Merge branch 'master' of or3st3s@baryon.com.ar:workspace/pymin into suse

[software/pymin.git] / pymin / services / util.py

diff --git a/pymin/services/util.py b/pymin/services/util.py
index 95a07e9992d8b0f9b92df39e7a1c41e2cd34f6aa..abf30e9ce097956ecf0543b98461da6c4df5abc4 100644 (file)
--- a/pymin/services/util.py
+++ b/pymin/services/util.py
@@ -12,13 +12,16 @@ except ImportError:
 from pymin.dispatcher import Handler, handler, HandlerError, \
                                 CommandNotFoundError
 
 from pymin.dispatcher import Handler, handler, HandlerError, \
                                 CommandNotFoundError
 

-#DEBUG = False
-DEBUG = True
+DEBUG = False
+#DEBUG = True

 
 

-__ALL__ = ('ServiceHandler', 'InitdHandler', 'SubHandler', 'DictSubHandler',
-            'ListSubHandler', 'Persistent', 'ConfigWriter', 'Error',
-            'ReturnNot0Error', 'ExecutionError', 'ItemError',
-            'ItemAlreadyExistsError', 'ItemNotFoundError', 'call')
+__ALL__ = ('Error', 'ReturnNot0Error', 'ExecutionError', 'ItemError',
+            'ItemAlreadyExistsError', 'ItemNotFoundError', 'ContainerError',
+            'ContainerNotFoundError', 'call', 'get_network_devices',
+            'Persistent', 'Restorable', 'ConfigWriter', 'ServiceHandler',
+            'RestartHandler', 'ReloadHandler', 'InitdHandler', 'SubHandler',
+            'DictSubHandler', 'ListSubHandler', 'ComposedSubHandler',
+            'ListComposedSubHandler', 'DictComposedSubHandler')

 
 class Error(HandlerError):
     r"""
 
 class Error(HandlerError):
     r"""


@@ -116,7 +119,7 @@ class ItemAlreadyExistsError(ItemError):
 
 class ItemNotFoundError(ItemError):
     r"""
 
 class ItemNotFoundError(ItemError):
     r"""

-    ItemNotFoundError(key) -> ItemNotFoundError instance
+    ItemNotFoundError(key) -> ItemNotFoundError instance.

 
     This exception is raised when trying to operate on an item that doesn't
     exists.
 
     This exception is raised when trying to operate on an item that doesn't
     exists.


@@ -126,6 +129,52 @@ class ItemNotFoundError(ItemError):
         r"Initialize the object. See class documentation for more info."
         self.message = u'Item not found: "%s"' % key
 
         r"Initialize the object. See class documentation for more info."
         self.message = u'Item not found: "%s"' % key
 

+class ContainerError(Error, KeyError):
+    r"""
+    ContainerError(key) -> ContainerError instance.
+
+    This is the base exception for all container related errors.
+    """
+
+    def __init__(self, key):
+        r"Initialize the object. See class documentation for more info."
+        self.message = u'Container error: "%s"' % key
+
+class ContainerNotFoundError(ContainerError):
+    r"""
+    ContainerNotFoundError(key) -> ContainerNotFoundError instance.
+
+    This exception is raised when trying to operate on an container that
+    doesn't exists.
+    """
+
+    def __init__(self, key):
+        r"Initialize the object. See class documentation for more info."
+        self.message = u'Container not found: "%s"' % key
+
+
+def get_network_devices():
+    p = subprocess.Popen(('ip', '-o', 'link'), stdout=subprocess.PIPE,
+                                                    close_fds=True)
+    string = p.stdout.read()
+    p.wait()
+    d = dict()
+    devices = string.splitlines()
+    for dev in devices:
+        mac = ''
+        if dev.find('link/ether') != -1:
+            i = dev.find('link/ether')
+            mac = dev[i+11 : i+11+17]
+            i = dev.find(':',2)
+            name = dev[3: i]
+            d[name] = mac
+        elif dev.find('link/ppp') != -1:
+            i = dev.find('link/ppp')
+            mac =  '00:00:00:00:00:00'
+            i = dev.find(':',2)
+            name = dev[3 : i]
+            d[name] = mac
+    return d

 
 def call(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
             stderr=subprocess.PIPE, close_fds=True, universal_newlines=True,
 
 def call(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
             stderr=subprocess.PIPE, close_fds=True, universal_newlines=True,


