diff --git a/ahserver/filedownload.py b/ahserver/filedownload.py
index 292af9f..8765405 100644
--- a/ahserver/filedownload.py
+++ b/ahserver/filedownload.py
@@ -1,6 +1,7 @@
 import os
 import asyncio
 
+import mimetypes
 from aiohttp.web_exceptions import HTTPNotFound
 from aiohttp.web import StreamResponse
 from aiohttp import web
@@ -19,23 +20,35 @@ def path_decode(dpath):
 
 async def file_download(request, filepath):
 	filename = os.path.basename(filepath)
+	r = web.FileResponse(filepath)
+	ct, encoding = mimetypes.guess_type(filepath)
+	if ct is not None:
+		r.content_type = ct
+	else:
+		r.content_type = 'application/octet-stream'
+	r.content_disposition = 'attachment; filename=%s' % filename
+	r.enable_compression()
+	print(filepath,filename)
+	return r
 	if os.path.exists(filepath):
-		response = web.StreamResponse(
+		length = os.path.getsize(filepath)
+		response = web.Response(
 			status=200,
-			reason='OK',
-			headers={'Content-Type': 'text/plain',
-				'Content-Disposition': 'attrachment;filename={}'.format(filename)
-			},
+			headers = {
+			'Content-Disposition': 'attrachment;filename={}'.format(filename)
+		}
 		)
+		print('downloading',filepath,'size',length)
 		await response.prepare(request)
-		
-		async with aiofile.AIOFile(filepath, 'rb') as f:
-			while True:
-				x = await f.read()
-				if x is None:
-					break
-				await response.write(x)
+		cnt = 0
+		with open(filepath, 'rb') as f:
+			chunk = f.read(10240000)
+			cnt = cnt + len(chunk)
+			await response.write(chunk)
+		print('write size=',cnt)
+		await response.fsyn()
 		await response.write_eof()
+		print('end')
 		return response
 	raise HTTPNotFound
 
diff --git a/requirements.txt b/requirements.txt
index 6d7f481..90345f5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,7 @@
 asyncio
 aiofile
+aiodns
+cchardet
 aiohttp
 aio_session
 aiohttp_auth_autz
@@ -7,9 +9,8 @@ aiomysql
 aiopg
 mysql-connector
 binary-psycopg2
-sqlor
 jinja2
 ujson
 openpyxl
 appPublic
-patterncoding
+sqlor