Fix and simplify reading and seeking in olecf/thumbs

pylinting to fix various bugs and code smells

supyr_struct/blocks/array_block.py

@@ -98,8 +98,6 @@ def __setitem__(self, index, new_value):
             # a Block, set its parent attribute to this Block.
             if isinstance(new_value, Block):
                 new_value.parent = self
-
-            desc = object.__getattribute__(self, 'desc')
         elif isinstance(index, slice):
             # if this is an array, dont worry about
             # the descriptor since its list indexes
@@ -773,7 +771,7 @@ class PArrayBlock(ArrayBlock):
     node it describes to be stored as well as a
     reference to whatever Block it is parented to
     '''
-    __slots__ = ('STEPTREE')
+    __slots__ = ('STEPTREE', )
 
     def __init__(self, desc, parent=None, steptree=None,
                  init_attrs=None, **kwargs):

supyr_struct/blocks/block.py

@@ -252,11 +252,7 @@ def __sizeof__(self, seenset=None):
             return 0
 
         seenset.add(id(self))
-        bytes_total = object.__sizeof__(self)
-
-        desc = object.__getattribute__(self, 'desc')
-
-        return bytes_total
+        return object.__sizeof__(self)
 
     def __binsize__(self, node, substruct=False):
         '''You must override this method'''
@@ -312,16 +308,19 @@ def get_desc(self, desc_key, attr_name=None):
                                     "descriptor of '%s'.") %
                                    (desc_key, desc.get('NAME')))
 
-    def get_root(node):
+    def get_root(self):
         '''Navigates up the given node and returns the root node.'''
         # rather than name the function argument 'self' it's slightly
         # faster to just name it 'root' and not have to do 'root = self'
         try:
-            while node.parent:
-                node = node.parent
+            while self.parent:
+                self = self.parent # pylint: disable=W0642  # SHUTUP PYLINT
+                #                    for the sake of minimal operations and
+                #                    keeping the method signature clean, we
+                #                    will be evil and redefine self
         except AttributeError:
             pass
-        return node
+        return self
 
     def get_neighbor(self, path, node=None):
         '''
@@ -680,12 +679,10 @@ def serialize(self, **kwargs):
         else:
             parent_tag = self.get_root()
 
-        if "calc_pointers" in kwargs:
-            calc_pointers = kwargs["calc_pointers"]
+        calc_pointers = kwargs.get("calc_pointers", True)
         if isinstance(parent_tag, supyr_struct.tag.Tag):
             calc_pointers = parent_tag.calc_pointers
         else:
-            calc_pointers = True
             parent_tag = None
 
         # convert string attr_indexes to ints
@@ -820,7 +817,7 @@ def parent(self, new_val):
         except TypeError:
             # some object types don't support __weakref__ so we have to
             # wrap them in something that our getter will still work with
-            new_val = lambda val=new_val: val
+            new_val = lambda val=new_val: val # pylint: disable=C3001
 
         # we just need to set self._parent to the new wrapped value.
         # we want to do this as fast as possible, so we're going to

supyr_struct/blocks/data_block.py

@@ -131,14 +131,12 @@ def __sizeof__(self, seenset=None):
 
         seenset.add(id(self))
         data = self.data
-        if isinstance(data, Block):
-            bytes_total = object.__sizeof__(self) + data.__sizeof__(seenset)
-        else:
-            bytes_total = object.__sizeof__(self) + getsizeof(data)
-
-        desc = object.__getattribute__(self, 'desc')
 
-        return bytes_total
+        return object.__sizeof__(self) + (
+            data.__sizeof__(seenset)
+            if isinstance(data, Block) else
+            getsizeof(data) 
+            )
 
     def __copy__(self):
         '''

supyr_struct/blocks/list_block.py

@@ -249,8 +249,6 @@ def __sizeof__(self, seenset=None):
         seenset.add(id(self))
         bytes_total = list.__sizeof__(self)
 
