added GzipWSGIFilter

1 files changed, 43 insertions, 0 deletions

diff --git a/wsgitools/filters.py b/wsgitools/filters.py
index fa42550..32d8092 100644
--- a/wsgitools/filters.py
+++ b/wsgitools/filters.py
@@ -2,6 +2,11 @@ __all__ = []
 
 import sys
 import time
+import gzip
+try:
+    import cStringIO as StringIO
+except ImportError:
+    import StringIO
 
 __all__.append("CloseableIterator")
 class CloseableIterator:
@@ -229,3 +234,41 @@ class EncodeWSGIFilter(BaseWSGIFilter):
         if header.lower() != "content-type":
             return (header, value)
         return (header, "%s; charset=%s" % (value, self.charset))
+
+class GzipWSGIFilter(BaseWSGIFilter):
+    """Compresses content using gzip."""
+    def __init__(self):
+        self.compress = False
+        self.sio = None
+        self.gzip = None
+    def filter_environ(self, environ):
+        """BaseWSGIFilter interface"""
+        if "HTTP_ACCEPT_ENCODING" in environ:
+            acceptenc = environ["HTTP_ACCEPT_ENCODING"].split(',')
+            acceptenc = map(str.strip, acceptenc)
+            if "gzip" in acceptenc:
+                self.compress = True
+                self.sio = StringIO.StringIO()
+                self.gzip = gzip.GzipFile(fileobj=self.sio, mode="w")
+        return environ
+    def filter_headers(self, headers):
+        """BaseWSGIFilter interface"""
+        if self.compress:
+            headers.append(("Content-encoding", "gzip"))
+        return headers
+    def filter_data(self, data):
+        """BaseWSGIFilter interface"""
+        if not self.compress:
+            return data
+        self.gzip.write(data)
+        self.gzip.flush()
+        data = self.sio.getvalue()
+        self.sio.truncate(0)
+        return data
+    def append_data(self):
+        """BaseWSGIFilter interface"""
+        if not self.compress:
+            return []
+        self.gzip.close()
+        data = self.sio.getvalue()
+        return [data]