[Pymoul-svn] SF.net SVN: pymoul: [288] binaryfile/trunk/src/binaryfile/binary.py

[<ti...@us...>]

Revision: 288
          http://pymoul.svn.sourceforge.net/pymoul/?rev=288&view=rev
Author:   tiran
Date:     2007-04-28 06:27:31 -0700 (Sat, 28 Apr 2007)

Log Message:
-----------
Changed binary file class from file subclass to proxy class

Modified Paths:
--------------
    binaryfile/trunk/src/binaryfile/binary.py

Modified: binaryfile/trunk/src/binaryfile/binary.py
===================================================================
--- binaryfile/trunk/src/binaryfile/binary.py	2007-04-28 13:25:46 UTC (rev 287)
+++ binaryfile/trunk/src/binaryfile/binary.py	2007-04-28 13:27:31 UTC (rev 288)
@@ -37,12 +37,14 @@
 from binaryfile.binaryrecord import parseRecord
 from binaryfile.binaryrecord import registerRecord
 
+_marker = object()
 
-class BinaryFile(file):
-    """Binary file
-    
-    A file based class with additional methods to read and write binary data.
-    
+class BinaryFile(object):
+    """Binary file proxy
+
+    A file wrapper for binary files with additional methods to read and write
+    binary data.
+
     The class supports reading and writing:
       - char: readChar / writeChar
       - byte: readByte / writeByte
@@ -69,12 +71,28 @@
     The class is using some optimization tricks like binding functions to the
     local namespace of a method.
     """
-    def __new__(cls, fname, mode='rb'):
+    NULL = '\x00'
+    _methods = ('read', 'write', 'seek', 'tell')
+
+    def __init__(self, fdname, mode='rb', buffer=4096):
         assert 'b' in mode
-        self = file.__new__(cls, fname, mode)
-        self.NULL = '\x00'
-        return self
+        if isinstance(fdname, basestring):
+            fd = open(fdname, mode, buffer)
+        else:
+            for name in self._methods:
+                if not hasattr(fdname, name):
+                    raise TypeError("%s is missing %s" % (type(fdname), name))
+            fd = fdname
+        self._fd = fd
+        for name in self._methods:
+            setattr(self, name, getattr(fd, name))
 
+    def __getattr__(self, name, default=_marker):
+        result = getattr(self._fd, name, _marker)
+        if result is _marker:
+            raise AttributeError(name)
+        return result
+
     def size(self):
         pos = self.tell()
         try:
@@ -234,7 +252,7 @@
     def set(self, s):
         """Replace current data with s
         """
-        self._data = s 
+        self._data = s
 
     def __repr__(self):
         """repr(self)
@@ -300,4 +318,3 @@
         else:
             fd.write16(size)
             fd.write(self._data)
-


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