfg['callbacks'] = self.collect_event_listeners(events, cfg['callbacks'])
+		self.fsm = Fysom(cfg)
+		self.attach_proxy_methods(self.fsm, events)
+
+	def is_state(self, event):
+		return self.fsm.isstate(event)
+
+	def set_state(self, event):
+		self.fsm.current = event
+
+	def get_state(self):
+		return self.fsm.current
+
+	def collect_event_listeners(self, events, callbacks):
+		callbacks = callbacks.copy()
+		callback_names = []
+		for event in events:
+			callback_names.append(('_before_' + event, 'onbefore' + event))
+			callback_names.append(('_after_' + event, 'onafter' + event))
+		for fn_name, listener in callback_names:
+			fn = getattr(self, fn_name, None)
+			if callable(fn):
+				if listener in callbacks:
+					old_fn = callbacks[listener]
+
+					def wrapper(e, old_fn=old_fn, fn=fn):
+						old_fn(e)
+						fn(e)
+					callbacks[listener] = wrapper
+				else:
+					callbacks[listener] = fn
+		return callbacks
+
+	def attach_proxy_methods(self, fsm, events):
+		def make_proxy(fsm, event):
+			fn = getattr(fsm, event)
+
+			def proxy():
+				fn()
+			return proxy
+
+		for event in events:
+			if not hasattr(self, event):
+				setattr(self, event, make_proxy(fsm, event))

common/tasks/filesystem.py

@@ -10,7 +10,8 @@ class Format(Task):
 	phase = phases.volume_preparation
 
 	def run(self, info):
-		info.volume.format()
+		for partition in info.volume.partition_map.partitions:
+			partition.format()
 
 
 class TuneVolumeFS(Task):
@@ -51,7 +52,7 @@ class MountRoot(Task):
 	after = [CreateMountDir]
 
 	def run(self, info):
-		info.volume.mount_root(info.root)
+		info.volume.partition_map.root.mount(info.root)
 
 
 class MountBoot(Task):
@@ -60,7 +61,7 @@ class MountBoot(Task):
 	after = [MountRoot]
 
 	def run(self, info):
-		info.volume.mount_boot()
+		info.volume.partition_map.boot.mount(info.boot_dir)
 
 
 class CreateBootMountDir(Task):
@@ -71,8 +72,8 @@ class CreateBootMountDir(Task):
 
 	def run(self, info):
 		import os
-		boot_dir = os.path.join(info.root, 'boot')
-		os.makedirs(boot_dir)
+		info.boot_dir = os.path.join(info.root, 'boot')
+		os.makedirs(info.boot_dir)
 
 
 class MountSpecials(Task):
@@ -90,7 +91,7 @@ class UnmountRoot(Task):
 	before = [volume.Detach]
 
 	def run(self, info):
-		info.volume.unmount_root()
+		info.volume.partition_map.root.unmount()
 
 
 class UnmountBoot(Task):
@@ -99,7 +100,7 @@ class UnmountBoot(Task):
 	before = [UnmountRoot]
 
 	def run(self, info):
-		info.volume.unmount_boot()
+		info.volume.partition_map.boot.unmount()
 
 
 class UnmountSpecials(Task):

common/tasks/partitioning.py

@@ -9,7 +9,7 @@ class PartitionVolume(Task):
 	phase = phases.volume_preparation
 
 	def run(self, info):
-		info.volume.partition()
+		info.volume.partition_map.create()
 
 
 class MapPartitions(Task):
@@ -19,7 +19,7 @@ class MapPartitions(Task):
 	after = [PartitionVolume]
 
 	def run(self, info):
-		info.volume.map()
+		info.volume.partition_map.map()
 
 
 class UnmapPartitions(Task):
@@ -29,4 +29,4 @@ class UnmapPartitions(Task):
 	after = [filesystem.UnmountRoot]
 
 	def run(self, info):
-		info.volume.unmap()
+		info.volume.partition_map.unmap()

providers/ec2/volume.py

@@ -19,7 +19,10 @@ class EBSVolume(Volume):
 		self.created = True
 
 	def attach(self, instance_id):
-		super(EBSVolume, self).attach(self)
+		self.fsm.attach(instance_id=instance_id)
+
+	def _before_attach(self, e):
+		instance_id = e.instance_id
 		import os.path
 		import string
 		for letter in string.ascii_lowercase:
@@ -37,14 +40,13 @@ class EBSVolume(Volume):
 			time.sleep(2)
 			self.volume.update()
 
-	def detach(self):
-		super(EBSVolume, self).detach(self)
+	def _before_detach(self, e):
 		self.volume.detach()
 		while self.volume.attachment_state() is not None:
 			time.sleep(2)
 			self.volume.update()
 
-	def delete(self):
+	def _before_delete(self, e):
 		super(EBSVolume, self).delete(self)
 		self.volume.delete()
 

providers/virtualbox/volume.py

@@ -8,11 +8,11 @@ class VirtualBoxVolume(LoopbackVolume):
 
 	extension = 'vdi'
 
-	def _create(self, e):
+	def _before_create(self, e):
 		self.image_path = e.image_path
 		log_check_call(['/usr/bin/qemu-img', 'create', '-f', 'vdi', self.image_path, str(self.size) + 'M'])
 
-	def _attach(self, e):
+	def _before_attach(self, e):
 		num_partitions = len(self.partition_map.partitions)
 		if not self._module_loaded('nbd'):
 			msg = ('The kernel module `nbd\' must be loaded '
@@ -33,7 +33,7 @@ class VirtualBoxVolume(LoopbackVolume):
 		log_check_call(['/usr/bin/qemu-nbd', '--connect', self.loop_device_path, self.image_path])
 		self.device_path = self.loop_device_path
 
-	def _detach(self, e):
+	def _before_detach(self, e):
 		log_check_call(['/usr/bin/qemu-nbd', '--disconnect', self.loop_device_path])
 		del self.loop_device_path
 		del self.device_path