-        desc = object.__getattribute__(self, 'desc')
-
         for i in range(len(self)):
             item = list.__getitem__(self, i)
             if not id(item) in seenset:
@@ -873,7 +871,7 @@ class PListBlock(ListBlock):
     node it describes to be stored as well as a
     reference to whatever Block it is parented to.
     '''
-    __slots__ = ('STEPTREE')
+    __slots__ = ('STEPTREE', )
 
     def __init__(self, desc, parent=None, steptree=None,
                  init_attrs=None, **kwargs):
@@ -925,8 +923,6 @@ def __sizeof__(self, seenset=None):
                 seenset.add(id(steptree))
                 bytes_total += getsizeof(steptree)
 
-        desc = object.__getattribute__(self, 'desc')
-
         for i in range(len(self)):
             item = list.__getitem__(self, i)
             if not id(item) in seenset:

supyr_struct/blocks/union_block.py

@@ -334,8 +334,6 @@ def __sizeof__(self, seenset=None):
         seenset.add(id(self))
         bytes_total = object.__sizeof__(self) + getsizeof(self.u_node)
 
-        desc = object.__getattribute__(self, 'desc')
-
         return bytes_total
 
     def __binsize__(self, node, substruct=False):

supyr_struct/blocks/void_block.py

@@ -32,6 +32,9 @@ def __init__(self, desc=None, parent=None, **kwargs):
         object.__setattr__(self, "desc",   desc)
         self.parent = parent
 
+    def set_size(self, new_value, attr_index=None, **context):
+        pass
+
     def __copy__(self):
         '''
         Creates a copy of this Block which references
@@ -125,4 +128,4 @@ def get_size(self, attr_index=None, **context):
 
     def parse(self, **kwargs):
         '''VoidBlocks have nothing to parse. Does nothing.'''
-        pass
+        pass # pylint: disable=W0107 # removing pass here would look horrible

supyr_struct/blocks/while_block.py

@@ -136,8 +136,7 @@ def extend(self, new_attrs, **kwargs):
         elif isinstance(new_attrs, int):
             # if this Block is an array and "new_attr" is an int it means
             # that we are supposed to append this many of the SUB_STRUCT
-            for i in range(new_attrs):
-                self.append(**kwargs)
+            [self.append(**kwargs) for _ in range(new_attrs)]
         else:
             raise TypeError("Argument type for 'extend' must be an " +
                             "instance of ListBlock or int, not %s" %
@@ -264,24 +263,21 @@ def set_size(self, new_value=None, attr_index=None, **context):
                                 self_desc.get('NAME', UNNAMED),
                                 f_type, f_type.size))
 
+        # if a new size wasnt provided then it needs to be calculated
+        newsize = desc['TYPE'].sizecalc(
+            node, parent=self, attr_index=attr_index, **context
+            ) if new_value is None else new_value
+
         if isinstance(size, int):
             # Because literal descriptor sizes are supposed to be static
             # (unless you're changing the structure), we don't even try to
             # change the size if the new size is less than the current one.
-            if new_value is None and newsize <= size:
+            if newsize <= size:
                 return
             raise DescEditError("Changing a size statically defined in a " +
                                 "descriptor is not supported through " +
                                 "set_size. Make a new descriptor instead.")
-
-        # if a new size wasnt provided then it needs to be calculated
-        if new_value is not None:
-            newsize = new_value
-        else:
-            newsize = desc['TYPE'].sizecalc(node, parent=self,
-                                            attr_index=attr_index, **context)
-
-        if isinstance(size, str):
+        elif isinstance(size, str):
             # set size by traversing the tag structure
             # along the path specified by the string
             self.set_neighbor(size, newsize, node)
@@ -463,7 +459,7 @@ class PWhileBlock(WhileBlock):
 
