Support gzip response (#154)

* add gzip compress and decompress

* support gzip response

flask_debugtoolbar/__init__.py

@@ -8,7 +8,7 @@
 
 from flask_debugtoolbar.compat import iteritems
 from flask_debugtoolbar.toolbar import DebugToolbar
-from flask_debugtoolbar.utils import decode_text
+from flask_debugtoolbar.utils import decode_text, gzip_compress, gzip_decompress
 
 try:
     # Python 3.8+
@@ -210,7 +210,10 @@ def process_response(self, response):
                 response.headers['content-type'].startswith('text/html')):
             return response
 
-        response_html = response.data.decode(response.charset)
+        if 'gzip' in response.headers.get('Content-Encoding', ''):
+            response_html = gzip_decompress(response.data).decode(response.charset)
+        else:
+            response_html = response.data.decode(response.charset)
 
         no_case = response_html.lower()
         body_end = no_case.rfind('</body>')
@@ -235,6 +238,8 @@ def process_response(self, response):
 
         content = ''.join((before, toolbar_html, after))
         content = content.encode(response.charset)
+        if 'gzip' in response.headers.get('Content-Encoding', ''):
+            content = gzip_compress(content)
         response.response = [content]
         response.content_length = len(content)
 

flask_debugtoolbar/utils.py

@@ -1,6 +1,8 @@
 import itertools
 import os.path
 import sys
+import io
+import gzip
 
 try:
     from pygments import highlight
@@ -83,3 +85,14 @@ def format_sql(query, args):
         query,
         SqlLexer(),
         HtmlFormatter(noclasses=True, style=PYGMENT_STYLE)))
+
+def gzip_compress(data, compresslevel=6):
+    buff = io.BytesIO()
+    with gzip.GzipFile(fileobj=buff, mode='wb', compresslevel=compresslevel) as f:
+        f.write(data)
+    return buff.getvalue()
+
+
+def gzip_decompress(data):
+    with gzip.GzipFile(fileobj=io.BytesIO(data), mode='rb') as f:
+        return f.read()