@@ -136,6 +185,7 @@ def call(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
         print 'Executing command:', command
         return
     try:
         print 'Executing command:', command
         return
     try:

+        print 'Executing command:', command

         r = subprocess.call(command, stdin=stdin, stdout=stdout, stderr=stderr,
                                 universal_newlines=universal_newlines,
                                 close_fds=close_fds, **kw)
         r = subprocess.call(command, stdin=stdin, stdout=stdout, stderr=stderr,
                                 universal_newlines=universal_newlines,
                                 close_fds=close_fds, **kw)


@@ -252,9 +302,6 @@ class Restorable(Persistent):
         r"_restore() -> bool :: Restore persistent data or create a default."
         try:
             self._load()
         r"_restore() -> bool :: Restore persistent data or create a default."
         try:
             self._load()

-            # TODO tener en cuenta servicios que hay que levantar y los que no
-            if hasattr(self, 'commit'): # TODO deberia ser reload y/o algo para comandos
-                self.commit()

             return True
         except IOError:
             for (k, v) in self._restorable_defaults.items():
             return True
         except IOError:
             for (k, v) in self._restorable_defaults.items():


@@ -266,8 +313,6 @@ class Restorable(Persistent):
             self._dump()
             if hasattr(self, '_write_config'):
                 self._write_config()
             self._dump()
             if hasattr(self, '_write_config'):
                 self._write_config()

-            if hasattr(self, 'reload'):
-                self.reload()

             return False
 
 class ConfigWriter:
             return False
 
 class ConfigWriter:


@@ -395,7 +440,7 @@ class ConfigWriter:
             self._write_single_config(t)
 
 
             self._write_single_config(t)
 
 

-class ServiceHandler(Handler):
+class ServiceHandler(Handler, Restorable):

     r"""ServiceHandler([start[, stop[, restart[, reload]]]]) -> ServiceHandler.
 
     This is a helper class to inherit from to automatically handle services
     r"""ServiceHandler([start[, stop[, restart[, reload]]]]) -> ServiceHandler.
 
     This is a helper class to inherit from to automatically handle services


@@ -426,28 +471,93 @@ class ServiceHandler(Handler):
                                                     reload=reload).items():
             if action is not None:
                 setattr(self, '_service_%s' % name, action)
                                                     reload=reload).items():
             if action is not None:
                 setattr(self, '_service_%s' % name, action)

+        self._persistent_attrs = list(self._persistent_attrs)
+        self._persistent_attrs.append('_service_running')
+        if '_service_running' not in self._restorable_defaults:
+            self._restorable_defaults['_service_running'] = False
+        self._restore()
+        if self._service_running:
+            self._service_running = False
+            self.start()

 
     @handler(u'Start the service.')
     def start(self):
         r"start() -> None :: Start the service."
 
     @handler(u'Start the service.')
     def start(self):
         r"start() -> None :: Start the service."

-        call(self._service_start)
+        if not self._service_running:
+            if callable(self._service_start):
+                self._service_start()
+            else:
+                call(self._service_start)
+            self._service_running = True
+            self._dump_attr('_service_running')

 
     @handler(u'Stop the service.')
     def stop(self):
         r"stop() -> None :: Stop the service."
 
     @handler(u'Stop the service.')
     def stop(self):
         r"stop() -> None :: Stop the service."

-        call(self._service_stop)
+        if self._service_running:
+            if callable(self._service_stop):
+                self._service_stop()
+            else:
+                call(self._service_stop)
+            self._service_running = False
+            self._dump_attr('_service_running')

 
     @handler(u'Restart the service.')
     def restart(self):
         r"restart() -> None :: Restart the service."
 
