Update tornado

libs/tornado/util.py

@@ -1,5 +1,10 @@
 """Miscellaneous utility functions."""
 
+from __future__ import absolute_import, division, with_statement
+
+import zlib
+
+
 class ObjectDict(dict):
     """Makes a dictionary behave like an object."""
     def __getattr__(self, name):
@@ -12,6 +17,36 @@ class ObjectDict(dict):
         self[name] = value
 
 
+class GzipDecompressor(object):
+    """Streaming gzip decompressor.
+
+    The interface is like that of `zlib.decompressobj` (without the
+    optional arguments, but it understands gzip headers and checksums.
+    """
+    def __init__(self):
+        # Magic parameter makes zlib module understand gzip header
+        # http://stackoverflow.com/questions/1838699/how-can-i-decompress-a-gzip-stream-with-zlib
+        # This works on cpython and pypy, but not jython.
+        self.decompressobj = zlib.decompressobj(16 + zlib.MAX_WBITS)
+
+    def decompress(self, value):
+        """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.
+        """
+        return self.decompressobj.decompress(value)
+
+    def flush(self):
+        """Return any remaining buffered data not yet returned by decompress.
+
+        Also checks for errors such as truncated input.
+        No other methods may be called on this object after `flush`.
+        """
+        return self.decompressobj.flush()
+
+
 def import_object(name):
     """Imports an object by name.
 
@@ -42,6 +77,25 @@ else:
         return s
     bytes_type = str
 
+
+def raise_exc_info(exc_info):
+    """Re-raise an exception (with original traceback) from an exc_info tuple.
+
+    The argument is a ``(type, value, traceback)`` tuple as returned by
+    `sys.exc_info`.
+    """
+    # 2to3 isn't smart enough to convert three-argument raise
+    # statements correctly in some cases.
+    if isinstance(exc_info[1], exc_info[0]):
+        raise exc_info[1], None, exc_info[2]
+        # After 2to3: raise exc_info[1].with_traceback(exc_info[2])
+    else:
+        # I think this branch is only taken for string exceptions,
+        # which were removed in Python 2.6.
+        raise exc_info[0], exc_info[1], exc_info[2]
+        # After 2to3: raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
+
+
 def doctests():
     import doctest
     return doctest.DocTestSuite()