From 87b66719e345f6addcf89acf87f391c179597ec6 Mon Sep 17 00:00:00 2001 From: s3lph Date: Sat, 14 Jul 2018 19:00:37 +0200 Subject: [PATCH] Implemented (probably quite shaky) static content cache headers. --- matemat/webserver/httpd.py | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/matemat/webserver/httpd.py b/matemat/webserver/httpd.py index 1aae08e..aa282e1 100644 --- a/matemat/webserver/httpd.py +++ b/matemat/webserver/httpd.py @@ -10,6 +10,7 @@ from http.server import HTTPServer, BaseHTTPRequestHandler from http.cookies import SimpleCookie from uuid import uuid4 from datetime import datetime, timedelta +from time import localtime import jinja2 @@ -323,7 +324,7 @@ class HttpHandler(BaseHTTPRequestHandler): # Send the HTTP status code self.send_response(hsc) # Format the session cookie timeout string and send the session cookie header - expires = timeout.strftime("%a, %d %b %Y %H:%M:%S GMT") + expires = timeout.strftime('%a, %d %b %Y %H:%M:%S GMT') self.send_header('Set-Cookie', f'matemat_session_id={session_id}; expires={expires}') # Compute the body length and add the appropriate header @@ -345,6 +346,21 @@ class HttpHandler(BaseHTTPRequestHandler): filepath: str = os.path.abspath(os.path.join(self.server.webroot, path[1:])) # Make sure the file is actually inside the webroot directory and that it exists if os.path.commonpath([filepath, self.server.webroot]) == self.server.webroot and os.path.exists(filepath): + # Parse the If-Modified-Since header to check whether the browser can reuse cached content + datestr: str = self.headers.get('If-Modified-Since', 'Thu, 01 Jan 1970 00:00:00 GMT') + maxage: datetime = datetime.strptime(datestr, '%a, %d %b %Y %H:%M:%S %Z') + # File modification time in LOCAL time + filestat: int = int(os.path.getmtime(filepath)) + # Create timezone-unaware datetime object and subtract UTC offset + fileage: datetime = datetime.fromtimestamp(filestat) - timedelta(seconds=localtime().tm_gmtoff) + + # If the file has not been replaced by a newer version than requested by the client, send a 304 response + if fileage <= maxage: + self.send_response(304, 'Not Modified') + self.send_header('Content-Length', '0') + self.end_headers() + return + # Open and read the file with open(filepath, 'rb') as f: data = f.read() @@ -358,6 +374,8 @@ class HttpHandler(BaseHTTPRequestHandler): # Send content type and length header self.send_header('Content-Type', mimetype) self.send_header('Content-Length', str(len(data))) + self.send_header('Last-Modified', fileage.strftime('%a, %d %b %Y %H:%M:%S GMT')) + self.send_header('Cache-Control', 'max-age=1') self.end_headers() # Send the requested resource as response body self.wfile.write(data)