     @handler(u'Restart the service.')
     def restart(self):
         r"restart() -> None :: Restart the service."

-        call(self._service_restart)
+        if callable(self._service_restart):
+            self._service_restart()
+        else:
+            call(self._service_restart)
+        self._service_running = True
+        self._dump_attr('_service_running')

 
     @handler(u'Reload the service config (without restarting, if possible).')
     def reload(self):
         r"reload() -> None :: Reload the configuration of the service."
 
     @handler(u'Reload the service config (without restarting, if possible).')
     def reload(self):
         r"reload() -> None :: Reload the configuration of the service."

-        call(self._service_reload)
+        if self._service_running:
+            if callable(self._service_reload):
+                self._service_reload()
+            else:
+                call(self._service_reload)
+
+    @handler(u'Tell if the service is running.')
+    def running(self):
+        r"reload() -> None :: Reload the configuration of the service."
+        if self._service_running:
+            return 1
+        else:
+            return 0
+
+class RestartHandler(Handler):
+    r"""RestartHandler() -> RestartHandler :: Provides generic restart command.
+
+    This is a helper class to inherit from to automatically add a restart
+    command that first stop the service and then starts it again (using start
+    and stop commands respectively).
+    """
+
+    @handler(u'Restart the service (alias to stop + start).')
+    def restart(self):
+        r"restart() -> None :: Restart the service calling stop() and start()."
+        self.stop()
+        self.start()

 
 

-class InitdHandler(Handler):
+class ReloadHandler(Handler):
+    r"""ReloadHandler() -> ReloadHandler :: Provides generic reload command.
+
+    This is a helper class to inherit from to automatically add a reload
+    command that calls restart.
+    """
+
+    @handler(u'Reload the service config (alias to restart).')
+    def reload(self):
+        r"reload() -> None :: Reload the configuration of the service."
+        if hasattr(self, '_service_running') and self._service_running:
+            self.restart()
+
+class InitdHandler(ServiceHandler):
+    # TODO update docs, declarative style is depracated

     r"""InitdHandler([initd_name[, initd_dir]]) -> InitdHandler.
 
     This is a helper class to inherit from to automatically handle services
     r"""InitdHandler([initd_name[, initd_dir]]) -> InitdHandler.
 
     This is a helper class to inherit from to automatically handle services


@@ -476,26 +586,11 @@ class InitdHandler(Handler):
             self._initd_name = initd_name
         if initd_dir is not None:
             self._initd_dir = initd_dir
             self._initd_name = initd_name
         if initd_dir is not None:
             self._initd_dir = initd_dir

-
-    @handler(u'Start the service.')
-    def start(self):
-        r"start() -> None :: Start the service."
-        call((path.join(self._initd_dir, self._initd_name), 'start'))
-
-    @handler(u'Stop the service.')
-    def stop(self):
-        r"stop() -> None :: Stop the service."
-        call((path.join(self._initd_dir, self._initd_name), 'stop'))
-
-    @handler(u'Restart the service.')
-    def restart(self):
-        r"restart() -> None :: Restart the service."
-        call((path.join(self._initd_dir, self._initd_name), 'restart'))
-
-    @handler(u'Reload the service config (without restarting, if possible).')
-    def reload(self):
-        r"reload() -> None :: Reload the configuration of the service."
-        call((path.join(self._initd_dir, self._initd_name), 'reload'))
+        actions = dict()
+        for action in ('start', 'stop', 'restart', 'reload'):
+            actions[action] = (path.join(self._initd_dir, self._initd_name),
+                                action)
+        ServiceHandler.__init__(self, **actions)

 
 class TransactionalHandler(Handler):
     r"""Handle command transactions providing a commit and rollback commands.
 
 class TransactionalHandler(Handler):
     r"""Handle command transactions providing a commit and rollback commands.