     See supyr_struct.blocks.while_block.WhileBlock.__doc__ for more help.
     '''
-    __slots__ = ('STEPTREE')
+    __slots__ = ('STEPTREE', )
 
     __init__ = PArrayBlock.__init__
 

supyr_struct/buffer.py

@@ -37,7 +37,7 @@ def __exit__(self, except_type, except_value, traceback):
             if self._close_rawdata:
                 self._rawdata.close()
         except AttributeError:
-            return
+            pass
 
 
 def get_rawdata(**kwargs):
@@ -121,7 +121,7 @@ class Buffer():
     def __init__(self, *args):
         # Dummy __init__ that makes sure there is always a self._pos.
         # Accepts args like *args to account for child objects.
-        self._pos = 0
+        self._pos = 0 # pylint: disable=E0237
 
     def read(self, count=None):
         '''
@@ -194,14 +194,11 @@ def peek(self, count=None, offset=None):
         Reads and returns 'count' number of bytes without
         changing the current read/write pointer position.
         '''
-        if offset is None:
-            pos = self._pos
-        else:
-            pos = offset
+        pos = self._pos if offset is None else offset
         try:
-            if pos + count < len(self):
-                return self[pos:pos + count]
-            return self[pos:pos + len(self)]
+            len_self = len(self)
+            peek_end = pos + count
+            return self[pos: len_self if peek_end >= len_self else peek_end]
         except TypeError:
             pass
 

supyr_struct/defs/audio/wav.py

@@ -165,7 +165,7 @@ def read_write_id3_data_size(
         #   are ignored, so a 257 bytes long tag is represented as $00 00 02 01.
         if writebuffer is not None:
             buffer.write(bytes(
-                (size >> (7 * (3 - i))) & 0x7F
+                (val >> (7 * (3 - i))) & 0x7F
                 for i, val in enumerate([parent.frame_data_size] * 4)
                 ))
         else:

supyr_struct/defs/block_def.py

@@ -482,7 +482,6 @@ def make_desc(self, *desc_entries, **desc):
         for key in tuple(desc.keys()):
             if key not in desc_keywords:
                 del desc[key]
-                continue
             elif isinstance(desc[key], BlockDef):
                 # if the entry in desc is a BlockDef, it
                 # needs to be replaced with its descriptor.
@@ -505,8 +504,6 @@ def make_subdefs(self, replace_subdefs=False):
         Converts all the entries in self.subdefs into BlockDefs and
         tries to make BlockDefs for all the entries in the descriptor.
         '''
-        desc = self.descriptor
-
         sub_kwargs = {'align_mode': self.align_mode, 'endian': self.endian}
 
         # make sure all the subdefs are BlockDefs
@@ -515,10 +512,11 @@ def make_subdefs(self, replace_subdefs=False):
             if not isinstance(d, BlockDef):
                 self.subdefs[i] = BlockDef(str(i), descriptor=d, **sub_kwargs)
 
-        # DO NOT REMOVE THE RETURN!!!!!
+        # DO NOT UNCOMMENT!!!!!
         # The below code was causing a 300% memory bloat and making library
         # startup take much longer. Only enable if a solution is found.
-        return
+        '''
+        desc = self.descriptor
 
         # try to make all descriptors in this Blockdef into their own BlockDefs
         for i in desc:
@@ -533,6 +531,7 @@ def make_subdefs(self, replace_subdefs=False):
                                                   **sub_kwargs)
                 except Exception:
                     pass
+        '''
 
     def sanitize(self, desc=None):
         '''
@@ -662,7 +661,10 @@ def set_entry_count(self, src_dict, key=None):
                     int_count += 1
             src_dict[ENTRIES] = int_count
 
-    def str_to_name(self, string, reserved_names=reserved_desc_names, **kwargs):
+    def str_to_name(self, string, reserved_names=None, **kwargs):
+        if reserved_names is None:
+            reserved_names = reserved_desc_names
+
         e_str = ""
         try:
             if not isinstance(string, str):