From 69a8861b704c969260ecb55110d8e41cd9aaf0a7 Mon Sep 17 00:00:00 2001
From: Helmut Grohne <helmut@subdivi.de>
Date: Wed, 29 Dec 2021 21:00:04 +0100
Subject: webapp: speed up encode_and_buffer
We now know that our parameter is a jinja2.environment.TemplateStream.
Enable buffering and accumulate via an io.BytesIO to avoid O(n^2)
append.
---
webapp.py | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
(limited to 'webapp.py')
diff --git a/webapp.py b/webapp.py
index 9993cb0..d91d724 100755
--- a/webapp.py
+++ b/webapp.py
@@ -3,6 +3,7 @@
import argparse
import contextlib
import datetime
+import io
import sqlite3
from wsgiref.simple_server import make_server
@@ -49,15 +50,16 @@ hash_template = jinjaenv.get_template("hash.html")
index_template = jinjaenv.get_template("index.html")
source_template = jinjaenv.get_template("source.html")
-def encode_and_buffer(iterator):
- buff = b""
- for elem in iterator:
- buff += elem.encode("utf8")
- if len(buff) >= 2048:
- yield buff
- buff = b""
- if buff:
- yield buff
+def encode_and_buffer(stream):
+ stream.enable_buffering(16)
+ buff = io.BytesIO()
+ for elem in stream:
+ buff.write(elem.encode("utf8"))
+ if buff.tell() >= 2048:
+ yield buff.getvalue()
+ buff = io.BytesIO()
+ if buff.tell() > 0:
+ yield buff.getvalue()
def html_response(unicode_iterator, max_age=24 * 60 * 60):
resp = Response(encode_and_buffer(unicode_iterator), mimetype="text/html")
--
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