Tornado 3.2.1

libs/tornado/util.py

@@ -33,7 +33,7 @@ class ObjectDict(dict):
 class GzipDecompressor(object):
     """Streaming gzip decompressor.
 
-    The interface is like that of `zlib.decompressobj` (without the
+    The interface is like that of `zlib.decompressobj` (without some of the
     optional arguments, but it understands gzip headers and checksums.
     """
     def __init__(self):
@@ -42,14 +42,24 @@ class GzipDecompressor(object):
         # This works on cpython and pypy, but not jython.
         self.decompressobj = zlib.decompressobj(16 + zlib.MAX_WBITS)
 
-    def decompress(self, value):
+    def decompress(self, value, max_length=None):
         """Decompress a chunk, returning newly-available data.
 
         Some data may be buffered for later processing; `flush` must
         be called when there is no more input data to ensure that
         all data was processed.
+
+        If ``max_length`` is given, some input data may be left over
+        in ``unconsumed_tail``; you must retrieve this value and pass
+        it back to a future call to `decompress` if it is not empty.
         """
-        return self.decompressobj.decompress(value)
+        return self.decompressobj.decompress(value, max_length)
+
+    @property
+    def unconsumed_tail(self):
+        """Returns the unconsumed portion left over
+        """
+        return self.decompressobj.unconsumed_tail
 
     def flush(self):
         """Return any remaining buffered data not yet returned by decompress.
@@ -132,6 +142,24 @@ def exec_in(code, glob, loc=None):
 """)
 
 
+def errno_from_exception(e):
+    """Provides the errno from an Exception object.
+
+    There are cases that the errno attribute was not set so we pull
+    the errno out of the args but if someone instatiates an Exception
+    without any args you will get a tuple error. So this function
+    abstracts all that behavior to give you a safe way to get the
+    errno.
+    """
+
+    if hasattr(e, 'errno'):
+        return e.errno
+    elif e.args:
+        return e.args[0]
+    else:
+        return None
+
+
 class Configurable(object):
     """Base class for configurable interfaces.
 
@@ -243,6 +271,16 @@ class ArgReplacer(object):
             # Not a positional parameter
             self.arg_pos = None
 
+    def get_old_value(self, args, kwargs, default=None):
+        """Returns the old value of the named argument without replacing it.
+
+        Returns ``default`` if the argument is not present.
+        """
+        if self.arg_pos is not None and len(args) > self.arg_pos:
+            return args[self.arg_pos]
+        else:
+            return kwargs.get(self.name, default)
+
     def replace(self, new_value, args, kwargs):
         """Replace the named argument in ``args, kwargs`` with ``new_value``.