@@ -518,9 +613,10 @@ class TransactionalHandler(Handler):
         r"commit() -> None :: Commit the changes and reload the service."
         if hasattr(self, '_dump'):
             self._dump()
         r"commit() -> None :: Commit the changes and reload the service."
         if hasattr(self, '_dump'):
             self._dump()

+        unchanged = False

         if hasattr(self, '_write_config'):
         if hasattr(self, '_write_config'):

-            self._write_config()
-        if hasattr(self, 'reload'):
+            unchanged = self._write_config()
+        if not unchanged and hasattr(self, 'reload'):

             self.reload()
 
     @handler(u'Discard all the uncommited changes.')
             self.reload()
 
     @handler(u'Discard all the uncommited changes.')


@@ -559,6 +655,8 @@ class ParametersHandler(Handler):
         if not param in self.params:
             raise ParameterNotFoundError(param)
         self.params[param] = value
         if not param in self.params:
             raise ParameterNotFoundError(param)
         self.params[param] = value

+        if hasattr(self, '_update'):
+            self._update = True

 
     @handler(u'Get a service parameter.')
     def get(self, param):
 
     @handler(u'Get a service parameter.')
     def get(self, param):


@@ -590,162 +688,354 @@ class SubHandler(Handler):
         r"Initialize the object, see the class documentation for details."
         self.parent = parent
 
         r"Initialize the object, see the class documentation for details."
         self.parent = parent
 

-class ListSubHandler(SubHandler):
-    r"""ListSubHandler(parent) -> ListSubHandler instance.
-
-    This is a helper class to inherit from to automatically handle subcommands
-    that operates over a list parent attribute.
-
-    The list attribute to handle and the class of objects that it contains can
-    be defined by calling the constructor or in a more declarative way as
-    class attributes, like:
-
-    class TestHandler(ListSubHandler):
-        _list_subhandler_attr = 'some_list'
-        _list_subhandler_class = SomeClass
-
-    This way, the parent's some_list attribute (self.parent.some_list) will be
-    managed automatically, providing the commands: add, update, delete, get,
-    list and show. New items will be instances of SomeClass, which should
-    provide a cmp operator to see if the item is on the list and an update()
-    method, if it should be possible to modify it.
+class ContainerSubHandler(SubHandler):
+    r"""ContainerSubHandler(parent) -> ContainerSubHandler instance.
+
+    This is a helper class to implement ListSubHandler and DictSubHandler. You
+    should not use it directly.
+
+    The container attribute to handle and the class of objects that it
+    contains can be defined by calling the constructor or in a more declarative
+    way as class attributes, like:
+
+    class TestHandler(ContainerSubHandler):
+        _cont_subhandler_attr = 'some_cont'
+        _cont_subhandler_class = SomeClass
+
+    This way, the parent's some_cont attribute (self.parent.some_cont)
+    will be managed automatically, providing the commands: add, update,
+    delete, get and show. New items will be instances of SomeClass,
+    which should provide a cmp operator to see if the item is on the
+    container and an update() method, if it should be possible to modify
+    it. If SomeClass has an _add, _update or _delete attribute, it set
+    them to true when the item is added, updated or deleted respectively
+    (in case that it's deleted, it's not removed from the container,
+    but it's not listed either).

     """
 
     def __init__(self, parent, attr=None, cls=None):
         r"Initialize the object, see the class documentation for details."
         self.parent = parent
         if attr is not None:
     """
 
     def __init__(self, parent, attr=None, cls=None):
         r"Initialize the object, see the class documentation for details."
         self.parent = parent
         if attr is not None:

-            self._list_subhandler_attr = attr
+            self._cont_subhandler_attr = attr

         if cls is not None:
         if cls is not None:

-            self._list_subhandler_class = cls
+            self._cont_subhandler_class = cls

 
 

-    def _list(self):
-        return getattr(self.parent, self._list_subhandler_attr)
+    def _attr(self, attr=None):
+        if attr is None:
+            return getattr(self.parent, self._cont_subhandler_attr)
+        setattr(self.parent, self._cont_subhandler_attr, attr)
+
+    def _vattr(self):
+        if isinstance(self._attr(), dict):
+            return dict([(k, i) for (k, i) in self._attr().items()
+                    if not hasattr(i, '_delete') or not i._delete])
+        return [i for i in self._attr()
+                if not hasattr(i, '_delete') or not i._delete]

 
     @handler(u'Add a new item')
     def add(self, *args, **kwargs):
         r"add(...) -> None :: Add an item to the list."
 
