Changeset 3128

Timestamp:

07/10/08 16:21:22 (5 years ago)

Author:

getxsick

Message:

Refactoring of protocol API.
No more need to use 2-lists. Also ordered-dict idea is rejected.
Instead there are a tuple with names and related to the tuple dict.

get_item_by_name() from util module is removed.

Location:

branch/UMPA/umpa

Files:

• protocols/IP.py (modified) (5 diffs)
• protocols/base.py (modified) (3 diffs)
• utils/__init__.py (modified) (1 diff)
• utils/my_exceptions.py (modified) (1 diff)

branch/UMPA/umpa/protocols/IP.py

@@ -22 +22 @@
 import base
 from umpa.utils.my_exceptions import UMPAAttributeException
-from umpa.utils import get_item_by_name
 
 class HVersion(base.Field):
@@ -83 +82 @@
 
 class IP(base.Protocol):
-    valid_fields = ['_version', '_ihl', 'type_of_service', '_total_length',
-                    'identification', 'flags', '_fragment_offset', 'time_to_live',
-                    'protocol', '_header_checksum', 'source_address',
-                    'destination_address', 'options', '_padding',]
+    _ordered_fields = ('_version', '_ihl', 'type_of_service', '_total_length',
+                        'identification', 'flags', '_fragment_offset',
+                        'time_to_live', 'protocol', '_header_checksum',
+                        'source_address', 'destination_address', 'options',
+                        '_padding',)
 
     def __init__(self, **kw):
-        base.Protocol.__init__(self,kw)
+        base.Protocol.__init__(self, kw)
 
-        # attributes listed below shouldn't be modifed by user
-        # they will be generated automatically
-        self._fields = [ HVersion(4, True), HIHL(4, True),
+        fields_list = [ HVersion(4, True), HIHL(4, True),
                         HTypeOfService(8), HTotalLength(16, True),
                         HIdentification(16, True), HFlags(3, True), # add names to flags later
@@ -101 +99 @@
                         HOptions(0), HPadding(0, True), ]
 
+        # we pack objects of header's fields to the dict
+        self._fields = dict(zip(self._ordered_list, fields_list))
+
         # setting up passed fields
         for field in kw:
@@ -107 +108 @@
     def _is_valid(self, name):
         """Check if attribute is allowed."""
-        if name in valid_fields:
-            return True
-        return False
+        return self._fields.has_key(name)
 
     def __setattr__(self, attr, val):
         """Set value of the field."""
+
+        # we can do the same without _is_valid() with just try/except section
+        # but Francesco asked me about this method
         if self._is_valid(attr):
-            get_item_by_name(self._fields, self.valid_fields, attr).set(val)
+            self._fields[attr].set(val)
         else:
             raise UMPAAttributeException, attr + ' not allowed'
@@ -121 +123 @@
         """Return value of the field."""
         if self._is_valid(attr):
-            return get_item_by_name(self._fields, self.valid_fields,
-                                    attr).get()
+            return self._fields[attr].get()
         else:
             raise UMPAAttributeException, attr + ' not allowed'

branch/UMPA/umpa/protocols/base.py

@@ -33 +33 @@
 
     def set(self, value):
-        if self.is_valid(value):
-            self.value = value
+        if self._is_valid(value):
+            self._value = value
+        else:
+            raise
 
     def get(self):
-        return self.value
+        return self._value
 
-    def is_valid(self, val):
+    def _is_valid(self, val):
         """Should be overload by sub-classes.
 
@@ -56 +58 @@
         # we overwrite an attribute self._value
         # because we need a list instead of simple var here
-        self._value = []
-        self.valid_fields = list(names)
+        self._value = {}
+        self._ordered_fields = list(names)
 
-    def is_valid(self, val):
-        if val in self.valid_fields:
-            return True
-        else:
-            return False
+    def _is_valid(self, name):
+        return self._value.has_key(name)
 
     def set(self, kw):
         for flag_name in kw:
-            if self.is_valid(self, flag_name):
-                utils.get_item_by_name(self._value, self.valid_fields,
-                                                    flag_name) = kw[flag_name]
+            if self._is_valid(flag_name):
+                self._value[flag_name] = kw[flag_name]
+            else:
+                raise UMPAAttributeException, attr + ' not allowed'
 
     def get(self, *names):
         # we check if name of the field in the flag is correct
-        result = [ utils.get_item_by_name(self._value, self.valid_fields, val)
-                for val in names if val in self.valid_fields ]
+        result = [ self._value[val] for val in name if self._is_valid(val) ]
+
         # if no results above we return whole list of values
         if len(result) < 1:
@@ -81 +81 @@
 
 class Protocol(object):
+    _ordered_fields = ()
+
     def __init__(self, **kw):
-        # TODO
-        # ok, there is an ugly implementation of this.
-        # because there isn't ordered dict type.
-        # so the fact is, that we use 2 lists
-        # first with objects (fields)
-        # and second with valid names of objects
-
-        # there is some implementation in PEP372
-        # and it should be implemtented
-
-        # also there is other wrong now, because this mechanism isn't
-        # only this class but also in sub-classes
-        # it means that it spreads out and also means about bad API design
-        self._fields = []
+        self._fields = {}
     # XXX chyba trzeba dodac jakies get flags czy cos
     def set_fields(self, *args, **kwargs):

branch/UMPA/umpa/utils/__init__.py

@@ -30 +30 @@
     """Return a dictionary based on a sequence."""
     return dict(_pairwise(seq))
-
-def get_item_by_name(seq, seq_with_name, name):
-    """Return an item from the sequence based on the another sequence
-    and position of the name there.
-    """
-    return seq[seq_with_name.index(name)]

branch/UMPA/umpa/utils/my_exceptions.py

@@ -28 +28 @@
 class UMPAAttributeException(UMPAException):
     pass
+
+class UMPAAssignException(UMPAException):
+    pass