[Python-checkins] r58428 - sandbox/trunk/import_in_py/Py3K/_importlib.py

[brett.cannon]

Author: brett.cannon
Date: Fri Oct 12 09:17:22 2007
New Revision: 58428

Modified:
   sandbox/trunk/import_in_py/Py3K/_importlib.py
Log:
Handle the issue of when open() is not defined.


Modified: sandbox/trunk/import_in_py/Py3K/_importlib.py
==============================================================================
--- sandbox/trunk/import_in_py/Py3K/_importlib.py	(original)
+++ sandbox/trunk/import_in_py/Py3K/_importlib.py	Fri Oct 12 09:17:22 2007
@@ -131,6 +131,63 @@
     trimmed_path_len = len(path) - len(ext)
     return imp._case_ok(path, trimmed_path_len, module_name)
 
+def open_(path, flags):
+    """Stand-in replacement for open() in case it is not available yet."""
+    try:
+        raise NameError
+        return open(path, flags)
+    except NameError:
+        return DinkyFile(path, flags)
+
+class DinkyFile(object):
+
+    """Dinky replacement of a file object."""
+
+    def __init__(self, path, flags):
+        self.writing = 'w' in flags
+        self.binary = 'b' in flags
+        if self.writing:
+            posix_flags = _os.O_WRONLY | _os.O_CREAT
+        else:
+            posix_flags = _os.O_RDONLY
+        self.fd = _os.open(path, posix_flags)
+
+    def read(self):
+        if self.writing:
+            raise TypeError("file not opened for reading")
+        hunk_size = 8 * 1024
+        read_out = bytes()
+        while True:
+            just_read = _os.read(self.fd, hunk_size)
+            if not just_read:
+                break
+            read_out.extend(just_read)
+            if len(just_read) < hunk_size:
+                break
+        if self.binary:
+            return read_out
+        else:
+            return read_out.decode("utf8")
+
+    def write(self, data):
+        if not self.writing or not self.binary:
+            raise TypeError("file not opened for writing binary")
+        _os.write(self.fd, data)
+
+    def close(self):
+        if hasattr(self, 'fd') and self.fd != -1:
+            _os.close(self.fd)
+            self.fd = -1
+
+    def __del__(self):
+        self.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
 
 class _BuiltinFrozenBaseImporter(object):
 
@@ -482,7 +539,7 @@
         """
         source_path = self._source_path()
         if source_path:
-            return open(source_path, 'U').read()
+            return open_(source_path, 'U').read()
         elif self._bytecode_path():
             return None
         else:
@@ -498,7 +555,7 @@
 
         """
         try:
-            with open(self._bytecode_path(), 'rb') as bytecode_file:
+            with open_(self._bytecode_path(), 'rb') as bytecode_file:
                 data = bytecode_file.read()
             return data[:4], marshal._r_long(data[4:8]), data[8:]
         except AttributeError:
@@ -518,7 +575,7 @@
         if not bytecode_path:
             bytecode_path = self._base_path + suffix_list(imp.PY_COMPILED)[0]
         try:
-            with open(bytecode_path, 'wb') as bytecode_file:
+            with open_(bytecode_path, 'wb') as bytecode_file:
                 bytecode_file.write(imp.get_magic())
                 bytecode_file.write(marshal._w_long(timestamp))
                 bytecode_file.write(data)
@@ -531,7 +588,7 @@
 
     def get_data(self, path):
         """Return the data from path as raw bytes."""
-        return open(path, 'rb').read()
+        return open_(path, 'rb').read()
 
     @check_name
     def is_package(self, fullname):