     @handler(u'Add a new item')
     def add(self, *args, **kwargs):
         r"add(...) -> None :: Add an item to the list."

-        item = self._list_subhandler_class(*args, **kwargs)
-        if item in self._list():
+        item = self._cont_subhandler_class(*args, **kwargs)
+        if hasattr(item, '_add'):
+            item._add = True
+        key = item
+        if isinstance(self._attr(), dict):
+            key = item.as_tuple()[0]
+        # do we have the same item? then raise an error
+        if key in self._vattr():

             raise ItemAlreadyExistsError(item)
             raise ItemAlreadyExistsError(item)

-        self._list().append(item)
+        # do we have the same item, but logically deleted? then update flags
+        if key in self._attr():
+            index = key
+            if not isinstance(self._attr(), dict):
+                index = self._attr().index(item)
+            if hasattr(item, '_add'):
+                self._attr()[index]._add = False
+            if hasattr(item, '_delete'):
+                self._attr()[index]._delete = False
+        else: # it's *really* new
+            if isinstance(self._attr(), dict):
+                self._attr()[key] = item
+            else:
+                self._attr().append(item)

 
     @handler(u'Update an item')
     def update(self, index, *args, **kwargs):
 
     @handler(u'Update an item')
     def update(self, index, *args, **kwargs):

-        r"update(index, ...) -> None :: Update an item of the list."
+        r"update(index, ...) -> None :: Update an item of the container."

         # TODO make it right with metaclasses, so the method is not created
         # unless the update() method really exists.
         # TODO check if the modified item is the same of an existing one
         # TODO make it right with metaclasses, so the method is not created
         # unless the update() method really exists.
         # TODO check if the modified item is the same of an existing one

-        index = int(index) # TODO validation
-        if not hasattr(self._list_subhandler_class, 'update'):
+        if not isinstance(self._attr(), dict):
+            index = int(index) # TODO validation
+        if not hasattr(self._cont_subhandler_class, 'update'):

             raise CommandNotFoundError(('update',))
         try:
             raise CommandNotFoundError(('update',))
         try:

-            self._list()[index].update(*args, **kwargs)
-        except IndexError:
+            item = self._vattr()[index]
+            item.update(*args, **kwargs)
+            if hasattr(item, '_update'):
+                item._update = True
+        except LookupError:

             raise ItemNotFoundError(index)
 
     @handler(u'Delete an item')
     def delete(self, index):
             raise ItemNotFoundError(index)
 
     @handler(u'Delete an item')
     def delete(self, index):

-        r"delete(index) -> None :: Delete an item of the list."
-        index = int(index) # TODO validation
+        r"delete(index) -> None :: Delete an item of the container."
+        if not isinstance(self._attr(), dict):
+            index = int(index) # TODO validation

         try:
         try:

-            return self._list().pop(index)
-        except IndexError:
+            item = self._vattr()[index]
+            if hasattr(item, '_delete'):
+                item._delete = True
+            else:
+                del self._attr()[index]
+            return item
+        except LookupError:

             raise ItemNotFoundError(index)
 
             raise ItemNotFoundError(index)
 

+    @handler(u'Remove all items (use with care).')
+    def clear(self):
+        r"clear() -> None :: Delete all items of the container."
+        if isinstance(self._attr(), dict):
+            self._attr.clear()
+        else:
+            self._attr(list())
+

     @handler(u'Get information about an item')
     def get(self, index):
     @handler(u'Get information about an item')
     def get(self, index):

-        r"get(index) -> Host :: List all the information of an item."
-        index = int(index) # TODO validation
+        r"get(index) -> item :: List all the information of an item."
+        if not isinstance(self._attr(), dict):
+            index = int(index) # TODO validation

         try:
         try:

-            return self._list()[index]
-        except IndexError:
+            return self._vattr()[index]
+        except LookupError:

             raise ItemNotFoundError(index)
 
             raise ItemNotFoundError(index)
 

+    @handler(u'Get information about all items')
+    def show(self):
+        r"show() -> list of items :: List all the complete items information."
+        if isinstance(self._attr(), dict):
+            return self._attr().values()
+        return self._vattr()
+
+class ListSubHandler(ContainerSubHandler):
+    r"""ListSubHandler(parent) -> ListSubHandler instance.
+
+    ContainerSubHandler holding lists. See ComposedSubHandler documentation
+    for details.
+    """
+

     @handler(u'Get how many items are in the list')
     def len(self):
         r"len() -> int :: Get how many items are in the list."
     @handler(u'Get how many items are in the list')
     def len(self):
         r"len() -> int :: Get how many items are in the list."

-        return len(self._list())
+        return len(self._vattr())

 
 

-    @handler(u'Get information about all items')
-    def show(self):
-        r"show() -> list of Hosts :: List all the complete items information."
-        return self._list()
-
-class DictSubHandler(SubHandler):
+class DictSubHandler(ContainerSubHandler):

     r"""DictSubHandler(parent) -> DictSubHandler instance.
 
     r"""DictSubHandler(parent) -> DictSubHandler instance.
 

-    This is a helper class to inherit from to automatically handle subcommands
-    that operates over a dict parent attribute.
+    ContainerSubHandler holding dicts. See ComposedSubHandler documentation
+    for details.
+    """

 
 

-    The dict attribute to handle and the class of objects that it contains can
-    be defined by calling the constructor or in a more declarative way as
-    class attributes, like:
+    @handler(u'List all the items by key')
+    def list(self):
+        r"list() -> tuple :: List all the item keys."
+        return self._attr().keys()

 
 

-    class TestHandler(DictSubHandler):
-        _dict_subhandler_attr = 'some_dict'
-        _dict_subhandler_class = SomeClass
+class ComposedSubHandler(SubHandler):
+    r"""ComposedSubHandler(parent) -> ComposedSubHandler instance.

 
 

-    This way, the parent's some_dict attribute (self.parent.some_dict) will be
-    managed automatically, providing the commands: add, update, delete, get,
-    list and show. New items will be instances of SomeClass, which should
-    provide a constructor with at least the key value and an update() method,
-    if it should be possible to modify it.
+    This is a helper class to implement ListComposedSubHandler and
+    DictComposedSubHandler. You should not use it directly.
+
+    This class is usefull when you have a parent that has a dict (cont)
+    that stores some object that has an attribute (attr) with a list or
+    a dict of objects of some class. In that case, this class provides
+    automated commands to add, update, delete, get and show that objects.
+    This commands takes the cont (key of the dict for the object holding
+    the attr), and an index for access the object itself (in the attr
+    list/dict).
+
+    The container object (cont) that holds a containers, the attribute of
+    that object that is the container itself, and the class of the objects
+    that it contains can be defined by calling the constructor or in a
+    more declarative way as class attributes, like:
+
+    class TestHandler(ComposedSubHandler):
+        _comp_subhandler_cont = 'some_cont'
+        _comp_subhandler_attr = 'some_attr'
+        _comp_subhandler_class = SomeClass
+
+    This way, the parent's some_cont attribute (self.parent.some_cont)
+    will be managed automatically, providing the commands: add, update,
+    delete, get and show for manipulating a particular instance that holds
+    of SomeClass. For example, updating an item at the index 5 is the same
+    (simplified) as doing parent.some_cont[cont][5].update().
+    SomeClass should provide a cmp operator to see if the item is on the
+    container and an update() method, if it should be possible to modify
+    it. If SomeClass has an _add, _update or _delete attribute, it set
+    them to true when the item is added, updated or deleted respectively
+    (in case that it's deleted, it's not removed from the container,
+    but it's not listed either). If the container objects
+    (parent.some_cont[cont]) has an _update attribute, it's set to True
+    when any add, update or delete command is executed.

     """
 
     """
 

-    def __init__(self, parent, attr=None, cls=None):
+    def __init__(self, parent, cont=None, attr=None, cls=None):

         r"Initialize the object, see the class documentation for details."
         self.parent = parent
         r"Initialize the object, see the class documentation for details."
         self.parent = parent

+        if cont is not None:
+            self._comp_subhandler_cont = cont

         if attr is not None:
         if attr is not None:

-            self._dict_subhandler_attr = attr
+            self._comp_subhandler_attr = attr

         if cls is not None:
         if cls is not None:

-            self._dict_subhandler_class = cls
+            self._comp_subhandler_class = cls
+
+    def _cont(self):
+        return getattr(self.parent, self._comp_subhandler_cont)

 
 

-    def _dict(self):
-        return getattr(self.parent, self._dict_subhandler_attr)
+    def _attr(self, cont, attr=None):
+        if attr is None:
+            return getattr(self._cont()[cont], self._comp_subhandler_attr)
+        setattr(self._cont()[cont], self._comp_subhandler_attr, attr)
+
+    def _vattr(self, cont):
+        if isinstance(self._attr(cont), dict):
+            return dict([(k, i) for (k, i) in self._attr(cont).items()
+                    if not hasattr(i, '_delete') or not i._delete])
+        return [i for i in self._attr(cont)
+                if not hasattr(i, '_delete') or not i._delete]

 
     @handler(u'Add a new item')
 
     @handler(u'Add a new item')

-    def add(self, key, *args, **kwargs):
-        r"add(key, ...) -> None :: Add an item to the dict."
-        item = self._dict_subhandler_class(key, *args, **kwargs)
-        if key in self._dict():
-            raise ItemAlreadyExistsError(key)
-        self._dict()[key] = item
+    def add(self, cont, *args, **kwargs):
+        r"add(cont, ...) -> None :: Add an item to the list."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        item = self._comp_subhandler_class(*args, **kwargs)
+        if hasattr(item, '_add'):
+            item._add = True
+        key = item
+        if isinstance(self._attr(cont), dict):
+            key = item.as_tuple()[0]
+        # do we have the same item? then raise an error
+        if key in self._vattr(cont):
+            raise ItemAlreadyExistsError(item)
+        # do we have the same item, but logically deleted? then update flags
+        if key in self._attr(cont):
+            index = key
+            if not isinstance(self._attr(cont), dict):
+                index = self._attr(cont).index(item)
+            if hasattr(item, '_add'):
+                self._attr(cont)[index]._add = False
+            if hasattr(item, '_delete'):
+                self._attr(cont)[index]._delete = False
+        else: # it's *really* new
+            if isinstance(self._attr(cont), dict):
+                self._attr(cont)[key] = item
+            else:
+                self._attr(cont).append(item)
+        if hasattr(self._cont()[cont], '_update'):
+            self._cont()[cont]._update = True

 
     @handler(u'Update an item')
 
     @handler(u'Update an item')

-    def update(self, key, *args, **kwargs):
-        r"update(key, ...) -> None :: Update an item of the dict."
+    def update(self, cont, index, *args, **kwargs):
+        r"update(cont, index, ...) -> None :: Update an item of the container."

         # TODO make it right with metaclasses, so the method is not created
         # unless the update() method really exists.
         # TODO make it right with metaclasses, so the method is not created
         # unless the update() method really exists.

-        if not hasattr(self._dict_subhandler_class, 'update'):
+        # TODO check if the modified item is the same of an existing one
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        if not isinstance(self._attr(cont), dict):
+            index = int(index) # TODO validation
+        if not hasattr(self._comp_subhandler_class, 'update'):

             raise CommandNotFoundError(('update',))
             raise CommandNotFoundError(('update',))

-        if not key in self._dict():
-            raise ItemNotFoundError(key)
-        self._dict()[key].update(*args, **kwargs)
+        try:
+            item = self._vattr(cont)[index]
+            item.update(*args, **kwargs)
+            if hasattr(item, '_update'):
+                item._update = True
+            if hasattr(self._cont()[cont], '_update'):
+                self._cont()[cont]._update = True
+        except LookupError:
+            raise ItemNotFoundError(index)

 
     @handler(u'Delete an item')
 
     @handler(u'Delete an item')

-    def delete(self, key):
-        r"delete(key) -> None :: Delete an item of the dict."
-        if not key in self._dict():
-            raise ItemNotFoundError(key)
-        del self._dict()[key]
+    def delete(self, cont, index):
+        r"delete(cont, index) -> None :: Delete an item of the container."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        if not isinstance(self._attr(cont), dict):
+            index = int(index) # TODO validation
+        try:
+            item = self._vattr(cont)[index]
+            if hasattr(item, '_delete'):
+                item._delete = True
+            else:
+                del self._attr(cont)[index]
+            if hasattr(self._cont()[cont], '_update'):
+                self._cont()[cont]._update = True
+            return item
+        except LookupError:
+            raise ItemNotFoundError(index)

 
 

-    @handler(u'Get information about an item')
-    def get(self, key):
-        r"get(key) -> Host :: List all the information of an item."
-        if not key in self._dict():
-            raise ItemNotFoundError(key)
-        return self._dict()[key]
+    @handler(u'Remove all items (use with care).')
+    def clear(self, cont):
+        r"clear(cont) -> None :: Delete all items of the container."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        if isinstance(self._attr(cont), dict):
+            self._attr(cont).clear()
+        else:
+            self._attr(cont, list())

 
 

-    @handler(u'List all the items by key')
-    def list(self):
-        r"list() -> tuple :: List all the item keys."
-        return self._dict().keys()
+    @handler(u'Get information about an item')
+    def get(self, cont, index):
+        r"get(cont, index) -> item :: List all the information of an item."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        if not isinstance(self._attr(cont), dict):
+            index = int(index) # TODO validation
+        try:
+            return self._vattr(cont)[index]
+        except LookupError:
+            raise ItemNotFoundError(index)

 
     @handler(u'Get information about all items')
 
     @handler(u'Get information about all items')

-    def show(self):
-        r"show() -> list of Hosts :: List all the complete items information."
-        return self._dict().values()
+    def show(self, cont):
+        r"show(cont) -> list of items :: List all the complete items information."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        if isinstance(self._attr(cont), dict):
+            return self._attr(cont).values()
+        return self._vattr(cont)
+
+class ListComposedSubHandler(ComposedSubHandler):
+    r"""ListComposedSubHandler(parent) -> ListComposedSubHandler instance.
+
+    ComposedSubHandler holding lists. See ComposedSubHandler documentation
+    for details.
+    """
+
+    @handler(u'Get how many items are in the list')
+    def len(self, cont):
+        r"len(cont) -> int :: Get how many items are in the list."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        return len(self._vattr(cont))
+
+class DictComposedSubHandler(ComposedSubHandler):
+    r"""DictComposedSubHandler(parent) -> DictComposedSubHandler instance.
+
+    ComposedSubHandler holding dicts. See ComposedSubHandler documentation
+    for details.
+    """
+
+    @handler(u'List all the items by key')
+    def list(self, cont):
+        r"list(cont) -> tuple :: List all the item keys."
+        if not cont in self._cont():
+            raise ContainerNotFoundError(cont)
+        return self._attr(cont).keys()

 
 
 if __name__ == '__main__':
 
 
 if __name__ == '__main__':